![Introducing Apex Understanding Apex Core Concepts
Convention Description
Italics In description of syntax, italics represent variables. You supply the actual value. In the
following example, three values need to be supplied: datatype variable_name [ =
value];
If the syntax is bold and italic, the text represents a code element that needs a value
supplied by you, such as a class name or variable value:
public static class YourClassHere { ... }
<> In descriptions of syntax, less-than and greater-than symbols (< >) are typed exactly as
shown.
<apex:pageBlockTable value="{!account.Contacts}" var="contact">
<apex:column value="{!contact.Name}"/>
<apex:column value="{!contact.MailingCity}"/>
<apex:column value="{!contact.Phone}"/>
</apex:pageBlockTable>
{} In descriptions of syntax, braces ({ }) are typed exactly as shown.
<apex:page>
Hello {!$User.FirstName}!
</apex:page>
[] In descriptions of syntax, anything included in brackets is optional. In the following
example, specifying value is optional:
data_type variable_name [ = value];
| In descriptions of syntax, the pipe sign means “or”. You can do one of the following
(not all). In the following example, you can create a new unpopulated set in one of two
ways, or you can populate the set:
Set<data_type> set_name
[= new Set<data_type>();] |
[= new Set<data_type{value [, value2. . .] };] |
;
Understanding Apex Core Concepts
Apex code typically contains many things that you might be familiar with from other programming languages:
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![Introducing Apex Understanding Apex Core Concepts
Naming Variables, Methods and Classes
You cannot use any of the Apex reserved keywords when naming variables, methods or classes. These include words that are
part of Apex and the Force.com platform, such as list, test, or account, as well as reserved keywords.
Using Variables and Expressions
Apex is a strongly-typed language, that is, you must declare the data type of a variable when you first refer to it. Apex data types
include basic types such as Integer, Date, and Boolean, as well as more advanced types such as lists, maps, objects and sObjects.
Variables are declared with a name and a data type. You can assign a value to a variable when you declare it. You can also
assign values later. Use the following syntax when declaring variables:
datatype variable_name [ = value];
Tip: Note that the semi-colon at the end of the above is not optional. You must end all statements with a semi-colon.
The following are examples of variable declarations:
// The following variable has the data type of Integer with the name Count,
// and has the value of 0.
Integer Count = 0;
// The following variable has the data type of Decimal with the name Total. Note
// that no value has been assigned to it.
Decimal Total;
// The following variable is an account, which is also referred to as an sObject.
Account MyAcct = new Account();
In Apex, all primitive data type arguments, such as Integer or String, are passed into methods by value. This means that any
changes to the arguments exist only within the scope of the method. When the method returns, the changes to the arguments
are lost.
Non-primitive data type arguments, such as sObjects, are also passed into methods by value. This means that when the method
returns, the passed-in argument still references the same object as before the method call and can't be changed to point to
another object. However, the values of the object's fields can be changed in the method.
Using Statements
A statement is any coded instruction that performs an action.
In Apex, statements must end with a semicolon and can be one of the following types:
• Assignment, such as assigning a value to a variable
• Conditional (if-else)
• Loops:
◊ Do-while
◊ While
◊ For
• Locking
• Data Manipulation Language (DML)
• Transaction Control
• Method Invoking
• Exception Handling
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![Introducing Apex Understanding Apex Core Concepts
A block is a series of statements that are grouped together with curly braces and can be used in any place where a single statement
would be allowed. For example:
if (true) {
System.debug(1);
System.debug(2);
} else {
System.debug(3);
System.debug(4);
}
In cases where a block consists of only one statement, the curly braces can be left off. For example:
if (true)
System.debug(1);
else
System.debug(2);
Using Collections
Apex has the following types of collections:
• Lists (arrays)
• Maps
• Sets
A list is a collection of elements, such as Integers, Strings, objects, or other collections. Use a list when the sequence of elements
is important. You can have duplicate elements in a list.
The first index position in a list is always 0.
To create a list:
• Use the new keyword
• Use the List keyword followed by the element type contained within <> characters.
Use the following syntax for creating a list:
List <datatype> list_name
[= new List<datatype>();] |
[=new List<datatype>{value [, value2. . .]};] |
;
The following example creates a list of Integer, and assigns it to the variable My_List. Remember, because Apex is strongly
typed, you must declare the data type of My_List as a list of Integer.
List<Integer> My_List = new List<Integer>();
For more information, see Lists on page 43.
A set is a collection of unique, unordered elements. It can contain primitive data types, such as String, Integer, Date, and so
on. It can also contain more complex data types, such as sObjects.
To create a set:
• Use the new keyword
• Use the Set keyword followed by the primitive data type contained within <> characters
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![Introducing Apex Understanding Apex Core Concepts
Use the following syntax for creating a set:
Set<datatype> set_name
[= new Set<datatype>();] |
[= new Set<datatype>{value [, value2. . .] };] |
;
The following example creates a set of String. The values for the set are passed in using the curly braces {}.
Set<String> My_String = new Set<String>{'a', 'b', 'c'};
For more information, see Sets on page 48.
A map is a collection of key-value pairs. Keys can be any primitive data type. Values can include primitive data types, as well
as objects and other collections. Use a map when finding something by key matters. You can have duplicate values in a map,
but each key must be unique.
To create a map:
• Use the new keyword
• Use the Map keyword followed by a key-value pair, delimited by a comma and enclosed in <> characters.
Use the following syntax for creating a map:
Map<key_datatype, value_datatype> map_name
[=new map<key_datatype, value_datatype>();] |
[=new map<key_datatype, value_datatype>
{key1_value => value1_value
[, key2_value => value2_value. . .]};] |
;
The following example creates a map that has a data type of Integer for the key and String for the value. In this example, the
values for the map are being passed in between the curly braces {} as the map is being created.
Map<Integer, String> My_Map = new Map<Integer, String>{1 => 'a', 2 => 'b', 3 => 'c'};
For more information, see Maps on page 50.
Using Branching
An if statement is a true-false test that enables your application to do different things based on a condition. The basic syntax
is as follows:
if (Condition){
// Do this if the condition is true
} else {
// Do this if the condition is not true
}
For more information, see Conditional (If-Else) Statements on page 68.
Using Loops
While the if statement enables your application to do things based on a condition, loops tell your application to do the same
thing again and again based on a condition. Apex supports the following types of loops:
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![Introducing Apex Writing Your First Apex Class and Trigger
12. Click Save.
You’ve just created a custom object called Book, and added a custom field to that custom object. Custom objects already have
some standard fields, like Name and CreatedBy, and allow you to add other fields that are more specific to your implementation.
For this tutorial, the Price field is part of our Book object and it is accessed by the Apex class you will write in the next step.
See Also:
Writing Your First Apex Class and Trigger
Adding an Apex Class
Adding an Apex Class
Prerequisites:
• A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization.
• The Book custom object
In this step, you add an Apex class that contains a method for updating the book price. This method is called by the trigger
that you will be adding in the next step.
1. Click Your Name > Setup > Develop > Apex Classes and click New.
2. In the class editor, enter this class definition:
public class MyHelloWorld {
}
The previous code is the class definition to which you will be adding one method in the next step. Apex code is generally
contained in classes. This class is defined as public, which means the class is available to other Apex classes and triggers.
For more information, see Classes, Objects, and Interfaces on page 111.
3. Add this method definition between the class opening and closing brackets.
public static void applyDiscount(Book__c[] books) {
for (Book__c b :books){
b.Price__c *= 0.9;
}
}
This method is called applyDiscount, and is both public and static. Because it is a static method, you don't need to
create an instance of the class to access the method—you can just use the name of the class followed by a dot (.) and the
name of the method. For more information, see Static and Instance on page 122.
This method takes one parameter, a list of Book records, which is assigned to the variable books. Notice the __c in the
object name Book__c. This indicates that it is a custom object that you created. Standard objects that are provided in the
Salesforce application, such as Account, don't end with this postfix.
The next section of code contains the rest of the method definition:
for (Book__c b :books){
b.Price__c *= 0.9;
}
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![Introducing Apex Writing Your First Apex Class and Trigger
Notice the __c after the field name Price__c. This indicates it is a custom field that you created. Standard fields that are
provided by default in Salesforce are accessed using the same type of dot notation but without the __c, for example, Name
doesn't end with __c in Book__c.Name. The statement b.Price__c *= 0.9; takes the old value of b.Price__c,
multiplies it by 0.9, which means its value will be discounted by 10%, and then stores the new value into the b.Price__c
field. The *= operator is a shortcut. Another way to write this statement is b.Price__c = b.Price__c * 0.9;. See
Understanding Expression Operators on page 60.
4. Click Save to save the new class. You should now have this full class definition.
public class MyHelloWorld {
public static void applyDiscount(Book__c[] books) {
for (Book__c b :books){
b.Price__c *= 0.9;
}
}
}
You now have a class that contains some code which iterates over a list of books and updates the Price field for each book.
This code is part of the applyDiscount static method that is called by the trigger that you will create in the next step.
See Also:
Writing Your First Apex Class and Trigger
Creating a Custom Object
Adding an Apex Trigger
Adding an Apex Trigger
Prerequisites:
• A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization.
• The MyHelloWorld Apex class.
In this step, you create a trigger for the Book__c custom object that calls the applyDiscount method of the MyHelloWorld
class that you created in the previous step.
A trigger is a piece of code that executes before or after records of a particular type are inserted, updated, or deleted from the
Force.com platform database. Every trigger runs with a set of context variables that provide access to the records that caused
the trigger to fire. All triggers run in bulk, that is, they process several records at once.
1. Click Your Name > Setup > Create > Objects and click the name of the object you just created, Book.
2. In the triggers section, click New.
3. In the trigger editor, delete the default template code and enter this trigger definition:
trigger HelloWorldTrigger on Book__c (before insert) {
Book__c[] books = Trigger.new;
MyHelloWorld.applyDiscount(books);
}
The first line of code defines the trigger:
trigger HelloWorldTrigger on Book__c (before insert) {
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![Introducing Apex Writing Your First Apex Class and Trigger
It gives the trigger a name, specifies the object on which it operates, and defines the events that cause it to fire. For example,
this trigger is called HelloWorldTrigger, it operates on the Book__c object, and runs before new books are inserted into
the database.
The next line in the trigger creates a list of book records named books and assigns it the contents of a trigger context
variable called Trigger.new. Trigger context variables such as Trigger.new are implicitly defined in all triggers and
provide access to the records that caused the trigger to fire. In this case, Trigger.new contains all the new books that
are about to be inserted.
Book__c[] books = Trigger.new;
The next line in the code calls the method applyDiscount in the MyHelloWorld class. It passes in the array of new
books.
MyHelloWorld.applyDiscount(books);
You now have all the code that is needed to update the price of all books that get inserted. However, there is still one piece
of the puzzle missing. Unit tests are an important part of writing code and are required. In the next step, you will see why this
is so and you will be able to add a test class.
See Also:
Writing Your First Apex Class and Trigger
Adding an Apex Class
Adding a Test Class
Adding a Test Class
Prerequisites:
• A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization.
• The HelloWorldTrigger Apex trigger.
In this step, you add a test class with one test method. You also run the test and verify code coverage. The test method exercises
and validates the code in the trigger and class. Also, it enables you to reach 100% code coverage for the trigger and class.
Note: Testing is an important part of the development process. Before you can deploy Apex or package it for the
Force.com AppExchange, the following must be true:
• 75% of your Apex code must be covered by unit tests, and all of those tests must complete successfully.
Note the following:
◊ When deploying to a production organization, every unit test in your organization namespace is executed.
◊ Calls to System.debug are not counted as part of Apex code coverage.
◊ Test methods and test classes are not counted as part of Apex code coverage.
◊ While only 75% of your Apex code must be covered by tests, your focus shouldn't be on the percentage of code
that is covered. Instead, you should make sure that every use case of your application is covered, including
positive and negative cases, as well as bulk and single record. This should lead to 75% or more of your code
being covered by unit tests.
• Every trigger has some test coverage.
• All classes and triggers compile successfully.
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![Introducing Apex Writing Your First Apex Class and Trigger
1. Click Your Name > Setup > Develop > Apex Classes and click New.
2. In the class editor, add this test class definition, and then click Save.
@isTest
private class HelloWorldTestClass {
static testMethod void validateHelloWorld() {
Book__c b = new Book__c(Name='Behind the Cloud', Price__c=100);
System.debug('Price before inserting new book: ' + b.Price__c);
// Insert book
insert b;
// Retrieve the new book
b = [SELECT Price__c FROM Book__c WHERE Id =:b.Id];
System.debug('Price after trigger fired: ' + b.Price__c);
// Test that the trigger correctly updated the price
System.assertEquals(90, b.Price__c);
}
}
This class is defined using the @isTest annotation. Classes defined as such can only contain test methods. One advantage
to creating a separate class for testing as opposed to adding test methods to an existing class is that classes defined with
isTest don't count against your organization limit of 3 MB for all Apex code. You can also add the @isTest annotation
to individual methods. For more information, see IsTest Annotation on page 138 and Understanding Execution Governors
and Limits on page 225.
The method validateHelloWorld is defined as a testMethod. This means that if any changes are made to the
database, they are automatically rolled back when execution completes and you don't have to delete any test data created
in the test method.
First the test method creates a new book and inserts it into the database temporarily. The System.debug statement writes
the value of the price in the debug log.
Book__c b = new Book__c(Name='Behind the Cloud', Price__c=100);
System.debug('Price before inserting new book: ' + b.Price__c);
// Insert book
insert b;
Once the book is inserted, the code retrieves the newly inserted book, using the ID that was initially assigned to the book
when it was inserted, and then logs the new price, that the trigger modified:
// Retrieve the new book
b = [SELECT Price__c FROM Book__c WHERE Id =:b.Id];
System.debug('Price after trigger fired: ' + b.Price__c);
When the MyHelloWorld class runs, it updates the Price__c field and reduces its value by 10%. The following line is
the actual test, verifying that the method applyDiscount actually ran and produced the expected result:
// Test that the trigger correctly updated the price
System.assertEquals(90, b.Price__c);
3. Click Run Test in the class page to run all the test methods in this class. In this case, we have only one test method.
The Apex Test Result page appears after the test finishes execution. It contains the test result details such as the number
of test failures, code coverage information, and a link to a downloadable log file.
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![Language Constructs Primitive Data Types
Data Type Description
String size: Strings have no limit on the number of characters they can include. Instead, the
heap size limit is used to ensure that your Apex programs don't grow too large.
Empty Strings and Trailing Whitespace: sObject String field values follow the same rules
as in the SOAP API: they can never be empty (only null), and they can never include leading
and trailing whitespace. These conventions are necessary for database storage.
Conversely, Strings in Apex can be null or empty, and can include leading and trailing
whitespace (such as might be used to construct a message).
The Solution sObject field SolutionNote operates as a special type of String. If you have
HTML Solutions enabled, any HTML tags used in this field are verified before the object
is created or updated. If invalid HTML is entered, an error is thrown. Any JavaScript used
in this field is removed before the object is created or updated. In the following example,
when the Solution displays on a detail page, the SolutionNote field has H1 HTML formatting
applied to it:
trigger t on Solution (before insert) {
Trigger.new[0].SolutionNote ='<h1>hello</h1>';
}
In the following example, when the Solution displays on a detail page, the SolutionNote field
only contains HelloGoodbye:
trigger t2 on Solution (before insert) {
Trigger.new[0].SolutionNote =
'<javascript>Hello</javascript>Goodbye';
}
For more information, see ““What are HTML Solutions?” in the online help.
Escape Sequences: All Strings in Apex use the same escape sequences as SOQL strings: b
(backspace), t (tab), n (line feed), f (form feed), r (carriage return), " (double quote),
' (single quote), and (backslash).
Comparison Operators: Unlike Java, Apex Strings support use of the comparison operators
==, !=, <, <=, >, and >=. Since Apex uses SOQL comparison semantics, results for Strings
are collated according to the context user's locale, and `are not case sensitive. For more
information, see Operators on page 60.
String Methods: As in Java, Strings can be manipulated with a number of standard methods.
See String Methods for information.
Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a
runtime error if you assign a String value that is too long for the field.
Time A value that indicates a particular time. Time values must always be created with a system
static method. See Time Methods on page 332.
In addition, two non-standard primitive data types cannot be used as variable or method types, but do appear in system static
methods:
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![Language Constructs sObject Types
Note: The ID of an sObject is a read-only value and can never be modified explicitly in Apex unless it is cleared
during a clone operation, or is assigned with a constructor. The Force.com platform assigns ID values automatically
when an object record is initially inserted to the database for the first time. For more information see Lists on page
43.
Custom Labels
Custom labels are not standard sObjects. You cannot create a new instance of a custom label. You can only access the value
of a custom label using system.label.label_name. For example:
String errorMsg = System.Label.generic_error;
For more information on custom labels, see “Custom Labels Overview” in the online help.
Accessing sObject Fields
As in Java, sObject fields can be accessed or changed with simple dot notation. For example:
Account a = new Account();
a.Name = 'Acme'; // Access the account name field and assign it 'Acme'
System generated fields, such as Created By or Last Modified Date, cannot be modified. If you try, the Apex runtime
engine generates an error. Additionally, formula field values and values for other fields that are read-only for the context user
cannot be changed.
If you use the generic sObject type, instead of a specific object such as Account, you can only retrieve the ID field. For example:
Account a = new Account(Name = 'Acme', BillingCity = 'San Francisco');
insert a;
sObject s = [SELECT Id, Name FROM Account WHERE Name = 'Acme' LIMIT 1];
// This is allowed
ID id = s.Id;
// The following lines result in errors when you try to save
String x = s.Name;
s.Id = [SELECT Id FROM Account WHERE Name = 'Acme' LIMIT 1];
Note: If your organization has enabled person accounts, you have two different kinds of accounts: business accounts
and person accounts. If your code creates a new account using name, a business account is created. If your code uses
LastName, a person account is created.
If you want to perform operations on an sObject, it is recommended that you first convert it into a specific object. For example:
Account a = new Account(Name = 'Acme', BillingCity = 'San Francisco');
insert a;
sObject s = [SELECT Id, Name FROM Account WHERE Name = 'Acme' LIMIT 1];
ID id = s.ID;
Account convertedAccount = (Account)s;
convertedAccount.name = 'Acme2';
update convertedAccount;
Contact sal = new Contact(FirstName = 'Sal', Account = convertedAccount);
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![Language Constructs sObject Types
The following example shows how you can use SOSL over a set of records to determine their object types. Once you have
converted the generic sObject record into a Contact, Lead, or Account, you can modify its fields accordingly:
public class convertToCLA {
List<Contact> contacts;
List<Lead> leads;
List<Account> accounts;
public void convertType(Integer phoneNumber) {
List<List<sObject>> results = [FIND '4155557000'
IN Phone FIELDS
RETURNING Contact(Id, Phone, FirstName, LastName),
Lead(Id, Phone, FirstName, LastName), Account(Id, Phone, Name)];
sObject[] records = ((List<sObject>)results[0]);
if (!records.isEmpty()) {
for (Integer i = 0; i < records.size(); i++) {
sObject record = records[i];
if (record.getSObjectType() == Contact.sObjectType) {
contacts.add((Contact) record);
} else if (record.getSObjectType() == Lead.sObjectType){
leads.add((Lead) record);
} else if (record.getSObjectType() == Account.sObjectType) {
accounts.add((Account) record);
}
}
}
}
}
Accessing sObject Fields Through Relationships
sObject records represent relationships to other records with two fields: an ID and an address that points to a representation
of the associated sObject. For example, the Contact sObject has both an AccountId field of type ID, and an Account field
of type Account that points to the associated sObject record itself.
The ID field can be used to change the account with which the contact is associated, while the sObject reference field can be
used to access data from the account. The reference field is only populated as the result of a SOQL or SOSL query (see note
below).
For example, the following Apex code shows how an account and a contact can be associated with one another, and then how
the contact can be used to modify a field on the account:
Note: In order to provide the most complete example, this code uses some elements that are described later in this
guide:
• For information on insert and update, see Insert Operation on page 274 and Update Operation on page 274.
• For information on SOQL and SOSL, see SOQL and SOSL Queries on page 73.
Account a = new Account(Name = 'Acme');
insert a; // Inserting the record automatically assigns a
// value to its ID field
Contact c = new Contact(LastName = 'Weissman');
c.AccountId = a.Id;
// The new contact now points at the new account
insert c;
// A SOQL query accesses data for the inserted contact,
// including a populated c.account field
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![Language Constructs sObject Types
c = [SELECT Account.Name FROM Contact WHERE Id = :c.Id];
// Now fields in both records can be changed through the contact
c.Account.Name = 'salesforce.com';
c.LastName = 'Roth';
// To update the database, the two types of records must be
// updated separately
update c; // This only changes the contact's last name
update c.Account; // This updates the account name
Note: The expression c.Account.Name, as well as any other expression that traverses a relationship, displays slightly
different characteristics when it is read as a value than when it is modified:
• When being read as a value, if c.Account is null, then c.Account.Name evaluates to null, but does not yield
a NullPointerException. This design allows developers to navigate multiple relationships without the tedium
of having to check for null values.
• When being modified, if c.Account is null, then c.Account.Name does yield a NullPointerException.
In addition, the sObject field key can be used with insert, update, or upsert to resolve foreign keys by external ID. For
example:
Account refAcct = new Account(externalId__c = '12345');
Contact c = new Contact(Account = refAcct, LastName = 'Kay');
insert c;
This inserts a new contact with the AccountId equal to the account with the external_id equal to ‘12345’. If there is no
such account, the insert fails.
Tip:
The following code is equivalent to the code above. However, because it uses a SOQL query, it is not as efficient. If
this code was called multiple times, it could reach the execution limit for the maximum number of SOQL queries.
For more information on execution limits, see Understanding Execution Governors and Limits on page 225.
Account refAcct = [SELECT Id FROM Account WHERE externalId__c='12345'];
Contact c = new Contact(Account = refAcct.Id);
insert c;
Validating sObjects and Fields
When Apex code is parsed and validated, all sObject and field references are validated against actual object and field names,
and a parse-time exception is thrown when an invalid name is used.
In addition, the Apex parser tracks the custom objects and fields that are used, both in the code's syntax as well as in embedded
SOQL and SOSL statements. The platform prevents users from making the following types of modifications when those
changes cause Apex code to become invalid:
• Changing a field or object name
• Converting from one data type to another
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![Language Constructs Collections
• Deleting a field or object
• Making certain organization-wide changes, such as record sharing, field history tracking, or record types
Collections
Apex has the following types of collections:
• Lists
• Maps
• Sets
Note: There is no limit on the number of items a collection can hold. However, there is a general limit on heap size.
Lists
A list is an ordered collection of typed primitives, sObjects, user-defined objects, Apex objects or collections that are distinguished
by their indices. For example, the following table is a visual representation of a list of Strings:
Index 0 Index 1 Index 2 Index 3 Index 4 Index 5
'Red' 'Orange' 'Yellow' 'Green' 'Blue' 'Purple'
The index position of the first element in a list is always 0.
Because lists can contain any collection, they can be nested within one another and become multidimensional. For example,
you can have a list of lists of sets of Integers. A list can contain up to four levels of nested collections inside it.
To declare a list, use the List keyword followed by the primitive data, sObject, nested list, map, or set type within <> characters.
For example:
// Create an empty list of String
List<String> my_list = new List<String>();
// Create a nested list
List<List<Set<Integer>>> my_list_2 = new List<List<Set<Integer>>>();
// Create a list of account records from a SOQL query
List<Account> accs = [SELECT Id, Name FROM Account LIMIT 1000];
To access elements in a list, use the system methods provided by Apex. For example:
List<Integer> MyList = new List<Integer>(); // Define a new list
MyList.add(47); // Adds a second element of value 47 to the end
// of the list
MyList.get(0); // Retrieves the element at index 0
MyList.set(0, 1); // Adds the integer 1 to the list at index 0
MyList.clear(); // Removes all elements from the list
For more information, including a complete list of all supported methods, see List Methods on page 333.
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![Language Constructs Collections
Using Array Notation for One-Dimensional Lists of Primitives or sObjects
When using one-dimensional lists of primitives or sObjects, you can also use more traditional array notation to declare and
reference list elements. For example, you can declare a one-dimensional list of primitives or sObjects by following the data or
sObject type name with the [] characters:
String[] colors = new List<String>();
To reference an element of a one-dimensional list of primitives or sObjects, you can also follow the name of the list with the
element's index position in square brackets. For example:
colors[3] = 'Green';
All lists are initialized to null. Lists can be assigned values and allocated memory using literal notation. For example:
Example Description
Defines an Integer list with no elements
List<Integer> ints = new Integer[0];
Defines an Account list with no elements
List<Account> accts = new Account[]{};
Defines an Integer list with memory allocated for six Integers
List<Integer> ints = new Integer[6];
Defines an Account list with memory allocated for three
List<Account> accts = new Account[] Accounts, including a new Account object in the first position,
{new Account(), null, new
Account()};
null in the second position, and another new Account object
in the third position
Defines the Contact list with a new list
List<Contact> contacts = new List<Contact>
(otherList);
Lists of sObjects
Apex automatically generates IDs for each object in a list of sObjects when the list is successfully inserted or upserted into the
database with a data manipulation language (DML) statement. Consequently, a list of sObjects cannot be inserted or upserted
if it contains the same sObject more than once, even if it has a null ID. This situation would imply that two IDs would need
to be written to the same structure in memory, which is illegal.
For example, the insert statement in the following block of code generates a ListException because it tries to insert a
list with two references to the same sObject (a):
try {
// Create a list with two references to the same sObject element
Account a = new Account();
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![Language Constructs Collections
Account[] accs = new Account[]{a, a};
// Attempt to insert it...
insert accs;
// Will not get here
System.assert(false);
} catch (ListException e) {
// But will get here
}
For more information on DML statements, see Apex Data Manipulation Language (DML) Operations on page 268.
You can use the generic sObject data type with lists. You can also create a generic instance of a list.
List Sorting
Using the List.sort method, you can sort lists of primitive data types, custom types (your Apex classes) that implement
the Comparable Interface, SelectOption elements, and sObjects (standard objects and custom objects).
Sorting is in ascending order for primitive data types.
For custom types, the sort criteria and sort order depends on the implementation that you provide for the compareTo method
of the Comparable interface. For more information on implementing the Comparable Interface for your own classes, see
Comparable Interface.
For sObjects, sorting is in ascending order and uses a sequence of comparison steps outlined in the next section. However,
you can also implement a custom sort order for sObjects by wrapping your sObject in an Apex class and implementing the
Comparable Interface, as shown in Custom Sort Order of sObjects.
For SelectOption, sorting is in ascending order based on the value and label fields. See Default Sort Order for SelectOption
for the sequence of comparison steps used for SelectOption.
Default Sort Order of sObjects
The List.sort method sorts sObjects in ascending order and compares sObjects using an ordered sequence of steps that
specify the labels or fields used. The comparison starts with the first step in the sequence and ends when two sObjects are
sorted using specified labels or fields. The following is the comparison sequence used:
1. The label of the sObject type.
For example, an Account sObject will appear before a Contact.
2. The Name field, if applicable.
For example, if the list contains two accounts named A and B respectively, account A comes before account B.
3. Standard fields, starting with the fields that come first in alphabetical order, except for the Id and Name fields.
For example, if two accounts have the same name, the first standard field used for sorting is AccountNumber.
4. Custom fields, starting with the fields that come first in alphabetical order.
For example, suppose two accounts have the same name and identical standard fields, and there are two custom fields,
FieldA and FieldB, the value of FieldA is used first for sorting.
Not all steps in this sequence are necessarily carried out. For example, if a list contains two sObjects of the same type and with
unique Name values, they’re sorted based on the Name field and sorting stops at step 2. Otherwise, if the names are identical
or the sObject doesn’t have a Name field, sorting proceeds to step 3 to sort by standard fields.
For text fields, the sort algorithm uses the Unicode sort order. Also, empty fields precede non-empty fields in the sort order.
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![Language Constructs Collections
This is an example of sorting a list of Account sObjects. This example shows how the Name field is used to place the Acme
account ahead of the two sForce accounts in the list. Since there are two accounts named sForce, the Industry field is used to
sort these remaining accounts because the Industry field comes before the Site field in alphabetical order.
Account[] acctList = new List<Account>();
acctList.add( new Account(
Name='sForce',
Industry='Biotechnology',
Site='Austin'));
acctList.add(new Account(
Name='sForce',
Industry='Agriculture',
Site='New York'));
acctList.add(new Account(
Name='Acme'));
System.debug(acctList);
acctList.sort();
System.assertEquals('Acme', acctList[0].Name);
System.assertEquals('sForce', acctList[1].Name);
System.assertEquals('Agriculture', acctList[1].Industry);
System.assertEquals('sForce', acctList[2].Name);
System.assertEquals('Biotechnology', acctList[2].Industry);
System.debug(acctList);
This example is similar to the previous one, except that it uses the Merchandise__c custom object. This example shows how
the Name field is used to place the Notebooks merchandise ahead of Pens in the list. Since there are two merchandise sObjects
with the Name field value of Pens, the Description field is used to sort these remaining merchandise items because the
Description field comes before the Price and Total_Inventory fields in alphabetical order.
Merchandise__c[] merchList = new List<Merchandise__c>();
merchList.add( new Merchandise__c(
Name='Pens',
Description__c='Red pens',
Price__c=2,
Total_Inventory__c=1000));
merchList.add( new Merchandise__c(
Name='Notebooks',
Description__c='Cool notebooks',
Price__c=3.50,
Total_Inventory__c=2000));
merchList.add( new Merchandise__c(
Name='Pens',
Description__c='Blue pens',
Price__c=1.75,
Total_Inventory__c=800));
System.debug(merchList);
merchList.sort();
System.assertEquals('Notebooks', merchList[0].Name);
System.assertEquals('Pens', merchList[1].Name);
System.assertEquals('Blue pens', merchList[1].Description__c);
System.assertEquals('Pens', merchList[2].Name);
System.assertEquals('Red pens', merchList[2].Description__c);
System.debug(merchList);
Custom Sort Order of sObjects
To implement a custom sort order for sObjects in lists, create a wrapper class for the sObject and implement the Comparable
Interface. The wrapper class contains the sObject in question and implements the compareTo method, in which you specify
the sort logic.
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![Language Constructs Collections
This example shows how to create a wrapper class for Opportunity. The implementation of the compareTo method in this
class compares two opportunities based on the Amount field—the class member variable contained in this instance, and the
opportunity object passed into the method.
global class OpportunityWrapper implements Comparable {
public Opportunity oppy;
// Constructor
public OpportunityWrapper(Opportunity op) {
oppy = op;
}
// Compare opportunities based on the opportunity amount.
global Integer compareTo(Object compareTo) {
// Cast argument to OpportunityWrapper
OpportunityWrapper compareToOppy = (OpportunityWrapper)compareTo;
// The return value of 0 indicates that both elements are equal.
Integer returnValue = 0;
if (oppy.Amount > compareToOppy.oppy.Amount) {
// Set return value to a positive value.
returnValue = 1;
} else if (oppy.Amount < compareToOppy.oppy.Amount) {
// Set return value to a negative value.
returnValue = -1;
}
return returnValue;
}
}
This example provides a test for the OpportunityWrapper class. It sorts a list of OpportunityWrapper objects and verifies
that the list elements are sorted by the opportunity amount.
@isTest
private class OpportunityWrapperTest {
static testmethod void test1() {
// Add the opportunity wrapper objects to a list.
OpportunityWrapper[] oppyList = new List<OpportunityWrapper>();
Date closeDate = Date.today().addDays(10);
oppyList.add( new OpportunityWrapper(new Opportunity(
Name='Edge Installation',
CloseDate=closeDate,
StageName='Prospecting',
Amount=50000)));
oppyList.add( new OpportunityWrapper(new Opportunity(
Name='United Oil Installations',
CloseDate=closeDate,
StageName='Needs Analysis',
Amount=100000)));
oppyList.add( new OpportunityWrapper(new Opportunity(
Name='Grand Hotels SLA',
CloseDate=closeDate,
StageName='Prospecting',
Amount=25000)));
// Sort the wrapper objects using the implementation of the
// compareTo method.
oppyList.sort();
// Verify the sort order
System.assertEquals('Grand Hotels SLA', oppyList[0].oppy.Name);
System.assertEquals(25000, oppyList[0].oppy.Amount);
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![Language Constructs Collections
System.assertEquals('Edge Installation', oppyList[1].oppy.Name);
System.assertEquals(50000, oppyList[1].oppy.Amount);
System.assertEquals('United Oil Installations', oppyList[2].oppy.Name);
System.assertEquals(100000, oppyList[2].oppy.Amount);
// Write the sorted list contents to the debug log.
System.debug(oppyList);
}
}
Default Sort Order for SelectOption
The List.sort method sorts SelectOption elements in ascending order using the value and label fields, and is based on this
comparison sequence.
1. The value field is used for sorting first.
2. If two value fields have the same value or are both empty, the label field is used.
Note that the disabled field is not used for sorting.
For text fields, the sort algorithm uses the Unicode sort order. Also, empty fields precede non-empty fields in the sort order.
In this example, a list contains three SelectOption elements. Two elements, United States and Mexico, have the same value
field (‘A’). The List.sort method sorts these two elements based on the label field, and places Mexico before United States,
as shown in the output. The last element in the sorted list is Canada and is sorted on its value field ‘C’, which comes after ‘A’.
List<SelectOption> options = new List<SelectOption>();
options.add(new SelectOption('A','United States'));
options.add(new SelectOption('C','Canada'));
options.add(new SelectOption('A','Mexico'));
System.debug('Before sorting: ' + options);
options.sort();
System.debug('After sorting: ' + options);
This is the output of the debug statements. It shows the list contents before and after the sort.
DEBUG|Before sorting: (System.SelectOption[value="A", label="United States",
disabled="false"],
System.SelectOption[value="C", label="Canada", disabled="false"],
System.SelectOption[value="A", label="Mexico", disabled="false"])
DEBUG|After sorting: (System.SelectOption[value="A", label="Mexico", disabled="false"],
System.SelectOption[value="A", label="United States", disabled="false"],
System.SelectOption[value="C", label="Canada", disabled="false"])
Sets
A set is an unordered collection of elements that do not contain any duplicates. Set elements can be of any data type—primitive
types, collections, sObjects, user-defined types, and built-in Apex types. For example, the following table represents a set of
strings, that uses city names:
'San Francisco' 'New York' 'Paris' 'Tokyo'
Sets can contain collections that can be nested within one another. For example, you can have a set of lists of sets of Integers.
A set can contain up to four levels of nested collections inside it.
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Maps
A map is a collection of key-value pairs where each unique key maps to a single value. Keys and values can be any data
type—primitive types, collections, sObjects, user-defined types, and built-in Apex types. For example, the following table
represents a map of countries and currencies:
Country (Key) 'United States' 'Japan' 'France' 'England' 'India'
Currency (Value) 'Dollar' 'Yen' 'Euro' 'Pound' 'Rupee'
Map keys and values can contain any collection, and can contain nested collections. For example, you can have a map of
Integers to maps, which, in turn, map Strings to lists. Map keys can contain up to only four levels of nested collections.
To declare a map, use the Map keyword followed by the data types of the key and the value within <> characters. For example:
Map<String, String> country_currencies = new Map<String, String>();
Map<ID, Set<String>> m = new Map<ID, Set<String>>();
Map<ID, Map<ID, Account[]>> m2 = new Map<ID, Map<ID, Account[]>>();
You can use the generic sObject data type with maps. You can also create a generic instance of a map.
As with lists, you can populate map key-value pairs when the map is declared by using curly brace ({}) syntax. Within the
curly braces, specify the key first, then specify the value for that key using =>. For example:
Map<String, String> MyStrings = new Map<String, String>{'a' => 'b', 'c' => 'd'.toUpperCase()};
Account[] accs = new Account[5]; // Account[] is synonymous with List<Account>
Map<Integer, List<Account>> m4 = new Map<Integer, List<Account>>{1 => accs};
In the first example, the value for the key a is b, and the value for the key c is d. In the second, the key 1 has the value of the
list accs.
This in an example of using sObjects as map keys.
Map<Account, String> mapKeyExample = new Map<Account, String>{
new Account(Name='Account1') => 'primary.person@account1.com',
new Account(Name='Account2') => 'decision.maker@account2.com'
};
To access elements in a map, use the Map methods provided by Apex. For example:
Account myAcct = new Account(); //Define a new account
Map<Integer, Account> m = new Map<Integer, Account>(); // Define a new map
m.put(1, myAcct); // Insert a new key-value pair in the map
System.assert(!m.containsKey(3)); // Assert that the map contains a key
Account a = m.get(1); // Retrieve a value, given a particular key
Set<Integer> s = m.keySet(); // Return a set that contains all of the keys in the map
For more information, including a complete list of all supported Map methods, see Map Methods on page 340.
Note the following considerations on maps:
• Unlike Java, Apex developers do not need to reference the algorithm that is used to implement a map in their declarations
(for example, HashMap or TreeMap). Apex uses a hash structure for all maps.
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![Language Constructs Collections
• Do not rely on the order in which map results are returned. The order of objects returned by maps may change without
warning. Always access map elements by key.
• A map key can hold the null value.
• Adding a map entry with a key that matches an existing key in the map overwrites the existing entry with that key with
the new entry.
• Uniqueness of map keys of user-defined types is determined by the equals and hashCode methods, which you provide
in your classes. Uniqueness of all other non-primitive types is determined by comparing the objects’ fields.
Maps from SObject Arrays
Maps from an ID or String data type to an sObject can be initialized from a list of sObjects. The IDs of the objects (which
must be non-null and distinct) are used as the keys. One common usage of this map type is for in-memory “joins” between
two tables. For instance, this example loads a map of IDs and Contacts:
Map<ID, Contact> m = new Map<ID, Contact>([SELECT Id, LastName FROM Contact]);
In the example, the SOQL query returns a list of contacts with their Id and LastName fields. The new operator uses the list
to create a map. For more information, see SOQL and SOSL Queries on page 73.
Parameterized Typing
Apex, in general, is a statically-typed programming language, which means users must specify the data type for a variable
before that variable can be used. For example, the following is legal in Apex:
Integer x = 1;
The following is not legal if x has not been defined earlier:
x = 1;
Lists, maps and sets are parameterized in Apex: they take any data type Apex supports for them as an argument. That data
type must be replaced with an actual data type upon construction of the list, map or set. For example:
List<String> myList = new List<String>();
Subtyping with Parameterized Lists
In Apex, if type T is a subtype of U, then List<T> would be a subtype of List<U>. For example, the following is legal:
List<String> slst = new List<String> {'foo', 'bar'};
List<Object> olst = slst;
Using Custom Types in Map Keys and Sets
When using a custom type (your Apex class) for the map key or set elements, provide equals and hashCode methods in
your class. Apex uses these two methods to determine equality and uniqueness of keys for your objects.
Adding equals and hashCode Methods to Your Class
To ensure that map keys of your custom type are compared correctly and their uniqueness can be determined consistently,
provide an implementation of the following two methods in your class:
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Overflow of Data Type Values
Arithmetic computations that produce values larger than the maximum value of the current type are said to overflow.
For example, Integer i = 2147483647 + 1; yields a value of –2147483648 because 2147483647 is the maximum
value for an Integer, so adding one to it wraps the value around to the minimum negative value for Integers, –2147483648.
If arithmetic computations generate results larger than the maximum value for the current type, the end result will be
incorrect because the computed values that are larger than the maximum will overflow. For example, the expression
Long MillsPerYear = 365 * 24 * 60 * 60 * 1000; results in an incorrect result because the products of
Integers on the right hand side are larger than the maximum Integer value and they overflow. As a result, the final
product isn't the expected one. You can avoid this by ensuring that the type of numeric values or variables you are using
in arithmetic operations are large enough to hold the results. In this example, append L to numeric values to make them
Long so the intermediate products will be Long as well and no overflow occurs. The following example shows how to
correctly compute the amount of milliseconds in a year by multiplying Long numeric values.
Long MillsPerYear = 365L * 24L * 60L * 60L * 1000L;
Long ExpectedValue = 31536000000L;
System.assertEquals(MillsPerYear, ExpectedValue);
Loss of Fractions in Divisions
When dividing numeric Integer or Long values, the fractional portion of the result, if any, is removed before performing
any implicit conversions to a Double or Decimal. For example, Double d = 5/3; returns 1.0 because the actual result
(1.666...) is an Integer and is rounded to 1 before being implicitly converted to a Double. To preserve the fractional
value, ensure that you are using Double or Decimal numeric values in the division. For example, Double d = 5.0/3.0;
returns 1.6666666666666667 because 5.0 and 3.0 represent Double values, which results in the quotient being a Double
as well and no fractional value is lost.
Variables
Local variables are declared with Java-style syntax. For example:
Integer i = 0;
String str;
Account a;
Account[] accts;
Set<String> s;
Map<ID, Account> m;
As with Java, multiple variables can be declared and initialized in a single statement, using comma separation. For example:
Integer i, j, k;
All variables allow null as a value and are initialized to null if they are not assigned another value. For instance, in the
following example, i, and k are assigned values, while j is set to null because it is not assigned:
Integer i = 0, j, k = 1;
Variables can be defined at any point in a block, and take on scope from that point forward. Sub-blocks cannot redefine a
variable name that has already been used in a parent block, but parallel blocks can reuse a variable name. For example:
Integer i;
{
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![Language Constructs Case Sensitivity
// Integer i; This declaration is not allowed
}
for (Integer j = 0; j < 10; j++);
for (Integer j = 0; j < 10; j++);
Case Sensitivity
To avoid confusion with case-insensitive SOQL and SOSL queries, Apex is also case-insensitive. This means:
• Variable and method names are case insensitive. For example:
Integer I;
//Integer i; This would be an error.
• References to object and field names are case insensitive. For example:
Account a1;
ACCOUNT a2;
• SOQL and SOSL statements are case insensitive. For example:
Account[] accts = [sELect ID From ACCouNT where nAme = 'fred'];
Also note that Apex uses the same filtering semantics as SOQL, which is the basis for comparisons in the SOAP API and
the Salesforce user interface. The use of these semantics can lead to some interesting behavior. For example, if an end user
generates a report based on a filter for values that come before 'm' in the alphabet (that is, values < 'm'), null fields are returned
in the result. The rationale for this behavior is that users typically think of a field without a value as just a “space” character,
rather than its actual “null” value. Consequently, in Apex, the following expressions all evaluate to true:
String s;
System.assert('a' == 'A');
System.assert(s < 'b');
System.assert(!(s > 'b'));
Note: Although s < 'b' evaluates to true in the example above, 'b.'compareTo(s) generates an error because
you are trying to compare a letter to a null value.
Constants
Constants can be defined using the final keyword, which means that the variable can be assigned at most once, either in
the declaration itself, or with a static initializer method if the constant is defined in a class. For example:
public class myCls {
static final Integer PRIVATE_INT_CONST;
static final Integer PRIVATE_INT_CONST2 = 200;
public static Integer calculate() {
return 2 + 7;
}
static {
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PRIVATE_INT_CONST = calculate();
}
}
For more information, see Using the final Keyword on page 131.
Expressions
An expression is a construct made up of variables, operators, and method invocations that evaluates to a single value. This
section provides an overview of expressions in Apex and contains the following:
• Understanding Expressions
• Understanding Expression Operators
• Understanding Operator Precedence
• Extending sObject and List Expressions
• Using Comments
Understanding Expressions
An expression is a construct made up of variables, operators, and method invocations that evaluates to a single value. In Apex,
an expression is always one of the following types:
• A literal expression. For example:
1 + 1
• A new sObject, Apex object, list, set, or map. For example:
new Account(<field_initializers>)
new Integer[<n>]
new Account[]{<elements>}
new List<Account>()
new Set<String>{}
new Map<String, Integer>()
new myRenamingClass(string oldName, string newName)
• Any value that can act as the left-hand of an assignment operator (L-values), including variables, one-dimensional list
positions, and most sObject or Apex object field references. For example:
Integer i
myList[3]
myContact.name
myRenamingClass.oldName
• Any sObject field reference that is not an L-value, including:
◊ The ID of an sObject in a list (see Lists)
◊ A set of child records associated with an sObject (for example, the set of contacts associated with a particular account).
This type of expression yields a query result, much like SOQL and SOSL queries.
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• A SOQL or SOSL query surrounded by square brackets, allowing for on-the-fly evaluation in Apex. For example:
Account[] aa = [SELECT Id, Name FROM Account WHERE Name ='Acme'];
Integer i = [SELECT COUNT() FROM Contact WHERE LastName ='Weissman'];
List<List<SObject>> searchList = [FIND 'map*' IN ALL FIELDS RETURNING Account (Id, Name),
Contact, Opportunity, Lead];
For information, see SOQL and SOSL Queries on page 73.
• A static or instance method invocation. For example:
System.assert(true)
myRenamingClass.replaceNames()
changePoint(new Point(x, y));
Understanding Expression Operators
Expressions can also be joined to one another with operators to create compound expressions. Apex supports the following
operators:
Operator Syntax Description
= x = y Assignment operator (Right associative). Assigns the value of y to the L-value
x. Note that the data type of x must match the data type of y, and cannot be
null.
+= x += y Addition assignment operator (Right associative). Adds the value of y to
the original value of x and then reassigns the new value to x. See + for
additional information. x and y cannot be null.
*= x *= y Multiplication assignment operator (Right associative). Multiplies the value
of y with the original value of x and then reassigns the new value to x. Note
that x and y must be Integers or Doubles, or a combination. x and y cannot
be null.
-= x -= y Subtraction assignment operator (Right associative). Subtracts the value of
y from the original value of x and then reassigns the new value to x. Note
that x and y must be Integers or Doubles, or a combination. x and y cannot
be null.
/= x /= y Division assignment operator (Right associative). Divides the original value
of x with the value of y and then reassigns the new value to x. Note that x
and y must be Integers or Doubles, or a combination. x and y cannot be
null.
|= x |= y OR assignment operator (Right associative). If x, a Boolean, and y, a Boolean,
are both false, then x remains false. Otherwise, x is assigned the value of true.
Note:
• This operator exhibits “short-circuiting” behavior, which means y is
evaluated only if x is false.
• x and y cannot be null.
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![Language Constructs Understanding Operator Precedence
Operator Syntax Description
() (x) Parentheses. Elevates the precedence of an expression x so that it is evaluated
first in a compound expression.
Understanding Operator Precedence
Apex uses the following operator precedence rules:
Precedence Operators Description
1 {} () ++ -- Grouping and prefix increments and decrements
2 ! -x +x (type) new Unary negation, type cast and object creation
3 * / Multiplication and division
4 + - Addition and subtraction
5 < <= > >= instanceof Greater-than and less-than comparisons, reference
tests
6 == != Comparisons: equal and not-equal
7 && Logical AND
8 || Logical OR
9 = += -= *= /= &= Assignment operators
Extending sObject and List Expressions
As in Java, sObject and list expressions can be extended with method references and list expressions, respectively, to form new
expressions.
In the following example, a new variable containing the length of the new account name is assigned to acctNameLength.
Integer acctNameLength = new Account[]{new Account(Name='Acme')}[0].Name.length();
In the above, new Account[] generates a list.
The list is populated by the SOQL statement {new Account(name='Acme')}.
Item 0, the first item in the list, is then accessed by the next part of the string [0].
The name of the sObject in the list is accessed, followed by the method returning the length name.length().
In the following example, a name that has been shifted to lower case is returned.
String nameChange = [SELECT Name FROM Account][0].Name.toLowerCase();
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![Language Constructs Using Comments
Using Comments
Both single and multiline comments are supported in Apex code:
• To create a single line comment, use //. All characters on the same line to the right of the // are ignored by the parser.
For example:
Integer i = 1; // This comment is ignored by the parser
• To create a multiline comment, use /* and */ to demarcate the beginning and end of the comment block. For example:
Integer i = 1; /* This comment can wrap over multiple
lines without getting interpreted by the
parser. */
Assignment Statements
An assignment statement is any statement that places a value into a variable, generally in one of the following two forms:
[LValue] = [new_value_expression];
[LValue] = [[inline_soql_query]];
In the forms above, [LValue] stands for any expression that can be placed on the left side of an assignment operator. These
include:
• A simple variable. For example:
Integer i = 1;
Account a = new Account();
Account[] accts = [SELECT Id FROM Account];
• A de-referenced list element. For example:
ints[0] = 1;
accts[0].Name = 'Acme';
• An sObject field reference that the context user has permission to edit. For example:
Account a = new Account(Name = 'Acme', BillingCity = 'San Francisco');
// IDs cannot be set manually
// a.Id = '00300000003T2PGAA0'; This code is invalid!
// Instead, insert the record. The system automatically assigns it an ID.
insert a;
// Fields also must be writeable for the context user
// a.CreatedDate = System.today(); This code is invalid because
// createdDate is read-only!
// Since the account a has been inserted, it is now possible to
// create a new contact that is related to it
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![Language Constructs Conditional (If-Else) Statements
Contact c = new Contact(LastName = 'Roth', Account = a);
// Notice that you can write to the account name directly through the contact
c.Account.Name = 'salesforce.com';
Assignment is always done by reference. For example:
Account a = new Account();
Account b;
Account[] c = new Account[]{};
a.Name = 'Acme';
b = a;
c.add(a);
// These asserts should now be true. You can reference the data
// originally allocated to account a through account b and account list c.
System.assertEquals(b.Name, 'Acme');
System.assertEquals(c[0].Name, 'Acme');
Similarly, two lists can point at the same value in memory. For example:
Account[] a = new Account[]{new Account()};
Account[] b = a;
a[0].Name = 'Acme';
System.assert(b[0].Name == 'Acme');
In addition to =, other valid assignment operators include +=, *=, /=, |=, &=, ++, and --. See Understanding Expression
Operators on page 60.
Conditional (If-Else) Statements
The conditional statement in Apex works similarly to Java:
if ([Boolean_condition])
// Statement 1
else
// Statement 2
The else portion is always optional, and always groups with the closest if. For example:
Integer x, sign;
// Your code
if (x <= 0) if (x == 0) sign = 0; else sign = -1;
is equivalent to:
Integer x, sign;
// Your code
if (x <= 0) {
if (x == 0) {
sign = 0;
} else {
sign = -1;
}
}
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![Language Constructs Loops
Repeated else if statements are also allowed. For example:
if (place == 1) {
medal_color = 'gold';
} else if (place == 2) {
medal_color = 'silver';
} else if (place == 3) {
medal_color = 'bronze';
} else {
medal_color = null;
}
Loops
Apex supports the following five types of procedural loops:
• do {statement} while (Boolean_condition);
• while (Boolean_condition) statement;
• for (initialization; Boolean_exit_condition; increment) statement;
• for (variable : array_or_set) statement;
• for (variable : [inline_soql_query]) statement;
All loops allow for loop control structures:
• break; exits the entire loop
• continue; skips to the next iteration of the loop
Do-While Loops
The Apex do-while loop repeatedly executes a block of code as long as a particular Boolean condition remains true. Its syntax
is:
do {
code_block
} while (condition);
Note: Curly braces ({}) are always required around a code_block.
As in Java, the Apex do-while loop does not check the Boolean condition statement until after the first loop is executed.
Consequently, the code block always runs at least once.
As an example, the following code outputs the numbers 1 - 10 into the debug log:
Integer count = 1;
do {
System.debug(count);
count++;
} while (count < 11);
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![Language Constructs While Loops
While Loops
The Apex while loop repeatedly executes a block of code as long as a particular Boolean condition remains true. Its syntax
is:
while (condition) {
code_block
}
Note: Curly braces ({}) are required around a code_block only if the block contains more than one statement.
Unlike do-while, the while loop checks the Boolean condition statement before the first loop is executed. Consequently,
it is possible for the code block to never execute.
As an example, the following code outputs the numbers 1 - 10 into the debug log:
Integer count = 1;
while (count < 11) {
System.debug(count);
count++;
}
For Loops
Apex supports three variations of the for loop:
• The traditional for loop:
for (init_stmt; exit_condition; increment_stmt) {
code_block
}
• The list or set iteration for loop:
for (variable : list_or_set) {
code_block
}
where variable must be of the same primitive or sObject type as list_or_set.
• The SOQL for loop:
for (variable : [soql_query]) {
code_block
}
or
for (variable_list : [soql_query]) {
code_block
}
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![Language Constructs For Loops
Both variable and variable_list must be of the same sObject type as is returned by the soql_query.
Note: Curly braces ({}) are required around a code_block only if the block contains more than one statement.
Each is discussed further in the sections that follow.
Traditional For Loops
The traditional for loop in Apex corresponds to the traditional syntax used in Java and other languages. Its syntax is:
for (init_stmt; exit_condition; increment_stmt) {
code_block
}
When executing this type of for loop, the Apex runtime engine performs the following steps, in order:
1. Execute the init_stmt component of the loop. Note that multiple variables can be declared and/or initialized in this
statement.
2. Perform the exit_condition check. If true, the loop continues. If false, the loop exits.
3. Execute the code_block.
4. Execute the increment_stmt statement.
5. Return to Step 2.
As an example, the following code outputs the numbers 1 - 10 into the debug log. Note that an additional initialization variable,
j, is included to demonstrate the syntax:
for (Integer i = 0, j = 0; i < 10; i++) {
System.debug(i+1);
}
List or Set Iteration For Loops
The list or set iteration for loop iterates over all the elements in a list or set. Its syntax is:
for (variable : list_or_set) {
code_block
}
where variable must be of the same primitive or sObject type as list_or_set.
When executing this type of for loop, the Apex runtime engine assigns variable to each element in list_or_set, and
runs the code_block for each value.
For example, the following code outputs the numbers 1 - 10 to the debug log:
Integer[] myInts = new Integer[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
for (Integer i : myInts) {
System.debug(i);
}
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![Language Constructs For Loops
SOQL For Loops
SOQL for loops iterate over all of the sObject records returned by a SOQL query. The syntax of a SOQL for loop is either:
for (variable : [soql_query]) {
code_block
}
or
for (variable_list : [soql_query]) {
code_block
}
Both variable and variable_list must be of the same type as the sObjects that are returned by the soql_query.
As in standard SOQL queries, the [soql_query] statement can refer to code expressions in their WHERE clauses using the
: syntax. For example:
String s = 'Acme';
for (Account a : [SELECT Id, Name from Account
where Name LIKE :(s+'%')]) {
// Your code
}
The following example combines creating a list from a SOQL query, with the DML update method.
// Create a list of account records from a SOQL query
List<Account> accs = [SELECT Id, Name FROM Account WHERE Name = 'Siebel'];
// Loop through the list and update the Name field
for(Account a : accs){
a.Name = 'Oracle';
}
// Update the database
update accs;
SOQL For Loops Versus Standard SOQL Queries
SOQL for loops differ from standard SOQL statements because of the method they use to retrieve sObjects. While the
standard queries discussed in SOQL and SOSL Queries can retrieve either the count of a query or a number of object records,
SOQL for loops retrieve all sObjects, using efficient chunking with calls to the query and queryMore methods of the
SOAP API. Developers should always use a SOQL for loop to process query results that return many records, to avoid the
limit on heap size.
Note that queries including an aggregate function don't support queryMore. A runtime exception occurs if you use a query
containing an aggregate function that returns more than 2000 rows in a for loop.
SOQL For Loop Formats
SOQL for loops can process records one at a time using a single sObject variable, or in batches of 200 sObjects at a time
using an sObject list:
• The single sObject format executes the for loop's <code_block> once per sObject record. Consequently, it is easy to
understand and use, but is grossly inefficient if you want to use data manipulation language (DML) statements within the
for loop body. Each DML statement ends up processing only one sObject at a time.
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![Language Constructs SOQL and SOSL Queries
• The sObject list format executes the for loop's <code_block> once per list of 200 sObjects. Consequently, it is a little
more difficult to understand and use, but is the optimal choice if you need to use DML statements within the for loop
body. Each DML statement can bulk process a list of sObjects at a time.
For example, the following code illustrates the difference between the two types of SOQL query for loops:
// Create a savepoint because the data should not be committed to the database
Savepoint sp = Database.setSavepoint();
insert new Account[]{new Account(Name = 'yyy'),
new Account(Name = 'yyy'),
new Account(Name = 'yyy')};
// The single sObject format executes the for loop once per returned record
Integer i = 0;
for (Account tmp : [SELECT Id FROM Account WHERE Name = 'yyy']) {
i++;
}
System.assert(i == 3); // Since there were three accounts named 'yyy' in the
// database, the loop executed three times
// The sObject list format executes the for loop once per returned batch
// of records
i = 0;
Integer j;
for (Account[] tmp : [SELECT Id FROM Account WHERE Name = 'yyy']) {
j = tmp.size();
i++;
}
System.assert(j == 3); // The list should have contained the three accounts
// named 'yyy'
System.assert(i == 1); // Since a single batch can hold up to 100 records and,
// only three records should have been returned, the
// loop should have executed only once
// Revert the database to the original state
Database.rollback(sp);
Note:
• The break and continue keywords can be used in both types of inline query for loop formats. When using
the sObject list format, continue skips to the next list of sObjects.
• DML statements can only process up to 10,000 records at a time, and sObject list for loops process records in
batches of 200. Consequently, if you are inserting, updating, or deleting more than one record per returned record
in an sObject list for loop, it is possible to encounter runtime limit errors. See Understanding Execution Governors
and Limits on page 225.
SOQL and SOSL Queries
You can evaluate Salesforce Object Query Language (SOQL) or Salesforce Object Search Language (SOSL) statements
on-the-fly in Apex by surrounding the statement in square brackets.
SOQL Statements
SOQL statements evaluate to a list of sObjects, a single sObject, or an Integer for count method queries.
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![Language Constructs SOQL and SOSL Queries
For example, you could retrieve a list of accounts that are named Acme:
List<Account> aa = [SELECT Id, Name FROM Account WHERE Name = 'Acme'];
From this list, you can access individual elements:
if (!aa.isEmpty()) {
// Execute commands
}
You can also create new objects from SOQL queries on existing ones. The following example creates a new contact for the
first account with the number of employees greater than 10:
Contact c = new Contact(Account = [SELECT Name FROM Account
WHERE NumberOfEmployees > 10 LIMIT 1]);
c.FirstName = 'James';
c.LastName = 'Yoyce';
Note that the newly created object contains null values for its fields, which will need to be set.
The count method can be used to return the number of rows returned by a query. The following example returns the total
number of contacts with the last name of Weissman:
Integer i = [SELECT COUNT() FROM Contact WHERE LastName = 'Weissman'];
You can also operate on the results using standard arithmetic:
Integer j = 5 * [SELECT COUNT() FROM Account];
For a full description of SOQL query syntax, see the Salesforce SOQL and SOSL Reference Guide.
SOSL Statements
SOSL statements evaluate to a list of lists of sObjects, where each list contains the search results for a particular sObject type.
The result lists are always returned in the same order as they were specified in the SOSL query. If a SOSL query does not
return any records for a specified sObject type, the search results include an empty list for that sObject.
For example, you can return a list of accounts, contacts, opportunities, and leads that begin with the phrase map:
List<List<SObject>> searchList = [FIND 'map*' IN ALL FIELDS RETURNING Account (Id, Name),
Contact, Opportunity, Lead];
Note:
The syntax of the FIND clause in Apex differs from the syntax of the FIND clause in the SOAP API:
• In Apex, the value of the FIND clause is demarcated with single quotes. For example:
FIND 'map*' IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity,
Lead
• In the Force.com API, the value of the FIND clause is demarcated with braces. For example:
FIND {map*} IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity,
Lead
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![Language Constructs Working with SOQL and SOSL Query Results
From searchList, you can create arrays for each object returned:
Account [] accounts = ((List<Account>)searchList[0]);
Contact [] contacts = ((List<Contact>)searchList[1]);
Opportunity [] opportunities = ((List<Opportunity>)searchList[2]);
Lead [] leads = ((List<Lead>)searchList[3]);
For a full description of SOSL query syntax, see the Salesforce SOQL and SOSL Reference Guide.
Working with SOQL and SOSL Query Results
SOQL and SOSL queries only return data for sObject fields that are selected in the original query. If you try to access a field
that was not selected in the SOQL or SOSL query (other than ID), you receive a runtime error, even if the field contains a
value in the database. The following code example causes a runtime error:
insert new Account(Name = 'Singha');
Account acc = [SELECT Id FROM Account WHERE Name = 'Singha' LIMIT 1];
// Note that name is not selected
String name = [SELECT Id FROM Account WHERE Name = 'Singha' LIMIT 1].Name;
The following is the same code example rewritten so it does not produce a runtime error. Note that Name has been added as
part of the select statement, after Id.
insert new Account(Name = 'Singha');
Account acc = [SELECT Id FROM Account WHERE Name = 'Singha' LIMIT 1];
// Note that name is now selected
String name = [SELECT Id, Name FROM Account WHERE Name = 'Singha' LIMIT 1].Name;
Even if only one sObject field is selected, a SOQL or SOSL query always returns data as complete records. Consequently,
you must dereference the field in order to access it. For example, this code retrieves an sObject list from the database with a
SOQL query, accesses the first account record in the list, and then dereferences the record's AnnualRevenue field:
Double rev = [SELECT AnnualRevenue FROM Account
WHERE Name = 'Acme'][0].AnnualRevenue;
// When only one result is returned in a SOQL query, it is not necessary
// to include the list's index.
Double rev2 = [SELECT AnnualRevenue FROM Account
WHERE Name = 'Acme' LIMIT 1].AnnualRevenue;
The only situation in which it is not necessary to dereference an sObject field in the result of an SOQL query, is when the
query returns an Integer as the result of a COUNT operation:
Integer i = [SELECT COUNT() FROM Account];
Fields in records returned by SOSL queries must always be dereferenced.
Also note that sObject fields that contain formulas return the value of the field at the time the SOQL or SOSL query was
issued. Any changes to other fields that are used within the formula are not reflected in the formula field value until the record
has been saved and re-queried in Apex. Like other read-only sObject fields, the values of the formula fields themselves cannot
be changed in Apex.
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![Language Constructs Working with SOQL Aggregate Functions
Working with SOQL Aggregate Functions
Aggregate functions in SOQL, such as SUM() and MAX(), allow you to roll up and summarize your data in a query. For more
information on aggregate functions, see ”Aggregate Functions” in the Salesforce SOQL and SOSL Reference Guide.
You can use aggregate functions without using a GROUP BY clause. For example, you could use the AVG() aggregate function
to find the average Amount for all your opportunities.
AggregateResult[] groupedResults
= [SELECT AVG(Amount)aver FROM Opportunity];
Object avgAmount = groupedResults[0].get('aver');
Note that any query that includes an aggregate function returns its results in an array of AggregateResult objects. AggregateResult
is a read-only sObject and is only used for query results.
Aggregate functions become a more powerful tool to generate reports when you use them with a GROUP BY clause. For
example, you could find the average Amount for all your opportunities by campaign.
AggregateResult[] groupedResults
= [SELECT CampaignId, AVG(Amount)
FROM Opportunity
GROUP BY CampaignId];
for (AggregateResult ar : groupedResults) {
System.debug('Campaign ID' + ar.get('CampaignId'));
System.debug('Average amount' + ar.get('expr0'));
}
Any aggregated field in a SELECT list that does not have an alias automatically gets an implied alias with a format expri,
where i denotes the order of the aggregated fields with no explicit aliases. The value of i starts at 0 and increments for every
aggregated field with no explicit alias. For more information, see ”Using Aliases with GROUP BY” in the Salesforce SOQL and
SOSL Reference Guide.
Note: Queries that include aggregate functions are subject to the same governor limits as other SOQL queries for
the total number of records returned. This limit includes any records included in the aggregation, not just the number
of rows returned by the query. If you encounter this limit, you should add a condition to the WHERE clause to reduce
the amount of records processed by the query.
Working with Very Large SOQL Queries
Your SOQL query may return so many sObjects that the limit on heap size is exceeded and an error occurs. To resolve, use
a SOQL query for loop instead, since it can process multiple batches of records through the use of internal calls to query
and queryMore.
For example, if the results are too large, the syntax below causes a runtime exception:
Account[] accts = [SELECT Id FROM Account];
Instead, use a SOQL query for loop as in one of the following examples:
// Use this format if you are not executing DML statements
// within the for loop
for (Account a : [SELECT Id, Name FROM Account
WHERE Name LIKE 'Acme%']) {
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![Language Constructs Working with Very Large SOQL Queries
// Your code without DML statements here
}
// Use this format for efficiency if you are executing DML statements
// within the for loop
for (List<Account> accts : [SELECT Id, Name FROM Account
WHERE Name LIKE 'Acme%']) {
// Your code here
update accts;
}
The following example demonstrates a SOQL query for loop used to mass update records. Suppose you want to change the
last name of a contact across all records for contacts whose first and last names match a specified criteria:
public void massUpdate() {
for (List<Contact> contacts:
[SELECT FirstName, LastName FROM Contact]) {
for(Contact c : contacts) {
if (c.FirstName == 'Barbara' &&
c.LastName == 'Gordon') {
c.LastName = 'Wayne';
}
}
update contacts;
}
}
Instead of using a SOQL query in a for loop, the preferred method of mass updating records is to use batch Apex, which
minimizes the risk of hitting governor limits.
For more information, see SOQL For Loops on page 72.
More Efficient SOQL Queries
For best performance, SOQL queries must be selective, particularly for queries inside of triggers. To avoid long execution
times, non-selective SOQL queries may be terminated by the system. Developers will receive an error message when a
non-selective query in a trigger executes against an object that contains more than 100,000 records. To avoid this error, ensure
that the query is selective.
Selective SOQL Query Criteria
• A query is selective when one of the query filters is on an indexed field and the query filter reduces the resulting
number of rows below a system-defined threshold. The performance of the SOQL query improves when two or
more filters used in the WHERE clause meet the mentioned conditions.
• The selectivity threshold is 10% of the records for the first million records and less than 5% of the records after the
first million records, up to a maximum of 333,000 records. In some circumstances, for example with a query filter
that is an indexed standard field, the threshold may be higher. Also, the selectivity threshold is subject to change.
Custom Index Considerations for Selective SOQL Queries
• The following fields are indexed by default: primary keys (Id, Name and Owner fields), foreign keys (lookup or
master-detail relationship fields), audit dates (such as LastModifiedDate), and custom fields marked as External ID
or Unique.
• Salesforce.com Support can add custom indexes on request for customers.
• A custom index can't be created on these types of fields: formula fields, multi-select picklists, currency fields in a
multicurrency organization, long text fields, and binary fields (fields of type blob, file, or encrypted text.) Note that
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![Language Constructs Using SOQL Queries That Return One Record
Using SOQL Queries That Return One Record
SOQL queries can be used to assign a single sObject value when the result list contains only one element. When the L-value
of an expression is a single sObject type, Apex automatically assigns the single sObject record in the query result list to the
L-value. A runtime exception results if zero sObjects or more than one sObject is found in the list. For example:
List<Account> accts = [SELECT Id FROM Account];
// These lines of code are only valid if one row is returned from
// the query. Notice that the second line dereferences the field from the
// query without assigning it to an intermediary sObject variable.
Account acct = [SELECT Id FROM Account];
String name = [SELECT Name FROM Account].Name;
Improving Performance by Not Searching on Null Values
In your SOQL and SOSL queries, avoid searching records that contain null values. Filter out null values first to improve
performance. In the following example, any records where the treadID value is null are filtered out of the returned values.
Public class TagWS {
/* getThreadTags
*
* a quick method to pull tags not in the existing list
*
*/
public static webservice List<String>
getThreadTags(String threadId, List<String> tags) {
system.debug(LoggingLevel.Debug,tags);
List<String> retVals = new List<String>();
Set<String> tagSet = new Set<String>();
Set<String> origTagSet = new Set<String>();
origTagSet.addAll(tags);
// Note WHERE clause verifies that threadId is not null
for(CSO_CaseThread_Tag__c t :
[SELECT Name FROM CSO_CaseThread_Tag__c
WHERE Thread__c = :threadId AND
WHERE threadID != null])
{
tagSet.add(t.Name);
}
for(String x : origTagSet) {
// return a minus version of it so the UI knows to clear it
if(!tagSet.contains(x)) retVals.add('-' + x);
}
for(String x : tagSet) {
// return a plus version so the UI knows it's new
if(!origTagSet.contains(x)) retvals.add('+' + x);
}
return retVals;
}
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![Language Constructs Understanding Foreign Key and Parent-Child Relationship SOQL Queries
Understanding Foreign Key and Parent-Child Relationship SOQL Queries
The SELECT statement of a SOQL query can be any valid SOQL statement, including foreign key and parent-child record
joins. If foreign key joins are included, the resulting sObjects can be referenced using normal field notation. For example:
System.debug([SELECT Account.Name FROM Contact
WHERE FirstName = 'Caroline'].Account.Name);
Additionally, parent-child relationships in sObjects act as SOQL queries as well. For example:
for (Account a : [SELECT Id, Name, (SELECT LastName FROM Contacts)
FROM Account
WHERE Name = 'Acme']) {
Contact[] cons = a.Contacts;
}
//The following example also works because we limit to only 1 contact
for (Account a : [SELECT Id, Name, (SELECT LastName FROM Contacts LIMIT 1)
FROM Account
WHERE Name = 'testAgg']) {
Contact c = a.Contacts;
}
Working with Polymorphic Relationships in SOQL Queries
A polymorphic relationship is a relationship between objects where a referenced object can be one of several different types.
For example, the What relationship field of an Event could be an Account, or a Campaign, or an Opportunity.
The following describes how to use SOQL queries with polymorphic relationships in Apex. If you want more general information
on polymorphic relationships, see Understanding Polymorphic Keys and Relationships in the Force.com SOQL and SOSL
Reference.
You can use SOQL queries that reference polymorphic fields in Apex to get results that depend on the object type referenced
by the polymorphic field. One approach is to filter your results using the Type qualifier. This example queries Events that are
related to an Account or Opportunity via the What field.
List<Event> = [SELECT Description FROM Event WHERE What.Type IN ('Account', 'Opportunity')];
Another approach would be to use the TYPEOF clause in the SOQL SELECT statement. This example also queries Events
that are related to an Account or Opportunity via the What field.
List<Event> = [SELECT TYPEOF What WHEN Account THEN Phone WHEN Opportunity THEN Amount END
FROM Event];
Note: TYPEOF is currently available as a Developer Preview as part of the SOQL Polymorphism feature. For more
information on enabling TYPEOF for your organization, contact salesforce.com.
These queries will return a list of sObjects where the relationship field references the desired object types.
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![Language Constructs Using Apex Variables in SOQL and SOSL Queries
If you need to access the referenced object in a polymorphic relationship, you can use the instanceof keyword to determine
the object type. The following example uses instanceof to determine whether an Account or Opportunity is related to an
Event.
Event myEvent = eventFromQuery;
if (myEvent.What instanceof Account) {
// myEvent.What references an Account, so process accordingly
} else if (myEvent.What instanceof Opportunity) {
// myEvent.What references an Opportunity, so process accordingly
}
Note that you must assign the referenced sObject that the query returns to a variable of the appropriate type before you can
pass it to another method. The following example queries for User or Group owners of Merchandise__c custom objects using
a SOQL query with a TYPEOF clause, uses instanceof to determine the owner type, and then assigns the owner objects to
User or Group type variables before passing them to utility methods.
public class PolymorphismExampleClass {
// Utility method for a User
public static void processUser(User theUser) {
System.debug('Processed User');
}
// Utility method for a Group
public static void processGroup(Group theGroup) {
System.debug('Processed Group');
}
public static void processOwnersOfMerchandise() {
// Select records based on the Owner polymorphic relationship field
List<Merchandise__c> merchandiseList = [SELECT TYPEOF Owner WHEN User THEN LastName
WHEN Group THEN Email END FROM Merchandise__c];
// We now have a list of Merchandise__c records owned by either a User or Group
for (Merchandise__c merch: merchandiseList) {
// We can use instanceof to check the polymorphic relationship type
// Note that we have to assign the polymorphic reference to the appropriate
// sObject type before passing to a method
if (merch.Owner instanceof User) {
User userOwner = merch.Owner;
processUser(userOwner);
} else if (merch.Owner instanceof Group) {
Group groupOwner = merch.Owner;
processGroup(groupOwner);
}
}
}
}
Using Apex Variables in SOQL and SOSL Queries
SOQL and SOSL statements in Apex can reference Apex code variables and expressions if they are preceded by a colon (:).
This use of a local code variable within a SOQL or SOSL statement is called a bind. The Apex parser first evaluates the local
variable in code context before executing the SOQL or SOSL statement. Bind expressions can be used as:
• The search string in FIND clauses.
• The filter literals in WHERE clauses.
• The value of the IN or NOT IN operator in WHERE clauses, allowing filtering on a dynamic set of values. Note that this is
of particular use with a list of IDs or Strings, though it works with lists of any type.
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![Language Constructs Using Apex Variables in SOQL and SOSL Queries
• The division names in WITH DIVISION clauses.
• The numeric value in LIMIT clauses.
Bind expressions can't be used with other clauses, such as INCLUDES.
For example:
Account A = new Account(Name='xxx');
insert A;
Account B;
// A simple bind
B = [SELECT Id FROM Account WHERE Id = :A.Id];
// A bind with arithmetic
B = [SELECT Id FROM Account
WHERE Name = :('x' + 'xx')];
String s = 'XXX';
// A bind with expressions
B = [SELECT Id FROM Account
WHERE Name = :'XXXX'.substring(0,3)];
// A bind with an expression that is itself a query result
B = [SELECT Id FROM Account
WHERE Name = :[SELECT Name FROM Account
WHERE Id = :A.Id].Name];
Contact C = new Contact(LastName='xxx', AccountId=A.Id);
insert new Contact[]{C, new Contact(LastName='yyy',
accountId=A.id)};
// Binds in both the parent and aggregate queries
B = [SELECT Id, (SELECT Id FROM Contacts
WHERE Id = :C.Id)
FROM Account
WHERE Id = :A.Id];
// One contact returned
Contact D = B.Contacts;
// A limit bind
Integer i = 1;
B = [SELECT Id FROM Account LIMIT :i];
// An IN-bind with an Id list. Note that a list of sObjects
// can also be used--the Ids of the objects are used for
// the bind
Contact[] cc = [SELECT Id FROM Contact LIMIT 2];
Task[] tt = [SELECT Id FROM Task WHERE WhoId IN :cc];
// An IN-bind with a String list
String[] ss = new String[]{'a', 'b'};
Account[] aa = [SELECT Id FROM Account
WHERE AccountNumber IN :ss];
// A SOSL query with binds in all possible clauses
String myString1 = 'aaa';
String myString2 = 'bbb';
Integer myInt3 = 11;
String myString4 = 'ccc';
Integer myInt5 = 22;
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![Language Constructs Querying All Records with a SOQL Statement
List<List<SObject>> searchList = [FIND :myString1 IN ALL FIELDS
RETURNING
Account (Id, Name WHERE Name LIKE :myString2
LIMIT :myInt3),
Contact,
Opportunity,
Lead
WITH DIVISION =:myString4
LIMIT :myInt5];
Querying All Records with a SOQL Statement
SOQL statements can use the ALL ROWS keywords to query all records in an organization, including deleted records and
archived activities. For example:
System.assertEquals(2, [SELECT COUNT() FROM Contact WHERE AccountId = a.Id ALL ROWS]);
You can use ALL ROWS to query records in your organization's Recycle Bin. You cannot use the ALL ROWS keywords with
the FOR UPDATE keywords.
Locking Statements
Apex allows developers to lock sObject records while they are being updated in order to prevent race conditions and other
thread safety problems. While an sObject record is locked, no other program or user is allowed to make updates.
To lock a set of sObject records in Apex, embed the keywords FOR UPDATE after any inline SOQL statement. For example,
the following statement, in addition to querying for two accounts, also locks the accounts that are returned:
Account [] accts = [SELECT Id FROM Account LIMIT 2 FOR UPDATE];
Note: You cannot use the ORDER BY keywords in any SOQL query that uses locking. However, query results are
automatically ordered by ID.
While the accounts are locked by this call, data manipulation language (DML) statements can modify their field values in the
database in the transaction.
Warning: Use care when setting locks in your Apex code. See Avoiding Deadlocks, below.
Locking in a SOQL For Loop
The FOR UPDATE keywords can also be used within SOQL for loops. For example:
for (Account[] accts : [SELECT Id FROM Account
FOR UPDATE]) {
// Your code
}
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![Language Constructs Exception Statements
The following is an example using the setSavepoint and rollback Database methods.
Account a = new Account(Name = 'xxx'); insert a;
System.assertEquals(null, [SELECT AccountNumber FROM Account WHERE Id = :a.Id].
AccountNumber);
// Create a savepoint while AccountNumber is null
Savepoint sp = Database.setSavepoint();
// Change the account number
a.AccountNumber = '123';
update a;
System.assertEquals('123', [SELECT AccountNumber FROM Account WHERE Id = :a.Id].
AccountNumber);
// Rollback to the previous null value
Database.rollback(sp);
System.assertEquals(null, [SELECT AccountNumber FROM Account WHERE Id = :a.Id].
AccountNumber);
Exception Statements
Apex uses exceptions to note errors and other events that disrupt the normal flow of code execution. throw statements can be
used to generate exceptions, while try, catch, and finally can be used to gracefully recover from an exception.
You can also create your own exceptions using the Exception class. For more information, see Exception Class on page 474.
Throw Statements
A throw statement allows you to signal that an error has occurred. To throw an exception, use the throw statement and
provide it with an exception object to provide information about the specific error. For example:
throw exceptionObject;
Try-Catch-Finally Statements
The try, catch, and finally statements can be used to gracefully recover from a thrown exception:
• The try statement identifies a block of code in which an exception can occur.
• The catch statement identifies a block of code that can handle a particular type of exception. A single try statement can
have multiple associated catch statements, however, each catch statement must have a unique exception type.
• The finally statement optionally identifies a block of code that is guaranteed to execute and allows you to clean up after
the code enclosed in the try block. A single try statement can have only one associated finally statement.
Syntax
The syntax of these statements is as follows:
try {
code_block
} catch (exceptionType) {
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![Invoking Apex Trigger Context Variables
Variable Usage
size The total number of records in a trigger invocation, both old and new.
Note: If any record that fires a trigger includes an invalid field value (for example, a formula that divides by zero),
that value is set to null in the new, newMap, old, and oldMap trigger context variables.
For example, in this simple trigger, Trigger.new is a list of sObjects and can be iterated over in a for loop, or used as a
bind variable in the IN clause of a SOQL query:
Trigger t on Account (after insert) {
for (Account a : Trigger.new) {
// Iterate over each sObject
}
// This single query finds every contact that is associated with any of the
// triggering accounts. Note that although Trigger.new is a collection of
// records, when used as a bind variable in a SOQL query, Apex automatically
// transforms the list of records into a list of corresponding Ids.
Contact[] cons = [SELECT LastName FROM Contact
WHERE AccountId IN :Trigger.new];
}
This trigger uses Boolean context variables like Trigger.isBefore and Trigger.isDelete to define code that only
executes for specific trigger conditions:
trigger myAccountTrigger on Account(before delete, before insert, before update,
after delete, after insert, after update) {
if (Trigger.isBefore) {
if (Trigger.isDelete) {
// In a before delete trigger, the trigger accesses the records that will be
// deleted with the Trigger.old list.
for (Account a : Trigger.old) {
if (a.name != 'okToDelete') {
a.addError('You can't delete this record!');
}
}
} else {
// In before insert or before update triggers, the trigger accesses the new records
// with the Trigger.new list.
for (Account a : Trigger.new) {
if (a.name == 'bad') {
a.name.addError('Bad name');
}
}
if (Trigger.isInsert) {
for (Account a : Trigger.new) {
System.assertEquals('xxx', a.accountNumber);
System.assertEquals('industry', a.industry);
System.assertEquals(100, a.numberofemployees);
System.assertEquals(100.0, a.annualrevenue);
a.accountNumber = 'yyy';
}
// If the trigger is not a before trigger, it must be an after trigger.
} else {
if (Trigger.isInsert) {
List<Contact> contacts = new List<Contact>();
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![Invoking Apex Common Bulk Trigger Idioms
Trigger Event Can change fields using Can update original object Can delete original object
trigger.new using an update DML using a delete DML
operation operation
after delete Not allowed. A runtime error Not applicable. The object has Not applicable. The object has
is thrown. trigger.new is already been deleted. already been deleted.
not available in after delete
triggers.
after undelete Not allowed. A runtime error Allowed. Allowed, but unnecessary. The
is thrown. trigger.old is object is deleted immediately
not available in after undelete after being inserted.
triggers.
Common Bulk Trigger Idioms
Although bulk triggers allow developers to process more records without exceeding execution governor limits, they can be
more difficult for developers to understand and code because they involve processing batches of several records at a time. The
following sections provide examples of idioms that should be used frequently when writing in bulk.
Using Maps and Sets in Bulk Triggers
Set and map data structures are critical for successful coding of bulk triggers. Sets can be used to isolate distinct records, while
maps can be used to hold query results organized by record ID.
For example, this bulk trigger from the sample quoting application first adds each pricebook entry associated with the
OpportunityLineItem records in Trigger.new to a set, ensuring that the set contains only distinct elements. It then queries
the PricebookEntries for their associated product color, and places the results in a map. Once the map is created, the trigger
iterates through the OpportunityLineItems in Trigger.new and uses the map to assign the appropriate color.
// When a new line item is added to an opportunity, this trigger copies the value of the
// associated product's color to the new record.
trigger oppLineTrigger on OpportunityLineItem (before insert) {
// For every OpportunityLineItem record, add its associated pricebook entry
// to a set so there are no duplicates.
Set<Id> pbeIds = new Set<Id>();
for (OpportunityLineItem oli : Trigger.new)
pbeIds.add(oli.pricebookentryid);
// Query the PricebookEntries for their associated product color and place the results
// in a map.
Map<Id, PricebookEntry> entries = new Map<Id, PricebookEntry>(
[select product2.color__c from pricebookentry
where id in :pbeIds]);
// Now use the map to set the appropriate color on every OpportunityLineItem processed
// by the trigger.
for (OpportunityLineItem oli : Trigger.new)
oli.color__c = entries.get(oli.pricebookEntryId).product2.color__c;
}
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![Invoking Apex Defining Triggers
Correlating Records with Query Results in Bulk Triggers
Use the Trigger.newMap and Trigger.oldMap ID-to-sObject maps to correlate records with query results. For example,
this trigger from the sample quoting app uses Trigger.oldMap to create a set of unique IDs (Trigger.oldMap.keySet()).
The set is then used as part of a query to create a list of quotes associated with the opportunities being processed by the trigger.
For every quote returned by the query, the related opportunity is retrieved from Trigger.oldMap and prevented from being
deleted:
trigger oppTrigger on Opportunity (before delete) {
for (Quote__c q : [SELECT opportunity__c FROM quote__c
WHERE opportunity__c IN :Trigger.oldMap.keySet()]) {
Trigger.oldMap.get(q.opportunity__c).addError('Cannot delete
opportunity with a quote');
}
}
Using Triggers to Insert or Update Records with Unique Fields
When an insert or upsert event causes a record to duplicate the value of a unique field in another new record in that batch,
the error message for the duplicate record includes the ID of the first record. However, it is possible that the error message
may not be correct by the time the request is finished.
When there are triggers present, the retry logic in bulk operations causes a rollback/retry cycle to occur. That retry cycle assigns
new keys to the new records. For example, if two records are inserted with the same value for a unique field, and you also have
an insert event defined for a trigger, the second duplicate record fails, reporting the ID of the first record. However, once
the system rolls back the changes and re-inserts the first record by itself, the record receives a new ID. That means the error
message reported by the second record is no longer valid.
Defining Triggers
Trigger code is stored as metadata under the object with which they are associated. To define a trigger in Salesforce:
1. For a standard object, click Your Name > Setup > Customize, click the name of the object, then click Triggers.
For a custom object, click Your Name > Setup > Create > Objects and click the name of the object.
For campaign members, click Your Name > Setup > Customize > Campaigns > Campaign Member > Triggers.
For case comments, click Your Name > Setup > Customize > Cases > Case Comments > Triggers.
For email messages, click Your Name > Setup > Customize > Cases > Email Messages > Triggers.
For the Attachment, ContentDocument, and Note standard objects, you can’t create a trigger in the Salesforce user interface.
For these objects, create a trigger using development tools, such as the Developer Console or the Force.com IDE.
Alternatively, you can also use the Metadata API.
2. In the Triggers related list, click New.
3. Click Version Settings to specify the version of Apex and the API used with this trigger. If your organization has installed
managed packages from the AppExchange, you can also specify which version of each managed package to use with this
trigger. Use the default values for all versions. This associates the trigger with the most recent version of Apex and the
API, as well as each managed package. You can specify an older version of a managed package if you want to access
components or functionality that differs from the most recent package version.
4. Click Apex Trigger and select the Is Active checkbox if the trigger should be compiled and enabled. Leave this checkbox
deselected if you only want to store the code in your organization's metadata. This checkbox is selected by default.
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![Invoking Apex Entity and Field Limitations in Triggers
Entity and Field Limitations in Triggers
QuestionDataCategorySelection Entity Not Available in After Insert Triggers
The after insert trigger that fires after inserting one ore more Question records doesn’t have access to the
QuestionDataCategorySelection records that are associated with the inserted Questions. For example, the following
query doesn’t return any results in an after insert trigger:
QuestionDataCategorySelection[] dcList =
[select Id,DataCategoryName from QuestionDataCategorySelection where ParentId IN :questions];
Fields Not Updateable in Before Triggers
Some field values are set during the system save operation, which occurs after before triggers have fired. As a result, these
fields cannot be modified or accurately detected in before insert or before update triggers. Some examples include:
• Task.isClosed
• Opportunity.amount*
• Opportunity.ForecastCategory
• Opportunity.isWon
• Opportunity.isClosed
• Contract.activatedDate
• Contract.activatedById
• Case.isClosed
• Solution.isReviewed
• Id (for all records)**
• createdDate (for all records)**
• lastUpdated (for all records)
* When Opportunity has no lineitems, Amount can be modified by a before trigger.
** Id and createdDate can be detected in before update triggers, but cannot be modified.
Trigger Exceptions
Triggers can be used to prevent DML operations from occurring by calling the addError() method on a record or field.
When used on Trigger.new records in insert and update triggers, and on Trigger.old records in delete triggers,
the custom error message is displayed in the application interface and logged.
Note: Users experience less of a delay in response time if errors are added to before triggers.
A subset of the records being processed can be marked with the addError() method:
• If the trigger was spawned by a DML statement in Apex, any one error results in the entire operation rolling back. However,
the runtime engine still processes every record in the operation to compile a comprehensive list of errors.
• If the trigger was spawned by a bulk DML call in the Force.com API, the runtime engine sets aside the bad records and
attempts to do a partial save of the records that did not generate errors. See Bulk DML Exception Handling on page 289.
If a trigger ever throws an unhandled exception, all records are marked with an error and no further processing takes place.
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![Invoking Apex Trigger and Bulk Request Best Practices
Trigger and Bulk Request Best Practices
A common development pitfall is the assumption that trigger invocations never include more than one record. Apex triggers
are optimized to operate in bulk, which, by definition, requires developers to write logic that supports bulk operations.
This is an example of a flawed programming pattern. It assumes that only one record is pulled in during a trigger invocation.
While this might support most user interface events, it does not support bulk operations invoked through the SOAP API or
Visualforce.
trigger MileageTrigger on Mileage__c (before insert, before update) {
User c = [SELECT Id FROM User WHERE mileageid__c = Trigger.new[0].id];
}
This is another example of a flawed programming pattern. It assumes that less than 100 records are pulled in during a trigger
invocation. If more than 20 records are pulled into this request, the trigger would exceed the SOQL query limit of 100 SELECT
statements:
trigger MileageTrigger on Mileage__c (before insert, before update) {
for(mileage__c m : Trigger.new){
User c = [SELECT Id FROM user WHERE mileageid__c = m.Id];
}
}
For more information on governor limits, see Understanding Execution Governors and Limits on page 225.
This example demonstrates the correct pattern to support the bulk nature of triggers while respecting the governor limits:
Trigger MileageTrigger on Mileage__c (before insert, before update) {
Set<ID> ids = Trigger.new.keySet();
List<User> c = [SELECT Id FROM user WHERE mileageid__c in :ids];
}
This pattern respects the bulk nature of the trigger by passing the Trigger.new collection to a set, then using the set in a
single SOQL query. This pattern captures all incoming records within the request while limiting the number of SOQL queries.
Best Practices for Designing Bulk Programs
The following are the best practices for this design pattern:
• Minimize the number of data manipulation language (DML) operations by adding records to collections and performing
DML operations against these collections.
• Minimize the number of SOQL statements by preprocessing records and generating sets, which can be placed in single
SOQL statement used with the IN clause.
See Also:
What are the Limitations of Apex?
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![Invoking Apex Apex Scheduler
You can also use the Schedulable interface with batch Apex classes. The following example implements the Schedulable
interface for a batch Apex class called batchable:
global class scheduledBatchable implements Schedulable{
global void execute(SchedulableContext sc) {
batchable b = new batchable();
database.executebatch(b);
}
}
Use the SchedulableContext object to keep track of the scheduled job once it's scheduled. The SchedulableContext method
getTriggerID returns the Id of the CronTrigger object associated with this scheduled job as a string. Use this method to
track the progress of the scheduled job.
To stop execution of a job that was scheduled, use the System.abortJob method with the ID returned by the.getTriggerID
method.
Testing the Apex Scheduler
The following is an example of how to test using the Apex scheduler.
The System.schedule method starts an asynchronous process. This means that when you test scheduled Apex, you must
ensure that the scheduled job is finished before testing against the results. Use the Test methods startTest and stopTest
around the System.schedule method to ensure it finishes before continuing your test. All asynchronous calls made after
the startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run
synchronously. If you don’t include the System.schedule method within the startTest and stopTest methods, the
scheduled job executes at the end of your test method for Apex saved using Salesforce.com API version 25.0 and later, but
not in earlier versions.
This is the class to be tested.
global class TestScheduledApexFromTestMethod implements Schedulable {
// This test runs a scheduled job at midnight Sept. 3rd. 2022
public static String CRON_EXP = '0 0 0 3 9 ? 2022';
global void execute(SchedulableContext ctx) {
CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered, NextFireTime
FROM CronTrigger WHERE Id = :ctx.getTriggerId()];
System.assertEquals(CRON_EXP, ct.CronExpression);
System.assertEquals(0, ct.TimesTriggered);
System.assertEquals('2022-09-03 00:00:00', String.valueOf(ct.NextFireTime));
Account a = [SELECT Id, Name FROM Account WHERE Name =
'testScheduledApexFromTestMethod'];
a.name = 'testScheduledApexFromTestMethodUpdated';
update a;
}
}
The following tests the above class:
@istest
class TestClass {
static testmethod void test() {
Test.startTest();
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![Invoking Apex Apex Scheduler
Account a = new Account();
a.Name = 'testScheduledApexFromTestMethod';
insert a;
// Schedule the test job
String jobId = System.schedule('testBasicScheduledApex',
TestScheduledApexFromTestMethod.CRON_EXP,
new TestScheduledApexFromTestMethod());
// Get the information from the CronTrigger API object
CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered,
NextFireTime
FROM CronTrigger WHERE id = :jobId];
// Verify the expressions are the same
System.assertEquals(TestScheduledApexFromTestMethod.CRON_EXP,
ct.CronExpression);
// Verify the job has not run
System.assertEquals(0, ct.TimesTriggered);
// Verify the next time the job will run
System.assertEquals('2022-09-03 00:00:00',
String.valueOf(ct.NextFireTime));
System.assertNotEquals('testScheduledApexFromTestMethodUpdated',
[SELECT id, name FROM account WHERE id = :a.id].name);
Test.stopTest();
System.assertEquals('testScheduledApexFromTestMethodUpdated',
[SELECT Id, Name FROM Account WHERE Id = :a.Id].Name);
}
}
Using the System.Schedule Method
After you implement a class with the Schedulable interface, use the System.Schedule method to execute it. The scheduler
runs as system: all classes are executed, whether the user has permission to execute the class or not.
Note: Use extreme care if you are planning to schedule a class from a trigger. You must be able to guarantee that the
trigger will not add more scheduled classes than the 25 that are allowed. In particular, consider API bulk updates,
import wizards, mass record changes through the user interface, and all cases where more than one record can be
updated at a time.
The System.Schedule method takes three arguments: a name for the job, an expression used to represent the time and
date the job is scheduled to run, and the name of the class. This expression has the following syntax:
Seconds Minutes Hours Day_of_month Month Day_of_week optional_year
Note: Salesforce only adds the process to the queue at the scheduled time. Actual execution may be delayed based
on service availability.
The System.Schedule method uses the user's timezone for the basis of all schedules.
The following are the values for the expression:
Name Values Special Characters
Seconds 0–59 None
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![Classes, Objects, and Interfaces Understanding Classes
Understanding Classes
As in Java, you can create classes in Apex. A class is a template or blueprint from which objects are created. An object is an
instance of a class. For example, the PurchaseOrder class describes an entire purchase order, and everything that you can
do with a purchase order. An instance of the PurchaseOrder class is a specific purchase order that you send or receive.
All objects have state and behavior, that is, things that an object knows about itself, and things that an object can do. The state
of a PurchaseOrder object—what it knows—includes the user who sent it, the date and time it was created, and whether it
was flagged as important. The behavior of a PurchaseOrder object—what it can do—includes checking inventory, shipping
a product, or notifying a customer.
A class can contain variables and methods. Variables are used to specify the state of an object, such as the object's Name or
Type. Since these variables are associated with a class and are members of it, they are commonly referred to as member variables.
Methods are used to control behavior, such as getOtherQuotes or copyLineItems.
An interface is like a class in which none of the methods have been implemented—the method signatures are there, but the
body of each method is empty. To use an interface, another class must implement it by providing a body for all of the methods
contained in the interface.
For more general information on classes, objects, and interfaces, see
http://java.sun.com/docs/books/tutorial/java/concepts/index.html
Defining Apex Classes
In Apex, you can define top-level classes (also called outer classes) as well as inner classes, that is, a class defined within another
class. You can only have inner classes one level deep. For example:
public class myOuterClass {
// Additional myOuterClass code here
class myInnerClass {
// myInnerClass code here
}
}
To define a class, specify the following:
1. Access modifiers:
• You must use one of the access modifiers (such as public or global) in the declaration of a top-level class.
• You do not have to use an access modifier in the declaration of an inner class.
2. Optional definition modifiers (such as virtual, abstract, and so on)
3. Required: The keyword class followed by the name of the class
4. Optional extensions and/or implementations
Use the following syntax for defining classes:
private | public | global
[virtual | abstract | with sharing | without sharing | (none)]
class ClassName [implements InterfaceNameList | (none)] [extends ClassName | (none)]
{
// The body of the class
}
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![Classes, Objects, and Interfaces Defining Class Methods
• Required: The name of the variable.
• Optional: The value of the variable.
Use the following syntax when defining a variable:
[public | private | protected | global | final] [static] data_type variable_name
[= value]
For example:
private static final Integer MY_INT;
private final Integer i = 1;
Defining Class Methods
To define a method, specify the following:
• Optional: Modifiers, such as public or protected.
• Required: The data type of the value returned by the method, such as String or Integer. Use void if the method does not
return a value.
• Required: A list of input parameters for the method, separated by commas, each preceded by its data type, and enclosed
in parentheses (). If there are no parameters, use a set of empty parentheses. A method can only have 32 input parameters.
• Required: The body of the method, enclosed in braces {}. All the code for the method, including any local variable
declarations, is contained here.
Use the following syntax when defining a method:
(public | private | protected | global ) [override] [static] data_type method_name
(input parameters)
{
// The body of the method
}
Note: You can only use override to override methods in classes that have been defined as virtual.
For example:
public static Integer getInt() {
return MY_INT;
}
As in Java, methods that return values can also be run as a statement if their results are not assigned to another variable.
Note that user-defined methods:
• Can be used anywhere that system methods are used.
• Can be recursive.
• Can have side effects, such as DML insert statements that initialize sObject record IDs. See Apex Data Manipulation
Language (DML) Operations on page 268.
• Can refer to themselves or to methods defined later in the same class or anonymous block. Apex parses methods in two
phases, so forward declarations are not needed.
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![Classes, Objects, and Interfaces Access Modifiers
Access Modifiers
Apex allows you to use the private, protected, public, and global access modifiers when defining methods and
variables.
While triggers and anonymous blocks can also use these access modifiers, they are not as useful in smaller portions of Apex.
For example, declaring a method as global in an anonymous block does not enable you to call it from outside of that code.
For more information on class access modifiers, see Defining Apex Classes on page 112.
Note: Interface methods have no access modifiers. They are always global. For more information, see Interfaces and
Extending Classes on page 127.
By default, a method or variable is visible only to the Apex code within the defining class. You must explicitly specify a method
or variable as public in order for it to be available to other classes in the same application namespace (see Namespace Prefix).
You can change the level of visibility by using the following access modifiers:
private
This is the default, and means that the method or variable is accessible only within the Apex class in which it is defined.
If you do not specify an access modifier, the method or variable is private.
protected
This means that the method or variable is visible to any inner classes in the defining Apex class. You can only use this
access modifier for instance methods and member variables. Note that it is strictly more permissive than the default
(private) setting, just like Java.
public
This means the method or variable can be used by any Apex in this application or namespace.
Note: In Apex, the public access modifier is not the same as it is in Java. This was done to discourage joining
applications, to keep the code for each application separate. In Apex, if you want to make something public like
it is in Java, you need to use the global access modifier.
global
This means the method or variable can be used by any Apex code that has access to the class, not just the Apex code in
the same application. This access modifier should be used for any method that needs to be referenced outside of the
application, either in the SOAP API or by other Apex code. If you declare a method or variable as global, you must
also declare the class that contains it as global.
Note: We recommend using the global access modifier rarely, if at all. Cross-application dependencies are
difficult to maintain.
To use the private, protected, public, or global access modifiers, use the following syntax:
[(none)|private|protected|public|global] declaration
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![Classes, Objects, and Interfaces Static and Instance
A trigger that uses this class could then selectively fail the first run of the trigger:
trigger t1 on Account (before delete, after delete, after undelete) {
if(Trigger.isBefore){
if(Trigger.isDelete){
if(p.firstRun){
Trigger.old[0].addError('Before Account Delete Error');
p.firstRun=false;
}
}
}
}
Class static variables cannot be accessed through an instance of that class. So if class C has a static variable S, and x is an
instance of C, then x.S is not a legal expression.
The same is true for instance methods: if M() is a static method then x.M() is not legal. Instead, your code should refer to
those static identifiers using the class: C.S and C.M().
If a local variable is named the same as the class name, these static methods and variables are hidden.
Inner classes behave like static Java inner classes, but do not require the static keyword. Inner classes can have instance
member variables like outer classes, but there is no implicit pointer to an instance of the outer class (using the this keyword).
Note: For Apex saved using Salesforce.com API version 20.0 or earlier, if an API call causes a trigger to fire, the
batch of 200 records to process is further split into batches of 100 records. For Apex saved using Salesforce.com API
version 21.0 and later, no further splits of API batches occur. Note that static variable values are reset between batches,
but governor limits are not. Do not use static variables to track state information between batches.
Using Instance Methods and Variables
Instance methods and member variables are used by an instance of a class, that is, by an object. Instance member variables are
declared inside a class, but not within a method. Instance methods usually use instance member variables to affect the behavior
of the method.
Suppose you wanted to have a class that collects two dimensional points and plot them on a graph. The following skeleton
class illustrates this, making use of member variables to hold the list of points and an inner class to manage the two-dimensional
list of points.
public class Plotter {
// This inner class manages the points
class Point {
Double x;
Double y;
Point(Double x, Double y) {
this.x = x;
this.y = y;
}
Double getXCoordinate() {
return x;
}
Double getYCoordinate() {
return y;
}
}
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![Classes, Objects, and Interfaces Custom Iterators
Using Custom Iterators
To use custom iterators, you must create an Apex class that implements the Iterator interface.
The Iterator interface has the following instance methods:
Name Arguments Returns Description
hasNext Boolean Returns true if there is another item in the collection
being traversed, false otherwise.
next Any type Returns the next item in the collection.
All methods in the Iterator interface must be declared as global or public.
You can only use a custom iterator in a while loop. For example:
IterableString x = new IterableString('This is a really cool test.');
while(x.hasNext()){
system.debug(x.next());
}
Iterators are not currently supported in for loops.
Using Custom Iterators with Iterable
If you do not want to use a custom iterator with a list, but instead want to create your own data structure, you can use the
Iterable interface to generate the data structure.
The Iterable interface has the following method:
Name Arguments Returns Description
iterator Iterator class Returns a reference to the iterator for this interface.
The iterator method must be declared as global or public. It creates a reference to the iterator that you can then use
to traverse the data structure.
In the following example a custom iterator iterates through a collection:
global class CustomIterable
implements Iterator<Account>{
List<Account> accs {get; set;}
Integer i {get; set;}
public CustomIterable(){
accs =
[SELECT Id, Name,
NumberOfEmployees
FROM Account
WHERE Name = 'false'];
i = 0;
}
global boolean hasNext(){
if(i >= accs.size()) {
return false;
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![Classes, Objects, and Interfaces Keywords
} else {
return true;
}
}
global Account next(){
// 8 is an arbitrary
// constant in this example
// that represents the
// maximum size of the list.
if(i == 8){return null;}
i++;
return accs[i-1];
}
}
The following calls the above code:
global class foo implements iterable<Account>{
global Iterator<Account> Iterator(){
return new CustomIterable();
}
}
The following is a batch job that uses an iterator:
global class batchClass implements Database.batchable<Account>{
global Iterable<Account> start(Database.batchableContext info){
return new foo();
}
global void execute(Database.batchableContext info, List<Account> scope){
List<Account> accsToUpdate = new List<Account>();
for(Account a : scope){
a.Name = 'true';
a.NumberOfEmployees = 69;
accsToUpdate.add(a);
}
update accsToUpdate;
}
global void finish(Database.batchableContext info){
}
}
Keywords
Apex has the following keywords available:
• final
• instanceof
• super
• this
• transient
• with sharing and without sharing
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![Classes, Objects, and Interfaces Using the with sharing or without sharing Keywords
// Code here
}
If a class is not declared as either with or without sharing, the current sharing rules remain in effect. This means that if the
class is called by a class that has sharing enforced, then sharing is enforced for the called class.
Both inner classes and outer classes can be declared as with sharing. The sharing setting applies to all code contained in
the class, including initialization code, constructors, and methods. Classes inherit this setting from a parent class when one
class extends or implements another, but inner classes do not inherit the sharing setting from their container class.
For example:
public with sharing class CWith {
// All code in this class operates with enforced sharing rules.
Account a = [SELECT . . . ];
public static void m() { . . . }
static {
. . .
}
{
. . .
}
public c() {
. . .
}
}
public without sharing class CWithout {
// All code in this class ignores sharing rules and operates
// as if the context user has the Modify All Data permission.
Account a = [SELECT . . . ];
. . .
public static void m() {
. . .
// This call into CWith operates with enforced sharing rules
// for the context user. When the call finishes, the code execution
// returns to without sharing mode.
CWith.m();
}
public class CInner {
// All code in this class executes with the same sharing context
// as the code that calls it.
// Inner classes are separate from outer classes.
. . .
// Again, this call into CWith operates with enforced sharing rules
// for the context user, regardless of the class that initially called this inner class.
// When the call finishes, the code execution returns to the sharing mode that was used
to call this inner class.
CWith.m();
}
public class CInnerWithOut exends CWithout {
// All code in this class ignores sharing rules because
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![Classes, Objects, and Interfaces IsTest Annotation
• The isTest(SeeAllData=true) annotation is used to open up data access when applied at the class or method
level. However, using isTest(SeeAllData=false) on a method doesn’t restrict organization data access for that
method if the containing class has already been defined with the isTest(SeeAllData=true) annotation. In this
case, the method will still have access to all the data in the organization.
This example shows how to define a test class with the isTest(SeeAllData=true) annotation. All the test methods in
this class have access to all data in the organization.
// All test methods in this class can access all data.
@isTest(SeeAllData=true)
public class TestDataAccessClass {
// This test accesses an existing account.
// It also creates and accesses a new test account.
static testmethod void myTestMethod1() {
// Query an existing account in the organization.
Account a = [SELECT Id, Name FROM Account WHERE Name='Acme' LIMIT 1];
System.assert(a != null);
// Create a test account based on the queried account.
Account testAccount = a.clone();
testAccount.Name = 'Acme Test';
insert testAccount;
// Query the test account that was inserted.
Account testAccount2 = [SELECT Id, Name FROM Account
WHERE Name='Acme Test' LIMIT 1];
System.assert(testAccount2 != null);
}
// Like the previous method, this test method can also access all data
// because the containing class is annotated with @isTest(SeeAllData=true).
@isTest static void myTestMethod2() {
// Can access all data in the organization.
}
}
This second example shows how to apply the isTest(SeeAllData=true) annotation on a test method. Because the class
that the test method is contained in isn’t defined with this annotation, you have to apply this annotation on the test method
to enable access to all data for that test method. The second test method doesn’t have this annotation, so it can access only
the data it creates in addition to objects that are used to manage your organization, such as users.
// This class contains test methods with different data access levels.
@isTest
private class ClassWithDifferentDataAccess {
// Test method that has access to all data.
@isTest(SeeAllData=true)
static void testWithAllDataAccess() {
// Can query all data in the organization.
}
// Test method that has access to only the data it creates
// and organization setup and metadata objects.
@isTest static void testWithOwnDataAccess() {
// This method can still access the User object.
// This query returns the first user object.
User u = [SELECT UserName,Email FROM User LIMIT 1];
System.debug('UserName: ' + u.UserName);
System.debug('Email: ' + u.Email);
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![Classes, Objects, and Interfaces ReadOnly Annotation
// Can access the test account that is created here.
Account a = new Account(Name='Test Account');
insert a;
// Access the account that was just created.
Account insertedAcct = [SELECT Id,Name FROM Account
WHERE Name='Test Account'];
System.assert(insertedAcct != null);
}
}
IsTest(OnInstall=true) Annotation
Use the IsTest(OnInstall=true) annotation to specify which Apex tests are executed during package installation. This
annotation is used for tests in managed or unmanaged packages. Only test methods with this annotation, or methods that are
part of a test class that has this annotation, will be executed during package installation. Tests annotated to run during package
installation must pass in order for the package installation to succeed. It is no longer possible to bypass a failing test during
package installation. A test method or a class that doesn't have this annotation, or that is annotated with
isTest(OnInstall=false) or isTest, won't be executed during installation.
This example shows how to annotate a test method that will be executed during package installation. In this example, test1
will be executed but test2 and test3 won't.
public class OnInstallClass {
// Implement logic for the class.
public void method1(){
// Some code
}
// This test method will be executed
// during the installation of the package.
@isTest(OnInstall=true)
static void test1() {
// Some test code
}
// Tests excluded from running during the
// the installation of a package.
@isTest
static void test2() {
// Some test code
}
static testmethod void test3() {
// Some test code
}
}
ReadOnly Annotation
The @ReadOnly annotation allows you to perform unrestricted queries against the Force.com database. All other limits still
apply. It's important to note that this annotation, while removing the limit of the number of returned rows for a request, blocks
you from performing the following operations within the request: DML operations, calls to System.schedule, calls to
methods annotated with @future, and sending emails.
The @ReadOnly annotation is available for Web services and the Schedulable interface. To use the @ReadOnly annotation,
the top level request must be in the schedule execution or the Web service invocation. For example, if a Visualforce page calls
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![Classes, Objects, and Interfaces RemoteAction Annotation
a Web service that contains the @ReadOnly annotation, the request fails because Visualforce is the top level request, not the
Web service.
Visualforce pages can call controller methods with the @ReadOnly annotation, and those methods will run with the same
relaxed restrictions. To increase other Visualforce-specific limits, such as the size of a collection that can be used by an iteration
component like <apex:pageBlockTable>, you can set the readonly attribute on the <apex:page> tag to true. For
more information, see Working with Large Sets of Data in the Visualforce Developer's Guide.
RemoteAction Annotation
The RemoteAction annotation provides support for Apex methods used in Visualforce to be called via JavaScript. This
process is often referred to as JavaScript remoting.
Note: Methods with the RemoteAction annotation must be static and either global or public.
To use JavaScript remoting in a Visualforce page, add the request as a JavaScript invocation with the following form:
[namespace.]controller.method(
[parameters...,]
callbackFunction,
[configuration]
);
• namespace is the namespace of the controller class. This is required if your organization has a namespace defined, or if
the class comes from an installed package.
• controller is the name of your Apex controller.
• method is the name of the Apex method you’re calling.
• parameters is the comma-separated list of parameters that your method takes.
• callbackFunction is the name of the JavaScript function that will handle the response from the controller. You can
also declare an anonymous function inline. callbackFunction receives the status of the method call and the result as
parameters.
• configuration configures the handling of the remote call and response. Use this to specify whether or not to escape
the Apex method’s response. The default value is {escape: true}.
In your controller, your Apex method declaration is preceded with the @RemoteAction annotation like this:
@RemoteAction
global static String getItemId(String objectName) { ... }
Your method can take Apex primitives, collections, typed and generic sObjects, and user-defined Apex classes and interfaces
as arguments. Generic sObjects must have an ID or sobjectType value to identify actual type. Interface parameters must have
an apexType to identify actual type. Your method can return Apex primitives, sObjects, collections, user-defined Apex classes
and enums, SaveResult, UpsertResult, DeleteResult, SelectOption, or PageReference.
For more information, see JavaScript Remoting for Apex Controllers in the Visualforce Developer's Guide.
Apex REST Annotations
Six new annotations have been added that enable you to expose an Apex class as a RESTful Web service.
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![Classes, Objects, and Interfaces Classes and Casting
HttpGet Annotation
The @HttpGet annotation is used at the method level and enables you to expose an Apex method as a REST resource. This
method is called when an HTTP GET request is sent, and returns the specified resource.
These are some considerations when using this annotation:
• To use this annotation, your Apex method must be defined as global static.
• Methods annotated with @HttpGet are also called if the HTTP request uses the HEAD request method.
HttpPatch Annotation
The @HttpPatch annotation is used at the method level and enables you to expose an Apex method as a REST resource.
This method is called when an HTTP PATCH request is sent, and updates the specified resource.
To use this annotation, your Apex method must be defined as global static.
HttpPost Annotation
The @HttpPost annotation is used at the method level and enables you to expose an Apex method as a REST resource. This
method is called when an HTTP POST request is sent, and creates a new resource.
To use this annotation, your Apex method must be defined as global static.
HttpPut Annotation
The @HttpPut annotation is used at the method level and enables you to expose an Apex method as a REST resource. This
method is called when an HTTP PUT request is sent, and creates or updates the specified resource.
To use this annotation, your Apex method must be defined as global static.
Classes and Casting
In general, all type information is available at runtime. This means that Apex enables casting, that is, a data type of one class
can be assigned to a data type of another class, but only if one class is a child of the other class. Use casting when you want to
convert an object from one data type to another.
In the following example, CustomReport extends the class Report. Therefore, it is a child of that class. This means that
you can use casting to assign objects with the parent data type (Report) to the objects of the child data type (CustomReport).
In the following code block, first, a custom report object is added to a list of report objects. After that, the custom report object
is returned as a report object, then is cast back into a custom report object.
Public virtual class Report {
Public class CustomReport extends Report {
// Create a list of report objects
Report[] Reports = new Report[5];
// Create a custom report object
CustomReport a = new CustomReport();
// Because the custom report is a sub class of the Report class,
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![Classes, Objects, and Interfaces Classes and Collections
Classes and Collections
Lists and maps can be used with classes and interfaces, in the same ways that lists and maps can be used with sObjects. This
means, for example, that you can use a user-defined data type only for the value of a map, not for the key. Likewise, you cannot
create a set of user-defined objects.
If you create a map or list of interfaces, any child type of the interface can be put into that collection. For instance, if the List
contains an interface i1, and MyC implements i1, then MyC can be placed in the list.
Collection Casting
Because collections in Apex have a declared type at runtime, Apex allows collection casting.
Collections can be cast in a similar manner that arrays can be cast in Java. For example, a list of CustomerPurchaseOrder
objects can be assigned to a list of PurchaseOrder objects if class CustomerPurchaseOrder is a child of class PurchaseOrder.
public virtual class PurchaseOrder {
Public class CustomerPurchaseOrder extends PurchaseOrder {
}
{
List<PurchaseOrder> POs = new PurchaseOrder[] {};
List<CustomerPurchaseOrder> CPOs = new CustomerPurchaseOrder[]{};
POs = CPOs;}
}
Once the CustomerPurchaseOrder list is assigned to the PurchaseOrder list variable, it can be cast back to a list of
CustomerPurchaseOrder objects, but only because that instance was originally instantiated as a list of CustomerPurchaseOrder.
A list of PurchaseOrder objects that is instantiated as such cannot be cast to a list of CustomerPurchaseOrder objects, even if
the list of PurchaseOrder objects contains only CustomerPurchaseOrder objects.
If the user of a PurchaseOrder list that only includes CustomerPurchaseOrders objects tries to insert a
non-CustomerPurchaseOrder subclass of PurchaseOrder (such as InternalPurchaseOrder), a runtime exception results.
This is because Apex collections have a declared type at runtime.
Note: Maps behave in the same way as lists with regards to the value side of the Map—if the value side of map A
can be cast to the value side of map B, and they have the same key type, then map A can be cast to map B. A runtime
error results if the casting is not valid with the particular map at runtime.
Differences Between Apex Classes and Java Classes
The following is a list of the major differences between Apex classes and Java classes:
• Inner classes and interfaces can only be declared one level deep inside an outer class.
• Static methods and variables can only be declared in a top-level class definition, not in an inner class.
• Inner classes behave like static Java inner classes, but do not require the static keyword. Inner classes can have instance
member variables like outer classes, but there is no implicit pointer to an instance of the outer class (using the this
keyword).
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![Classes, Objects, and Interfaces Namespace Prefix
the current user's read, create, or update access for a field. In addition, you can call the isDeletable method provided by
Schema.DescribeSObjectResult to check if the current user has permission to delete a specific sObject.
These are some examples of how to call the access control methods.
To check the field-level update permission of the contact's email field before updating it:
if (Schema.sObjectType.Contact.fields.Email.isUpdateable()) {
// Update contact phone number
}
To check the field-level create permission of the contact's email field before creating a new contact:
if (Schema.sObjectType.Contact.fields.Email.isCreateable()) {
// Create new contact
}
To check the field-level read permission of the contact's email field before querying for this field:
if (Schema.sObjectType.Contact.fields.Email.isAccessible()) {
Contact c = [SELECT Email FROM Contact WHERE Id= :Id];
}
To check the object-level permission for the contact before deleting the contact.
if (Schema.sObjectType.Contact.isDeletable()) {
// Delete contact
}
Sharing rules are distinct from object-level and field-level permissions. They can coexist. If sharing rules are defined in
Salesforce, you can enforce them at the class level by declaring the class with the with sharing keyword. For more information,
see Using the with sharing or without sharing Keywords. If you call the sObject describe result and field describe
result access control methods, the verification of object and field-level permissions is performed in addition to the sharing
rules that are in effect. Sometimes, the access level granted by a sharing rule could conflict with an object-level or field-level
permission.
Namespace Prefix
The application supports the use of namespace prefixes. Namespace prefixes are used in managed Force.com AppExchange
packages to differentiate custom object and field names from those in use by other organizations. After a developer registers
a globally unique namespace prefix and registers it with AppExchange registry, external references to custom object and field
names in the developer's managed packages take on the following long format:
namespace_prefix__obj_or_field_name__c
Because these fully-qualified names can be onerous to update in working SOQL statements, SOSL statements, and Apex
once a class is marked as “managed,” Apex supports a default namespace for schema names. When looking at identifiers, the
parser considers the namespace of the current object and then assumes that it is the namespace of all other objects and fields
unless otherwise specified. Consequently, a stored class should refer to custom object and field names directly (using
obj_or_field_name__c) for those objects that are defined within its same application namespace.
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![Classes, Objects, and Interfaces Using Namespaces When Invoking Methods
Tip: Only use namespace prefixes when referring to custom objects and fields in managed packages that have been
installed to your organization from theAppExchange.
Using Namespaces When Invoking Methods
To invoke a method that is defined in a managed package, Apex allows fully-qualified identifiers of the form:
namespace_prefix.class.method(args)
Use the special namespace System to disambiguate the built-in static classes from any user-defined ones (for example,
System.System.debug()).
Without the System namespace prefix, system static class names such as Math and System can be overridden by user-defined
classes with the same name, as outlined below.
Tip: Only use namespace prefixes when invoking methods in managed packages that have been installed to your
organization from theAppExchange.
Namespace, Class, and Variable Name Precedence
Because local variables, class names, and namespaces can all hypothetically use the same identifiers, the Apex parser evaluates
expressions in the form of name1.name2.[...].nameN as follows:
1. The parser first assumes that name1 is a local variable with name2 - nameN as field references.
2. If the first assumption does not hold true, the parser then assumes that name1 is a class name and name2 is a static variable
name with name3 - nameN as field references.
3. If the second assumption does not hold true, the parser then assumes that name1 is a namespace name, name2 is a class
name, name3 is a static variable name, and name4 - nameN are field references.
4. If the third assumption does not hold true, the parser reports an error.
If the expression ends with a set of parentheses (for example, name1.name2.[...].nameM.nameN()), the Apex parser
evaluates the expression as follows:
1. The parser first assumes that name1 is a local variable with name2 - nameM as field references, and nameN as a method
invocation.
2. If the first assumption does not hold true:
• If the expression contains only two identifiers (name1.name2()), the parser then assumes that name1 is a class name
and name2 is a method invocation.
• If the expression contains more than two identifiers, the parser then assumes that name1 is a class name, name2 is a
static variable name with name3 - nameM as field references, and nameN is a method invocation.
3. If the second assumption does not hold true, the parser then assumes that name1 is a namespace name, name2 is a class
name, name3 is a static variable name, name4 - nameM are field references, and nameN is a method invocation.
4. If the third assumption does not hold true, the parser reports an error.
However, with class variables Apex also uses dot notation to reference member variables. Those member variables might refer
to other class instances, or they might refer to an sObject which has its own dot notation rules to refer to field names (possibly
navigating foreign keys).
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![Classes, Objects, and Interfaces Setting the Salesforce API Version for Classes and Triggers
Setting the Salesforce API Version for Classes and Triggers
To set the Salesforce.com API and Apex version for a class or trigger:
1. Edit either a class or trigger, and click Version Settings.
2. Select the Version of the Salesforce.com API. This is also the version of Apex associated with the class or trigger.
3. Click Save.
If you pass an object as a parameter in a method call from one Apex class, C1, to another class, C2, and C2 has different fields
exposed due to the Salesforce.com API version setting, the fields in the objects are controlled by the version settings of C2.
Using the following example, the Categories field is set to null after calling the insertIdea method in class C2 from
a method in the test class C1, because the Categories field is not available in version 13.0 of the API.
The first class is saved using Salesforce.com API version 13.0:
// This class is saved using Salesforce API version 13.0
// Version 13.0 does not include the Idea.categories field
global class C2
{
global Idea insertIdea(Idea a) {
insert a; // category field set to null on insert
// retrieve the new idea
Idea insertedIdea = [SELECT title FROM Idea WHERE Id =:a.Id];
return insertedIdea;
}
}
The following class is saved using Salesforce.com API version 16.0:
@isTest
// This class is bound to API version 16.0 by Version Settings
private class C1
{
static testMethod void testC2Method() {
Idea i = new Idea();
i.CommunityId = '09aD000000004YCIAY';
i.Title = 'Testing Version Settings';
i.Body = 'Categories field is included in API version 16.0';
i.Categories = 'test';
C2 c2 = new C2();
Idea returnedIdea = c2.insertIdea(i);
// retrieve the new idea
Idea ideaMoreFields = [SELECT title, categories FROM Idea
WHERE Id = :returnedIdea.Id];
// assert that the categories field from the object created
// in this class is not null
System.assert(i.Categories != null);
// assert that the categories field created in C2 is null
System.assert(ideaMoreFields.Categories == null);
}
}
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![Testing Apex Using the runAs Method
• This access restriction to test data applies to all code running in test context. For example, if a test method causes a
trigger to execute and the test can’t access organization data, the trigger won’t be able to either.
• If a test makes a Visualforce request, the executing test stays in test context but runs in a different thread, so test data
isolation is no longer enforced. In this case, the test will be able to access all data in the organization after initiating
the Visualforce request. However, if the Visualforce request performs a callback, such as a JavaScript remoting call,
any data inserted by the callback won't be visible to the test.
• There might be some cases where you can’t create certain types of data from your test method because of specific
limitations. Here are some examples of such limitations.
◊ Inserting a pricebook entry for a product isn’t feasible from a test since the standard pricebook isn’t accessible
and can’t be created in a running test. Also, inserting a pricebook entry for a custom pricebook isn’t supported
since this requires defining a standard pricebook. For such situations, annotate your test method with
IsTest(SeeAllData=true) so that your test can access organization data.
◊ Some standard objects aren’t createable. For more information on these objects, see the Object Reference for Salesforce
and Force.com.
◊ For some sObjects that have fields with unique constraints, inserting duplicate sObject records results in an error.
For example, inserting CollaborationGroup sObjects with the same name results in an error because
CollaborationGroup records must have unique names. This happens whether or not your test is annotated with
IsTest(SeeAllData=true).
◊ Records that are created only after related records are committed to the database, like tracked changes in Chatter.
Tracked changes for a record (FeedTrackedChange records) in Chatter feeds aren't available when test methods
modify the associated record. FeedTrackedChange records require the change to the parent record they're associated
with to be committed to the database before they're created. Since test methods don't commit data, they don't
result in the creation of FeedTrackedChange records.
Using the runAs Method
Generally, all Apex code runs in system mode, and the permissions and record sharing of the current user are not taken into
account. The system method runAs enables you to write test methods that change either the user contexts to an existing user
or a new user, or to run using the code from a specific version of a managed package. When running as a user, all of that user's
record sharing is then enforced. You can only use runAs in a test method. The original system context is started again after
all runAs test methods complete. For information on using the runAs method and specifying a package version context, see
Testing Behavior in Package Versions on page 235.
Note: Every call to runAs counts against the total number of DML statements issued in the process.
In the following example, a new test user is created, then code is run as that user, with that user's permissions and record
access:
public class TestRunAs {
public static testMethod void testRunAs() {
// Setup test data
// This code runs as the system user
Profile p = [SELECT Id FROM Profile WHERE Name='Standard User'];
User u = new User(Alias = 'standt', Email='standarduser@testorg.com',
EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
LocaleSidKey='en_US', ProfileId = p.Id,
TimeZoneSidKey='America/Los_Angeles', UserName='standarduser@testorg.com');
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![Testing Apex Using Limits, startTest, and stopTest
System.runAs(u) {
// The following code runs as user 'u'
System.debug('Current User: ' + UserInfo.getUserName());
System.debug('Current Profile: ' + UserInfo.getProfileId()); }
}
}
You can nest more than one runAs method. For example:
public class TestRunAs2 {
public static testMethod void test2() {
Profile p = [SELECT Id FROM Profile WHERE Name='Standard User'];
User u2 = new User(Alias = 'newUser', Email='newuser@testorg.com',
EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US',
LocaleSidKey='en_US', ProfileId = p.Id,
TimeZoneSidKey='America/Los_Angeles', UserName='newuser@testorg.com');
System.runAs(u2) {
// The following code runs as user u2.
System.debug('Current User: ' + UserInfo.getUserName());
System.debug('Current Profile: ' + UserInfo.getProfileId());
// The following code runs as user u3.
User u3 = [SELECT Id FROM User WHERE UserName='newuser@testorg.com'];
System.runAs(u3) {
System.debug('Current User: ' + UserInfo.getUserName());
System.debug('Current Profile: ' + UserInfo.getProfileId());
}
// Any additional code here would run as user u2.
}
}
}
Best Practices for Using runAs
The following items use the permissions granted by the user specified with runAs running as a specific user:
• Dynamic Apex
• Methods using with sharing or without sharing
• Shared records
The original permissions are reset after runAs completes.
The runAs method ignores user license limits. You can create new users with runAs even if your organization has no additional
user licenses.
Using Limits, startTest, and stopTest
The Limits methods return the specific limit for the particular governor, such as the number of calls of a method or the amount
of heap size remaining.
There are two versions of every method: the first returns the amount of the resource that has been used in the current context,
while the second version contains the word “limit” and returns the total amount of the resource that is available for that context.
For example, getCallouts returns the number of callouts to an external service that have already been processed in the
current context, while getLimitCallouts returns the total number of callouts available in the given context.
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![Testing Apex Adding SOSL Queries to Unit Tests
In addition to the Limits methods, use the startTest and stopTest methods to validate how close the code is to reaching
governor limits.
The startTest method marks the point in your test code when your test actually begins. Each testMethod is allowed to
call this method only once. All of the code before this method should be used to initialize variables, populate data structures,
and so on, allowing you to set up everything you need to run your test. Any code that executes after the call to startTest
and before stopTest is assigned a new set of governor limits.
The startTest method does not refresh the context of the test: it adds a context to your test. For example, if your class
makes 98 SOQL queries before it calls startTest, and the first significant statement after startTest is a DML statement,
the program can now make an additional 100 queries. Once stopTest is called, however, the program goes back into the
original context, and can only make 2 additional SOQL queries before reaching the limit of 100.
The stopTest method marks the point in your test code when your test ends. Use this method in conjunction with the
startTest method. Each testMethod is allowed to call this method only once. Any code that executes after the stopTest
method is assigned the original limits that were in effect before startTest was called. All asynchronous calls made after the
startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run synchronously.
Adding SOSL Queries to Unit Tests
To ensure that test methods always behave in a predictable way, any Salesforce Object Search Language (SOSL) query that
is added to an Apex test method returns an empty set of search results when the test method executes. If you do not want the
query to return an empty list of results, you can use the Test.setFixedSearchResults system method to define a list of
record IDs that are returned by the search. All SOSL queries that take place later in the test method return the list of record
IDs that were specified by the Test.setFixedSearchResults method. Additionally, the test method can call
Test.setFixedSearchResults multiple times to define different result sets for different SOSL queries. If you do not
call the Test.setFixedSearchResults method in a test method, or if you call this method without specifying a list of
record IDs, any SOSL queries that take place later in the test method return an empty list of results.
The list of record IDs specified by the Test.setFixedSearchResults method replaces the results that would normally
be returned by the SOSL query if it were not subject to any WHERE or LIMIT clauses. If these clauses exist in the SOSL query,
they are applied to the list of fixed search results. For example:
public class SoslFixedResultsTest1 {
public static testMethod void testSoslFixedResults() {
Id [] fixedSearchResults= new Id[1];
fixedSearchResults[0] = '001x0000003G89h';
Test.setFixedSearchResults(fixedSearchResults);
List<List<SObject>> searchList = [FIND 'test'
IN ALL FIELDS RETURNING
Account(id, name WHERE name = 'test' LIMIT 1)];
}
}
Although the account record with an ID of 001x0000003G89h may not match the query string in the FIND clause ('test'),
the record is passed into the RETURNING clause of the SOSL statement. If the record with ID 001x0000003G89h matches
the WHERE clause filter, the record is returned. If it does not match the WHERE clause, no record is returned.
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![Testing Apex Running Unit Test Methods
Running Unit Test Methods
You can run unit tests for:
• A specific class
• A subset of classes
• All unit tests in your organization
To run a test, use any of the following:
• The Salesforce user interface
• The Force.com IDE
• The API
Running Tests Through the Salesforce User Interface
You can run unit tests on the Apex Test Execution page. Tests started on this page run asynchronously, that is, you don't have
to wait for a test class execution to finish. The Apex Test Execution page refreshes the status of a test and displays the results
after the test completes.
To use the Apex Test Execution page:
1. Click Your Name > Setup > Develop > Apex Test Execution.
2. Click Select Tests....
Note: If you have Apex classes that are installed from a managed package, you must compile these classes first by
clicking Compile all classes on the Apex Classes page so that they appear in the list. See “Managing Apex Classes”
in the online help.
3. Select the tests to run. The list of tests contains classes that contain test methods.
• To select tests from an installed managed package, select its corresponding namespace from the drop-down list. Only
the classes of the managed package with the selected namespace appear in the list.
• To select tests that exist locally in your organization, select [My Namespace] from the drop-down list. Only local
classes that aren't from managed packages appear in the list.
• To select any test, select [All Namespaces] from the drop-down list. All the classes in the organization appear, whether
or not they are from a managed package.
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![Testing Apex Running Unit Test Methods
// Enqueue all classes ending in "Test".
public static ID enqueueTests() {
ApexClass[] testClasses =
[SELECT Id FROM ApexClass
WHERE Name LIKE '%Test'];
if (testClasses.size() > 0) {
ApexTestQueueItem[] queueItems = new List<ApexTestQueueItem>();
for (ApexClass cls : testClasses) {
queueItems.add(new ApexTestQueueItem(ApexClassId=cls.Id));
}
insert queueItems;
// Get the job ID of the first queue item returned.
ApexTestQueueItem item =
[SELECT ParentJobId FROM ApexTestQueueItem
WHERE Id=:queueItems[0].Id LIMIT 1];
return item.parentjobid;
}
return null;
}
// Get the status and pass rate for each class
// whose tests were run by the job.
// that correspond to the specified job ID.
public static void checkClassStatus(ID jobId) {
ApexTestQueueItem[] items =
[SELECT ApexClass.Name, Status, ExtendedStatus
FROM ApexTestQueueItem
WHERE ParentJobId=:jobId];
for (ApexTestQueueItem item : items) {
String extStatus = item.extendedstatus == null ? '' : item.extendedStatus;
System.debug(item.ApexClass.Name + ': ' + item.Status + extStatus);
}
}
// Get the result for each test method that was executed.
public static void checkMethodStatus(ID jobId) {
ApexTestResult[] results =
[SELECT Outcome, ApexClass.Name, MethodName, Message, StackTrace
FROM ApexTestResult
WHERE AsyncApexJobId=:jobId];
for (ApexTestResult atr : results) {
System.debug(atr.ApexClass.Name + '.' + atr.MethodName + ': ' + atr.Outcome);
if (atr.message != null) {
System.debug(atr.Message + 'n at ' + atr.StackTrace);
}
}
}
}
You can also use the runTests() call from the SOAP API to run tests synchronously:
RunTestsResult[] runTests(RunTestsRequest ri)
This call allows you to run all tests in all classes, all tests in a specific namespace, or all tests in a subset of classes in a specific
namespace, as specified in the RunTestsRequest object. It returns the following:
• Total number of tests that ran
• Code coverage statistics (described below)
• Error information for each failed test
• Information for each test that succeeds
• Time it took to run the test
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![Testing Apex Testing Example
Record IDs are not created in ascending order unless you insert multiple records with the same request. For example, if
you create an account A, and receive the ID 001D000000IEEmT, then create account B, the ID of account B may or may
not be sequentially higher.
• On the list of Apex classes, there is a Code Coverage column. If you click the coverage percent number, a page displays,
highlighting all the lines of code for that class or trigger that are covered by tests in blue, as well as highlighting all the
lines of code that are not covered by tests in red. It also lists how many times a particular line in the class or trigger was
executed by the test
• Set up test data:
◊ Create the necessary data in test classes, so the tests do not have to rely on data in a particular organization.
◊ Create all test data before calling the starttest method.
◊ Since tests don't commit, you won't need to delete any data.
• Write comments stating not only what is supposed to be tested, but the assumptions the tester made about the data, the
expected outcome, and so on.
• Test the classes in your application individually. Never test your entire application in a single test.
If you are running many tests, consider the following:
• In the Force.com IDE, you may need to increase the Read timeout value for your Apex project. See
https://wiki.developerforce.com/index.php/Apex_Toolkit_for_Eclipse for details.
• In the Salesforce user interface, you may need to test the classes in your organization individually, instead of trying to run
all of the tests at the same time using the Run All Tests button.
Testing Example
The following example includes cases for the following types of tests:
• Positive case with single and multiple records
• Negative case with single and multiple records
• Testing with other users
The test is used with a simple mileage tracking application. The existing code for the application verifies that not more than
500 miles are entered in a single day. The primary object is a custom object named Mileage__c. Here is the entire test class.
The following sections step through specific portions of the code.
@isTest
private class MileageTrackerTestSuite {
static testMethod void runPositiveTestCases() {
Double totalMiles = 0;
final Double maxtotalMiles = 500;
final Double singletotalMiles = 300;
final Double u2Miles = 100;
//Set up user
User u1 = [SELECT Id FROM User WHERE Alias='auser'];
//Run As U1
System.RunAs(u1){
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![Testing Apex Testing Example
System.debug('Inserting 300 miles... (single record validation)');
Mileage__c testMiles1 = new Mileage__c(Miles__c = 300, Date__c = System.today());
insert testMiles1;
//Validate single insert
for(Mileage__c m:[SELECT miles__c FROM Mileage__c
WHERE CreatedDate = TODAY
and CreatedById = :u1.id
and miles__c != null]) {
totalMiles += m.miles__c;
}
System.assertEquals(singletotalMiles, totalMiles);
//Bulk validation
totalMiles = 0;
System.debug('Inserting 200 mileage records... (bulk validation)');
List<Mileage__c> testMiles2 = new List<Mileage__c>();
for(integer i=0; i<200; i++) {
testMiles2.add( new Mileage__c(Miles__c = 1, Date__c = System.today()) );
}
insert testMiles2;
for(Mileage__c m:[SELECT miles__c FROM Mileage__c
WHERE CreatedDate = TODAY
and CreatedById = :u1.Id
and miles__c != null]) {
totalMiles += m.miles__c;
}
System.assertEquals(maxtotalMiles, totalMiles);
}//end RunAs(u1)
//Validate additional user:
totalMiles = 0;
//Setup RunAs
User u2 = [SELECT Id FROM User WHERE Alias='tuser'];
System.RunAs(u2){
Mileage__c testMiles3 = new Mileage__c(Miles__c = 100, Date__c = System.today());
insert testMiles3;
for(Mileage__c m:[SELECT miles__c FROM Mileage__c
WHERE CreatedDate = TODAY
and CreatedById = :u2.Id
and miles__c != null]) {
totalMiles += m.miles__c;
}
//Validate
System.assertEquals(u2Miles, totalMiles);
} //System.RunAs(u2)
} // runPositiveTestCases()
static testMethod void runNegativeTestCases() {
User u3 = [SELECT Id FROM User WHERE Alias='tuser'];
System.RunAs(u3){
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![Testing Apex Testing Example
System.debug('Inserting a record with 501 miles... (negative test case)');
Mileage__c testMiles3 = new Mileage__c( Miles__c = 501, Date__c = System.today() );
try {
insert testMiles3;
} catch (DmlException e) {
//Assert Error Message
System.assert( e.getMessage().contains('Insert failed. First exception on ' +
'row 0; first error: FIELD_CUSTOM_VALIDATION_EXCEPTION, ' +
'Mileage request exceeds daily limit(500): [Miles__c]'),
e.getMessage() );
//Assert field
System.assertEquals(Mileage__c.Miles__c, e.getDmlFields(0)[0]);
//Assert Status Code
System.assertEquals('FIELD_CUSTOM_VALIDATION_EXCEPTION' ,
e.getDmlStatusCode(0) );
} //catch
} //RunAs(u3)
} // runNegativeTestCases()
} // class MileageTrackerTestSuite
Positive Test Case
The following steps through the above code, in particular, the positive test case for single and multiple records.
1. Add text to the debug log, indicating the next step of the code:
System.debug('Inserting 300 more miles...single record validation');
2. Create a Mileage__c object and insert it into the database.
Mileage__c testMiles1 = new Mileage__c(Miles__c = 300, Date__c = System.today() );
insert testMiles1;
3. Validate the code by returning the inserted records:
for(Mileage__c m:[SELECT miles__c FROM Mileage__c
WHERE CreatedDate = TODAY
and CreatedById = :createdbyId
and miles__c != null]) {
totalMiles += m.miles__c;
}
4. Use the system.assertEquals method to verify that the expected result is returned:
System.assertEquals(singletotalMiles, totalMiles);
5. Before moving to the next test, set the number of total miles back to 0:
totalMiles = 0;
6. Validate the code by creating a bulk insert of 200 records.
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![Testing Apex Testing Example
First, add text to the debug log, indicating the next step of the code:
System.debug('Inserting 200 Mileage records...bulk validation');
7. Then insert 200 Mileage__c records:
List<Mileage__c> testMiles2 = new List<Mileage__c>();
for(Integer i=0; i<200; i++){
testMiles2.add( new Mileage__c(Miles__c = 1, Date__c = System.today()) );
}
insert testMiles2;
8. Use System.assertEquals to verify that the expected result is returned:
for(Mileage__c m:[SELECT miles__c FROM Mileage__c
WHERE CreatedDate = TODAY
and CreatedById = :CreatedbyId
and miles__c != null]) {
totalMiles += m.miles__c;
}
System.assertEquals(maxtotalMiles, totalMiles);
Negative Test Case
The following steps through the above code, in particular, the negative test case.
1. Create a static test method called runNegativeTestCases:
static testMethod void runNegativeTestCases(){
2. Add text to the debug log, indicating the next step of the code:
System.debug('Inserting 501 miles... negative test case');
3. Create a Mileage__c record with 501 miles.
Mileage__c testMiles3 = new Mileage__c(Miles__c = 501, Date__c = System.today());
4. Place the insert statement within a try/catch block. This allows you to catch the validation exception and assert the
generated error message.
try {
insert testMiles3;
} catch (DmlException e) {
5. Now use the System.assert and System.assertEquals to do the testing. Add the following code to the catch
block you previously created:
//Assert Error Message
System.assert(e.getMessage().contains('Insert failed. First exception '+
'on row 0; first error: FIELD_CUSTOM_VALIDATION_EXCEPTION, '+
'Mileage request exceeds daily limit(500): [Miles__c]'),
e.getMessage());
//Assert Field
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![Testing Apex Testing Example
System.assertEquals(Mileage__c.Miles__c, e.getDmlFields(0)[0]);
//Assert Status Code
System.assertEquals('FIELD_CUSTOM_VALIDATION_EXCEPTION' ,
e.getDmlStatusCode(0));
}
}
}
Testing as a Second User
The following steps through the above code, in particular, running as a second user.
1. Before moving to the next test, set the number of total miles back to 0:
totalMiles = 0;
2. Set up the next user.
User u2 = [SELECT Id FROM User WHERE Alias='tuser'];
System.RunAs(u2){
3. Add text to the debug log, indicating the next step of the code:
System.debug('Setting up testing - deleting any mileage records for ' +
UserInfo.getUserName() +
' from today');
4. Then insert one Mileage__c record:
Mileage__c testMiles3 = new Mileage__c(Miles__c = 100, Date__c = System.today());
insert testMiles3;
5. Validate the code by returning the inserted records:
for(Mileage__c m:[SELECT miles__c FROM Mileage__c
WHERE CreatedDate = TODAY
and CreatedById = :u2.Id
and miles__c != null]) {
totalMiles += m.miles__c;
}
6. Use the system.assertEquals method to verify that the expected result is returned:
System.assertEquals(u2Miles, totalMiles);
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![Dynamic Apex Understanding Apex Describe Information
within the package to grant access to standard sObjects not included as part of the managed package. While Partners can
request access to standard objects, custom objects are not included as part of the managed package and can never be referenced
or accessed by dynamic Apex that is packaged.
For more information, see “About API and Dynamic Apex Access in Packages” in the Salesforce online help.
Using sObject Tokens
SObjects, such as Account and MyCustomObject__c, act as static classes with special static methods and member variables
for accessing token and describe result information. You must explicitly reference an sObject and field name at compile time
to gain access to the describe result.
To access the token for an sObject, use one of the following methods:
• Access the sObjectType member variable on an sObject type, such as Account.
• Call the getSObjectType method on an sObject describe result, an sObject variable, a list, or a map.
Schema.SObjectType is the data type for an sObject token.
In the following example, the token for the Account sObject is returned:
Schema.sObjectType t = Account.sObjectType;
The following also returns a token for the Account sObject:
Account A = new Account();
Schema.sObjectType T = A.getSObjectType();
This example can be used to determine whether an sObject or a list of sObjects is of a particular type:
public class sObjectTest {
{
// Create a generic sObject variable s
SObject s = Database.query('SELECT Id FROM Account LIMIT 1');
// Verify if that sObject variable is an Account token
System.assertEquals(s.getSObjectType(), Account.sObjectType);
// Create a list of generic sObjects
List<sObject> l = new Account[]{};
// Verify if the list of sObjects contains Account tokens
System.assertEquals(l.getSObjectType(), Account.sObjectType);
}
}
Some standard sObjects have a field called sObjectType, for example, AssignmentRule, QueueSObject, and RecordType.
For these types of sObjects, always use the getSObjectType method for retrieving the token. If you use the property, for
example, RecordType.sObjectType, the field is returned.
Using sObject Describe Results
To access the describe result for an sObject, use one of the following methods:
• Call the getDescribe method on an sObject token.
• Use the Schema sObjectType static variable with the name of the sObject. For example, Schema.sObjectType.Lead.
Schema.DescribeSObjectResult is the data type for an sObject describe result.
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![Dynamic Apex Understanding Apex Describe Information
// Verify the new sObject got inserted.
Account[] b = [SELECT Name from Account WHERE Name = :acctName];
system.assert(b.size() > 0);
}
}
Accessing All Field Describe Results for an sObject
Use the field describe result's getMap method to return a map that represents the relationship between all the field names
(keys) and the field tokens (values) for an sObject.
The following example generates a map that can be used to access a field by name:
Map<String, Schema.SObjectField> M = Schema.SObjectType.Account.fields.getMap();
Note: The value type of this map is not a field describe result. Using the describe results would take too many system
resources. Instead, it is a map of tokens that you can use to find the appropriate field. After you determine the field,
generate the describe result for it.
The map has the following characteristics:
• It is dynamic, that is, it is generated at runtime on the fields for that sObject.
• All field names are case insensitive.
• The keys use namespaces as required.
• The keys reflect whether the field is a custom object.
For example, if the code block that generates the map is in namespace N1, and a field is also in N1, the key in the map is
represented as MyField__c. However, if the code block is in namespace N1, and the field is in namespace N2, the key is
N2__MyField__c.
In addition, standard fields have no namespace prefix.
Accessing All Data Categories Associated with an sObject
Use the describeDataCategory Groups and describeDataCategory GroupStructures methods to return the
categories associated with a specific object:
1. Return all the category groups associated with the objects of your choice (see describeDataCategory Groups on page 349).
2. From the returned map, get the category group name and sObject name you want to further interrogate (see Schema.Describe
DataCategoryGroupResult on page 350).
3. Specify the category group and associated object, then retrieve the categories available to this object (see describeDataCategory
GroupStructures on page 349).
The describeDataCategory GroupStructures method returns the categories available for the object in the category
group you specified. For additional information about data categories, see “What are Data Categories?” in the Salesforce online
help.
In the following example, the describeDataCategoryGroupSample method returns all the category groups associated
with the Article and Question objects. The describeDataCategoryGroupStructures method returns all the categories
available for articles and questions in the Regions category group. For additional information about articles and questions, see
“Managing Articles and Translations” and “Answers Overview” in the Salesforce online help.
To use the following example, you must:
• Enable Salesforce Knowledge.
• Enable the answers feature.
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![Dynamic Apex Understanding Apex Describe Information
for(DescribeDataCategoryGroupResult singleResult :
describeCategoryResult){
DataCategoryGroupSobjectTypePair p =
new DataCategoryGroupSobjectTypePair();
p.setSobject(singleResult.getSobject());
p.setDataCategoryGroupName(singleResult.getName());
pairs.add(p);
}
//describeDataCategoryGroupStructures()
describeCategoryStructureResult =
Schema.describeDataCategoryGroupStructures(pairs, false);
//Getting data from the result
for(DescribeDataCategoryGroupStructureResult singleResult :
describeCategoryStructureResult){
//Get name of the associated Sobject
singleResult.getSobject();
//Get the name of the data category group
singleResult.getName();
//Get the name of the data category group
singleResult.getLabel();
//Get the description of the data category group
singleResult.getDescription();
//Get the top level categories
DataCategory [] toplevelCategories =
singleResult.getTopCategories();
//Recursively get all the categories
List<DataCategory> allCategories =
getAllCategories(toplevelCategories);
for(DataCategory category : allCategories) {
//Get the name of the category
category.getName();
//Get the label of the category
category.getLabel();
//Get the list of sub categories in the category
DataCategory [] childCategories =
category.getChildCategories();
}
}
} catch (Exception e){
}
return describeCategoryStructureResult;
}
private static DataCategory[] getAllCategories(DataCategory [] categories){
if(categories.isEmpty()){
return new DataCategory[]{};
} else {
DataCategory [] categoriesClone = categories.clone();
DataCategory category = categoriesClone[0];
DataCategory[] allCategories = new DataCategory[]{category};
categoriesClone.remove(0);
categoriesClone.addAll(category.getChildCategories());
allCategories.addAll(getAllCategories(categoriesClone));
return allCategories;
}
}
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![Dynamic Apex Understanding Apex Describe Information
}
Testing Access to All Data Categories Associated with an sObject
The following example tests the describeDataCategoryGroupSample method shown in Accessing All Data Categories
Associated with an sObject. It ensures that the returned category group and associated objects are correct.
@isTest
private class DescribeDataCategoryGroupSampleTest {
public static testMethod void describeDataCategoryGroupSampleTest(){
List<DescribeDataCategoryGroupResult>describeResult =
DescribeDataCategoryGroupSample.describeDataCategoryGroupSample();
//Assuming that you have KnowledgeArticleVersion and Questions
//associated with only one category group 'Regions'.
System.assert(describeResult.size() == 2,
'The results should only contain two results: ' + describeResult.size());
for(DescribeDataCategoryGroupResult result : describeResult) {
//Storing the results
String name = result.getName();
String label = result.getLabel();
String description = result.getDescription();
String objectNames = result.getSobject();
//asserting the values to make sure
System.assert(name == 'Regions',
'Incorrect name was returned: ' + name);
System.assert(label == 'Regions of the World',
'Incorrect label was returned: ' + label);
System.assert(description == 'This is the category group for all the regions',
'Incorrect description was returned: ' + description);
System.assert(objectNames.contains('KnowledgeArticleVersion')
|| objectNames.contains('Question'),
'Incorrect sObject was returned: ' + objectNames);
}
}
}
This example tests the describeDataCategoryGroupStructures method shown in Accessing All Data Categories
Associated with an sObject. It ensures that the returned category group, categories and associated objects are correct.
@isTest
private class DescribeDataCategoryGroupStructuresTest {
public static testMethod void getDescribeDataCategoryGroupStructureResultsTest(){
List<Schema.DescribeDataCategoryGroupStructureResult> describeResult =
DescribeDataCategoryGroupStructures.getDescribeDataCategoryGroupStructureResults();
System.assert(describeResult.size() == 2,
'The results should only contain 2 results: ' + describeResult.size());
//Creating category info
CategoryInfo world = new CategoryInfo('World', 'World');
CategoryInfo asia = new CategoryInfo('Asia', 'Asia');
CategoryInfo northAmerica = new CategoryInfo('NorthAmerica',
'North America');
CategoryInfo southAmerica = new CategoryInfo('SouthAmerica',
'South America');
CategoryInfo europe = new CategoryInfo('Europe', 'Europe');
List<CategoryInfo> info = new CategoryInfo[] {
asia, northAmerica, southAmerica, europe
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![Dynamic Apex Understanding Apex Describe Information
};
for (Schema.DescribeDataCategoryGroupStructureResult result : describeResult) {
String name = result.getName();
String label = result.getLabel();
String description = result.getDescription();
String objectNames = result.getSobject();
//asserting the values to make sure
System.assert(name == 'Regions',
'Incorrect name was returned: ' + name);
System.assert(label == 'Regions of the World',
'Incorrect label was returned: ' + label);
System.assert(description == 'This is the category group for all the regions',
'Incorrect description was returned: ' + description);
System.assert(objectNames.contains('KnowledgeArticleVersion')
|| objectNames.contains('Question'),
'Incorrect sObject was returned: ' + objectNames);
DataCategory [] topLevelCategories = result.getTopCategories();
System.assert(topLevelCategories.size() == 1,
'Incorrect number of top level categories returned: ' + topLevelCategories.size());
System.assert(topLevelCategories[0].getLabel() == world.getLabel() &&
topLevelCategories[0].getName() == world.getName());
//checking if the correct children are returned
DataCategory [] children = topLevelCategories[0].getChildCategories();
System.assert(children.size() == 4,
'Incorrect number of children returned: ' + children.size());
for(Integer i=0; i < children.size(); i++){
System.assert(children[i].getLabel() == info[i].getLabel() &&
children[i].getName() == info[i].getName());
}
}
}
private class CategoryInfo {
private final String name;
private final String label;
private CategoryInfo(String n, String l){
this.name = n;
this.label = l;
}
public String getName(){
return this.name;
}
public String getLabel(){
return this.label;
}
}
}
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![Dynamic Apex Dynamic DML
This is another example that shows how to obtain the sObject token through the Schema.getGlobalDescribe method
and then creates a new sObject using the newSObject method on the token. This example also contains a test method that
verifies the dynamic creation of an account.
public class DynamicSObjectCreation {
public static sObject createObject(String typeName) {
Schema.SObjectType targetType = Schema.getGlobalDescribe().get(typeName);
if (targetType == null) {
// throw an exception
}
// Instantiate an sObject with the type passed in as an argument
// at run time.
return targetType.newSObject();
}
static testmethod void testObjectCreation() {
String typeName = 'Account';
String acctName = 'Acme';
// Create a new sObject by passing the sObject type as an argument.
Account a = (Account)createObject(typeName);
System.assertEquals(typeName, String.valueOf(a.getSobjectType()));
// Set the account name and insert the account.
a.Name = acctName;
insert a;
// Verify the new sObject got inserted.
Account[] b = [SELECT Name from Account WHERE Name = :acctName];
system.assert(b.size() > 0);
}
}
You can also specify an ID with newSObject to create an sObject that references an existing record that you can update later.
For example:
SObject s = Database.query('SELECT Id FROM account LIMIT 1')[0].getSObjectType().
newSObject([SELECT Id FROM Account LIMIT 1][0].Id);
See Schema.sObjectType on page 366.
Setting and Retrieving Field Values
Use the get and put methods on an object to set or retrieve values for fields using either the API name of the field expressed
as a String, or the field's token. In the following example, the API name of the field AccountNumber is used:
SObject s = [SELECT AccountNumber FROM Account LIMIT 1];
Object o = s.get('AccountNumber');
s.put('AccountNumber', 'abc');
The following example uses the AccountNumber field's token instead:
Schema.DescribeFieldResult f = Schema.sObjectType.Account.fields.AccountNumber;
Sobject s = Database.query('SELECT AccountNumber FROM Account LIMIT 1');
s.put(f.getsObjectField(), '12345');
The Object scalar data type can be used as a generic data type to set or retrieve field values on an sObject. This is equivalent
to the anyType field type. Note that the Object data type is different from the sObject data type, which can be used as a generic
type for any sObject.
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![Dynamic Apex Dynamic DML
Note: Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you
assign a String value that is too long for the field.
Setting and Retrieving Foreign Keys
Apex supports populating foreign keys by name (or external ID) in the same way as the API. To set or retrieve the scalar ID
value of a foreign key, use the get or put methods.
To set or retrieve the record associated with a foreign key, use the getSObject and putSObject methods. Note that these
methods must be used with the sObject data type, not Object. For example:
SObject c =
Database.query('SELECT Id, FirstName, AccountId, Account.Name FROM Contact LIMIT 1');
SObject a = c.getSObject('Account');
There is no need to specify the external ID for a parent sObject value while working with child sObjects. If you provide an
ID in the parent sObject, it is ignored by the DML operation. Apex assumes the foreign key is populated through a relationship
SOQL query, which always returns a parent object with a populated ID. If you have an ID, use it with the child object.
For example, suppose that custom object C1 has a foreign key c2__c that links to a child custom object C2. You want to
create a C1 object and have it associated with a C2 record named 'xxx' (assigned to the value c2__r). You do not need the
ID of the 'xxx' record, as it is populated through the relationship of parent to child. For example:
insert new C1__c(name = 'x', c2__r = new C2__c(name = 'xxx'));
If you had assigned a value to the ID for c2__r, it would be ignored. If you do have the ID, assign it to the object (c2__c),
not the record.
You can also access foreign keys using dynamic Apex. The following example shows how to get the values from a subquery in
a parent-to-child relationship using dynamic Apex:
String queryString = 'SELECT Id, Name, ' +
'(SELECT FirstName, LastName FROM Contacts LIMIT 1) FROM Account';
SObject[] queryParentObject = Database.query(queryString);
for (SObject parentRecord : queryParentObject){
Object ParentFieldValue = parentRecord.get('Name');
// Prevent a null relationship from being accessed
SObject[] childRecordsFromParent = parentRecord.getSObjects('Contacts');
if (childRecordsFromParent != null) {
for (SObject childRecord : childRecordsFromParent){
Object ChildFieldValue1 = childRecord.get('FirstName');
Object ChildFieldValue2 = childRecord.get('LastName');
System.debug('Account Name: ' + ParentFieldValue +
'. Contact Name: '+ ChildFieldValue1 + ' ' + ChildFieldValue2);
}
}
}
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![Batch Apex Using Batch Apex
Each execution of a batch Apex job is considered a discrete transaction. For example, a batch Apex job that contains 1,000
records and is executed without the optional scope parameter from Database.executeBatch is considered five transactions
of 200 records each. The Apex governor limits are reset for each transaction. If the first transaction succeeds but the second
fails, the database updates made in the first transaction are not rolled back.
Using Database.BatchableContext
All of the methods in the Database.Batchable interface require a reference to a Database.BatchableContext object.
Use this object to track the progress of the batch job.
The following is the instance method with the Database.BatchableContext object:
Name Arguments Returns Description
getJobID ID Returns the ID of the AsyncApexJob object associated
with this batch job as a string. Use this method to track
the progress of records in the batch job. You can also
use this ID with the System.abortJob method.
The following example uses the Database.BatchableContext to query the AsyncApexJob associated with the batch
job.
global void finish(Database.BatchableContext BC){
// Get the ID of the AsyncApexJob representing this batch job
// from Database.BatchableContext.
// Query the AsyncApexJob object to retrieve the current job's information.
AsyncApexJob a = [SELECT Id, Status, NumberOfErrors, JobItemsProcessed,
TotalJobItems, CreatedBy.Email
FROM AsyncApexJob WHERE Id =
:BC.getJobId()];
// Send an email to the Apex job's submitter notifying of job completion.
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
String[] toAddresses = new String[] {a.CreatedBy.Email};
mail.setToAddresses(toAddresses);
mail.setSubject('Apex Sharing Recalculation ' + a.Status);
mail.setPlainTextBody
('The batch Apex job processed ' + a.TotalJobItems +
' batches with '+ a.NumberOfErrors + ' failures.');
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
Using Database.QueryLocator to Define Scope
The start method can return either a Database.QueryLocator object that contains the records to be used in the batch
job or an iterable.
The following example uses a Database.QueryLocator:
global class SearchAndReplace implements Database.Batchable<sObject>{
global final String Query;
global final String Entity;
global final String Field;
global final String Value;
global SearchAndReplace(String q, String e, String f, String v){
Query=q; Entity=e; Field=f;Value=v;
}
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![Batch Apex Using Batch Apex
The Database.executeBatch method returns the ID of the AsyncApexJob object, which can then be used to track the
progress of the job. For example:
ID batchprocessid = Database.executeBatch(reassign);
AsyncApexJob aaj = [SELECT Id, Status, JobItemsProcessed, TotalJobItems, NumberOfErrors
FROM AsyncApexJob WHERE ID =: batchprocessid ];
For more information about the AsyncApexJob object, see AsyncApexJob in the Object Reference for Salesforce and Force.com.
You can also use this ID with the System.abortJob method.
Batch Apex Examples
The following example uses a Database.QueryLocator:
global class UpdateAccountFields implements Database.Batchable<sObject>{
global final String Query;
global final String Entity;
global final String Field;
global final String Value;
global UpdateAccountFields(String q, String e, String f, String v){
Query=q; Entity=e; Field=f;Value=v;
}
global Database.QueryLocator start(Database.BatchableContext BC){
return Database.getQueryLocator(query);
}
global void execute(Database.BatchableContext BC,
List<sObject> scope){
for(Sobject s : scope){s.put(Field,Value);
} update scope;
}
global void finish(Database.BatchableContext BC){
}
}
The following code can be used to call the above class:
Id batchInstanceId = Database.executeBatch(new UpdateAccountFields(q,e,f,v), 5);
The following class uses batch Apex to reassign all accounts owned by a specific user to a different user.
global class OwnerReassignment implements Database.Batchable<sObject>{
String query;
String email;
Id toUserId;
Id fromUserId;
global Database.querylocator start(Database.BatchableContext BC){
return Database.getQueryLocator(query);}
global void execute(Database.BatchableContext BC, List<sObject> scope){
List<Account> accns = new List<Account>();
for(sObject s : scope){Account a = (Account)s;
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![Batch Apex Using Batch Apex
if(a.OwnerId==fromUserId){
a.OwnerId=toUserId;
accns.add(a);
}
}
update accns;
}
global void finish(Database.BatchableContext BC){
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
mail.setToAddresses(new String[] {email});
mail.setReplyTo('batch@acme.com');
mail.setSenderDisplayName('Batch Processing');
mail.setSubject('Batch Process Completed');
mail.setPlainTextBody('Batch Process has completed');
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
}
Use the following to execute the OwnerReassignment class in the previous example:
OwnerReassignment reassign = new OwnerReassignment();
reassign.query = 'SELECT Id, Name, Ownerid FROM Account ' +
'WHERE ownerid='' + u.id + ''';
reassign.email='admin@acme.com';
reassign.fromUserId = u;
reassign.toUserId = u2;
ID batchprocessid = Database.executeBatch(reassign);
The following is an example of a batch Apex class for deleting records.
global class BatchDelete implements Database.Batchable<sObject> {
public String query;
global Database.QueryLocator start(Database.BatchableContext BC){
return Database.getQueryLocator(query);
}
global void execute(Database.BatchableContext BC, List<sObject> scope){
delete scope;
DataBase.emptyRecycleBin(scope);
}
global void finish(Database.BatchableContext BC){
}
}
This code calls the BatchDelete batch Apex class to delete old documents. The specified query selects documents to delete
for all documents that are in a specified folder and that are older than a specified date. Next, the sample invokes the batch job.
BatchDelete BDel = new BatchDelete();
Datetime d = Datetime.now();
d = d.addDays(-1);
// Replace this value with the folder ID that contains
// the documents to delete.
String folderId = '00lD000000116lD';
// Query for selecting the documents to delete
BDel.query = 'SELECT Id FROM Document WHERE FolderId='' + folderId +
'' AND CreatedDate < '+d.format('yyyy-MM-dd')+'T'+
d.format('HH:mm')+':00.000Z';
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![Batch Apex Using Batch Apex
global class MyBatchable implements Database.Batchable<sObject> {
private final String initialState;
String query;
global MyBatchable(String intialState) {
this.initialState = initialState;
}
global Database.QueryLocator start(Database.BatchableContext BC) {
// Access initialState here
return Database.getQueryLocator(query);
}
global void execute(Database.BatchableContext BC,
List<sObject> batch) {
// Access initialState here
}
global void finish(Database.BatchableContext BC) {
// Access initialState here
}
}
Note that initialState is the initial state of the class. You cannot use it to pass information between instances of the class
during execution of the batch job. For example, if you changed the value of initialState in execute, the second chunk
of processed records would not be able to access the new value: only the initial value would be accessible.
Testing Batch Apex
When testing your batch Apex, you can test only one execution of the execute method. You can use the scope parameter
of the executeBatch method to limit the number of records passed into the execute method to ensure that you aren't
running into governor limits.
The executeBatch method starts an asynchronous process. This means that when you test batch Apex, you must make
certain that the batch job is finished before testing against the results. Use the Test methods startTest and stopTest
around the executeBatch method to ensure it finishes before continuing your test. All asynchronous calls made after the
startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run synchronously.
If you don’t include the executeBatch method within the startTest and stopTest methods, the batch job executes at
the end of your test method for Apex saved using Salesforce.com API version 25.0 and later, but not in earlier versions.
Starting with Apex saved using Salesforce.com API version 22.0, exceptions that occur during the execution of a batch Apex
job that is invoked by a test method are now passed to the calling test method, and as a result, causes the test method to fail.
If you want to handle exceptions in the test method, enclose the code in try and catch statements. You must place the
catch block after the stopTest method. Note however that with Apex saved using Salesforce.com API version 21.0 and
earlier, such exceptions don't get passed to the test method and don't cause test methods to fail.
Note: Asynchronous calls, such as @future or executeBatch, called in a startTest, stopTest block, do not
count against your limits for the number of queued jobs.
The example below tests the OwnerReassignment class.
public static testMethod void testBatch() {
user u = [SELECT ID, UserName FROM User
WHERE username='testuser1@acme.com'];
user u2 = [SELECT ID, UserName FROM User
WHERE username='testuser2@acme.com'];
String u2id = u2.id;
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![Batch Apex Sharing a Record Using Apex
// Process the save results.
if(sr.isSuccess()){
// Indicates success
return true;
}
else {
// Get first save result error.
Database.Error err = sr.getErrors()[0];
// Check if the error is related to trival access level.
// Access levels equal or more permissive than the object's default
// access level are not allowed.
// These sharing records are not required and thus an insert exception is acceptable.
if(err.getStatusCode() == StatusCode.FIELD_FILTER_VALIDATION_EXCEPTION &&
err.getMessage().contains('AccessLevel')){
// Indicates success.
return true;
}
else{
// Indicates failure.
return false;
}
}
}
// Test for the manualShareRead method
static testMethod void testManualShareRead(){
// Select users for the test.
List<User> users = [SELECT Id FROM User WHERE IsActive = true LIMIT 2];
Id User1Id = users[0].Id;
Id User2Id = users[1].Id;
// Create new job.
Job__c j = new Job__c();
j.Name = 'Test Job';
j.OwnerId = user1Id;
insert j;
// Insert manual share for user who is not record owner.
System.assertEquals(manualShareRead(j.Id, user2Id), true);
// Query job sharing records.
List<Job__Share> jShrs = [SELECT Id, UserOrGroupId, AccessLevel,
RowCause FROM job__share WHERE ParentId = :j.Id AND UserOrGroupId= :user2Id];
// Test for only one manual share on job.
System.assertEquals(jShrs.size(), 1, 'Set the object's sharing model to Private.');
// Test attributes of manual share.
System.assertEquals(jShrs[0].AccessLevel, 'Read');
System.assertEquals(jShrs[0].RowCause, 'Manual');
System.assertEquals(jShrs[0].UserOrGroupId, user2Id);
// Test invalid job Id.
delete j;
// Insert manual share for deleted job id.
System.assertEquals(manualShareRead(j.Id, user2Id), false);
}
}
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![Batch Apex Sharing a Record Using Apex
Apex Managed Sharing Example
For this example, suppose you are building a recruiting application and have an object called Job. You want to validate that
the recruiter and hiring manager listed on the job have access to the record. The following trigger grants the recruiter and
hiring manager access when the job record is created. This example requires a custom object called Job, with two lookup fields
associated with User records called Hiring_Manager and Recruiter. Also, the Job custom object should have two sharing
reasons added called Hiring_Manager and Recruiter.
trigger JobApexSharing on Job__c (after insert) {
if(trigger.isInsert){
// Create a new list of sharing objects for Job
List<Job__Share> jobShrs = new List<Job__Share>();
// Declare variables for recruiting and hiring manager sharing
Job__Share recruiterShr;
Job__Share hmShr;
for(Job__c job : trigger.new){
// Instantiate the sharing objects
recruiterShr = new Job__Share();
hmShr = new Job__Share();
// Set the ID of record being shared
recruiterShr.ParentId = job.Id;
hmShr.ParentId = job.Id;
// Set the ID of user or group being granted access
recruiterShr.UserOrGroupId = job.Recruiter__c;
hmShr.UserOrGroupId = job.Hiring_Manager__c;
// Set the access level
recruiterShr.AccessLevel = 'edit';
hmShr.AccessLevel = 'read';
// Set the Apex sharing reason for hiring manager and recruiter
recruiterShr.RowCause = Schema.Job__Share.RowCause.Recruiter__c;
hmShr.RowCause = Schema.Job__Share.RowCause.Hiring_Manager__c;
// Add objects to list for insert
jobShrs.add(recruiterShr);
jobShrs.add(hmShr);
}
// Insert sharing records and capture save result
// The false parameter allows for partial processing if multiple records are passed
// into the operation
Database.SaveResult[] lsr = Database.insert(jobShrs,false);
// Create counter
Integer i=0;
// Process the save results
for(Database.SaveResult sr : lsr){
if(!sr.isSuccess()){
// Get the first save result error
Database.Error err = sr.getErrors()[0];
// Check if the error is related to a trivial access level
// Access levels equal or more permissive than the object's default
// access level are not allowed.
// These sharing records are not required and thus an insert exception is
// acceptable.
if(!(err.getStatusCode() == StatusCode.FIELD_FILTER_VALIDATION_EXCEPTION
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![Batch Apex Recalculating Apex Managed Sharing
&& err.getMessage().contains('AccessLevel'))){
// Throw an error when the error is not related to trivial access level.
trigger.newMap.get(jobShrs[i].ParentId).
addError(
'Unable to grant sharing access due to following exception: '
+ err.getMessage());
}
}
i++;
}
}
}
Under certain circumstances, inserting a share row results in an update of an existing share row. Consider these examples:
• If a manual share access level is set to Read and you insert a new one that’s set to Write, the original share rows are updated
to Write, indicating the higher level of access.
• If users can access an account because they can access its child records (contact, case, opportunity, and so on), and an
account sharing rule is created, the row cause of the parent implicit share is replaced by the sharing rule row cause, indicating
the higher level of access.
Important: The object’s organization-wide default access level must not be set to the most permissive access level.
For custom objects, this is Public Read/Write. For more information, see Access Levels on page 199.
Recalculating Apex Managed Sharing
Salesforce automatically recalculates sharing for all records on an object when its organization-wide sharing default access level
changes. The recalculation adds Force.com managed sharing when appropriate. In addition, all types of sharing are removed
if the access they grant is considered redundant. For example, manual sharing, which grants Read Only access to a user, is
deleted when the object’s sharing model changes from Private to Public Read Only.
To recalculate Apex managed sharing, you must write an Apex class that implements a Salesforce-provided interface to do
the recalculation. You must then associate the class with the custom object, on the custom object's detail page, in the Apex
Sharing Recalculation related list.
Note: Apex sharing reasons and Apex managed sharing recalculation are only available for custom objects.
You can execute this class from the custom object detail page where the Apex sharing reason is specified. An administrator
might need to recalculate the Apex managed sharing for an object if a locking issue prevented Apex code from granting access
to a user as defined by the application’s logic. You can also use the Database.executeBatch method to programmatically
invoke an Apex managed sharing recalculation.
Note: Every time a custom object's organization-wide sharing default access level is updated, any Apex recalculation
classes defined for associated custom object are also executed.
To monitor or stop the execution of the Apex recalculation, click Your Name > Setup > Monitoring > Apex Jobs. For more
information, see “Monitoring the Apex Job Queue” in the Salesforce online help.
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![Batch Apex Recalculating Apex Managed Sharing
Creating an Apex Class for Recalculating Sharing
To recalculate Apex managed sharing, you must write an Apex class to do the recalculation. This class must implement the
Salesforce-provided interface Database.Batchable.
The Database.Batchable interface is used for all batch Apex processes, including recalculating Apex managed sharing.
You can implement this interface more than once in your organization. For more information on the methods that must be
implemented, see Using Batch Apex on page 188.
Before creating an Apex managed sharing recalculation class, also consider the best practices.
Important: The object’s organization-wide default access level must not be set to the most permissive access level.
For custom objects, this is Public Read/Write. For more information, see Access Levels on page 199.
Apex Managed Sharing Recalculation Example
For this example, suppose you are building a recruiting application and have an object called Job. You want to validate that
the recruiter and hiring manager listed on the job have access to the record. The following Apex class performs this validation.
This example requires a custom object called Job, with two lookup fields associated with User records called Hiring_Manager
and Recruiter. Also, the Job custom object should have two sharing reasons added called Hiring_Manager and Recruiter.
Before you run this sample, replace the email address with a valid email address that you want to to send error notifications
and job completion notifications to.
global class JobSharingRecalc implements Database.Batchable<sObject> {
// String to hold email address that emails will be sent to.
// Replace its value with a valid email address.
static String emailAddress = 'admin@yourcompany.com';
// The start method is called at the beginning of a sharing recalculation.
// This method returns a SOQL query locator containing the records
// to be recalculated.
global Database.QueryLocator start(Database.BatchableContext BC){
return Database.getQueryLocator([SELECT Id, Hiring_Manager__c, Recruiter__c
FROM Job__c]);
}
// The executeBatch method is called for each chunk of records returned from start.
global void execute(Database.BatchableContext BC, List<sObject> scope){
// Create a map for the chunk of records passed into method.
Map<ID, Job__c> jobMap = new Map<ID, Job__c>((List<Job__c>)scope);
// Create a list of Job__Share objects to be inserted.
List<Job__Share> newJobShrs = new List<Job__Share>();
// Locate all existing sharing records for the Job records in the batch.
// Only records using an Apex sharing reason for this app should be returned.
List<Job__Share> oldJobShrs = [SELECT Id FROM Job__Share WHERE Id IN
:jobMap.keySet() AND
(RowCause = :Schema.Job__Share.rowCause.Recruiter__c OR
RowCause = :Schema.Job__Share.rowCause.Hiring_Manager__c)];
// Construct new sharing records for the hiring manager and recruiter
// on each Job record.
for(Job__c job : jobMap.values()){
Job__Share jobHMShr = new Job__Share();
Job__Share jobRecShr = new Job__Share();
// Set the ID of user (hiring manager) on the Job record being granted access.
jobHMShr.UserOrGroupId = job.Hiring_Manager__c;
// The hiring manager on the job should always have 'Read Only' access.
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![Batch Apex Recalculating Apex Managed Sharing
jobHMShr.AccessLevel = 'Read';
// The ID of the record being shared
jobHMShr.ParentId = job.Id;
// Set the rowCause to the Apex sharing reason for hiring manager.
// This establishes the sharing record as Apex managed sharing.
jobHMShr.RowCause = Schema.Job__Share.RowCause.Hiring_Manager__c;
// Add sharing record to list for insertion.
newJobShrs.add(jobHMShr);
// Set the ID of user (recruiter) on the Job record being granted access.
jobRecShr.UserOrGroupId = job.Recruiter__c;
// The recruiter on the job should always have 'Read/Write' access.
jobRecShr.AccessLevel = 'Edit';
// The ID of the record being shared
jobRecShr.ParentId = job.Id;
// Set the rowCause to the Apex sharing reason for recruiter.
// This establishes the sharing record as Apex managed sharing.
jobRecShr.RowCause = Schema.Job__Share.RowCause.Recruiter__c;
// Add the sharing record to the list for insertion.
newJobShrs.add(jobRecShr);
}
try {
// Delete the existing sharing records.
// This allows new sharing records to be written from scratch.
Delete oldJobShrs;
// Insert the new sharing records and capture the save result.
// The false parameter allows for partial processing if multiple records are
// passed into operation.
Database.SaveResult[] lsr = Database.insert(newJobShrs,false);
// Process the save results for insert.
for(Database.SaveResult sr : lsr){
if(!sr.isSuccess()){
// Get the first save result error.
Database.Error err = sr.getErrors()[0];
// Check if the error is related to trivial access level.
// Access levels equal or more permissive than the object's default
// access level are not allowed.
// These sharing records are not required and thus an insert exception
// is acceptable.
if(!(err.getStatusCode() == StatusCode.FIELD_FILTER_VALIDATION_EXCEPTION
&& err.getMessage().contains('AccessLevel'))){
// Error is not related to trivial access level.
// Send an email to the Apex job's submitter.
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
String[] toAddresses = new String[] {emailAddress};
mail.setToAddresses(toAddresses);
mail.setSubject('Apex Sharing Recalculation Exception');
mail.setPlainTextBody(
'The Apex sharing recalculation threw the following exception: ' +
err.getMessage());
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
}
}
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![Batch Apex Recalculating Apex Managed Sharing
} catch(DmlException e) {
// Send an email to the Apex job's submitter on failure.
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
String[] toAddresses = new String[] {emailAddress};
mail.setToAddresses(toAddresses);
mail.setSubject('Apex Sharing Recalculation Exception');
mail.setPlainTextBody(
'The Apex sharing recalculation threw the following exception: ' +
e.getMessage());
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
}
// The finish method is called at the end of a sharing recalculation.
global void finish(Database.BatchableContext BC){
// Send an email to the Apex job's submitter notifying of job completion.
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
String[] toAddresses = new String[] {emailAddress};
mail.setToAddresses(toAddresses);
mail.setSubject('Apex Sharing Recalculation Completed.');
mail.setPlainTextBody
('The Apex sharing recalculation finished processing');
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
}
Testing Apex Managed Sharing Recalculations
This example inserts five Job records and invokes the batch job that is implemented in the batch class of the previous example.
This example requires a custom object called Job, with two lookup fields associated with User records called Hiring_Manager
and Recruiter. Also, the Job custom object should have two sharing reasons added called Hiring_Manager and Recruiter.
Before you run this test, set the organization-wide default sharing for Job to Private. Note that since email messages aren’t
sent from tests, and because the batch class is invoked by a test method, the email notifications won’t be sent in this case.
@isTest
private class JobSharingTester {
// Test for the JobSharingRecalc class
static testMethod void testApexSharing(){
// Instantiate the class implementing the Database.Batchable interface.
JobSharingRecalc recalc = new JobSharingRecalc();
// Select users for the test.
List<User> users = [SELECT Id FROM User WHERE IsActive = true LIMIT 2];
ID User1Id = users[0].Id;
ID User2Id = users[1].Id;
// Insert some test job records.
List<Job__c> testJobs = new List<Job__c>();
for (Integer i=0;i<5;i++) {
Job__c j = new Job__c();
j.Name = 'Test Job ' + i;
j.Recruiter__c = User1Id;
j.Hiring_Manager__c = User2Id;
testJobs.add(j);
}
insert testJobs;
Test.startTest();
// Invoke the Batch class.
String jobId = Database.executeBatch(recalc);
Test.stopTest();
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![Batch Apex Recalculating Apex Managed Sharing
// Get the Apex job and verify there are no errors.
AsyncApexJob aaj = [Select JobType, TotalJobItems, JobItemsProcessed, Status,
CompletedDate, CreatedDate, NumberOfErrors
from AsyncApexJob where Id = :jobId];
System.assertEquals(0, aaj.NumberOfErrors);
// This query returns jobs and related sharing records that were inserted
// by the batch job's execute method.
List<Job__c> jobs = [SELECT Id, Hiring_Manager__c, Recruiter__c,
(SELECT Id, ParentId, UserOrGroupId, AccessLevel, RowCause FROM Shares
WHERE (RowCause = :Schema.Job__Share.rowCause.Recruiter__c OR
RowCause = :Schema.Job__Share.rowCause.Hiring_Manager__c))
FROM Job__c];
// Validate that Apex managed sharing exists on jobs.
for(Job__c job : jobs){
// Two Apex managed sharing records should exist for each job
// when using the Private org-wide default.
System.assert(job.Shares.size() == 2);
for(Job__Share jobShr : job.Shares){
// Test the sharing record for hiring manager on job.
if(jobShr.RowCause == Schema.Job__Share.RowCause.Hiring_Manager__c){
System.assertEquals(jobShr.UserOrGroupId,job.Hiring_Manager__c);
System.assertEquals(jobShr.AccessLevel,'Read');
}
// Test the sharing record for recruiter on job.
else if(jobShr.RowCause == Schema.Job__Share.RowCause.Recruiter__c){
System.assertEquals(jobShr.UserOrGroupId,job.Recruiter__c);
System.assertEquals(jobShr.AccessLevel,'Edit');
}
}
}
}
}
Associating an Apex Class Used for Recalculation
An Apex class used for recalculation must be associated with a custom object.
To associate an Apex managed sharing recalculation class with a custom object:
1. Click Your Name > Setup > Create > Objects.
2. Select the custom object.
3. Click New in the Apex Sharing Recalculations related list.
4. Choose the Apex class that recalculates the Apex sharing for this object. The class you choose must implement the
Database.Batchable interface. You cannot associate the same Apex class multiple times with the same custom object.
5. Click Save.
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![Debugging Apex Understanding the Debug Log
Execution Units
An execution unit is equivalent to a transaction. It contains everything that occurred within the transaction. The execution
is delimited by EXECUTION_STARTED and EXECUTION_FINISHED.
Code Units
A code unit is a discrete unit of work within a transaction. For example, a trigger is one unit of code, as is a webService
method, or a validation rule.
Note: A class is not a discrete unit of code.
Units of code are indicated by CODE_UNIT_STARTED and CODE_UNIT_FINISHED. Units of work can embed other
units of work. For example:
EXECUTION_STARTED
CODE_UNIT_STARTED|[EXTERNAL]execute_anonymous_apex
CODE_UNIT_STARTED|[EXTERNAL]MyTrigger on Account trigger event BeforeInsert for [new]
CODE_UNIT_FINISHED <-- The trigger ends
CODE_UNIT_FINISHED <-- The executeAnonymous ends
EXECUTION_FINISHED
Units of code include, but are not limited to, the following:
• Triggers
• Workflow invocations and time-based workflow
• Validation rules
• Approval processes
• Apex lead convert
• @future method invocations
• Web service invocations
• executeAnonymous calls
• Visualforce property accesses on Apex controllers
• Visualforce actions on Apex controllers
• Execution of the batch Apex start and finish methods, as well as each execution of the execute method
• Execution of the Apex System.Schedule execute method
• Incoming email handling
Log Lines
Included inside the units of code. These indicate what code or rules are being executed, or messages being specifically
written to the debug log. For example:
Figure 5: Debug Log Line Example
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![Debugging Apex Understanding the Debug Log
Log lines are made up of a set of fields, delimited by a pipe (|). The format is:
• timestamp: consists of the time when the event occurred and a value between parentheses. The time is in the user's
time zone and in the format HH:mm:ss.SSS. The value represents the time elapsed in nanoseconds since the start
of the request. The elapsed time value is excluded from logs reviewed in the Developer Console.
• event identifier: consists of the specific event that triggered the debug log being written to, such as SAVEPOINT_RESET
or VALIDATION_RULE, and any additional information logged with that event, such as the method name or the line
and character number where the code was executed.
Additional Log Data
In addition, the log contains the following information:
• Cumulative resource usage—Logged at the end of many code units, such as triggers, executeAnonymous, batch
Apex message processing, @future methods, Apex test methods, Apex web service methods, and Apex lead convert.
• Cumulative profiling information—Logged once at the end of the transaction. Contains information about the most
expensive queries (that used the most resources), DML invocations, and so on.
The following is an example debug log:
22.0
APEX_CODE,DEBUG;APEX_PROFILING,INFO;CALLOUT,INFO;DB,INFO;SYSTEM,DEBUG;VALIDATION,INFO;VISUALFORCE,INFO;
WORKFLOW,INFO
11:47:46.030 (30064000)|EXECUTION_STARTED
11:47:46.030 (30159000)|CODE_UNIT_STARTED|[EXTERNAL]|TRIGGERS
11:47:46.030 (30271000)|CODE_UNIT_STARTED|[EXTERNAL]|01qD00000004JvP|myAccountTrigger on
Account trigger event BeforeUpdate for [001D000000IzMaE]
11:47:46.038 (38296000)|SYSTEM_METHOD_ENTRY|[2]|System.debug(ANY)
11:47:46.038 (38450000)|USER_DEBUG|[2]|DEBUG|Hello World!
11:47:46.038 (38520000)|SYSTEM_METHOD_EXIT|[2]|System.debug(ANY)
11:47:46.546 (38587000)|CUMULATIVE_LIMIT_USAGE
11:47:46.546|LIMIT_USAGE_FOR_NS|(default)|
Number of SOQL queries: 0 out of 100
Number of query rows: 0 out of 50000
Number of SOSL queries: 0 out of 20
Number of DML statements: 0 out of 150
Number of DML rows: 0 out of 10000
Number of script statements: 1 out of 200000
Maximum heap size: 0 out of 6000000
Number of callouts: 0 out of 10
Number of Email Invocations: 0 out of 10
Number of fields describes: 0 out of 100
Number of record type describes: 0 out of 100
Number of child relationships describes: 0 out of 100
Number of picklist describes: 0 out of 100
Number of future calls: 0 out of 10
11:47:46.546|CUMULATIVE_LIMIT_USAGE_END
11:47:46.038 (38715000)|CODE_UNIT_FINISHED|myAccountTrigger on Account trigger event
BeforeUpdate for [001D000000IzMaE]
11:47:47.154 (1154831000)|CODE_UNIT_FINISHED|TRIGGERS
11:47:47.154 (1154881000)|EXECUTION_FINISHED
Setting Debug Log Filters for Apex Classes and Triggers
Debug log filtering provides a mechanism for fine-tuning the log verbosity at the trigger and class level. This is especially
helpful when debugging Apex logic. For example, to evaluate the output of a complex process, you can raise the log verbosity
for a given class while turning off logging for other classes or triggers within a single request.
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![Debugging Apex Working with Logs in the Developer Console
• INFO
• DEBUG
• FINE
• FINER
• FINEST
Important: Before running a deployment, verify that the Apex Code log level is not set to FINEST. If the Apex
Code log level is set to FINEST, the deployment might take longer than expected. If the Developer Console is open,
the log levels in the Developer Console affect all logs, including logs created during a deployment.
Debug Event Types
The following is an example of what is written to the debug log. The event is USER_DEBUG. The format is timestamp |
event identifier:
• timestamp: consists of the time when the event occurred and a value between parentheses. The time is in the user's time
zone and in the format HH:mm:ss.SSS. The value represents the time elapsed in nanoseconds since the start of the request.
The elapsed time value is excluded from logs reviewed in the Developer Console.
• event identifier: consists of the specific event that triggered the debug log being written to, such as SAVEPOINT_RESET or
VALIDATION_RULE, and any additional information logged with that event, such as the method name or the line and
character number where the code was executed.
The following is an example of a debug log line.
Figure 7: Debug Log Line Example
In this example, the event identifier is made up of the following:
• Event name:
USER_DEBUG
• Line number of the event in the code:
[2]
• Logging level the System.Debug method was set to:
DEBUG
• User-supplied string for the System.Debug method:
Hello world!
The following example of a log line is triggered by this code snippet.
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![Debugging Apex Working with Logs in the Developer Console
Figure 8: Debug Log Line Code Snippet
The following log line is recorded when the test reaches line 5 in the code:
15:51:01.071 (55856000)|DML_BEGIN|[5]|Op:Insert|Type:Invoice_Statement__c|Rows:1
In this example, the event identifier is made up of the following:
• Event name:
DML_BEGIN
• Line number of the event in the code:
[5]
• DML operation type—Insert:
Op:Insert
• Object name:
Type:Invoice_Statement__c
• Number of rows passed into the DML operation:
Rows:1
The following table lists the event types that are logged, what fields or other information get logged with each event, as well
as what combination of log level and category cause an event to be logged.
Event Name Fields or Information Logged With Event Category Logged Level Logged
BULK_HEAP_ALLOCATE Number of bytes allocated Apex Code FINEST
CALLOUT_REQUEST Line number, request headers Callout INFO and above
CALLOUT_RESPONSE Line number, response body Callout INFO and above
CODE_UNIT_FINISHED None Apex Code ERROR and above
CODE_UNIT_STARTED Line number, code unit name, such as Apex Code ERROR and above
MyTrigger on Account trigger
event BeforeInsert for [new]
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![Exposing Apex Methods as SOAP Web Services Considerations for Using the WebService Keyword
• Methods defined with the webService keyword are inherently global. These methods can be used by any Apex code that
has access to the class. You can consider the webService keyword as a type of access modifier that enables more access
than global.
• You must define any method that uses the webService keyword as static.
• You cannot deprecate webService methods or variables in managed package code.
• Because there are no SOAP analogs for certain Apex elements, methods defined with the webService keyword cannot
take the following elements as parameters. While these elements can be used within the method, they also cannot be
marked as return values.
◊ Maps
◊ Sets
◊ Pattern objects
◊ Matcher objects
◊ Exception objects
• You must use the webService keyword with any member variables that you want to expose as part of a Web service. You
should not mark these member variables as static.
• Salesforce denies access to Web service and executeanonymous requests from an AppExchange package that has
Restricted access.
• Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String
value that is too long for the field.
The following example shows a class with Web service member variables as well as a Web service method:
global class SpecialAccounts {
global class AccountInfo {
webService String AcctName;
webService Integer AcctNumber;
}
webService static Account createAccount(AccountInfo info) {
Account acct = new Account();
acct.Name = info.AcctName;
acct.AccountNumber = String.valueOf(info.AcctNumber);
insert acct;
return acct;
}
webService static Id [] createAccounts(Account parent,
Account child, Account grandChild) {
insert parent;
child.parentId = parent.Id;
insert child;
grandChild.parentId = child.Id;
insert grandChild;
Id [] results = new Id[3];
results[0] = parent.Id;
results[1] = child.Id;
results[2] = grandChild.Id;
return results;
}
testMethod static void testAccountCreate() {
AccountInfo info = new AccountInfo();
info.AcctName = 'Manoj Cheenath';
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![Exposing Apex Classes as REST Web Services Apex REST Code Samples
Apex REST Code Samples
These code samples show you how to expose Apex classes and methods through the REST architecture and how to call those
resources from a client.
• Apex REST Basic Code Sample: Provides an example of an Apex REST class with three methods that you can call to
delete a record, get a record, and update a record.
• Apex REST Code Sample Using RestRequest: Provides an example of an Apex REST class that adds an attachment to
a record by using the RestRequest object
Apex REST Basic Code Sample
This sample shows you how to implement a simple REST API in Apex that handles three different HTTP request methods.
For more information about authenticating with cURL, see the Quick Start section of the REST API Developer's Guide.
1. Create an Apex class in your instance, by clicking Your Name > Setup > Develop > Apex Classes > New and add this
code to your new class:
@RestResource(urlMapping='/Account/*')
global with sharing class MyRestResource {
@HttpDelete
global static void doDelete() {
RestRequest req = RestContext.request;
RestResponse res = RestContext.response;
String accountId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1);
Account account = [SELECT Id FROM Account WHERE Id = :accountId];
delete account;
}
@HttpGet
global static Account doGet() {
RestRequest req = RestContext.request;
RestResponse res = RestContext.response;
String accountId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1);
Account result = [SELECT Id, Name, Phone, Website FROM Account WHERE Id =
:accountId];
return result;
}
@HttpPost
global static String doPost(String name,
String phone, String website) {
Account account = new Account();
account.Name = name;
account.phone = phone;
account.website = website;
insert account;
return account.Id;
}
}
2. To call the doGet method from a client, open a command-line window and execute the following cURL command to
retrieve an account by ID:
curl -H "Authorization: Bearer sessionId"
"https://instance.salesforce.com/services/apexrest/Account/accountId"
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![Invoking Callouts Using Apex Supported WSDL Features
• blob
• decimal
• enum
Apex does not support any other WSDL constructs, types, or services, including:
• RPC/encoded services
• WSDL files with mulitple portTypes, multiple services, or multiple bindings
• WSDL files that import external schemas. For example, the following WSDL fragment imports an external schema, which
is not supported:
<wsdl:types>
<xsd:schema
elementFormDefault="qualified"
targetNamespace="http://s3.amazonaws.com/doc/2006-03-01/">
<xsd:include schemaLocation="AmazonS3.xsd"/>
</xsd:schema>
</wsdl:types>
However, an import within the same schema is supported. In the following example, the external WSDL is pasted into
the WSDL you are converting:
<wsdl:types>
<xsd:schema
xmlns:tns="http://s3.amazonaws.com/doc/2006-03-01/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
targetNamespace="http://s3.amazonaws.com/doc/2006-03-01/">
<xsd:element name="CreateBucket">
<xsd:complexType>
<xsd:sequence>
[...]
</xsd:schema>
</wsdl:types>
• Any schema types not documented in the previous table
• WSDLs that exceed the size limit, including the Salesforce WSDLs
• WSDLs that don’t use the document literal wrapped style. The following WSDL snippet doesn’t use document literal
wrapped style and results in an “Unable to find complexType” error when imported.
<wsdl:types>
<xsd:schema targetNamespace="http://test.org/AccountPollInterface/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:element name="SFDCPollAccountsResponse" type="tns:SFDCPollResponse"/>
<xsd:simpleType name="SFDCPollResponse">
<xsd:restriction base="xsd:string" />
</xsd:simpleType>
</xsd:schema>
</wsdl:types>
This modified version wraps the simpleType element as a complexType that contains a sequence of elements. This
follows the document literal style and is supported.
<wsdl:types>
<xsd:schema targetNamespace="http://test.org/AccountPollInterface/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
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![Invoking Callouts Using Apex Understanding the Generated Code
<wsdl:output message="tns:EchoStringSoapOut" />
</wsdl:operation>
</wsdl:portType>
<!--The code below defines how the types map to SOAP. -->
<wsdl:binding name="DocSampleBinding" type="tns:DocSamplePortType">
<wsdl:operation name="EchoString">
<soap:operation soapAction="urn:dotnet.callouttest.soap.sforce.com/EchoString"
style="document" />
<wsdl:input>
<soap:body use="literal" />
</wsdl:input>
<wsdl:output>
<soap:body use="literal" />
</wsdl:output>
</wsdl:operation>
</wsdl:binding>
<!-- Finally, the code below defines the endpoint, which maps to the endpoint in the class
-->
<wsdl:service name="DocSample">
<wsdl:port name="DocSamplePort" binding="tns:DocSampleBinding">
<soap:address location="http://YourServer/YourService" />
</wsdl:port>
</wsdl:service>
</wsdl:definitions>
From this WSDL document, the following Apex class is auto-generated. The class name docSample is the name you specify
when importing the WSDL.
//Generated by wsdl2apex
public class docSample {
public class EchoStringResponse_element {
public String EchoStringResult;
private String[] EchoStringResult_type_info = new String[]{
'EchoStringResult',
'http://www.w3.org/2001/XMLSchema',
'string','0','1','false'};
private String[] apex_schema_type_info = new String[]{
'http://doc.sample.com/docSample',
'true'};
private String[] field_order_type_info = new String[]{
'EchoStringResult'};
}
public class DocSamplePort {
public String endpoint_x = 'http://YourServer/YourService';
private String[] ns_map_type_info = new String[]{
'http://doc.sample.com/docSample',
'docSample'};
public String EchoString(String input) {
docSample.EchoString_element request_x =
new docSample.EchoString_element();
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![Invoking Callouts Using Apex Testing Web Service Callouts
docSample.EchoStringResponse_element response_x;
request_x.input = input;
Map<String, docSample.EchoStringResponse_element> response_map_x =
new Map<String, docSample.EchoStringResponse_element>();
response_map_x.put('response_x', response_x);
WebServiceCallout.invoke(
this,
request_x,
response_map_x,
new String[]{endpoint_x,
'urn:dotnet.callouttest.soap.sforce.com/EchoString',
'http://doc.sample.com/docSample',
'EchoString',
'http://doc.sample.com/docSample',
'EchoStringResponse',
'docSample.EchoStringResponse_element'}
);
response_x = response_map_x.get('response_x');
return response_x.EchoStringResult;
}
}
public class EchoString_element {
public String input;
private String[] input_type_info = new String[]{
'input',
'http://www.w3.org/2001/XMLSchema',
'string','0','1','false'};
private String[] apex_schema_type_info = new String[]{
'http://doc.sample.com/docSample',
'true'};
private String[] field_order_type_info = new String[]{'input'};
}
}
Note the following mappings from the original WSDL document:
• The WSDL target namespace maps to the Apex class name.
• Each complex type becomes a class. Each element in the type is a public field in the class.
• The WSDL port name maps to the stub class.
• Each operation in the WSDL maps to a public method.
The class generated above can be used to invoke external Web services. The following code shows how to call the echoString
method on the external server:
docSample.DocSamplePort stub = new docSample.DocSamplePort();
String input = 'This is the input string';
String output = stub.EchoString(input);
Testing Web Service Callouts
Generated code is saved as an Apex class containing the methods you can invoke for calling the Web service. To deploy or
package this Apex class and other accompanying code, 75% of the code must have test coverage, including the methods in the
generated class. By default, test methods don’t support Web service callouts and tests that perform Web service callouts are
skipped. To prevent tests from being skipped and to increase code coverage, Apex provides the built-in WebServiceMock
interface and the Test.setMock method that you can use to receive fake responses in a test method.
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![Reference Apex Data Manipulation Language (DML) Operations
Apex Data Manipulation Language (DML) Operations
Use data manipulation language (DML) operations to insert, update, delete, and restore data in a database.
You can execute DML operations using two different forms:
• Apex DML statements, such as:
insert SObject[]
• Apex DML database methods, such as:
Database.SaveResult[] result = Database.Insert(SObject[])
While most DML operations are available in either form, some exist only in one form or the other.
The different DML operation forms enable different types of exception processing:
• Use DML statements if you want any error that occurs during bulk DML processing to be thrown as an Apex exception
that immediately interrupts control flow (by using try. . .catch blocks). This behavior is similar to the way exceptions
are handled in most database procedural languages.
• Use DML database methods if you want to allow partial success of a bulk DML operation—if a record fails, the remainder
of the DML operation can still succeed. Your application can then inspect the rejected records and possibly retry the
operation. When using this form, you can write code that never throws DML exception errors. Instead, your code can use
the appropriate results array to judge success or failure. Note that DML database methods also include a syntax that supports
thrown exceptions, similar to DML statements.
The following Apex DML operations are available:
• convertLead1
• delete
• insert
• merge2
• undelete
• update
• upsert
System Context and Sharing Rules
Most DML operations execute in system context, ignoring the current user's permissions, field-level security, organization-wide
defaults, position in the role hierarchy, and sharing rules. However, when a DML operation is called in a class defined with
the with sharing keywords, the current user's sharing rules are taken into account. For more information, see Using the
with sharing or without sharing Keywords on page 134.
String Field Truncation and API Version
Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String
value that is too long for the field.
1
convertLead is only available as a database method.
2
merge is only available as an Apex DML statement.
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![Reference ConvertLead Operation
ConvertLead Operation
The convertLead DML operation converts a lead into an account and contact, as well as (optionally) an opportunity.
Note: convertLead is only available as a database method.
Database Method Syntax
• LeadConvertResult Database.convertLead(LeadConvert leadToConvert, Boolean opt_allOrNone)
• LeadConvertResult[] Database.convertLead(LeadConvert[] leadsToConvert, Boolean opt_allOrNone)
The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this
parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that
can be used to verify which records succeeded, which failed, and why.
Rules and Guidelines
When converting leads, consider the following rules and guidelines:
• Field mappings: The system automatically maps standard lead fields to standard account, contact, and opportunity fields.
For custom lead fields, your Salesforce administrator can specify how they map to custom account, contact, and opportunity
fields. For more information about field mappings, see the Salesforce online help.
• Merged fields: If data is merged into existing account and contact objects, only empty fields in the target object are
overwritten—existing data (including IDs) are not overwritten. The only exception is if you specify
setOverwriteLeadSource on the LeadConvert object to true, in which case the LeadSource field in the target contact
object is overwritten with the contents of the LeadSource field in the source LeadConvert object.
• Record types: If the organization uses record types, the default record type of the new owner is assigned to records created
during lead conversion. The default record type of the user converting the lead determines the lead source values available
during conversion. If the desired lead source values are not available, add the values to the default record type of the user
converting the lead. For more information about record types, see the Salesforce online help.
• Picklist values: The system assigns the default picklist values for the account, contact, and opportunity when mapping any
standard lead picklist fields that are blank. If your organization uses record types, blank values are replaced with the default
picklist values of the new record owner.
• Automatic feed subscriptions: When you convert a lead into a new account, contact, and opportunity, the lead owner is
unsubscribed from the lead account. The lead owner, the owner of the generated records, and users that were subscribed
to the lead aren’t automatically subscribed to the generated records, unless they have automatic subscriptions enabled in
their Chatter feed settings. They must have automatic subscriptions enabled to see changes to the account, contact, and
opportunity records in their news feed. Users must enable automatic subscriptions by selecting the Automatically
follow records that I create checkbox in User Name > Setup > My Chatter Settings > My Feeds to subscribe
to records they create. A user can subscribe to a record so that changes to the record are displayed in the news feed on the
user's home page. This is a useful way to stay up-to-date with changes to records in Salesforce.
Basic Steps for Converting Leads
Converting leads involves the following basic steps:
1. Your application determines the IDs of any lead(s) to be converted.
2. Optionally, your application determines the IDs of any account(s) into which to merge the lead. Your application can use
SOQL to search for accounts that match the lead name, as in the following example:
SELECT Id, Name FROM Account WHERE Name='CompanyNameOfLeadBeingMerged'
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![Reference ConvertLead Operation
Name Arguments Return Type Description
Important: If you are converting a lead into a person
account, do not specify setContactId or an error
will result. Specify only setAccountId of the person
account.
If setContactID is specified, then the application creates a
new contact that is implicitly associated with the account. The
contact name and other existing data are not overwritten (unless
setOverwriteLeadSource is set to true, in which case only
the LeadSource field is overwritten).
setConvertedStatus String Status Void Sets the lead status value for a converted lead. This field is
required.
setDoNotCreateOpportunity Boolean Void Specifies whether to create an opportunity during lead
CreateOpportunity conversion. The default value is false: opportunities are
created by default. Set this flag to true only if you do not want
to create an opportunity from the lead.
setLeadId ID ID Void Sets the ID of the lead to convert. This field is required.
setOpportunityName String OppName Void Sets the name of the opportunity to create. If no name is
specified, this value defaults to the company name of the lead.
The maximum length of this field is 80 characters. If
setDoNotCreateOpportunity is true, no Opportunity is
created and this field must be left blank; otherwise, an error is
returned.
setOverwriteLeadSource Boolean Void Specifies whether to overwrite the LeadSource field on the
Oewieedore
vrrtLaSuc target contact object with the contents of the LeadSource
field in the source lead object. The default value is false, to not
overwrite the field. If you specify this as true, you must also
specify setContactId for the target contact.
setOwnerId ID ID Void Specifies the ID of the person to own any newly created account,
contact, and opportunity. If the application does not specify
this value, the owner of the new object will be the owner of the
lead. This method is not applicable when merging with existing
objects—if setOwnerId is specified, the ownerId field is not
overwritten in an existing account or contact.
setSendNotificationEmail Boolean Void Specifies whether to send a notification email to the owner
SendEmail specified by setOwnerId. The default value is false, that is, to
not send email.
LeadConvertResult Object
An array of LeadConvertResult objects is returned with the convertLead database method. Each element in the
LeadConvertResult array corresponds to the SObject array passed as the SObject[] parameter in the convertLead database
method, that is, the first element in the LeadConvertResult array matches the first element passed in the SObject array, the
second element corresponds with the second element, and so on. If only one SObject is passed in, the LeadConvertResults
array contains a single element.
A LeadConvertResult object has the following methods:
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![Reference Delete Operation
Name Type Description
getAccountId ID The ID of the new account (if a new account was specified)
or the ID of the account specified when convertLead was
invoked
getContactId ID The ID of the new contact (if a new contact was specified) or
the ID of the contact specified when convertLead was
invoked
getErrors Database.Error If an error occurred, an array of one or more database error
[]Database.Error [] objects providing the error code and description. For more
information, see Database Error Object Methods on page 396.
getLeadId ID The ID of the converted lead
getOpportunityId ID The ID of the new opportunity, if one was created when
convertLead was invoked
isSuccess Boolean A Boolean value that is set to true if the DML operation was
successful for this object, false otherwise
Database Method Example
Lead myLead = new Lead(LastName = 'Fry', Company='Fry And Sons');
insert myLead;
Database.LeadConvert lc = new database.LeadConvert();
lc.setLeadId(myLead.id);
LeadStatus convertStatus = [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true
LIMIT 1];
lc.setConvertedStatus(convertStatus.MasterLabel);
Database.LeadConvertResult lcr = Database.convertLead(lc);
System.assert(lcr.isSuccess());
Delete Operation
The delete DML operation deletes one or more existing sObject records, such as individual accounts or contacts, from your
organization’s data. delete is analogous to the delete() statement in the SOAP API.
DML Statement Syntax
delete sObject | Record.ID
Database Method Syntax
• DeleteResult Database.Delete((sObject recordToDelete | RecordID ID), Boolean opt_allOrNone)
• DeleteResult[] Database.Delete((sObject[] recordsToDelete | RecordIDs LIST<>IDs{}), Boolean opt_allOrNone)
The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this
parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that
can be used to verify which records succeeded, which failed, and why.
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![Reference Delete Operation
Rules and Guidelines
When deleting sObject records, consider the following rules and guidelines:
• To ensure referential integrity, delete supports cascading deletions. If you delete a parent object, you delete its children
automatically, as long as each child record can be deleted.
For example, if you delete a case record, Apex automatically deletes any CaseComment, CaseHistory, and CaseSolution
records associated with that case. However, if a particular child record is not deletable or is currently being used, then the
delete operation on the parent case record fails.
• Certain sObjects can't be deleted. To delete an sObject record, the deletable property of the sObject must be set to
true. Also, see sObjects That Do Not Support DML Operations on page 286.
• You can pass a maximum of 10,000 sObject records to a single delete method.
DeleteResult Object
An array of Database.DeleteResult objects is returned with the delete database method. Each element in the DeleteResult
array corresponds to the sObject array passed as the sObject[] parameter in the delete database method, that is, the first
element in the DeleteResult array matches the first element passed in the sObject array, the second element corresponds with
the second element, and so on. If only one sObject is passed in, the DeleteResults array contains a single element.
A Database.DeleteResult object has the following methods:
Name Type Description
getErrors Database.Error If an error occurred, an array of one or more database error objects
[] providing the error code and description. For more information,
see Database Error Object Methods on page 396.
getId ID The ID of the sObject you were trying to delete. If this field
contains a value, the object was successfully deleted. If this field
is empty, the operation was not successful for that object.
isSuccess Boolean A Boolean value that is set to true if the DML operation was
successful for this object, false otherwise
DML Statement Example
The following example deletes all accounts that are named 'DotCom':
Account[] doomedAccts = [SELECT Id, Name FROM Account
WHERE Name = 'DotCom'];
try {
delete doomedAccts;
} catch (DmlException e) {
// Process exception here
}
Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289.
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![Reference Insert Operation
Database Method Example
The following example deletes an account named 'DotCom':
Account[] doomedAccts = [SELECT Id, Name FROM Account WHERE Name = 'DotCom'];
Database.DeleteResult[] DR_Dels = Database.delete(doomedAccts);
Insert Operation
The insert DML operation adds one or more sObjects, such as individual accounts or contacts, to your organization’s data.
insert is analogous to the INSERT statement in SQL.
DML Statement Syntax
insert sObject
insert sObject[]
Database Method Syntax
• SaveResult Database.insert(sObject recordToInsert, Boolean opt_allOrNone | database.DMLOptions
opt_DMLOptions)
• SaveResult[] Database.insert(sObject[] recordsToInsert, Boolean opt_allOrNone | database.DMLOptions
opt_DMLOptions)
The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this
parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that
can be used to verify which records succeeded, which failed, and why.
For example:
Database.SaveResult[] MySaveResult = Database.Insert(MyAccounts, false);
The optional opt_DMLOptions parameter specifies additional data for the transaction, such as assignment rule information
or rollback behavior when errors occur during record insertions.
For example:
//AssignmentRuleHeader
//UseDefaultRule
Database.DMLOptions dmo = new database.DMLOptions();
dmo.AssignmentRuleHeader.UseDefaultRule= true;
Lead l = new Lead(Company='ABC', LastName='Smith');
l.setOptions(dmo);
insert l;
For more information, see Database DMLOptions Properties on page 393.
Rules and Guidelines
When inserting sObject records, consider the following rules and guidelines:
• Certain sObjects cannot be created. To create an sObject record, the createable property of the sObject must be set to
true.
• You must supply a non-null value for all required fields.
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![Reference Insert Operation
• You can pass a maximum of 10,000 sObject records to a single insert method.
• The insert statement automatically sets the ID value of all new sObject records. Inserting a record that already has an
ID—and therefore already exists in your organization's data—produces an error. See Lists for more information.
• For some sObjects that have fields with unique constraints, inserting duplicate sObject records results in an error. For
example, inserting CollaborationGroup sObjects with the same name results in an error because CollaborationGroup
records must have unique names.
• The insert statement can only set the foreign key ID of related sObject records. Fields on related records cannot be
updated with insert. For example, if inserting a new contact, you can specify the contact's related account record by
setting the value of the AccountId field. However, you cannot change the account's name without updating the account
itself with a separate DML call.
• The insert statement is not supported with some sObjects. See sObjects That Do Not Support DML Operations on
page 286.
• This operation checks each batch of records for duplicate ID values. If there are duplicates, the first five are processed. For
the sixth and all additional duplicate IDs, the SaveResult for those entries is marked with an error similar to the following:
Maximum number of duplicate updates in one batch (5 allowed). Attempt to update
Id more than once in this API call: number_of_attempts.
SaveResult Object
An array of SaveResult objects is returned with the insert and update database methods. Each element in the SaveResult
array corresponds to the sObject array passed as the sObject[] parameter in the database method, that is, the first element
in the SaveResult array matches the first element passed in the sObject array, the second element corresponds with the second
element, and so on. If only one sObject is passed in, the SaveResults array contains a single element.
A SaveResult object has the following methods:
Name Type Description
getErrors Database.Error [] If an error occurred, an array of one or
more database error objects providing the
error code and description. For more
information, see Database Error Object
Methods on page 396.
getId ID The ID of the sObject you were trying
to insert or update. If this field contains
a value, the object was successfully
inserted or updated. If this field is empty,
the operation was not successful for that
object.
isSuccess Boolean A Boolean that is set to true if the DML
operation was successful for this object,
false otherwise.
DML Statement Example
The following example inserts an account named 'Acme':
Account newAcct = new Account(name = 'Acme');
try {
insert newAcct;
} catch (DmlException e) {
// Process exception here
}
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![Reference Insert Operation
Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289.
Database Method Example
The following example inserts an account named 'Acme':
Account a = new Account(name = 'Acme');
Database.SaveResult[] lsr = Database.insert(new Account[]{a, new Account(Name = 'Acme')},
false);
// Iterate through the Save Results
for(Database.SaveResult sr:lsr){
if(!sr.isSuccess())
Database.Error err = sr.getErrors()[0];
}
Creating Parent and Child Records in a Single Statement Using Foreign Keys
You can use external ID fields as foreign keys to create parent and child records of different sObject types in a single step
instead of creating the parent record first, querying its ID, and then creating the child record. To do this:
• Create the child sObject and populate its required fields, and optionally other fields.
• Create the parent reference sObject used only for setting the parent foreign key reference on the child sObject. This sObject
has only the external ID field defined and no other fields set.
• Set the foreign key field of the child sObject to the parent reference sObject you just created.
• Create another parent sObject to be passed to the insert statement. This sObject must have the required fields (and
optionally other fields) set in addition to the external ID field.
• Call insert by passing it an array of sObjects to create. The parent sObject must precede the child sObject in the array,
that is, the array index of the parent must be lower than the child’s index.
The parent and child records are records related through a predefined relationship, such as a master-detail or lookup relationship.
You can create related records that are up to 10 levels deep. Also, the related records created in a single call must have different
sObject types. For more information, see Creating Records for Different Object Types in the SOAP API Developer's Guide.
The following example shows how to create an opportunity with a parent account using the same insert statement. The
example creates an Opportunity sObject and populates some of its fields, then creates two Account objects. The first account
is only for the foreign key relationship, and the second is for the account creation and has the account fields set. Both accounts
have the external ID field, MyExtID__c, set. Next, the sample calls Database.insert by passing it an array of sObjects.
The first element in the array is the parent sObject and the second is the opportunity sObject. The Database.insert
statement creates the opportunity with its parent account in a single step. Finally, the sample checks the results and writes the
IDs of the created records to the debug log, or the first error if record creation fails. This sample requires an external ID text
field on Account called MyExtID.
public class ParentChildSample {
public static void InsertParentChild() {
Date dt = Date.today();
dt = dt.addDays(7);
Opportunity newOpportunity = new Opportunity(
Name='OpportunityWithAccountInsert',
StageName='Prospecting',
CloseDate=dt);
// Create the parent reference.
// Used only for foreign key reference
// and doesn't contain any other fields.
Account accountReference = new Account(
MyExtID__c='SAP111111');
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![Reference Merge Statement
newOpportunity.Account = accountReference;
// Create the Account object to insert.
// Same as above but has Name field.
// Used for the insert.
Account parentAccount = new Account(
Name='Hallie',
MyExtID__c='SAP111111');
// Create the account and the opportunity.
Database.SaveResult[] results = Database.insert(new SObject[] {
parentAccount, newOpportunity });
// Check results.
for (Integer i = 0; i < results.size(); i++) {
if (results[i].isSuccess()) {
System.debug('Successfully created ID: '
+ results[i].getId());
} else {
System.debug('Error: could not create sobject '
+ 'for array element ' + i + '.');
System.debug(' The error reported was: '
+ results[i].getErrors()[0].getMessage() + 'n');
}
}
}
}
Merge Statement
The merge statement merges up to three records of the same sObject type into one of the records, deleting the others, and
re-parenting any related records.
Note: This DML operation does not have a matching database system method.
Syntax
merge sObject sObject
merge sObject sObject[]
merge sObject ID
merge sObject ID[]
The first parameter represents the master record into which the other records are to be merged. The second parameter represents
the one or two other records that should be merged and then deleted. You can pass these other records into the merge statement
as a single sObject record or ID, or as a list of two sObject records or IDs.
Rules and Guidelines
When merging sObject records, consider the following rules and guidelines:
• Only leads, contacts, and accounts can be merged. See sObjects That Do Not Support DML Operations on page 286.
• You can pass a master record and up to two additional sObject records to a single merge method.
For more information on merging leads, contacts and accounts, see the Salesforce online help.
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![Reference Undelete Operation
Example
The following example merges two accounts named 'Acme Inc.' and 'Acme' into a single record:
List<Account> ls = new List<Account>{new Account(name='Acme Inc.'),new Account(name='Acme')};
insert ls;
Account masterAcct = [SELECT Id, Name FROM Account WHERE Name = 'Acme Inc.' LIMIT 1];
Account mergeAcct = [SELECT Id, Name FROM Account WHERE Name = 'Acme' LIMIT 1];
try {
merge masterAcct mergeAcct;
} catch (DmlException e) {
// Process exception here
}
Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289.
Undelete Operation
The undelete DML operation restores one or more existing sObject records, such as individual accounts or contacts, from
your organization’s Recycle Bin. undelete is analogous to the UNDELETE statement in SQL.
DML Statement Syntax
undelete sObject | Record.ID
undelete sObject[] | LIST<>ID[]
Database Method Syntax
• UndeleteResult Database.Undelete((sObject recordToUndelete | RecordID ID), Boolean opt_allOrNone)
• UndeleteResult[] Database.Undelete((sObject[] recordsToUndelete | RecordIDs LIST<>IDs{}), Boolean
opt_allOrNone)
The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this
parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that
can be used to verify which records succeeded, which failed, and why.
Rules and Guidelines
When undeleting sObject records, consider the following rules and guidelines:
• To ensure referential integrity, undelete restores the record associations for the following types of relationships:
◊ Parent accounts (as specified in the Parent Account field on an account)
◊ Parent cases (as specified in the Parent Case field on a case)
◊ Master solutions for translated solutions (as specified in the Master Solution field on a solution)
◊ Managers of contacts (as specified in the Reports To field on a contact)
◊ Products related to assets (as specified in the Product field on an asset)
◊ Opportunities related to quotes (as specified in the Opportunity field on a quote)
◊ All custom lookup relationships
◊ Relationship group members on accounts and relationship groups, with some exceptions
◊ Tags
◊ An article's categories, publication state, and assignments
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![Reference Undelete Operation
Note: Salesforce only restores lookup relationships that have not been replaced. For example, if an asset is related
to a different product prior to the original product record being undeleted, that asset-product relationship is not
restored.
• Certain sObjects can't be undeleted. To verify if an sObject record can be undeleted, check that the undeletable property
of the sObject is set to true.
• You can pass a maximum of 10,000 sObject records to a single undelete method.
• You can undelete records that were deleted as the result of a merge, but the child objects will have been re-parented, which
cannot be undone.
• Use the ALL ROWS parameters with a SOQL query to identify deleted records, including records deleted as a result of a
merge. See Querying All Records with a SOQL Statement on page 83.
• Undelete is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286.
UndeleteResult Object
An array of Database.UndeleteResult objects is returned with the undelete database method. Each element in the
UndeleteResult array corresponds to the sObject array passed as the sObject[] parameter in the undelete database method,
that is, the first element in the UndeleteResult array matches the first element passed in the sObject array, the second element
corresponds with the second element, and so on. If only one sObject is passed in, the UndeleteResults array contains a single
element.
An undeleteResult object has the following methods:
Name Type Description
getErrors Database.Error [] If an error occurred, an array of one or
more database error objects providing the
error code and description. For more
information, see Database Error Object
Methods on page 396.
getId ID The ID of the sObject you were trying
to undelete. If this field contains a value,
the object was successfully undeleted. If
this field is empty, the operation was not
successful for that object.
isSuccess Boolean A Boolean value that is set to true if the
DML operation was successful for this
object, false otherwise
DML Statement Example
The following example undeletes an account named 'Trump'. The ALL ROWS keyword queries all rows for both top level and
aggregate relationships, including deleted records and archived activities.
Account a = new Account(Name='AC1');
insert(a);
insert(new Contact(LastName='Carter',AccountId=a.Id));
Account[] savedAccts = [SELECT Id, Name FROM Account WHERE Name = 'Trump' ALL ROWS];
try {
undelete savedAccts;
} catch (DmlException e) {
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![Reference Update Operation
// Process exception here
}
Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289.
Database Method Example
The following example undeletes an account named 'Trump'. The ALL ROWS keyword queries all rows for both top level and
aggregate relationships, including deleted records and archived activities.
public class DmlTest2 {
public void undeleteExample() {
Account[] SavedAccts = [SELECT Id, Name FROM Account WHERE Name = 'Trump' ALL ROWS];
Database.UndeleteResult[] UDR_Dels = Database.undelete(SavedAccts);
for(integer i =0; i< 10; i++)
if(UDR_Dels[i].getErrors().size()>0){
// Process any errors here
}
}
}
Update Operation
The update DML operation modifies one or more existing sObject records, such as individual accounts or contactsinvoice
statements, in your organization’s data. update is analogous to the UPDATE statement in SQL.
DML Statement Syntax
update sObject
update sObject[]
Database Method Syntax
• UpdateResult Update(sObject recordToUpdate, Boolean opt_allOrNone | database.DMLOptions opt_DMLOptions)
• UpdateResult[] Update(sObject[] recordsToUpdate[], Boolean opt_allOrNone | database.DMLOptions
opt_DMLOptions)
The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this
parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that
can be used to verify which records succeeded, which failed, and why.
The optional opt_DMLOptions parameter specifies additional data for the transaction, such as assignment rule information
or rollback behavior when errors occur during record insertions.
For more information, see Database DMLOptions Properties on page 393.
Rules and Guidelines
When updating sObject records, consider the following rules and guidelines:
• Certain sObjects cannot be updated. To update an sObject record, the updateable property of the sObject must be set
to true.
• When updating required fields you must supply a non-null value.
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![Reference Update Operation
• Unlike the SOAP API, Apex allows you to change field values to null without updating the fieldsToNull array on
the sObject record. The API requires an update to this array due to the inconsistent handling of null values by many
SOAP providers. Because Apex runs solely on the Force.com platform, this workaround is unnecessary.
• The ID of an updated sObject record cannot be modified, but related record IDs can.
• This operation checks each batch of records for duplicate ID values. If there are duplicates, the first five are processed. For
the sixth and all additional duplicate IDs, the SaveResult for those entries is marked with an error similar to the following:
Maximum number of duplicate updates in one batch (5 allowed). Attempt to update
Id more than once in this API call: number_of_attempts.
• The update statement automatically modifies the values of certain fields such as LastModifiedDate,
LastModifiedById, and SystemModstamp. You cannot explicitly specify these values in your Apex.
• You can pass a maximum of 10,000 sObject records to a single update method.
• A single update statement can only modify one type of sObject at a time. For example, if updating an account field
through an existing contact that has also been modified, two update statements are required:
// Use a SOQL query to access data for a contact
Contact c = [SELECT Account.Name FROM Contact
WHERE LastName = 'Carter' LIMIT 1];
// Now we can change fields for both the contact and its
// associated account
c.Account.Name = 'salesforce.com';
c.LastName = 'Roth';
// To update the database, the two types of records must be
// updated separately
update c; // This only changes the contact's last name
update c.Account; // This updates the account name
• Update is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286.
SaveResult Object
An array of SaveResult objects is returned with the insert and update database methods. Each element in the SaveResult
array corresponds to the sObject array passed as the sObject[] parameter in the database method, that is, the first element
in the SaveResult array matches the first element passed in the sObject array, the second element corresponds with the second
element, and so on. If only one sObject is passed in, the SaveResults array contains a single element.
A SaveResult object has the following methods:
Name Type Description
getErrors Database.Error [] If an error occurred, an array of one or
more database error objects providing the
error code and description. For more
information, see Database Error Object
Methods on page 396.
getId ID The ID of the sObject you were trying
to insert or update. If this field contains
a value, the object was successfully
inserted or updated. If this field is empty,
the operation was not successful for that
object.
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![Reference Upsert Operation
Name Type Description
isSuccess Boolean A Boolean that is set to true if the DML
operation was successful for this object,
false otherwise.
DML Statement Example
The following example updates the BillingCity field on a single account named 'Acme':
Account a = new Account(Name='Acme2');
insert(a);
Account myAcct = [SELECT Id, Name, BillingCity FROM Account WHERE Id = :a.Id];
myAcct.BillingCity = 'San Francisco';
try {
update myAcct;
} catch (DmlException e) {
// Process exception here
}
Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289.
Database Method Example
The following example updates the BillingCity field on a single account named 'Acme':
Account a = new Account(Name='Acme2');
insert(a);
Account myAcct = [SELECT Id, Name, BillingCity FROM Account WHERE Id = :a.Id];
myAcct.BillingCity = 'San Francisco';
Database.SaveResult SR = database.update(myAcct);
for(Database.Error err: SR.getErrors())
{
// process any errors here
}
Upsert Operation
The upsert DML operation creates new sObject records and updates existing sObject records within a single statement,
using an optional custom field to determine the presence of existing objects.
DML Statement Syntax
upsert sObject opt_external_id
upsert sObject[] opt_external_id
opt_external_id is an optional variable that specifies the custom field that should be used to match records that already
exist in your organization's data. This custom field must be created with the External Id attribute selected. Additionally,
if the field does not have the Unique attribute selected, the context user must have the “View All” object-level permission for
the target object or the “View All Data” permission so that upsert does not accidentally insert a duplicate record.
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![Reference Upsert Operation
If opt_external_id is not specified, the sObject record's ID field is used by default.
Note: Custom field matching is case-insensitive only if the custom field has the Unique and Treat "ABC" and "abc"
as duplicate values (case insensitive) attributes selected as part of the field definition. If this is the case, “ABC123”
is matched with “abc123.” For more information, see “Creating Custom Fields” in the online help.
Database Method Syntax
• UpsertResult Database.Upsert(sObject recordToUpsert, Schema.SObjectField External_ID_Field, Boolean
opt_allOrNone)
• UpsertResult[] Database.Upsert(sObject[] recordsToUpsert, Schema.SObjectField External_ID_Field, Boolean
opt_allOrNone)
The optional External_ID_Field parameter is an optional variable that specifies the custom field that should be used to
match records that already exist in your organization's data. This custom field must be created with the External Id attribute
selected. Additionally, if the field does not have the Unique attribute selected, the context user must have the “View All”
object-level permission for the target object or the “View All Data” permission so that upsert does not accidentally insert a
duplicate record.
The External_ID_Field is of type Schema.SObjectField, that is, a field token. Find the token for the field by using the
fields special method. For example, Schema.SObjectField f = Account.Fields.MyExternalId.
If External_ID_Field is not specified, the sObject record's ID field is used by default.
Note: Custom field matching is case-insensitive only if the custom field has the Unique and Treat "ABC" and "abc"
as duplicate values (case insensitive) attributes selected as part of the field definition. If this is the case, “ABC123”
is matched with “abc123.” For more information, see “Creating Custom Fields” in the online help.
The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this
parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that
can be used to verify which records succeeded, which failed, and why.
How Upsert Chooses to Insert or Update
Upsert uses the sObject record's primary key (or the external ID, if specified) to determine whether it should create a new
object record or update an existing one:
• If the key is not matched, then a new object record is created.
• If the key is matched once, then the existing object record is updated.
• If the key is matched multiple times, then an error is generated and the object record is neither inserted or updated.
Rules and Guidelines
When upserting sObject records, consider the following rules and guidelines:
• Certain sObjects cannot be inserted or updated. To insert an sObject record, the createable property of the sObject
must be set to true. To update an sObject record, the updateable property of the sObject must be set to true.
• You must supply a non-null value for all required fields on any record that will be inserted.
• The ID of an sObject record cannot be modified, but related record IDs can. This action is interpreted as an update.
• The upsert statement automatically modifies the values of certain fields such as LastModifiedDate,
LastModifiedById, and SystemModstamp. You cannot explicitly specify these values in your Apex.
• Each upsert statement consists of two operations, one for inserting records and one for updating records. Each of these
operations is subject to the runtime limits for insert and update, respectively. For example, if you upsert more than
10,000 records and all of them are being updated, you receive an error. (See Understanding Execution Governors and
Limits on page 225)
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![Reference Upsert Operation
• The upsert statement can only set the ID of related sObject records. Fields on related records cannot be modified with
upsert. For example, if updating an existing contact, you can specify the contact's related account record by setting the
value of the AccountId field. However, you cannot change the account's name without updating the account itself with
a separate DML statement.
• Upsert is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286.
• You can use foreign keys to upsert sObject records if they have been set as reference fields. For more information, see Field
Types in the Object Reference for Salesforce and Force.com.
UpsertResult Object
An array of Database.UpsertResult objects is returned with the upsert database method. Each element in the UpsertResult
array corresponds to the sObject array passed as the sObject[] parameter in the upsert database method, that is, the first
element in the UpsertResult array matches the first element passed in the sObject array, the second element corresponds with
the second element, and so on. If only one sObject is passed in, the UpsertResults array contains a single element.
An UpsertResult object has the following methods:
Name Type Description
getErrors Database.Error [] If an error occurred, an array of one or
more database error objects providing the
error code and description. For more
information, see Database Error Object
Methods on page 396.
getId ID The ID of the sObject you were trying
to update or insert. If this field contains
a value, the object was successfully
updated or inserted. If this field is empty,
the operation was not successful for that
object.
isCreated Boolean A Boolean value that is set to true if the
record was created, false if the record was
updated.
isSuccess Boolean A Boolean value that is set to true if the
DML operation was successful for this
object, false otherwise.
DML Statement Examples
The following example updates the city name for all existing accounts located in the city formerly known as Bombay, and also
inserts a new account located in San Francisco:
Account[] acctsList = [SELECT Id, Name, BillingCity
FROM Account WHERE BillingCity = 'Bombay'];
for (Account a : acctsList) {
a.BillingCity = 'Mumbai';
}
Account newAcct = new Account(Name = 'Acme', BillingCity = 'San Francisco');
acctsList.add(newAcct);
try {
upsert acctsList;
} catch (DmlException e) {
// Process exception here
}
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![Reference Upsert Operation
Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289.
Use of upsert with an external ID can reduce the number of DML statements in your code, and help you to avoid hitting
governor limits (see Understanding Execution Governors and Limits). This next example uses upsert and an external ID
field Line_Item_Id__c on the Asset object to maintain a one-to-one relationship between an asset and an opportunity line
item.
Note: Before running this sample, create a custom text field on the Asset object named Line_Item_Id__c and
mark it as an external ID. For information on custom fields, see the Salesforce online help.
public void upsertExample() {
Opportunity opp = [SELECT Id, Name, AccountId,
(SELECT Id, PricebookEntry.Product2Id, PricebookEntry.Name
FROM OpportunityLineItems)
FROM Opportunity
WHERE HasOpportunityLineItem = true
LIMIT 1];
Asset[] assets = new Asset[]{};
// Create an asset for each line item on the opportunity
for (OpportunityLineItem lineItem:opp.OpportunityLineItems) {
//This code populates the line item Id, AccountId, and Product2Id for each asset
Asset asset = new Asset(Name = lineItem.PricebookEntry.Name,
Line_Item_ID__c = lineItem.Id,
AccountId = opp.AccountId,
Product2Id = lineItem.PricebookEntry.Product2Id);
assets.add(asset);
}
try {
upsert assets Line_Item_ID__c; // This line upserts the assets list with
// the Line_Item_Id__c field specified as the
// Asset field that should be used for matching
// the record that should be upserted.
} catch (DmlException e) {
System.debug(e.getMessage());
}
}
Database Method Example
The following is an example that uses the Database upsert method to upsert a collection of leads that are passed in. This
example allows for partial processing of records, that is, in case some records fail processing, the remaining records are still
inserted or updated. It iterates through the results and adds a new task to each record that was processed successfully. The
task sObjects are saved in a list, which is then bulk inserted. This example also contains a test method for testing the example.
/* This class demonstrates and tests the use of the
* partial processing DML operations */
public class dmlSamples {
/* This method accepts a collection of lead records and
creates a task for the owner(s) of any leads that were
created as new, that is, not updated as a result of the upsert
operation */
public static List<Database.upsertResult> upsertLeads(List<Lead> leads) {
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![Reference sObjects That Do Not Support DML Operations
/* Perform the upsert. In this case the unique identifier for the
insert or update decision is the Salesforce record ID. If the
record ID is null the row will be inserted, otherwise an update
will be attempted. */
List<Database.upsertResult> uResults = Database.upsert(leads,false);
/* This is the list for new tasks that will be inserted when new
leads are created. */
List<Task> tasks = new List<Task>();
for(Database.upsertResult result:uResults) {
if (result.isSuccess() && result.isCreated())
tasks.add(new Task(Subject = 'Follow-up', WhoId = result.getId()));
}
/* If there are tasks to be inserted, insert them */
Database.insert(tasks);
return uResults;
}
public static testMethod void testUpsertLeads() {
/* We only need to test the insert side of upsert */
List<Lead> leads = new List<Lead>();
/* Create a set of leads for testing */
for(Integer i = 0;i < 100; i++) {
leads.add(new Lead(LastName = 'testLead', Company = 'testCompany'));
}
/* Switch to the runtime limit context */
Test.startTest();
/* Exercise the method */
List<Database.upsertResult> results = DmlSamples.upsertLeads(leads);
/* Switch back to the test context for limits */
Test.stopTest();
/* ID set for asserting the tasks were created as expected */
Set<Id> ids = new Set<Id>();
/* Iterate over the results, asserting success and adding the new ID
to the set for use in the comprehensive assertion phase below. */
for(Database.upsertResult result:results) {
System.assert(result.isSuccess());
ids.add(result.getId());
}
/* Assert that exactly one task exists for each lead that was inserted. */
for(Lead l:[SELECT Id, (SELECT Subject FROM Tasks) FROM Lead WHERE Id IN :ids]) {
System.assertEquals(1,l.tasks.size());
}
}
}
sObjects That Do Not Support DML Operations
DML operations are not supported with the following sObjects in Apex:
• AccountTerritoryAssignmentRule
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You can update a user in a transaction with other sObjects in Apex code that is saved using Salesforce.com API version
15.0 and later if the following fields are not also updated:
◊ UserRoleId
◊ IsActive
◊ ForecastEnabled
◊ IsPortalEnabled
◊ Username
◊ ProfileId
• UserRole
• UserTerritory
• Territory
• Custom settings in Apex code that is saved using Salesforce.com API version 17.0 and earlier.
For these sObjects, there are no restrictions on delete DML operations.
If you are using a Visualforce page with a custom controller, you can only perform DML operations on a single type of sObject
within a single request or action. However, you can perform DML operations on different types of sObjects in subsequent
requests, for example, you could create an account with a save button, then create a user with a submit button.
You can perform DML operations on more than one type of sObject in a single class using the following process:
1. Create a method that performs a DML operation on one type of sObject.
2. Create a second method that uses the future annotation to manipulate a second sObject type.
Mixed DML Operations Are Allowed in Test Methods in System.RunAs() Blocks
Test methods allow for performing mixed DML operations between the sObjects listed earlier and other sObjects if the code
that performs the DML operations is enclosed within System.runAs method blocks. This enables you, for example, to
create a user with a role and other sObjects in the same test.
The following example shows how to enclose mixed DML operations within System.runAs blocks to avoid the mixed DML
error. The first block runs in the current user’s context. It creates a test user and a test account. The second block runs in the
test user’s context and updates the account. Replace the user role value in the query with an existing user role in your organization
before running this example.
@isTest
private class MixedDML {
static testMethod void MixedDMLExample() {
User u;
Account a;
User thisUser = [SELECT Id FROM User WHERE Id = :UserInfo.getUserId()];
// Insert account as current user
System.runAs (thisUser) {
Profile p = [SELECT Id FROM Profile WHERE Name='Standard User'];
UserRole r = [SELECT Id FROM UserRole WHERE Name='SalesRep'];
u = new User(alias = 'jsmtih', email='jsmith@acme.com',
emailencodingkey='UTF-8', lastname='Smith',
languagelocalekey='en_US',
localesidkey='en_US', profileid = p.Id, userroleid = r.Id,
timezonesidkey='America/Los_Angeles',
username='jsmith@acme.com');
insert u;
a = new Account(name='Acme');
insert a;
}
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![Reference Apex Primitive Methods
then does a describe to obtain the object name and constructs a query dynamicallly. It then queries for all sObjects and updates
their owner ID fields to the new owner ID.
public class MyDynamicSolution {
@future
public static void updateOwner(List<ID> objIds, ID newOwnerId) {
// Validate input
System.assert(objIds != null);
System.assert(objIds.size() > 0);
System.assert(newOwnerId != null);
// Get the sObject token from the first ID
// (the List contains IDs of sObjects of the same type).
Schema.SObjectType token = objIds[0].getSObjectType();
// Using the token, do a describe
// and construct a query dynamically.
Schema.DescribeSObjectResult dr = token.getDescribe();
String queryString = 'SELECT ownerId FROM ' + dr.getName() +
' WHERE ';
for(ID objId : objIds) {
queryString += 'Id='' + objId + '' OR ';
}
// Remove the last ' OR'
queryString = queryString.subString(0, queryString.length() - 4);
sObject[] objDBList = Database.query(queryString);
System.assert(objDBList.size() > 0);
// Update the owner ID on the sObjects
for(Integer i=0;i<objDBList.size();i++) {
objDBList[i].put('ownerId', newOwnerId);
}
Database.SaveResult[] srList = Database.update(objDBList, false);
for(Database.SaveResult sr : srList) {
if (sr.isSuccess()) {
System.debug('Updated owner ID successfully for ' +
dr.getName() + ' ID ' + sr.getId());
}
else {
System.debug('Updating ' + dr.getName() + ' returned the following errors.');
for(Database.Error e : sr.getErrors()) {
System.debug(e.getMessage());
}
}
}
}
}
Integer Methods
The following are the system static methods for Integer.
Name Arguments Return Type Description
valueOf anyType x Integer Casts x, a history tracking table field of type anyType,
to an Integer. For more information on the anyType
data type, see Field Types in the Object Reference for
Salesforce and Force.com.
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Force dotcom apex code developers guide
- 1. salesforce: Winter ’13 Force.com Apex Code Developer's Guide Last updated: December 7 2012 © Copyright 2000–2012 salesforce.com, inc. All rights reserved. Salesforce.com is a registered trademark of salesforce.com, inc., as are other names and marks. Other marks appearing herein may be trademarks of their respective owners.
- 3. Table of Contents Table of Contents Chapter 1: Introducing Apex...............................................................................................................11 What is Apex?.........................................................................................................................................................................12 How Does Apex Work?..............................................................................................................................................13 What is the Apex Development Process?....................................................................................................................14 Using a Developer or Sandbox Organization...................................................................................................14 Learning Apex.................................................................................................................................................17 Writing Apex...................................................................................................................................................18 Writing Tests...................................................................................................................................................19 Deploying Apex to a Sandbox Organization...................................................................................................19 Deploying Apex to a Salesforce Production Organization...............................................................................20 Adding Apex Code to a Force.com AppExchange App..................................................................................20 When Should I Use Apex?..........................................................................................................................................21 What are the Limitations of Apex?.............................................................................................................................21 What's New?...........................................................................................................................................................................22 Apex Quick Start.....................................................................................................................................................................22 Documentation Typographical Conventions...............................................................................................................22 Understanding Apex Core Concepts...........................................................................................................................23 Writing Your First Apex Class and Trigger................................................................................................................28 Creating a Custom Object...............................................................................................................................28 Adding an Apex Class.....................................................................................................................................29 Adding an Apex Trigger..................................................................................................................................30 Adding a Test Class.........................................................................................................................................31 Deploying Components to Production............................................................................................................33 Chapter 2: Language Constructs.........................................................................................................35 Data Types..............................................................................................................................................................................36 Primitive Data Types...................................................................................................................................................36 sObject Types..............................................................................................................................................................39 Accessing sObject Fields..................................................................................................................................40 Accessing sObject Fields Through Relationships............................................................................................41 Validating sObjects and Fields .......................................................................................................................42 Collections...................................................................................................................................................................43 Lists.................................................................................................................................................................43 Sets..................................................................................................................................................................48 Maps................................................................................................................................................................50 Parameterized Typing......................................................................................................................................51 Using Custom Types in Map Keys and Sets....................................................................................................51 Iterating Collections........................................................................................................................................54 Enums.........................................................................................................................................................................54 Understanding Rules of Conversion............................................................................................................................56 Variables..................................................................................................................................................................................57 i
- 4. Table of Contents Case Sensitivity............................................................................................................................................................58 Constants.....................................................................................................................................................................58 Expressions..............................................................................................................................................................................59 Understanding Expressions.........................................................................................................................................59 Understanding Expression Operators..........................................................................................................................60 Understanding Operator Precedence...........................................................................................................................66 Extending sObject and List Expressions.....................................................................................................................66 Using Comments.........................................................................................................................................................67 Assignment Statements...........................................................................................................................................................67 Conditional (If-Else) Statements............................................................................................................................................68 Loops.......................................................................................................................................................................................69 Do-While Loops.........................................................................................................................................................69 While Loops................................................................................................................................................................70 For Loops....................................................................................................................................................................70 Traditional For Loops.....................................................................................................................................71 List or Set Iteration For Loops........................................................................................................................71 SOQL For Loops............................................................................................................................................72 SOQL and SOSL Queries......................................................................................................................................................73 Working with SOQL and SOSL Query Results.........................................................................................................75 Working with SOQL Aggregate Functions................................................................................................................76 Working with Very Large SOQL Queries..................................................................................................................76 Using SOQL Queries That Return One Record........................................................................................................79 Improving Performance by Not Searching on Null Values.........................................................................................79 Understanding Foreign Key and Parent-Child Relationship SOQL Queries.............................................................80 Working with Polymorphic Relationships in SOQL Queries.....................................................................................80 Using Apex Variables in SOQL and SOSL Queries...................................................................................................81 Querying All Records with a SOQL Statement..........................................................................................................83 Locking Statements.................................................................................................................................................................83 Locking in a SOQL For Loop....................................................................................................................................83 Avoiding Deadlocks....................................................................................................................................................84 Transaction Control................................................................................................................................................................84 Exception Statements..............................................................................................................................................................85 Throw Statements.......................................................................................................................................................85 Try-Catch-Finally Statements.....................................................................................................................................85 Chapter 3: Invoking Apex...................................................................................................................87 Triggers...................................................................................................................................................................................88 Bulk Triggers...............................................................................................................................................................89 Trigger Syntax.............................................................................................................................................................89 Trigger Context Variables...........................................................................................................................................90 Context Variable Considerations.................................................................................................................................92 Common Bulk Trigger Idioms....................................................................................................................................93 Using Maps and Sets in Bulk Triggers............................................................................................................93 Correlating Records with Query Results in Bulk Triggers..............................................................................94 Using Triggers to Insert or Update Records with Unique Fields.....................................................................94 ii
- 5. Table of Contents Defining Triggers........................................................................................................................................................94 Triggers and Merge Statements..................................................................................................................................96 Triggers and Recovered Records.................................................................................................................................97 Triggers and Order of Execution.................................................................................................................................97 Operations that Don't Invoke Triggers.......................................................................................................................99 Entity and Field Limitations in Triggers...................................................................................................................101 Trigger Exceptions....................................................................................................................................................101 Trigger and Bulk Request Best Practices...................................................................................................................102 Apex Scheduler......................................................................................................................................................................103 Anonymous Blocks................................................................................................................................................................108 Apex in AJAX.......................................................................................................................................................................109 Chapter 4: Classes, Objects, and Interfaces........................................................................................111 Understanding Classes..........................................................................................................................................................112 Defining Apex Classes...............................................................................................................................................112 Extended Class Example...........................................................................................................................................113 Declaring Class Variables..........................................................................................................................................116 Defining Class Methods............................................................................................................................................117 Using Constructors....................................................................................................................................................119 Access Modifiers........................................................................................................................................................121 Static and Instance.....................................................................................................................................................122 Using Static Methods and Variables..............................................................................................................122 Using Instance Methods and Variables..........................................................................................................123 Using Initialization Code...............................................................................................................................124 Apex Properties.........................................................................................................................................................125 Interfaces and Extending Classes..........................................................................................................................................127 Custom Iterators........................................................................................................................................................128 Keywords...............................................................................................................................................................................130 Using the final Keyword............................................................................................................................................131 Using the instanceof Keyword...................................................................................................................................131 Using the super Keyword...........................................................................................................................................131 Using the this Keyword.............................................................................................................................................132 Using the transient Keyword.....................................................................................................................................133 Using the with sharing or without sharing Keywords................................................................................................134 Annotations...........................................................................................................................................................................136 Deprecated Annotation.............................................................................................................................................137 Future Annotation.....................................................................................................................................................137 IsTest Annotation.....................................................................................................................................................138 ReadOnly Annotation...............................................................................................................................................141 RemoteAction Annotation........................................................................................................................................142 Apex REST Annotations..........................................................................................................................................142 RestResource Annotation..............................................................................................................................143 HttpDelete Annotation.................................................................................................................................143 HttpGet Annotation......................................................................................................................................144 HttpPatch Annotation...................................................................................................................................144 iii
- 6. Table of Contents HttpPost Annotation.....................................................................................................................................144 HttpPut Annotation......................................................................................................................................144 Classes and Casting...............................................................................................................................................................144 Classes and Collections.............................................................................................................................................146 Collection Casting.....................................................................................................................................................146 Differences Between Apex Classes and Java Classes.............................................................................................................146 Class Definition Creation......................................................................................................................................................147 Naming Conventions.................................................................................................................................................149 Name Shadowing......................................................................................................................................................149 Class Security........................................................................................................................................................................149 Enforcing Object and Field Permissions...............................................................................................................................150 Namespace Prefix..................................................................................................................................................................151 Using Namespaces When Invoking Methods...........................................................................................................152 Namespace, Class, and Variable Name Precedence...................................................................................................152 Type Resolution and System Namespace for Types..................................................................................................153 Version Settings....................................................................................................................................................................153 Setting the Salesforce API Version for Classes and Triggers....................................................................................154 Setting Package Versions for Apex Classes and Triggers..........................................................................................155 Chapter 5: Testing Apex...................................................................................................................156 Understanding Testing in Apex............................................................................................................................................157 Why Test Apex?........................................................................................................................................................157 What to Test in Apex................................................................................................................................................157 Unit Testing Apex.................................................................................................................................................................158 Isolation of Test Data from Organization Data in Unit Tests..................................................................................159 Using the runAs Method...........................................................................................................................................160 Using Limits, startTest, and stopTest.......................................................................................................................161 Adding SOSL Queries to Unit Tests........................................................................................................................162 Running Unit Test Methods.................................................................................................................................................163 Testing Best Practices...........................................................................................................................................................167 Testing Example...................................................................................................................................................................168 Chapter 6: Dynamic Apex.................................................................................................................173 Understanding Apex Describe Information..........................................................................................................................174 Dynamic SOQL....................................................................................................................................................................183 Dynamic SOSL.....................................................................................................................................................................183 Dynamic DML.....................................................................................................................................................................184 Chapter 7: Batch Apex......................................................................................................................187 Using Batch Apex..................................................................................................................................................................188 Understanding Apex Managed Sharing................................................................................................................................197 Understanding Sharing..............................................................................................................................................197 Sharing a Record Using Apex....................................................................................................................................199 Recalculating Apex Managed Sharing.......................................................................................................................204 Chapter 8: Debugging Apex..............................................................................................................209 iv
- 7. Table of Contents Understanding the Debug Log..............................................................................................................................................210 Working with Logs in the Developer Console..........................................................................................................214 Debugging Apex API Calls.......................................................................................................................................223 Handling Uncaught Exceptions............................................................................................................................................224 Understanding Execution Governors and Limits..................................................................................................................225 Using Governor Limit Email Warnings...............................................................................................................................230 Chapter 9: Developing Apex in Managed Packages............................................................................231 Package Versions...................................................................................................................................................................232 Deprecating Apex..................................................................................................................................................................232 Behavior in Package Versions................................................................................................................................................233 Versioning Apex Code Behavior...............................................................................................................................233 Apex Code Items that Are Not Versioned................................................................................................................234 Testing Behavior in Package Versions.......................................................................................................................235 Chapter 10: Exposing Apex Methods as SOAP Web Services..............................................................237 WebService Methods............................................................................................................................................................238 Exposing Data with WebService Methods................................................................................................................238 Considerations for Using the WebService Keyword..................................................................................................238 Overloading Web Service Methods...........................................................................................................................240 Chapter 11: Exposing Apex Classes as REST Web Services................................................................241 Introduction to Apex REST..................................................................................................................................................242 Apex REST Annotations......................................................................................................................................................242 Apex REST Methods............................................................................................................................................................242 Exposing Data with Apex REST Web Service Methods......................................................................................................247 Apex REST Code Samples...................................................................................................................................................248 Apex REST Basic Code Sample...............................................................................................................................248 Apex REST Code Sample Using RestRequest.........................................................................................................249 Chapter 12: Invoking Callouts Using Apex........................................................................................251 Adding Remote Site Settings................................................................................................................................................252 SOAP Services: Defining a Class from a WSDL Document...............................................................................................252 Invoking an External Service.....................................................................................................................................253 HTTP Header Support.............................................................................................................................................253 Supported WSDL Features.......................................................................................................................................254 Understanding the Generated Code..........................................................................................................................257 Testing Web Service Callouts...................................................................................................................................259 Considerations Using WSDLs..................................................................................................................................261 Mapping Headers..........................................................................................................................................261 Understanding Runtime Events.....................................................................................................................262 Understanding Unsupported Characters in Variable Names.........................................................................262 Debugging Classes Generated from WSDL Files.........................................................................................262 Invoking HTTP Callouts......................................................................................................................................................262 Using Certificates..................................................................................................................................................................263 Generating Certificates..............................................................................................................................................263 v
- 8. Table of Contents Using Certificates with SOAP Services.....................................................................................................................264 Using Certificates with HTTP Requests...................................................................................................................265 Callout Limits and Limitations.............................................................................................................................................265 Chapter 13: Reference.......................................................................................................................267 Apex Data Manipulation Language (DML) Operations......................................................................................................268 ConvertLead Operation............................................................................................................................................269 Delete Operation.......................................................................................................................................................272 Insert Operation........................................................................................................................................................274 Merge Statement.......................................................................................................................................................277 Undelete Operation...................................................................................................................................................278 Update Operation......................................................................................................................................................280 Upsert Operation.......................................................................................................................................................282 sObjects That Do Not Support DML Operations....................................................................................................286 sObjects That Cannot Be Used Together in DML Operations................................................................................287 Bulk DML Exception Handling...............................................................................................................................289 Apex Standard Classes and Methods....................................................................................................................................289 Apex Primitive Methods...........................................................................................................................................290 Blob Methods................................................................................................................................................290 Boolean Methods...........................................................................................................................................291 Date Methods................................................................................................................................................291 Datetime Methods.........................................................................................................................................294 Decimal Methods..........................................................................................................................................299 Double Methods............................................................................................................................................304 ID Methods...................................................................................................................................................306 Integer Methods............................................................................................................................................307 Long Methods...............................................................................................................................................308 String Methods..............................................................................................................................................308 Time Methods...............................................................................................................................................332 Apex Collection Methods..........................................................................................................................................333 List Methods.................................................................................................................................................333 Map Methods................................................................................................................................................340 Set Methods...................................................................................................................................................344 Enum Methods.........................................................................................................................................................347 Apex sObject Methods..............................................................................................................................................348 Schema Methods...........................................................................................................................................348 sObject Methods............................................................................................................................................352 sObject Describe Result Methods.................................................................................................................357 Describe Field Result Methods.....................................................................................................................361 Schema.FieldSet Methods.............................................................................................................................369 Custom Settings Methods.............................................................................................................................372 Apex System Methods...............................................................................................................................................380 ApexPages Methods......................................................................................................................................380 Approval Methods.........................................................................................................................................381 Database Methods.........................................................................................................................................382 vi
- 9. Table of Contents JSON Support...............................................................................................................................................396 Limits Methods.............................................................................................................................................413 Math Methods...............................................................................................................................................416 MultiStaticResourceCalloutMock Methods..................................................................................................421 Apex REST...................................................................................................................................................421 Search Methods.............................................................................................................................................427 StaticResourceCalloutMock Methods...........................................................................................................427 System Methods............................................................................................................................................428 Test Methods.................................................................................................................................................439 Type Methods...............................................................................................................................................444 URL Methods...............................................................................................................................................448 UserInfo Methods..........................................................................................................................................451 Version Methods...........................................................................................................................................452 Using Exception Methods.........................................................................................................................................454 Apex Classes..........................................................................................................................................................................457 Apex Email Classes...................................................................................................................................................457 Outbound Email............................................................................................................................................457 Inbound Email...............................................................................................................................................469 Exception Class.........................................................................................................................................................474 Constructing an Exception............................................................................................................................475 Using Exception Variables.............................................................................................................................476 Visualforce Classes.....................................................................................................................................................476 Action Class...................................................................................................................................................477 Dynamic Component Methods and Properties.............................................................................................478 IdeaStandardController Class........................................................................................................................479 IdeaStandardSetController Class...................................................................................................................482 KnowledgeArticleVersionStandardController Class......................................................................................486 Message Class................................................................................................................................................489 PageReference Class......................................................................................................................................490 SelectOption Class.........................................................................................................................................496 StandardController Class...............................................................................................................................498 StandardSetController Class..........................................................................................................................500 Flow.Interview Class.................................................................................................................................................503 Pattern and Matcher Classes.....................................................................................................................................504 Using Patterns and Matchers.........................................................................................................................504 Using Regions................................................................................................................................................505 Using Match Operations...............................................................................................................................505 Using Bounds................................................................................................................................................506 Understanding Capturing Groups.................................................................................................................506 Pattern and Matcher Example.......................................................................................................................506 Pattern Methods............................................................................................................................................507 Matcher Methods..........................................................................................................................................509 HTTP (RESTful) Services Classes...........................................................................................................................514 HTTP Classes...............................................................................................................................................515 Crypto Class..................................................................................................................................................525 vii
- 10. Table of Contents EncodingUtil Class........................................................................................................................................531 XML Classes.............................................................................................................................................................532 XmlStream Classes........................................................................................................................................532 DOM Classes................................................................................................................................................539 Apex Approval Processing Classes............................................................................................................................545 Apex Approval Processing Example..............................................................................................................545 ProcessRequest Class.....................................................................................................................................546 ProcessResult Class........................................................................................................................................547 ProcessSubmitRequest Class.........................................................................................................................547 ProcessWorkitemRequest Class....................................................................................................................548 BusinessHours Class..................................................................................................................................................549 Apex Community Classes..........................................................................................................................................551 Answers Class................................................................................................................................................551 Ideas Class.....................................................................................................................................................552 Knowledge Management Publishing Service Class...................................................................................................555 Site Class...................................................................................................................................................................559 Cookie Class..............................................................................................................................................................565 Network Class...........................................................................................................................................................567 Apex Interfaces......................................................................................................................................................................567 Auth.RegistrationHandler Interface..........................................................................................................................569 Comparable Interface................................................................................................................................................572 HttpCalloutMock Interface.......................................................................................................................................574 InstallHandler Interface.............................................................................................................................................574 Support.EmailTemplateSelector Interface................................................................................................................576 Site.UrlRewriter Interface..........................................................................................................................................577 Using the Process.Plugin Interface............................................................................................................................584 Process.Plugin Interface.................................................................................................................................585 Process.PluginRequest Class..........................................................................................................................586 Process.PluginResult Class............................................................................................................................587 Process.PluginDescribeResult Class..............................................................................................................587 Process.Plugin Data Type Conversions.........................................................................................................590 Sample Process.Plugin Implementation for Lead Conversion.......................................................................590 UninstallHandler Interface........................................................................................................................................596 WebServiceMock Interface.......................................................................................................................................598 Chapter 14: Deploying Apex.............................................................................................................599 Using Change Sets To Deploy Apex.....................................................................................................................................600 Using the Force.com IDE to Deploy Apex...........................................................................................................................600 Using the Force.com Migration Tool....................................................................................................................................601 Understanding deploy................................................................................................................................................602 Understanding retrieveCode......................................................................................................................................604 Understanding runTests()..........................................................................................................................................605 Using SOAP API to Deploy Apex........................................................................................................................................606 Appendices......................................................................................................................................607 viii
- 11. Table of Contents Appendix A: Shipping Invoice Example....................................................................................607 Shipping Invoice Example Walk-Through...............................................................................................................607 Shipping Invoice Example Code...............................................................................................................................610 Appendix B: Reserved Keywords..............................................................................................619 Appendix C: Security Tips for Apex and Visualforce Development.............................................621 Cross Site Scripting (XSS)........................................................................................................................................621 Unescaped Output and Formulas in Visualforce Pages.............................................................................................623 Cross-Site Request Forgery (CSRF).........................................................................................................................624 SOQL Injection........................................................................................................................................................625 Data Access Control..................................................................................................................................................627 Appendix D: SOAP API and SOAP Headers for Apex..............................................................629 ApexTestQueueItem.................................................................................................................................................630 ApexTestResult.........................................................................................................................................................631 compileAndTest()......................................................................................................................................................634 CompileAndTestRequest..............................................................................................................................635 CompileAndTestResult.................................................................................................................................636 compileClasses()........................................................................................................................................................638 compileTriggers()......................................................................................................................................................639 executeanonymous()..................................................................................................................................................639 ExecuteAnonymousResult.............................................................................................................................640 runTests()..................................................................................................................................................................640 RunTestsRequest...........................................................................................................................................642 RunTestsResult..............................................................................................................................................642 DebuggingHeader.....................................................................................................................................................646 PackageVersionHeader..............................................................................................................................................647 Glossary...........................................................................................................................................649 Index...............................................................................................................................................666 ix
- 12. Table of Contents x
- 13. Chapter 1 Introducing Apex In this chapter ... Salesforce.com has changed the way organizations do business by moving enterprise applications that were traditionally client-server-based into an • What is Apex? on-demand, multitenant Web environment, the Force.com platform. This • What's New? environment allows organizations to run and customize applications, such as • Apex Quick Start Salesforce Automation and Service & Support, and build new custom applications based on particular business needs. While many customization options are available through the Salesforce user interface, such as the ability to define new fields, objects, workflow, and approval processes, developers can also use the SOAP API to issue data manipulation commands such as delete(), update() or upsert(), from client-side programs. These client-side programs, typically written in Java, JavaScript, .NET, or other programming languages grant organizations more flexibility in their customizations. However, because the controlling logic for these client-side programs is not located on Force.com platform servers, they are restricted by: • The performance costs of making multiple round-trips to the salesforce.com site to accomplish common business transactions • The cost and complexity of hosting server code, such as Java or .NET, in a secure and robust environment To address these issues, and to revolutionize the way that developers create on-demand applications, salesforce.com introduces Force.com Apex code, the first multitenant, on-demand programming language for developers interested in building the next generation of business applications. • What is Apex?—more about when to use Apex, the development process, and some limitations • What's new in this Apex release? • Apex Quick Start—delve straight into the code and write your first Apex class and trigger 11
- 14. Introducing Apex What is Apex? What is Apex? Apex is a strongly typed, object-oriented programming language that allows developers to execute flow and transaction control statements on the Force.com platform server in conjunction with calls to the Force.com API. Using syntax that looks like Java and acts like database stored procedures, Apex enables developers to add business logic to most system events, including button clicks, related record updates, and Visualforce pages. Apex code can be initiated by Web service requests and from triggers on objects. Figure 1: You can add Apex to most system events. As a language, Apex is: Integrated Apex provides built-in support for common Force.com platform idioms, including: • Data manipulation language (DML) calls, such as INSERT, UPDATE, and DELETE, that include built-in DmlException handling • Inline Salesforce Object Query Language (SOQL) and Salesforce Object Search Language (SOSL) queries that return lists of sObject records • Looping that allows for bulk processing of multiple records at a time • Locking syntax that prevents record update conflicts • Custom public Force.com API calls that can be built from stored Apex methods 12
- 15. Introducing Apex How Does Apex Work? • Warnings and errors issued when a user tries to edit or delete a custom object or field that is referenced by Apex Easy to use Apex is based on familiar Java idioms, such as variable and expression syntax, block and conditional statement syntax, loop syntax, object and array notation, and so on. Where Apex introduces new elements, it uses syntax and semantics that are easy to understand and encourage efficient use of the Force.com platform. Consequently, Apex produces code that is both succinct and easy to write. Data focused Apex is designed to thread together multiple query and DML statements into a single unit of work on the Force.com platform server, much as developers use database stored procedures to thread together multiple transaction statements on a database server. Note that like other database stored procedures, Apex does not attempt to provide general support for rendering elements in the user interface. Rigorous Apex is a strongly-typed language that uses direct references to schema objects such as object and field names. It fails quickly at compile time if any references are invalid, and stores all custom field, object, and class dependencies in metadata to ensure they are not deleted while required by active Apex code. Hosted Apex is interpreted, executed, and controlled entirely by the Force.com platform. Multitenant aware Like the rest of the Force.com platform, Apex runs in a multitenant environment. Consequently, the Apex runtime engine is designed to guard closely against runaway code, preventing them from monopolizing shared resources. Any code that violate these limits fail with easy-to-understand error messages. Automatically upgradeable Apex never needs to be rewritten when other parts of the Force.com platform are upgraded. Because the compiled code is stored as metadata in the platform, it always gets automatically upgraded with the rest of the system. Easy to test Apex provides built-in support for unit test creation and execution, including test results that indicate how much code is covered, and which parts of your code could be more efficient. Salesforce.com ensures that Apex code always work as expected by executing all unit tests stored in metadata prior to any platform upgrades. Versioned You can save your Apex code against different versions of the Force.com API. This enables you to maintain behavior. Apex is included in Unlimited Edition, Developer Edition, Enterprise Edition, and Database.com. How Does Apex Work? All Apex runs entirely on-demand on the Force.com platform, as shown in the following architecture diagram: 13
- 16. Introducing Apex What is the Apex Development Process? Figure 2: Apex is compiled, stored, and run entirely on the Force.com platform. When a developer writes and saves Apex code to the platform, the platform application server first compiles the code into an abstract set of instructions that can be understood by the Apex runtime interpreter, and then saves those instructions as metadata. When an end-user triggers the execution of Apex, perhaps by clicking a button or accessing a Visualforce page, the platform application server retrieves the compiled instructions from the metadata and sends them through the runtime interpreter before returning the result. The end-user observes no differences in execution time from standard platform requests. What is the Apex Development Process? We recommend the following process for developing Apex: 1. Obtain a Developer Edition account. 2. Learn more about Apex. 3. Write your Apex. 4. While writing Apex, you should also be writing tests. 5. Optionally deploy your Apex to a sandbox organization and do final unit tests. 6. Deploy your Apex to your Salesforce production organization. In addition to deploying your Apex, once it is written and tested, you can also add your classes and triggers to a Force.com AppExchange App package. Using a Developer or Sandbox Organization There are three types of organizations where you can run your Apex: • A developer organization: an organization created with a Developer Edition account. • A production organization: an organization that has live users accessing your data. • A sandbox organization: an organization created on your production organization that is a copy of your production organization. 14
- 17. Introducing Apex What is the Apex Development Process? Note: Apex triggers are available in the Trial Edition of Salesforce; however, they are disabled when you convert to any other edition. If your newly-signed-up organization includes Apex, you must deploy your code to your organization using one of the deployment methods. You can't develop Apex in your Salesforce production organization. Live users accessing the system while you're developing can destabilize your data or corrupt your application. Instead, we recommend that you do all your development work in either a sandbox or a Developer Edition organization. If you aren't already a member of the developer community, go to http://developer.force.com/join and follow the instructions to sign up for a Developer Edition account. A Developer Edition account gives you access to a free Developer Edition organization. Even if you already have an Enterprise or Unlimited Edition organization and a sandbox for creating Apex, we strongly recommends that you take advantage of the resources available in the developer community. Note: You cannot make changes to Apex using the Salesforce user interface in a Salesforce production organization. Creating a Sandbox Organization To create or refresh a sandbox organization: 1. Click Your Name > Setup > Data Management > Sandbox. 2. Do one of the following: • Click New Sandbox. For information on different kinds of sandboxes, see “Sandbox Overview” in the online help. Salesforce deactivates the New Sandbox button when an organization reaches its sandbox limit. If necessary, contact salesforce.com to order more sandboxes for your organization. Note that Salesforce deactivates all refresh links if you have exceeded your sandbox limit. • Click Refresh to replace an existing sandbox with a new copy. Salesforce only displays the Refresh link for sandboxes that are eligible for refreshing. For full-copy sandboxes, this is any time after 29 days from the previous creation or refresh of that sandbox. For configuration-only sandboxes (including developer sandboxes), you can refresh once per day. Your existing copy of this sandbox remains available while you wait for the refresh to complete. The refreshed copy is inactive until you activate it. 3. Enter a name and description for the sandbox. You can only change the name when you create or refresh a sandbox. Tip: We recommend that you choose a name that: • Reflects the purpose of this sandbox, such as “QA.” • Has few characters because Salesforce automatically appends the sandbox name to usernames and email addresses on user records in the sandbox environment. Names with fewer characters make sandbox logins easier to type. 4. Select the type of sandbox: • Configuration Only: Configuration-only sandboxes copy all of your production organization's reports, dashboards, price books, products, apps, and customizations under Your Name > Setup, but exclude all of your organization's standard and custom object records, documents, and attachments. Creating a configuration-only sandbox can decrease the time it takes to create or refresh a sandbox from several hours to just a few minutes, but it can only include up to 500 MB of data. You can refresh a configuration-only sandbox once per day. • Developer: Developer sandboxes are special configuration-only sandboxes intended for coding and testing by a single developer. Multiple users can log into a single developer sandbox, but their primary purpose is to provide an environment in which changes under active development can be isolated until they’re ready to be shared. Just like configuration-only sandboxes, developer sandboxes copy all application and configuration information to the sandbox. Developer sandboxes 15
- 18. Introducing Apex What is the Apex Development Process? are limited to 10 MB of test or sample data, which is enough for many development and testing tasks. You can refresh a developer sandbox once per day. • Full: Full sandboxes copy your entire production organization and all its data, including standard and custom object records, documents, and attachments. You can refresh a full-copy sandbox every 29 days. If you have reduced the number of sandboxes you purchased, but you still have more sandboxes of a specific type than allowed, you will be required to match your sandboxes to the number of sandboxes that you purchased. For example, if you have two full sandboxes but purchased only one, you cannot refresh your full sandbox as a full sandbox. Instead, you must choose one full sandbox to convert to a smaller sandbox, such as configuration-only or developer sandbox, depending on which type of sandbox you have available. Note: Configuration-only and developer sandboxes copy all of your production organization's reports, dashboards, price books, products, apps, and customizations under Your Name > Setup, but exclude all of your organization's standard and custom object records, documents, and attachments. Because they copy much less data, creating these sandbox types can substantially decrease the time it takes to create or refresh a sandbox. If you are refreshing an existing sandbox, the radio button usually preselects the sandbox type corresponding to the sandbox you are refreshing. For example, if you refresh a configuration-only sandbox, the radio button preselects Configuration Only. Whether refreshing an existing sandbox or creating a new one, some radio buttons may be disabled if you have already created the number of sandboxes of that sandbox type allowed for your organization. 5. For a full sandbox, choose how much object history, case history, and opportunity history to copy, and whether or not to copy Chatter data. Object history is the field history tracking of custom and most standard objects; case history and opportunity history serve the same purpose for cases and opportunities. You can copy from 0 to 180 days of history, in 30–day increments. The default value is 0 days. Chatter data includes feeds, messages, and discovery topics. Decreasing the amount of data you copy can significantly speed up sandbox copy time. 6. Click Start Copy. The process may take several minutes, hours, or even days, depending on the size of your organization and whether you are creating a full copy or configuration-only copy. Tip: Try to limit changes in your production organization while the sandbox copy proceeds. 7. You will receive a notification email when your newly created or refreshed sandbox has completed copying. If you are creating a new sandbox, the newly created sandbox is now ready for use. If you are refreshing an existing sandbox, an additional step is required to complete the sandbox copy process. The new sandbox must be activated. To delete your existing sandbox and activate the new one: a. Return to the sandbox list by logging into your production organization and navigating to Your Name > Setup > Data Management > Sandbox. b. Click the Activate link next to the sandbox you wish to activate. This will take you to a page warning of removal of your existing sandbox. c. Read the warning carefully and if you agree to the removal, enter the acknowledgment text at the prompt and click the Activate button. When the activation process is complete, you will receive a notification email. Warning: Activating a replacement sandbox that was created using the Refresh link completely deletes the sandbox it is refreshing. All configuration and data in the prior sandbox copy will be lost, including any application or data changes you have made. Please read the warning carefully, and press the Activate link only if you have no 16
- 19. Introducing Apex What is the Apex Development Process? further need for the contents of the sandbox copy currently in use. Your production organization and its data will not be affected. 8. Once your new sandbox is complete, or your refreshed sandbox is activated, you can click the link in the notification email to access your sandbox. You can log into the sandbox at test.salesforce.com/login.jsp by appending .sandbox_name to your Salesforce username. For example, if your username for your production organization is user1@acme.com, then your username for a sandbox named “test” is user1@acme.com.test. For more information, see “Username and Email Address Modification” in the online help. Note: Salesforce automatically changes sandbox usernames but does not change passwords. Learning Apex After you have your developer account, there are many resources available to you for learning about Apex: Force.com Workbook: Get Started Building Your First App in the Cloud Beginning programmers A set of ten 30-minute tutorials that introduce various Force.com platform features. The Force.com Workbook tutorials are centered around building a very simple warehouse management system. You'll start developing the application from the bottom up; that is, you'll first build a database model for keeping track of merchandise. You'll continue by adding business logic: validation rules to ensure that there is enough stock, workflow to update inventory when something is sold, approvals to send email notifications for large invoice values, and trigger logic to update the prices in open invoices. Once the database and business logic are complete, you'll create a user interface to display a product inventory to staff, a public website to display a product catalog, and then the start of a simple store front. If you'd like to develop offline and integrate with the app, we've added a final tutorial to use Adobe Flash Builder for Force.com. Force.com Workbook: HTML | PDF Apex Workbook Beginning programmers The Apex Workbook introduces you to the Apex programming language through a set of tutorials. You’ll learn the fundamentals of Apex and how you can use it on the Force.com platform to add custom business logic through triggers, unit tests, scheduled Apex, batch Apex, REST Web services, and Visualforce controllers. Apex Workbook: HTML | PDF Developer Force Apex Page Beginning and advanced programmers The Apex page on Developer Force has links to several resources including articles about the Apex programming language. These resources provide a quick introduction to Apex and include best practices for Apex development. Force.com Cookbook Beginning and advanced programmers This collaborative site provides many recipes for using the Web services API, developing Apex code, and creating Visualforce pages. The Force.com Cookbook helps developers become familiar with common Force.com programming 17
- 20. Introducing Apex What is the Apex Development Process? techniques and best practices. You can read and comment on existing recipes, or submit your own recipes, at developer.force.com/cookbook. Development Life Cycle: Enterprise Development on the Force.com Platform Architects and advanced programmers Whether you are an architect, administrator, developer, or manager, the Development Life Cycle Guide prepares you to undertake the development and release of complex applications on the Force.com platform. Training Courses Training classes are also available from salesforce.com Training & Certification. You can find a complete list of courses at www.salesforce.com/training. In This Book (Apex Developer's Guide) Beginning programmers should look at the following: • Introducing Apex, and in particular: ◊ Documentation Conventions ◊ Core Concepts ◊ Quick Start Tutorial • Classes, Objects, and Interfaces • Testing Apex • Understanding Execution Governors and Limits In addition to the above, advanced programmers should look at: • Trigger and Bulk Request Best Practices • Advanced Apex Programming Example • Understanding Apex Describe Information • Asynchronous Execution (@future Annotation) • Batch Apex and Apex Scheduler Writing Apex You can write Apex code and tests in any of the following editing environments: • The Force.com IDE is a plug-in for the Eclipse IDE. The Force.com IDE provides a unified interface for building and deploying Force.com applications. Designed for developers and development teams, the IDE provides tools to accelerate Force.com application development, including source code editors, test execution tools, wizards and integrated help. This tool includes basic color-coding, outline view, integrated unit testing, and auto-compilation on save with error message display. See the website for information about installation and usage. Note: The Force.com IDE is a free resource provided by salesforce.com to support its users and partners but isn't considered part of our services for purposes of the salesforce.com Master Subscription Agreement. • The Salesforce user interface. All classes and triggers are compiled when they are saved, and any syntax errors are flagged. You cannot save your code until it compiles without errors. The Salesforce user interface also numbers the lines in the code, and uses color coding to distinguish different elements, such as comments, keywords, literal strings, and so on. 18
- 21. Introducing Apex What is the Apex Development Process? ◊ For a trigger on a standard object, click Your Name > Setup > Customize, click the name of the object, and click Triggers. In the Triggers detail page, click New, and then enter your code in the Body text box. ◊ For a trigger on a custom object, click Your Name > Setup > Develop > Objects, and click the name of the object. In the Triggers related list, click New, and then enter your code in the Body text box. ◊ For a class, click Your Name > Setup > Develop > Apex Classes. Click New, and then enter your code in the Body text box. Note: You cannot make changes to Apex using the Salesforce user interface in a Salesforce production organization. • Any text editor, such as Notepad. You can write your Apex code, then either copy and paste it into your application, or use one of the API calls to deploy it. Tip: If you want to extend the Eclipse plug-in or develop an Apex IDE of your own, the SOAP API includes methods for compiling triggers and classes, and executing test methods, while the Metadata API includes methods for deploying code to production environments. For more information, see Deploying Apex on page 599 and SOAP API and SOAP Headers for Apex on page 629. Writing Tests Testing is the key to successful long term development, and is a critical component of the development process. We strongly recommend that you use a test-driven development process, that is, test development that occurs at the same time as code development. To facilitate the development of robust, error-free code, Apex supports the creation and execution of unit tests. Unit tests are class methods that verify whether a particular piece of code is working properly. Unit test methods take no arguments, commit no data to the database, send no emails, and are flagged with the testMethod keyword in the method definition. In addition, before you deploy Apex or package it for the Force.com AppExchange, the following must be true: • 75% of your Apex code must be covered by unit tests, and all of those tests must complete successfully. Note the following: ◊ When deploying to a production organization, every unit test in your organization namespace is executed. ◊ Calls to System.debug are not counted as part of Apex code coverage. ◊ Test methods and test classes are not counted as part of Apex code coverage. ◊ While only 75% of your Apex code must be covered by tests, your focus shouldn't be on the percentage of code that is covered. Instead, you should make sure that every use case of your application is covered, including positive and negative cases, as well as bulk and single record. This should lead to 75% or more of your code being covered by unit tests. • Every trigger has some test coverage. • All classes and triggers compile successfully. For more information on writing tests, see Testing Apex on page 156. Deploying Apex to a Sandbox Organization Salesforce gives you the ability to create multiple copies of your organization in separate environments for a variety of purposes, such as testing and training, without compromising the data and applications in your Salesforce production organization. These copies are called sandboxes and are nearly identical to your Salesforce production organization. Sandboxes are completely 19
- 22. Introducing Apex What is the Apex Development Process? isolated from your Salesforce production organization, so operations you perform in your sandboxes do not affect your Salesforce production organization, and vice versa. To deploy Apex from a local project in the Force.com IDE to a Salesforce organization, use the Force.com Component Deployment Wizard. For more information about the Force.com IDE, see http://wiki.developerforce.com/index.php/Force.com_IDE. You can also use the deploy() Metadata API call to deploy your Apex from a developer organization to a sandbox organization. A useful API call is runTests(). In a development or sandbox organization, you can run the unit tests for a specific class, a list of classes, or a namespace. Salesforce includes a Force.com Migration Tool that allows you to issue these commands in a console window, or your can implement your own deployment code. Note: The Force.com IDE and the Force.com Migration Tool are free resources provided by salesforce.com to support its users and partners, but aren't considered part of our services for purposes of the salesforce.com Master Subscription Agreement. For more information, see Using the Force.com Migration Tool and Deploying Apex. Deploying Apex to a Salesforce Production Organization After you have finished all of your unit tests and verified that your Apex code is executing properly, the final step is deploying Apex to your Salesforce production organization. To deploy Apex from a local project in the Force.com IDE to a Salesforce organization, use the Force.com Component Deployment Wizard. For more information about the Force.com IDE, see http://wiki.developerforce.com/index.php/Force.com_IDE. Also, you can deploy Apex through change sets in the Salesforce user interface. For more information and for additional deployment options, see Deploying Apex on page 599. Adding Apex Code to a Force.com AppExchange App You can also include an Apex class or trigger in an app that you are creating for AppExchange. Any Apex that is included as part of a package must have at least 75% cumulative test coverage. Each trigger must also have some test coverage. When you upload your package to AppExchange, all tests are run to ensure that they run without errors. In addition, tests with the@isTest(OnInstall=true) annotation run when the package is installed in the installer's organization. You can specify which tests should run during package install by annotating them with @isTest(OnInstall=true). This subset of tests must pass for the package install to succeed. In addition, salesforce.com recommends that any AppExchange package that contains Apex be a managed package. For more information, see the Force.com Quick Reference for Developing Packages. For more information about Apex in managed packages, see Developing Apex in Managed Packages on page 231. Note: Packaging Apex classes that contain references to custom labels which have translations: To include the translations in the package, enable the Translation Workbench and explicitly package the individual languages used in the translated custom labels. See “Custom Labels Overview” in the online help. 20
- 23. Introducing Apex When Should I Use Apex? When Should I Use Apex? The Salesforce prebuilt applications provide powerful CRM functionality. In addition, Salesforce provides the ability to customize the prebuilt applications to fit your organization. However, your organization may have complex business processes that are unsupported by the existing functionality. When this is the case, the Force.com platform includes a number of ways for advanced administrators and developers to implement custom functionality. These include Apex, Visualforce, and the SOAP API. Apex Use Apex if you want to: • Create Web services. • Create email services. • Perform complex validation over multiple objects. • Create complex business processes that are not supported by workflow. • Create custom transactional logic (logic that occurs over the entire transaction, not just with a single record or object.) • Attach custom logic to another operation, such as saving a record, so that it occurs whenever the operation is executed, regardless of whether it originates in the user interface, a Visualforce page, or from SOAP API. Visualforce Visualforce consists of a tag-based markup language that gives developers a more powerful way of building applications and customizing the Salesforce user interface. With Visualforce you can: • Build wizards and other multistep processes. • Create your own custom flow control through an application. • Define navigation patterns and data-specific rules for optimal, efficient application interaction. For more information, see the Visualforce Developer's Guide. SOAP API Use standard SOAP API calls if you want to add functionality to a composite application that processes only one type of record at a time and does not require any transactional control (such as setting a Savepoint or rolling back changes). For more information, see the SOAP API Developer's Guide. What are the Limitations of Apex? Apex radically changes the way that developers create on-demand business applications, but it is not currently meant to be a general purpose programming language. As of this release, Apex cannot be used to: • Render elements in the user interface other than error messages • Change standard functionality—Apex can only prevent the functionality from happening, or add additional functionality • Create temporary files • Spawn threads Tip: All Apex code runs on the Force.com platform, which is a shared resource used by all other organizations. To guarantee consistent performance and scalability, the execution of Apex is bound by governor limits that ensure no single Apex 21
- 24. Introducing Apex What's New? execution impacts the overall service of Salesforce. This means all Apex code is limited by the number of operations (such as DML or SOQL) that it can perform within one process. All Apex requests return a collection that contains from 1 to 50,000 records. You cannot assume that your code only works on a single record at a time. Therefore, you must implement programming patterns that take bulk processing into account. If you do not, you may run into the governor limits. See Also: Understanding Execution Governors and Limits Trigger and Bulk Request Best Practices What's New? Review the Winter ’13 Release Notes for a summary of new and changed Apex features in Winter ’13. Apex Quick Start Once you have a Developer Edition or sandbox organization, you may want to learn some of the core concepts of Apex. Because Apex is very similar to Java, you may recognize much of the functionality. After reviewing the basics, you are ready to write your first Apex program—a very simple class, trigger, and unit test. In addition, there is a more complex shipping invoice example that you can also walk through. This example illustrates many more features of the language. Note: The Hello World and the shipping invoice samples require custom fields and objects. You can either create these on your own, or download the objects, fields and Apex code as a managed packaged from Force.com AppExchange. For more information, see wiki.developerforce.com/index.php/Documentation. Documentation Typographical Conventions Apex and Visualforce documentation uses the following typographical conventions. Convention Description Courier font In descriptions of syntax, monospace font indicates items that you should type as shown, except for brackets. For example: Public class HelloWorld 22
- 25. Introducing Apex Understanding Apex Core Concepts Convention Description Italics In description of syntax, italics represent variables. You supply the actual value. In the following example, three values need to be supplied: datatype variable_name [ = value]; If the syntax is bold and italic, the text represents a code element that needs a value supplied by you, such as a class name or variable value: public static class YourClassHere { ... } <> In descriptions of syntax, less-than and greater-than symbols (< >) are typed exactly as shown. <apex:pageBlockTable value="{!account.Contacts}" var="contact"> <apex:column value="{!contact.Name}"/> <apex:column value="{!contact.MailingCity}"/> <apex:column value="{!contact.Phone}"/> </apex:pageBlockTable> {} In descriptions of syntax, braces ({ }) are typed exactly as shown. <apex:page> Hello {!$User.FirstName}! </apex:page> [] In descriptions of syntax, anything included in brackets is optional. In the following example, specifying value is optional: data_type variable_name [ = value]; | In descriptions of syntax, the pipe sign means “or”. You can do one of the following (not all). In the following example, you can create a new unpopulated set in one of two ways, or you can populate the set: Set<data_type> set_name [= new Set<data_type>();] | [= new Set<data_type{value [, value2. . .] };] | ; Understanding Apex Core Concepts Apex code typically contains many things that you might be familiar with from other programming languages: 23
- 26. Introducing Apex Understanding Apex Core Concepts Figure 3: Programming elements in Apex The section describes the basic functionality of Apex, as well as some of the core concepts. Using Version Settings In the Salesforce user interface you can specify a version of the Salesforce.com API against which to save your Apex class or trigger. This setting indicates not only the version of SOAP API to use, but which version of Apex as well. You can change the version after saving. Every class or trigger name must be unique. You cannot save the same class or trigger against different versions. You can also use version settings to associate a class or trigger with a particular version of a managed package that is installed in your organization from AppExchange. This version of the managed package will continue to be used by the class or trigger if later versions of the managed package are installed, unless you manually update the version setting. To add an installed managed package to the settings list, select a package from the list of available packages. The list is only displayed if you have an installed managed package that is not already associated with the class or trigger. For more information about using version settings with managed packages, see “About Package Versions” in the Salesforce online help. 24
- 27. Introducing Apex Understanding Apex Core Concepts Naming Variables, Methods and Classes You cannot use any of the Apex reserved keywords when naming variables, methods or classes. These include words that are part of Apex and the Force.com platform, such as list, test, or account, as well as reserved keywords. Using Variables and Expressions Apex is a strongly-typed language, that is, you must declare the data type of a variable when you first refer to it. Apex data types include basic types such as Integer, Date, and Boolean, as well as more advanced types such as lists, maps, objects and sObjects. Variables are declared with a name and a data type. You can assign a value to a variable when you declare it. You can also assign values later. Use the following syntax when declaring variables: datatype variable_name [ = value]; Tip: Note that the semi-colon at the end of the above is not optional. You must end all statements with a semi-colon. The following are examples of variable declarations: // The following variable has the data type of Integer with the name Count, // and has the value of 0. Integer Count = 0; // The following variable has the data type of Decimal with the name Total. Note // that no value has been assigned to it. Decimal Total; // The following variable is an account, which is also referred to as an sObject. Account MyAcct = new Account(); In Apex, all primitive data type arguments, such as Integer or String, are passed into methods by value. This means that any changes to the arguments exist only within the scope of the method. When the method returns, the changes to the arguments are lost. Non-primitive data type arguments, such as sObjects, are also passed into methods by value. This means that when the method returns, the passed-in argument still references the same object as before the method call and can't be changed to point to another object. However, the values of the object's fields can be changed in the method. Using Statements A statement is any coded instruction that performs an action. In Apex, statements must end with a semicolon and can be one of the following types: • Assignment, such as assigning a value to a variable • Conditional (if-else) • Loops: ◊ Do-while ◊ While ◊ For • Locking • Data Manipulation Language (DML) • Transaction Control • Method Invoking • Exception Handling 25
- 28. Introducing Apex Understanding Apex Core Concepts A block is a series of statements that are grouped together with curly braces and can be used in any place where a single statement would be allowed. For example: if (true) { System.debug(1); System.debug(2); } else { System.debug(3); System.debug(4); } In cases where a block consists of only one statement, the curly braces can be left off. For example: if (true) System.debug(1); else System.debug(2); Using Collections Apex has the following types of collections: • Lists (arrays) • Maps • Sets A list is a collection of elements, such as Integers, Strings, objects, or other collections. Use a list when the sequence of elements is important. You can have duplicate elements in a list. The first index position in a list is always 0. To create a list: • Use the new keyword • Use the List keyword followed by the element type contained within <> characters. Use the following syntax for creating a list: List <datatype> list_name [= new List<datatype>();] | [=new List<datatype>{value [, value2. . .]};] | ; The following example creates a list of Integer, and assigns it to the variable My_List. Remember, because Apex is strongly typed, you must declare the data type of My_List as a list of Integer. List<Integer> My_List = new List<Integer>(); For more information, see Lists on page 43. A set is a collection of unique, unordered elements. It can contain primitive data types, such as String, Integer, Date, and so on. It can also contain more complex data types, such as sObjects. To create a set: • Use the new keyword • Use the Set keyword followed by the primitive data type contained within <> characters 26
- 29. Introducing Apex Understanding Apex Core Concepts Use the following syntax for creating a set: Set<datatype> set_name [= new Set<datatype>();] | [= new Set<datatype>{value [, value2. . .] };] | ; The following example creates a set of String. The values for the set are passed in using the curly braces {}. Set<String> My_String = new Set<String>{'a', 'b', 'c'}; For more information, see Sets on page 48. A map is a collection of key-value pairs. Keys can be any primitive data type. Values can include primitive data types, as well as objects and other collections. Use a map when finding something by key matters. You can have duplicate values in a map, but each key must be unique. To create a map: • Use the new keyword • Use the Map keyword followed by a key-value pair, delimited by a comma and enclosed in <> characters. Use the following syntax for creating a map: Map<key_datatype, value_datatype> map_name [=new map<key_datatype, value_datatype>();] | [=new map<key_datatype, value_datatype> {key1_value => value1_value [, key2_value => value2_value. . .]};] | ; The following example creates a map that has a data type of Integer for the key and String for the value. In this example, the values for the map are being passed in between the curly braces {} as the map is being created. Map<Integer, String> My_Map = new Map<Integer, String>{1 => 'a', 2 => 'b', 3 => 'c'}; For more information, see Maps on page 50. Using Branching An if statement is a true-false test that enables your application to do different things based on a condition. The basic syntax is as follows: if (Condition){ // Do this if the condition is true } else { // Do this if the condition is not true } For more information, see Conditional (If-Else) Statements on page 68. Using Loops While the if statement enables your application to do things based on a condition, loops tell your application to do the same thing again and again based on a condition. Apex supports the following types of loops: 27
- 30. Introducing Apex Writing Your First Apex Class and Trigger • Do-while • While • For A Do-while loop checks the condition after the code has executed. A While loop checks the condition at the start, before the code executes. A For loop enables you to more finely control the condition used with the loop. In addition, Apex supports traditional For loops where you set the conditions, as well as For loops that use lists and SOQL queries as part of the condition. For more information, see Loops on page 69. Writing Your First Apex Class and Trigger This step-by-step tutorial shows how to create a simple Apex class and trigger. It also shows how to deploy these components to a production organization. This tutorial is based on a custom object called Book that is created in the first step. This custom object is updated through a trigger. See Also: Creating a Custom Object Adding an Apex Class Adding an Apex Trigger Adding a Test Class Deploying Components to Production Creating a Custom Object Prerequisites: A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization. For more information about creating a sandbox organization, see “Sandbox Overview” in the Salesforce online help. To sign up for a free Developer organization, see the Developer Edition Environment Sign Up Page. In this step, you create a custom object called Book with one custom field called Price. 1. Log into your sandbox or Developer organization. 2. Click Your Name > Setup > Create > Objects and click New Custom Object. 3. Enter Book for the label. 4. Enter Books for the plural label. 5. Click Save. Ta dah! You've now created your first custom object. Now let's create a custom field. 6. In the Custom Fields & Relationships section of the Book detail page, click New. 7. Select Number for the data type and click Next. 8. Enter Price for the field label. 9. Enter 16 in the length text box. 10. Enter 2 in the decimal places text box, and click Next. 11. Click Next to accept the default values for field-level security. 28
- 31. Introducing Apex Writing Your First Apex Class and Trigger 12. Click Save. You’ve just created a custom object called Book, and added a custom field to that custom object. Custom objects already have some standard fields, like Name and CreatedBy, and allow you to add other fields that are more specific to your implementation. For this tutorial, the Price field is part of our Book object and it is accessed by the Apex class you will write in the next step. See Also: Writing Your First Apex Class and Trigger Adding an Apex Class Adding an Apex Class Prerequisites: • A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization. • The Book custom object In this step, you add an Apex class that contains a method for updating the book price. This method is called by the trigger that you will be adding in the next step. 1. Click Your Name > Setup > Develop > Apex Classes and click New. 2. In the class editor, enter this class definition: public class MyHelloWorld { } The previous code is the class definition to which you will be adding one method in the next step. Apex code is generally contained in classes. This class is defined as public, which means the class is available to other Apex classes and triggers. For more information, see Classes, Objects, and Interfaces on page 111. 3. Add this method definition between the class opening and closing brackets. public static void applyDiscount(Book__c[] books) { for (Book__c b :books){ b.Price__c *= 0.9; } } This method is called applyDiscount, and is both public and static. Because it is a static method, you don't need to create an instance of the class to access the method—you can just use the name of the class followed by a dot (.) and the name of the method. For more information, see Static and Instance on page 122. This method takes one parameter, a list of Book records, which is assigned to the variable books. Notice the __c in the object name Book__c. This indicates that it is a custom object that you created. Standard objects that are provided in the Salesforce application, such as Account, don't end with this postfix. The next section of code contains the rest of the method definition: for (Book__c b :books){ b.Price__c *= 0.9; } 29
- 32. Introducing Apex Writing Your First Apex Class and Trigger Notice the __c after the field name Price__c. This indicates it is a custom field that you created. Standard fields that are provided by default in Salesforce are accessed using the same type of dot notation but without the __c, for example, Name doesn't end with __c in Book__c.Name. The statement b.Price__c *= 0.9; takes the old value of b.Price__c, multiplies it by 0.9, which means its value will be discounted by 10%, and then stores the new value into the b.Price__c field. The *= operator is a shortcut. Another way to write this statement is b.Price__c = b.Price__c * 0.9;. See Understanding Expression Operators on page 60. 4. Click Save to save the new class. You should now have this full class definition. public class MyHelloWorld { public static void applyDiscount(Book__c[] books) { for (Book__c b :books){ b.Price__c *= 0.9; } } } You now have a class that contains some code which iterates over a list of books and updates the Price field for each book. This code is part of the applyDiscount static method that is called by the trigger that you will create in the next step. See Also: Writing Your First Apex Class and Trigger Creating a Custom Object Adding an Apex Trigger Adding an Apex Trigger Prerequisites: • A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization. • The MyHelloWorld Apex class. In this step, you create a trigger for the Book__c custom object that calls the applyDiscount method of the MyHelloWorld class that you created in the previous step. A trigger is a piece of code that executes before or after records of a particular type are inserted, updated, or deleted from the Force.com platform database. Every trigger runs with a set of context variables that provide access to the records that caused the trigger to fire. All triggers run in bulk, that is, they process several records at once. 1. Click Your Name > Setup > Create > Objects and click the name of the object you just created, Book. 2. In the triggers section, click New. 3. In the trigger editor, delete the default template code and enter this trigger definition: trigger HelloWorldTrigger on Book__c (before insert) { Book__c[] books = Trigger.new; MyHelloWorld.applyDiscount(books); } The first line of code defines the trigger: trigger HelloWorldTrigger on Book__c (before insert) { 30
- 33. Introducing Apex Writing Your First Apex Class and Trigger It gives the trigger a name, specifies the object on which it operates, and defines the events that cause it to fire. For example, this trigger is called HelloWorldTrigger, it operates on the Book__c object, and runs before new books are inserted into the database. The next line in the trigger creates a list of book records named books and assigns it the contents of a trigger context variable called Trigger.new. Trigger context variables such as Trigger.new are implicitly defined in all triggers and provide access to the records that caused the trigger to fire. In this case, Trigger.new contains all the new books that are about to be inserted. Book__c[] books = Trigger.new; The next line in the code calls the method applyDiscount in the MyHelloWorld class. It passes in the array of new books. MyHelloWorld.applyDiscount(books); You now have all the code that is needed to update the price of all books that get inserted. However, there is still one piece of the puzzle missing. Unit tests are an important part of writing code and are required. In the next step, you will see why this is so and you will be able to add a test class. See Also: Writing Your First Apex Class and Trigger Adding an Apex Class Adding a Test Class Adding a Test Class Prerequisites: • A Salesforce account in a sandbox Unlimited or Enterprise Edition organization, or an account in a Developer organization. • The HelloWorldTrigger Apex trigger. In this step, you add a test class with one test method. You also run the test and verify code coverage. The test method exercises and validates the code in the trigger and class. Also, it enables you to reach 100% code coverage for the trigger and class. Note: Testing is an important part of the development process. Before you can deploy Apex or package it for the Force.com AppExchange, the following must be true: • 75% of your Apex code must be covered by unit tests, and all of those tests must complete successfully. Note the following: ◊ When deploying to a production organization, every unit test in your organization namespace is executed. ◊ Calls to System.debug are not counted as part of Apex code coverage. ◊ Test methods and test classes are not counted as part of Apex code coverage. ◊ While only 75% of your Apex code must be covered by tests, your focus shouldn't be on the percentage of code that is covered. Instead, you should make sure that every use case of your application is covered, including positive and negative cases, as well as bulk and single record. This should lead to 75% or more of your code being covered by unit tests. • Every trigger has some test coverage. • All classes and triggers compile successfully. 31
- 34. Introducing Apex Writing Your First Apex Class and Trigger 1. Click Your Name > Setup > Develop > Apex Classes and click New. 2. In the class editor, add this test class definition, and then click Save. @isTest private class HelloWorldTestClass { static testMethod void validateHelloWorld() { Book__c b = new Book__c(Name='Behind the Cloud', Price__c=100); System.debug('Price before inserting new book: ' + b.Price__c); // Insert book insert b; // Retrieve the new book b = [SELECT Price__c FROM Book__c WHERE Id =:b.Id]; System.debug('Price after trigger fired: ' + b.Price__c); // Test that the trigger correctly updated the price System.assertEquals(90, b.Price__c); } } This class is defined using the @isTest annotation. Classes defined as such can only contain test methods. One advantage to creating a separate class for testing as opposed to adding test methods to an existing class is that classes defined with isTest don't count against your organization limit of 3 MB for all Apex code. You can also add the @isTest annotation to individual methods. For more information, see IsTest Annotation on page 138 and Understanding Execution Governors and Limits on page 225. The method validateHelloWorld is defined as a testMethod. This means that if any changes are made to the database, they are automatically rolled back when execution completes and you don't have to delete any test data created in the test method. First the test method creates a new book and inserts it into the database temporarily. The System.debug statement writes the value of the price in the debug log. Book__c b = new Book__c(Name='Behind the Cloud', Price__c=100); System.debug('Price before inserting new book: ' + b.Price__c); // Insert book insert b; Once the book is inserted, the code retrieves the newly inserted book, using the ID that was initially assigned to the book when it was inserted, and then logs the new price, that the trigger modified: // Retrieve the new book b = [SELECT Price__c FROM Book__c WHERE Id =:b.Id]; System.debug('Price after trigger fired: ' + b.Price__c); When the MyHelloWorld class runs, it updates the Price__c field and reduces its value by 10%. The following line is the actual test, verifying that the method applyDiscount actually ran and produced the expected result: // Test that the trigger correctly updated the price System.assertEquals(90, b.Price__c); 3. Click Run Test in the class page to run all the test methods in this class. In this case, we have only one test method. The Apex Test Result page appears after the test finishes execution. It contains the test result details such as the number of test failures, code coverage information, and a link to a downloadable log file. 32
- 35. Introducing Apex Writing Your First Apex Class and Trigger 4. Click Download and select to open the log file. You can find logging information about the trigger event, the call to the applyDiscount class method, and the debug output of the price before and after the trigger. Alternatively, you can use the Developer Console for debugging Apex code. See “Developer Console” in the Salesforce online help. 5. You can also run the test through the Apex Test Execution page, which runs the test asynchronously, which means that you don't have to wait for the test run to finish to get the test result, but you can perform other tasks in the user interface while the test is still running and then visit this page later to check the test status. a. Click Your Name > Setup > Develop > Apex Test Execution. b. Click Run Tests. c. Select the class HelloWorldTestClass, and then click Run. After a test finishes running, you can: • Click the test to see result details; if a test fails, the first error message and the stack trace display. • Click View to see the source Apex code. 6. After the test execution completes, verify the amount of code coverage. a. Click Your Name > Setup > Develop > Apex Classes. b. Click Calculate your organization's code coverage to see the amount of code in your organization that is covered by unit tests. c. In the Code Coverage column, click 100% to see the lines of code covered by unit tests. Take a look at the list of triggers by clicking Your Name > Setup > Develop > Apex Triggers. You'll see that the trigger you wrote also has 100% of its code covered. By now, you completed all the steps necessary for having some Apex code that has been tested and that runs in your development environment. In the real world, after you’ve sufficiently tested your code and you’re satisfied with it, you want to deploy the code along with any other prerequisite components to a production organization. The next step will show you how to do this for the code and custom object you’ve just created. See Also: Writing Your First Apex Class and Trigger Adding an Apex Trigger Deploying Components to Production Deploying Components to Production Prerequisites: • A Salesforce account in a sandbox Unlimited or Enterprise Edition organization. • The HelloWorldTestClass Apex test class. • A deployment connection between the sandbox and production organizations that allows inbound change sets to be received by the production organization. See “Change Sets Overview” in the Salesforce online help. • Create and Upload Change Sets user permissions to create, edit, or upload outbound change sets. In this step, you deploy the Apex code and the custom object you created previously to your production organization using change sets. This procedure doesn't apply to Developer organizations since change sets are available only in Unlimited, Enterprise, or Database.com Edition organizations. If you have a Developer Edition account, you can use other deployment methods. See Deploying Apex. 33
- 36. Introducing Apex Writing Your First Apex Class and Trigger 1. Click Your Name > Setup > Deploy > Outbound Changesets. 2. If a splash page appears, click Continue. 3. In the Change Sets list, click New. 4. Enter a name for your change set, for example, HelloWorldChangeSet, and optionally a description. Click Save. 5. In the change set components section, click Add. 6. Select Apex Class from the component type drop-down list, then select the MyHelloWorld and the HelloWorldTestClass classes from the list and click Add to Change Set. 7. Click View/Add Dependencies to add the dependent components. 8. Select the top checkbox to select all components. Click Add To Change Set. 9. In the change set detail section of the change set page, click Upload. 10. Select the target organization, in this case production, and click Upload. 11. After the change set upload completes, deploy it in your production organization. a. Log into your production organization. b. Click Your Name > Setup > Deploy > Inbound Change Sets. c. If a splash page appears, click Continue. d. In the change sets awaiting deployment list, click your change set's name. e. Click Deploy. In this tutorial, you learned how to create a custom object, how to add an Apex trigger, class, and test class, and how to test your code. Finally, you also learned how to upload the code and the custom object using Change Sets. See Also: Writing Your First Apex Class and Trigger Adding a Test Class 34
- 37. Chapter 2 Language Constructs In this chapter ... Apex is a strongly typed, object-oriented, and case-insensitive programming language. The Apex language constructs are building blocks that enable you to • Data Types write programs in Apex. Using those language constructs, you can declare variables • Variables and constants of built-in data types—primitives and sObjects—enumerations, • Expressions and custom data types based on system and user-provided Apex types. Apex • Assignment Statements provides expressions, assignment, and conditional statements. Like other programming languages, Apex provides exception handling and has different • Conditional (If-Else) Statements types of loops. Unlike other languages, Apex has a special type of loop called • Loops SOQL for loop, which allows for batching query results. Apex is integrated with • SOQL and SOSL Queries the database—it allows you to write inline queries, perform record locking, and • Locking Statements control transactions. • Transaction Control The following language constructs form the base parts of Apex: • Exception Statements • Data Types • Variables • Expressions • Assignment Statements • Conditional (If-Else) Statements • Loops • SOQL and SOSL Queries • Locking Statements • Transaction Control • Exception Statements Apex is contained in either a trigger or a class. For more information, see Triggers on page 88 and Classes, Objects, and Interfaces on page 111. 35
- 38. Language Constructs Data Types Data Types In Apex, all variables and expressions have a data type that is one of the following: • A primitive, such as an Integer, Double, Long, Date, Datetime, String, ID, or Boolean (see Primitive Data Types on page 36) • An sObject, either as a generic sObject or as a specific sObject, such as an Account, Contact, or MyCustomObject__c (see sObject Types on page 39) • A collection, including: ◊ A list (or array) of primitives, sObjects, user defined objects, objects created from Apex classes, or collections (see Lists on page 43) ◊ A set of primitives (see Sets on page 48) ◊ A map from a primitive to a primitive, sObject, or collection (see Maps on page 50) • A typed list of values, also known as an enum (see Enums on page 54) • Objects created from user-defined Apex classes (see Classes, Objects, and Interfaces on page 111) • Objects created from system supplied Apex classes (see Apex Classes on page 457) • Null (for the null constant, which can be assigned to any variable) Methods can return values of any of the listed types, or return no value and be of type Void. Type checking is strictly enforced at compile time. For example, the parser generates an error if an object field of type Integer is assigned a value of type String. However, all compile-time exceptions are returned as specific fault codes, with the line number and column of the error. For more information, see Debugging Apex on page 209. Primitive Data Types Apex uses the same primitive data types as the SOAP API. All primitive data types are passed by value. All Apex variables, whether they’re class member variables or method variables, are initialized to null. Make sure that you initialize your variables to appropriate values before using them. For example, initialize a Boolean variable to false. Apex primitive data types include: Data Type Description Blob A collection of binary data stored as a single object. You can convert this datatype to String or from String using the toString and valueOf methods, respectively. Blobs can be accepted as Web service arguments, stored in a document (the body of a document is a Blob), or sent as attachments. For more information, see Crypto Class on page 525. Boolean A value that can only be assigned true, false, or null. For example: Boolean isWinner = true; Date A value that indicates a particular day. Unlike Datetime values, Date values contain no information about time. Date values must always be created with a system static method. You cannot manipulate a Date value, such as add days, merely by adding a number to a Date variable. You must use the Date methods instead. 36
- 39. Language Constructs Primitive Data Types Data Type Description Datetime A value that indicates a particular day and time, such as a timestamp. Datetime values must always be created with a system static method. You cannot manipulate a Datetime value, such as add minutes, merely by adding a number to a Datetime variable. You must use the Datetime methods instead. Decimal A number that includes a decimal point. Decimal is an arbitrary precision number. Currency fields are automatically assigned the type Decimal. If you do not explicitly set the scale, that is, the number of decimal places, for a Decimal using the setScale method, the scale is determined by the item from which the Decimal is created. • If the Decimal is created as part of a query, the scale is based on the scale of the field returned from the query. • If the Decimal is created from a String, the scale is the number of characters after the decimal point of the String. • If the Decimal is created from a non-decimal number, the scale is determined by converting the number to a String and then using the number of characters after the decimal point. Double A 64-bit number that includes a decimal point. Doubles have a minimum value of -263 and a maximum value of 263-1. For example: Double d=3.14159; Note that scientific notation (e) for Doubles is not supported. ID Any valid 18-character Force.com record identifier. For example: ID id='00300000003T2PGAA0'; Note that if you set ID to a 15-character value, Apex automatically converts the value to its 18-character representation. All invalid ID values are rejected with a runtime exception. Integer A 32-bit number that does not include a decimal point. Integers have a minimum value of -2,147,483,648 and a maximum value of 2,147,483,647. For example: Integer i = 1; Long A 64-bit number that does not include a decimal point. Longs have a minimum value of -263 and a maximum value of 263-1. Use this datatype when you need a range of values wider than those provided by Integer. For example: Long l = 2147483648L; String Any set of characters surrounded by single quotes. For example, String s = 'The quick brown fox jumped over the lazy dog.'; 37
- 40. Language Constructs Primitive Data Types Data Type Description String size: Strings have no limit on the number of characters they can include. Instead, the heap size limit is used to ensure that your Apex programs don't grow too large. Empty Strings and Trailing Whitespace: sObject String field values follow the same rules as in the SOAP API: they can never be empty (only null), and they can never include leading and trailing whitespace. These conventions are necessary for database storage. Conversely, Strings in Apex can be null or empty, and can include leading and trailing whitespace (such as might be used to construct a message). The Solution sObject field SolutionNote operates as a special type of String. If you have HTML Solutions enabled, any HTML tags used in this field are verified before the object is created or updated. If invalid HTML is entered, an error is thrown. Any JavaScript used in this field is removed before the object is created or updated. In the following example, when the Solution displays on a detail page, the SolutionNote field has H1 HTML formatting applied to it: trigger t on Solution (before insert) { Trigger.new[0].SolutionNote ='<h1>hello</h1>'; } In the following example, when the Solution displays on a detail page, the SolutionNote field only contains HelloGoodbye: trigger t2 on Solution (before insert) { Trigger.new[0].SolutionNote = '<javascript>Hello</javascript>Goodbye'; } For more information, see ““What are HTML Solutions?” in the online help. Escape Sequences: All Strings in Apex use the same escape sequences as SOQL strings: b (backspace), t (tab), n (line feed), f (form feed), r (carriage return), " (double quote), ' (single quote), and (backslash). Comparison Operators: Unlike Java, Apex Strings support use of the comparison operators ==, !=, <, <=, >, and >=. Since Apex uses SOQL comparison semantics, results for Strings are collated according to the context user's locale, and `are not case sensitive. For more information, see Operators on page 60. String Methods: As in Java, Strings can be manipulated with a number of standard methods. See String Methods for information. Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String value that is too long for the field. Time A value that indicates a particular time. Time values must always be created with a system static method. See Time Methods on page 332. In addition, two non-standard primitive data types cannot be used as variable or method types, but do appear in system static methods: 38
- 41. Language Constructs sObject Types • AnyType. The valueOf static method converts an sObject field of type AnyType to a standard primitive. AnyType is used within the Force.com platform database exclusively for sObject fields in field history tracking tables. • Currency. The Currency.newInstance static method creates a literal of type Currency. This method is for use solely within SOQL and SOSL WHERE clauses to filter against sObject currency fields. You cannot instantiate Currency in any other type of Apex. For more information on the AnyType data type, see Field Types in the Object Reference for Salesforce and Force.com. sObject Types In this developer's guide, the term sObject refers to any object that can be stored in the Force.com platform database. An sObject variable represents a row of data and can only be declared in Apex using the SOAP API name of the object. For example: Account a = new Account(); MyCustomObject__c co = new MyCustomObject__c(); Similar to the SOAP API, Apex allows the use of the generic sObject abstract type to represent any object. The sObject data type can be used in code that processes different types of sObjects. The new operator still requires a concrete sObject type, so all instances are specific sObjects. For example: sObject s = new Account(); You can also use casting between the generic sObject type and the specific sObject type. For example: // Cast the generic variable s from the example above // into a specific account and account variable a Account a = (Account)s; // The following generates a runtime error Contact c = (Contact)s; Because sObjects work like objects, you can also have the following: Object obj = s; // and a = (Account)obj; DML operations work on variables declared as the generic sObject data type as well as with regular sObjects. sObject variables are initialized to null, but can be assigned a valid object reference with the new operator. For example: Account a = new Account(); Developers can also specify initial field values with comma-separated name = value pairs when instantiating a new sObject. For example: Account a = new Account(name = 'Acme', billingcity = 'San Francisco'); For information on accessing existing sObjects from the Force.com platform database, see SOQL and SOSL Queries on page 73. 39
- 42. Language Constructs sObject Types Note: The ID of an sObject is a read-only value and can never be modified explicitly in Apex unless it is cleared during a clone operation, or is assigned with a constructor. The Force.com platform assigns ID values automatically when an object record is initially inserted to the database for the first time. For more information see Lists on page 43. Custom Labels Custom labels are not standard sObjects. You cannot create a new instance of a custom label. You can only access the value of a custom label using system.label.label_name. For example: String errorMsg = System.Label.generic_error; For more information on custom labels, see “Custom Labels Overview” in the online help. Accessing sObject Fields As in Java, sObject fields can be accessed or changed with simple dot notation. For example: Account a = new Account(); a.Name = 'Acme'; // Access the account name field and assign it 'Acme' System generated fields, such as Created By or Last Modified Date, cannot be modified. If you try, the Apex runtime engine generates an error. Additionally, formula field values and values for other fields that are read-only for the context user cannot be changed. If you use the generic sObject type, instead of a specific object such as Account, you can only retrieve the ID field. For example: Account a = new Account(Name = 'Acme', BillingCity = 'San Francisco'); insert a; sObject s = [SELECT Id, Name FROM Account WHERE Name = 'Acme' LIMIT 1]; // This is allowed ID id = s.Id; // The following lines result in errors when you try to save String x = s.Name; s.Id = [SELECT Id FROM Account WHERE Name = 'Acme' LIMIT 1]; Note: If your organization has enabled person accounts, you have two different kinds of accounts: business accounts and person accounts. If your code creates a new account using name, a business account is created. If your code uses LastName, a person account is created. If you want to perform operations on an sObject, it is recommended that you first convert it into a specific object. For example: Account a = new Account(Name = 'Acme', BillingCity = 'San Francisco'); insert a; sObject s = [SELECT Id, Name FROM Account WHERE Name = 'Acme' LIMIT 1]; ID id = s.ID; Account convertedAccount = (Account)s; convertedAccount.name = 'Acme2'; update convertedAccount; Contact sal = new Contact(FirstName = 'Sal', Account = convertedAccount); 40
- 43. Language Constructs sObject Types The following example shows how you can use SOSL over a set of records to determine their object types. Once you have converted the generic sObject record into a Contact, Lead, or Account, you can modify its fields accordingly: public class convertToCLA { List<Contact> contacts; List<Lead> leads; List<Account> accounts; public void convertType(Integer phoneNumber) { List<List<sObject>> results = [FIND '4155557000' IN Phone FIELDS RETURNING Contact(Id, Phone, FirstName, LastName), Lead(Id, Phone, FirstName, LastName), Account(Id, Phone, Name)]; sObject[] records = ((List<sObject>)results[0]); if (!records.isEmpty()) { for (Integer i = 0; i < records.size(); i++) { sObject record = records[i]; if (record.getSObjectType() == Contact.sObjectType) { contacts.add((Contact) record); } else if (record.getSObjectType() == Lead.sObjectType){ leads.add((Lead) record); } else if (record.getSObjectType() == Account.sObjectType) { accounts.add((Account) record); } } } } } Accessing sObject Fields Through Relationships sObject records represent relationships to other records with two fields: an ID and an address that points to a representation of the associated sObject. For example, the Contact sObject has both an AccountId field of type ID, and an Account field of type Account that points to the associated sObject record itself. The ID field can be used to change the account with which the contact is associated, while the sObject reference field can be used to access data from the account. The reference field is only populated as the result of a SOQL or SOSL query (see note below). For example, the following Apex code shows how an account and a contact can be associated with one another, and then how the contact can be used to modify a field on the account: Note: In order to provide the most complete example, this code uses some elements that are described later in this guide: • For information on insert and update, see Insert Operation on page 274 and Update Operation on page 274. • For information on SOQL and SOSL, see SOQL and SOSL Queries on page 73. Account a = new Account(Name = 'Acme'); insert a; // Inserting the record automatically assigns a // value to its ID field Contact c = new Contact(LastName = 'Weissman'); c.AccountId = a.Id; // The new contact now points at the new account insert c; // A SOQL query accesses data for the inserted contact, // including a populated c.account field 41
- 44. Language Constructs sObject Types c = [SELECT Account.Name FROM Contact WHERE Id = :c.Id]; // Now fields in both records can be changed through the contact c.Account.Name = 'salesforce.com'; c.LastName = 'Roth'; // To update the database, the two types of records must be // updated separately update c; // This only changes the contact's last name update c.Account; // This updates the account name Note: The expression c.Account.Name, as well as any other expression that traverses a relationship, displays slightly different characteristics when it is read as a value than when it is modified: • When being read as a value, if c.Account is null, then c.Account.Name evaluates to null, but does not yield a NullPointerException. This design allows developers to navigate multiple relationships without the tedium of having to check for null values. • When being modified, if c.Account is null, then c.Account.Name does yield a NullPointerException. In addition, the sObject field key can be used with insert, update, or upsert to resolve foreign keys by external ID. For example: Account refAcct = new Account(externalId__c = '12345'); Contact c = new Contact(Account = refAcct, LastName = 'Kay'); insert c; This inserts a new contact with the AccountId equal to the account with the external_id equal to ‘12345’. If there is no such account, the insert fails. Tip: The following code is equivalent to the code above. However, because it uses a SOQL query, it is not as efficient. If this code was called multiple times, it could reach the execution limit for the maximum number of SOQL queries. For more information on execution limits, see Understanding Execution Governors and Limits on page 225. Account refAcct = [SELECT Id FROM Account WHERE externalId__c='12345']; Contact c = new Contact(Account = refAcct.Id); insert c; Validating sObjects and Fields When Apex code is parsed and validated, all sObject and field references are validated against actual object and field names, and a parse-time exception is thrown when an invalid name is used. In addition, the Apex parser tracks the custom objects and fields that are used, both in the code's syntax as well as in embedded SOQL and SOSL statements. The platform prevents users from making the following types of modifications when those changes cause Apex code to become invalid: • Changing a field or object name • Converting from one data type to another 42
- 45. Language Constructs Collections • Deleting a field or object • Making certain organization-wide changes, such as record sharing, field history tracking, or record types Collections Apex has the following types of collections: • Lists • Maps • Sets Note: There is no limit on the number of items a collection can hold. However, there is a general limit on heap size. Lists A list is an ordered collection of typed primitives, sObjects, user-defined objects, Apex objects or collections that are distinguished by their indices. For example, the following table is a visual representation of a list of Strings: Index 0 Index 1 Index 2 Index 3 Index 4 Index 5 'Red' 'Orange' 'Yellow' 'Green' 'Blue' 'Purple' The index position of the first element in a list is always 0. Because lists can contain any collection, they can be nested within one another and become multidimensional. For example, you can have a list of lists of sets of Integers. A list can contain up to four levels of nested collections inside it. To declare a list, use the List keyword followed by the primitive data, sObject, nested list, map, or set type within <> characters. For example: // Create an empty list of String List<String> my_list = new List<String>(); // Create a nested list List<List<Set<Integer>>> my_list_2 = new List<List<Set<Integer>>>(); // Create a list of account records from a SOQL query List<Account> accs = [SELECT Id, Name FROM Account LIMIT 1000]; To access elements in a list, use the system methods provided by Apex. For example: List<Integer> MyList = new List<Integer>(); // Define a new list MyList.add(47); // Adds a second element of value 47 to the end // of the list MyList.get(0); // Retrieves the element at index 0 MyList.set(0, 1); // Adds the integer 1 to the list at index 0 MyList.clear(); // Removes all elements from the list For more information, including a complete list of all supported methods, see List Methods on page 333. 43
- 46. Language Constructs Collections Using Array Notation for One-Dimensional Lists of Primitives or sObjects When using one-dimensional lists of primitives or sObjects, you can also use more traditional array notation to declare and reference list elements. For example, you can declare a one-dimensional list of primitives or sObjects by following the data or sObject type name with the [] characters: String[] colors = new List<String>(); To reference an element of a one-dimensional list of primitives or sObjects, you can also follow the name of the list with the element's index position in square brackets. For example: colors[3] = 'Green'; All lists are initialized to null. Lists can be assigned values and allocated memory using literal notation. For example: Example Description Defines an Integer list with no elements List<Integer> ints = new Integer[0]; Defines an Account list with no elements List<Account> accts = new Account[]{}; Defines an Integer list with memory allocated for six Integers List<Integer> ints = new Integer[6]; Defines an Account list with memory allocated for three List<Account> accts = new Account[] Accounts, including a new Account object in the first position, {new Account(), null, new Account()}; null in the second position, and another new Account object in the third position Defines the Contact list with a new list List<Contact> contacts = new List<Contact> (otherList); Lists of sObjects Apex automatically generates IDs for each object in a list of sObjects when the list is successfully inserted or upserted into the database with a data manipulation language (DML) statement. Consequently, a list of sObjects cannot be inserted or upserted if it contains the same sObject more than once, even if it has a null ID. This situation would imply that two IDs would need to be written to the same structure in memory, which is illegal. For example, the insert statement in the following block of code generates a ListException because it tries to insert a list with two references to the same sObject (a): try { // Create a list with two references to the same sObject element Account a = new Account(); 44
- 47. Language Constructs Collections Account[] accs = new Account[]{a, a}; // Attempt to insert it... insert accs; // Will not get here System.assert(false); } catch (ListException e) { // But will get here } For more information on DML statements, see Apex Data Manipulation Language (DML) Operations on page 268. You can use the generic sObject data type with lists. You can also create a generic instance of a list. List Sorting Using the List.sort method, you can sort lists of primitive data types, custom types (your Apex classes) that implement the Comparable Interface, SelectOption elements, and sObjects (standard objects and custom objects). Sorting is in ascending order for primitive data types. For custom types, the sort criteria and sort order depends on the implementation that you provide for the compareTo method of the Comparable interface. For more information on implementing the Comparable Interface for your own classes, see Comparable Interface. For sObjects, sorting is in ascending order and uses a sequence of comparison steps outlined in the next section. However, you can also implement a custom sort order for sObjects by wrapping your sObject in an Apex class and implementing the Comparable Interface, as shown in Custom Sort Order of sObjects. For SelectOption, sorting is in ascending order based on the value and label fields. See Default Sort Order for SelectOption for the sequence of comparison steps used for SelectOption. Default Sort Order of sObjects The List.sort method sorts sObjects in ascending order and compares sObjects using an ordered sequence of steps that specify the labels or fields used. The comparison starts with the first step in the sequence and ends when two sObjects are sorted using specified labels or fields. The following is the comparison sequence used: 1. The label of the sObject type. For example, an Account sObject will appear before a Contact. 2. The Name field, if applicable. For example, if the list contains two accounts named A and B respectively, account A comes before account B. 3. Standard fields, starting with the fields that come first in alphabetical order, except for the Id and Name fields. For example, if two accounts have the same name, the first standard field used for sorting is AccountNumber. 4. Custom fields, starting with the fields that come first in alphabetical order. For example, suppose two accounts have the same name and identical standard fields, and there are two custom fields, FieldA and FieldB, the value of FieldA is used first for sorting. Not all steps in this sequence are necessarily carried out. For example, if a list contains two sObjects of the same type and with unique Name values, they’re sorted based on the Name field and sorting stops at step 2. Otherwise, if the names are identical or the sObject doesn’t have a Name field, sorting proceeds to step 3 to sort by standard fields. For text fields, the sort algorithm uses the Unicode sort order. Also, empty fields precede non-empty fields in the sort order. 45
- 48. Language Constructs Collections This is an example of sorting a list of Account sObjects. This example shows how the Name field is used to place the Acme account ahead of the two sForce accounts in the list. Since there are two accounts named sForce, the Industry field is used to sort these remaining accounts because the Industry field comes before the Site field in alphabetical order. Account[] acctList = new List<Account>(); acctList.add( new Account( Name='sForce', Industry='Biotechnology', Site='Austin')); acctList.add(new Account( Name='sForce', Industry='Agriculture', Site='New York')); acctList.add(new Account( Name='Acme')); System.debug(acctList); acctList.sort(); System.assertEquals('Acme', acctList[0].Name); System.assertEquals('sForce', acctList[1].Name); System.assertEquals('Agriculture', acctList[1].Industry); System.assertEquals('sForce', acctList[2].Name); System.assertEquals('Biotechnology', acctList[2].Industry); System.debug(acctList); This example is similar to the previous one, except that it uses the Merchandise__c custom object. This example shows how the Name field is used to place the Notebooks merchandise ahead of Pens in the list. Since there are two merchandise sObjects with the Name field value of Pens, the Description field is used to sort these remaining merchandise items because the Description field comes before the Price and Total_Inventory fields in alphabetical order. Merchandise__c[] merchList = new List<Merchandise__c>(); merchList.add( new Merchandise__c( Name='Pens', Description__c='Red pens', Price__c=2, Total_Inventory__c=1000)); merchList.add( new Merchandise__c( Name='Notebooks', Description__c='Cool notebooks', Price__c=3.50, Total_Inventory__c=2000)); merchList.add( new Merchandise__c( Name='Pens', Description__c='Blue pens', Price__c=1.75, Total_Inventory__c=800)); System.debug(merchList); merchList.sort(); System.assertEquals('Notebooks', merchList[0].Name); System.assertEquals('Pens', merchList[1].Name); System.assertEquals('Blue pens', merchList[1].Description__c); System.assertEquals('Pens', merchList[2].Name); System.assertEquals('Red pens', merchList[2].Description__c); System.debug(merchList); Custom Sort Order of sObjects To implement a custom sort order for sObjects in lists, create a wrapper class for the sObject and implement the Comparable Interface. The wrapper class contains the sObject in question and implements the compareTo method, in which you specify the sort logic. 46
- 49. Language Constructs Collections This example shows how to create a wrapper class for Opportunity. The implementation of the compareTo method in this class compares two opportunities based on the Amount field—the class member variable contained in this instance, and the opportunity object passed into the method. global class OpportunityWrapper implements Comparable { public Opportunity oppy; // Constructor public OpportunityWrapper(Opportunity op) { oppy = op; } // Compare opportunities based on the opportunity amount. global Integer compareTo(Object compareTo) { // Cast argument to OpportunityWrapper OpportunityWrapper compareToOppy = (OpportunityWrapper)compareTo; // The return value of 0 indicates that both elements are equal. Integer returnValue = 0; if (oppy.Amount > compareToOppy.oppy.Amount) { // Set return value to a positive value. returnValue = 1; } else if (oppy.Amount < compareToOppy.oppy.Amount) { // Set return value to a negative value. returnValue = -1; } return returnValue; } } This example provides a test for the OpportunityWrapper class. It sorts a list of OpportunityWrapper objects and verifies that the list elements are sorted by the opportunity amount. @isTest private class OpportunityWrapperTest { static testmethod void test1() { // Add the opportunity wrapper objects to a list. OpportunityWrapper[] oppyList = new List<OpportunityWrapper>(); Date closeDate = Date.today().addDays(10); oppyList.add( new OpportunityWrapper(new Opportunity( Name='Edge Installation', CloseDate=closeDate, StageName='Prospecting', Amount=50000))); oppyList.add( new OpportunityWrapper(new Opportunity( Name='United Oil Installations', CloseDate=closeDate, StageName='Needs Analysis', Amount=100000))); oppyList.add( new OpportunityWrapper(new Opportunity( Name='Grand Hotels SLA', CloseDate=closeDate, StageName='Prospecting', Amount=25000))); // Sort the wrapper objects using the implementation of the // compareTo method. oppyList.sort(); // Verify the sort order System.assertEquals('Grand Hotels SLA', oppyList[0].oppy.Name); System.assertEquals(25000, oppyList[0].oppy.Amount); 47
- 50. Language Constructs Collections System.assertEquals('Edge Installation', oppyList[1].oppy.Name); System.assertEquals(50000, oppyList[1].oppy.Amount); System.assertEquals('United Oil Installations', oppyList[2].oppy.Name); System.assertEquals(100000, oppyList[2].oppy.Amount); // Write the sorted list contents to the debug log. System.debug(oppyList); } } Default Sort Order for SelectOption The List.sort method sorts SelectOption elements in ascending order using the value and label fields, and is based on this comparison sequence. 1. The value field is used for sorting first. 2. If two value fields have the same value or are both empty, the label field is used. Note that the disabled field is not used for sorting. For text fields, the sort algorithm uses the Unicode sort order. Also, empty fields precede non-empty fields in the sort order. In this example, a list contains three SelectOption elements. Two elements, United States and Mexico, have the same value field (‘A’). The List.sort method sorts these two elements based on the label field, and places Mexico before United States, as shown in the output. The last element in the sorted list is Canada and is sorted on its value field ‘C’, which comes after ‘A’. List<SelectOption> options = new List<SelectOption>(); options.add(new SelectOption('A','United States')); options.add(new SelectOption('C','Canada')); options.add(new SelectOption('A','Mexico')); System.debug('Before sorting: ' + options); options.sort(); System.debug('After sorting: ' + options); This is the output of the debug statements. It shows the list contents before and after the sort. DEBUG|Before sorting: (System.SelectOption[value="A", label="United States", disabled="false"], System.SelectOption[value="C", label="Canada", disabled="false"], System.SelectOption[value="A", label="Mexico", disabled="false"]) DEBUG|After sorting: (System.SelectOption[value="A", label="Mexico", disabled="false"], System.SelectOption[value="A", label="United States", disabled="false"], System.SelectOption[value="C", label="Canada", disabled="false"]) Sets A set is an unordered collection of elements that do not contain any duplicates. Set elements can be of any data type—primitive types, collections, sObjects, user-defined types, and built-in Apex types. For example, the following table represents a set of strings, that uses city names: 'San Francisco' 'New York' 'Paris' 'Tokyo' Sets can contain collections that can be nested within one another. For example, you can have a set of lists of sets of Integers. A set can contain up to four levels of nested collections inside it. 48
- 51. Language Constructs Collections To declare a set, use the Set keyword followed by the primitive data type name within <> characters. For example: new Set<String>() The following are ways to declare and populate a set: Set<String> s1 = new Set<String>{'a', 'b + c'}; // Defines a new set with two elements Set<String> s2 = new Set<String>(s1); // Defines a new set that contains the // elements of the set created in the previous step To access elements in a set, use the system methods provided by Apex. For example: Set<Integer> s = new Set<Integer>(); // Define a new set s.add(1); // Add an element to the set System.assert(s.contains(1)); // Assert that the set contains an element s.remove(1); // Remove the element from the set Uniqueness of non-primitive objects is determined by comparing the objects’ fields, except for objects of user-defined types. For example, if you try to add two accounts with the same name to a set, only one is added. // Create two accounts, a1 and a2 Account a1 = new account(name='MyAccount'); Account a2 = new account(name='MyAccount'); // Add both accounts to the new set Set<Account> accountSet = new Set<Account>{a1, a2}; // Verify that the set only contains one item System.assertEquals(accountSet.size(), 1); However, if you add a description to one of the accounts, it is considered unique: // Create two accounts, a1 and a2, and add a description to a2 Account a1 = new account(name='MyAccount'); Account a2 = new account(name='MyAccount', description='My test account'); // Add both accounts to the new set Set<Account> accountSet = new Set<Account>{a1, a2}; // Verify that the set contains two items System.assertEquals(accountSet.size(), 2); Uniqueness of objects of user-defined types is determined by the equals and hashCode methods, which you provide in your classes. For more information, including a complete list of all supported set system methods, see Set Methods on page 344. Note the following limitations on sets: • Unlike Java, Apex developers do not need to reference the algorithm that is used to implement a set in their declarations (for example, HashSet or TreeSet). Apex uses a hash structure for all sets. • A set is an unordered collection. Do not rely on the order in which set results are returned. The order of objects returned by sets may change without warning. 49
- 52. Language Constructs Collections Maps A map is a collection of key-value pairs where each unique key maps to a single value. Keys and values can be any data type—primitive types, collections, sObjects, user-defined types, and built-in Apex types. For example, the following table represents a map of countries and currencies: Country (Key) 'United States' 'Japan' 'France' 'England' 'India' Currency (Value) 'Dollar' 'Yen' 'Euro' 'Pound' 'Rupee' Map keys and values can contain any collection, and can contain nested collections. For example, you can have a map of Integers to maps, which, in turn, map Strings to lists. Map keys can contain up to only four levels of nested collections. To declare a map, use the Map keyword followed by the data types of the key and the value within <> characters. For example: Map<String, String> country_currencies = new Map<String, String>(); Map<ID, Set<String>> m = new Map<ID, Set<String>>(); Map<ID, Map<ID, Account[]>> m2 = new Map<ID, Map<ID, Account[]>>(); You can use the generic sObject data type with maps. You can also create a generic instance of a map. As with lists, you can populate map key-value pairs when the map is declared by using curly brace ({}) syntax. Within the curly braces, specify the key first, then specify the value for that key using =>. For example: Map<String, String> MyStrings = new Map<String, String>{'a' => 'b', 'c' => 'd'.toUpperCase()}; Account[] accs = new Account[5]; // Account[] is synonymous with List<Account> Map<Integer, List<Account>> m4 = new Map<Integer, List<Account>>{1 => accs}; In the first example, the value for the key a is b, and the value for the key c is d. In the second, the key 1 has the value of the list accs. This in an example of using sObjects as map keys. Map<Account, String> mapKeyExample = new Map<Account, String>{ new Account(Name='Account1') => 'primary.person@account1.com', new Account(Name='Account2') => 'decision.maker@account2.com' }; To access elements in a map, use the Map methods provided by Apex. For example: Account myAcct = new Account(); //Define a new account Map<Integer, Account> m = new Map<Integer, Account>(); // Define a new map m.put(1, myAcct); // Insert a new key-value pair in the map System.assert(!m.containsKey(3)); // Assert that the map contains a key Account a = m.get(1); // Retrieve a value, given a particular key Set<Integer> s = m.keySet(); // Return a set that contains all of the keys in the map For more information, including a complete list of all supported Map methods, see Map Methods on page 340. Note the following considerations on maps: • Unlike Java, Apex developers do not need to reference the algorithm that is used to implement a map in their declarations (for example, HashMap or TreeMap). Apex uses a hash structure for all maps. 50
- 53. Language Constructs Collections • Do not rely on the order in which map results are returned. The order of objects returned by maps may change without warning. Always access map elements by key. • A map key can hold the null value. • Adding a map entry with a key that matches an existing key in the map overwrites the existing entry with that key with the new entry. • Uniqueness of map keys of user-defined types is determined by the equals and hashCode methods, which you provide in your classes. Uniqueness of all other non-primitive types is determined by comparing the objects’ fields. Maps from SObject Arrays Maps from an ID or String data type to an sObject can be initialized from a list of sObjects. The IDs of the objects (which must be non-null and distinct) are used as the keys. One common usage of this map type is for in-memory “joins” between two tables. For instance, this example loads a map of IDs and Contacts: Map<ID, Contact> m = new Map<ID, Contact>([SELECT Id, LastName FROM Contact]); In the example, the SOQL query returns a list of contacts with their Id and LastName fields. The new operator uses the list to create a map. For more information, see SOQL and SOSL Queries on page 73. Parameterized Typing Apex, in general, is a statically-typed programming language, which means users must specify the data type for a variable before that variable can be used. For example, the following is legal in Apex: Integer x = 1; The following is not legal if x has not been defined earlier: x = 1; Lists, maps and sets are parameterized in Apex: they take any data type Apex supports for them as an argument. That data type must be replaced with an actual data type upon construction of the list, map or set. For example: List<String> myList = new List<String>(); Subtyping with Parameterized Lists In Apex, if type T is a subtype of U, then List<T> would be a subtype of List<U>. For example, the following is legal: List<String> slst = new List<String> {'foo', 'bar'}; List<Object> olst = slst; Using Custom Types in Map Keys and Sets When using a custom type (your Apex class) for the map key or set elements, provide equals and hashCode methods in your class. Apex uses these two methods to determine equality and uniqueness of keys for your objects. Adding equals and hashCode Methods to Your Class To ensure that map keys of your custom type are compared correctly and their uniqueness can be determined consistently, provide an implementation of the following two methods in your class: 51
- 54. Language Constructs Collections • The equals method with this signature: public Boolean equals(Object obj) { // Your implementation } Keep in mind the following when implementing the equals method. Assuming x, y, and z are non-null instances of your class, the equals method must be: ◊ Reflexive: x.equals(x) ◊ Symmetric: x.equals(y) should return true if and only if y.equals(x) returns true ◊ Transitive: if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true ◊ Consistent: multiple invocations of x.equals(y) consistently return true or consistently return false ◊ For any non-null reference value x, x.equals(null) should return false The equals method in Apex is based on the equals method in Java. • The hashCode method with this signature: public Integer hashCode() { // Your implementation } Keep in mind the following when implementing the hashCode method. ◊ If the hashCode method is invoked on the same object more than once during execution of an Apex request, it must return the same value. ◊ If two objects are equal, based on the equals method, hashCode must return the same value. ◊ If two objects are unequal, based on the result of the equals method, it is not required that hashCode return distinct values. The hashCode method in Apex is based on the hashCode method in Java. Another benefit of providing the equals method in your class is that it simplifies comparing your objects. You will be able to use the == operator to compare objects, or the equals method. For example: // obj1 and obj2 are instances of MyClass if (obj1 == obj2) { // Do something } if (obj1.equals(obj2)) { // Do something } Sample This sample shows how to implement the equals and hashCode methods. The class that provides those methods is listed first. It also contains a constructor that takes two Integers. The second example is a code snippet that creates three objects of the class, two of which have the same values. Next, map entries are added using the pair objects as keys. The sample verifies that the map has only two entries since the entry that was added last has the same key as the first entry, and hence, overwrote it. The sample then uses the == operator, which works as expected because the class implements equals. Also, some additional map operations are performed, like checking whether the map contains certain keys, and writing all keys and values to the 52
- 55. Language Constructs Collections debug log. Finally, the sample creates a set and adds the same objects to it. It verifies that the set size is two, since only two objects out of the three are unique. public class PairNumbers { Integer x,y; public PairNumbers(Integer a, Integer b) { x=a; y=b; } public Boolean equals(Object obj) { if (obj instanceof PairNumbers) { PairNumbers p = (PairNumbers)obj; return ((x==p.x) && (y==p.y)); } return false; } public Integer hashCode() { return (31 * x) ^ y; } } This code snippet makes use of the PairNumbers class. Map<PairNumbers, String> m = new Map<PairNumbers, String>(); PairNumbers p1 = new PairNumbers(1,2); PairNumbers p2 = new PairNumbers(3,4); // Duplicate key PairNumbers p3 = new PairNumbers(1,2); m.put(p1, 'first'); m.put(p2, 'second'); m.put(p3, 'third'); // Map size is 2 because the entry with // the duplicate key overwrote the first entry. System.assertEquals(2, m.size()); // Use the == operator if (p1 == p3) { System.debug('p1 and p3 are equal.'); } // Perform some other operations System.assertEquals(true, m.containsKey(p1)); System.assertEquals(true, m.containsKey(p2)); System.assertEquals(false, m.containsKey(new PairNumbers(5,6))); for(PairNumbers pn : m.keySet()) { System.debug('Key: ' + pn); } List<String> mValues = m.values(); System.debug('m.values: ' + mValues); // Create a set Set<PairNumbers> s1 = new Set<PairNumbers>(); s1.add(p1); s1.add(p2); s1.add(p3); // Verify that we have only two elements // since the p3 is equal to p1. System.assertEquals(2, s1.size()); 53
- 56. Language Constructs Enums Iterating Collections Collections can consist of lists, sets, or maps. Modifying a collection's elements while iterating through that collection is not supported and causes an error. Do not directly add or remove elements while iterating through the collection that includes them. Adding Elements During Iteration To add elements while iterating a list, set or map, keep the new elements in a temporary list, set, or map and add them to the original after you finish iterating the collection. Removing Elements During Iteration To remove elements while iterating a list, create a new list, then copy the elements you wish to keep. Alternatively, add the elements you wish to remove to a temporary list and remove them after you finish iterating the collection. Note: The List.remove method performs linearly. Using it to remove elements has time and resource implications. To remove elements while iterating a map or set, keep the keys you wish to remove in a temporary list, then remove them after you finish iterating the collection. Enums An enum is an abstract data type with values that each take on exactly one of a finite set of identifiers that you specify. Enums are typically used to define a set of possible values that do not otherwise have a numerical order, such as the suit of a card, or a particular season of the year. Although each value corresponds to a distinct integer value, the enum hides this implementation so that you do not inadvertently misuse the values, such as using them to perform arithmetic. After you create an enum, variables, method arguments, and return types can be declared of that type. Note: Unlike Java, the enum type itself has no constructor syntax. To define an enum, use the enum keyword in your declaration and use curly braces to demarcate the list of possible values. For example, the following code creates an enum called Season: public enum Season {WINTER, SPRING, SUMMER, FALL} By creating the enum Season, you have also created a new data type called Season. You can use this new data type as you might any other data type. For example: Season e = Season.WINTER; Season m(Integer x, Season e) { If (e == Season.SUMMER) return e; //... } 54
- 57. Language Constructs Enums You can also define a class as an enum. Note that when you create an enum class you do not use the class keyword in the definition. public enum MyEnumClass { X, Y } You can use an enum in any place you can use another data type name. If you define a variable whose type is an enum, any object you assign to it must be an instance of that enum class. Any webService methods can use enum types as part of their signature. When this occurs, the associated WSDL file includes definitions for the enum and its values, which can then be used by the API client. Apex provides the following system-defined enums: • System.StatusCode This enum corresponds to the API error code that is exposed in the WSDL document for all API operations. For example: StatusCode.CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY StatusCode.INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY The full list of status codes is available in the WSDL file for your organization. For more information about accessing the WSDL file for your organization, see “Downloading Salesforce WSDLs and Client Authentication Certificates” in the Salesforce online help. • System.XmlTag: This enum returns a list of XML tags used for parsing the result XML from a webService method. For more information, see XmlStreamReader Class on page 532. • System.ApplicationReadWriteMode: This enum indicates if an organization is in 5 Minute Upgrade read-only mode during Salesforce upgrades and downtimes. For more information, see Using the System.ApplicationReadWriteMode Enum on page 436. • System.LoggingLevel: This enum is used with the system.debug method, to specify the log level for all debug calls. For more information, see System Methods on page 428. • System.RoundingMode: This enum is used by methods that perform mathematical operations to specify the rounding behavior for the operation, such as the Decimal divide method and the Double round method. For more information, see Rounding Mode on page 303. • System.SoapType: This enum is returned by the field describe result getSoapType method. For more informations, see Schema.SOAPType Enum Values on page 368. • System.DisplayType: This enum is returned by the field describe result getType method. For more information, see Schema.DisplayType Enum Values on page 365. • System.JSONToken: This enum is used for parsing JSON content. For more information, see System.JSONToken Enum on page 412. • ApexPages.Severity: 55
- 58. Language Constructs Understanding Rules of Conversion This enum specifies the severity of a Visualforce message. For more information, see ApexPages.Severity Enum on page 490. • Dom.XmlNodeType: This enum specifies the node type in a DOM document. For more information, see Node Types on page 541. Note: System-defined enums cannot be used in Web service methods. All enum values, including system enums, have common methods associated with them. For more information, see Enum Methods on page 347. You cannot add user-defined methods to enum values. Understanding Rules of Conversion In general, Apex requires you to explicitly convert one data type to another. For example, a variable of the Integer data type cannot be implicitly converted to a String. You must use the string.format method. However, a few data types can be implicitly converted, without using a method. Numbers form a hierarchy of types. Variables of lower numeric types can always be assigned to higher types without explicit conversion. The following is the hierarchy for numbers, from lowest to highest: 1. Integer 2. Long 3. Double 4. Decimal Note: Once a value has been passed from a number of a lower type to a number of a higher type, the value is converted to the higher type of number. Note that the hierarchy and implicit conversion is unlike the Java hierarchy of numbers, where the base interface number is used and implicit object conversion is never allowed. In addition to numbers, other data types can be implicitly converted. The following rules apply: • IDs can always be assigned to Strings. • Strings can be assigned to IDs. However, at runtime, the value is checked to ensure that it is a legitimate ID. If it is not, a runtime exception is thrown. • The instanceOf keyword can always be used to test whether a string is an ID. Additional Considerations for Data Types Data Types of Numeric Values Numeric values represent Integer values unless they are appended with L for a Long or with .0 for a Double or Decimal. For example, the expression Long d = 123; declares a Long variable named d and assigns it to an Integer numeric value (123), which is implicitly converted to a Long. The Integer value on the right hand side is within the range for Integers and the assignment succeeds. However, if the numeric value on the right hand side exceeds the maximum value for an Integer, you get a compilation error. In this case, the solution is to append L to the numeric value so that it represents a Long value which has a wider range, as shown in this example: Long d = 2147483648L;. 56
- 59. Language Constructs Variables Overflow of Data Type Values Arithmetic computations that produce values larger than the maximum value of the current type are said to overflow. For example, Integer i = 2147483647 + 1; yields a value of –2147483648 because 2147483647 is the maximum value for an Integer, so adding one to it wraps the value around to the minimum negative value for Integers, –2147483648. If arithmetic computations generate results larger than the maximum value for the current type, the end result will be incorrect because the computed values that are larger than the maximum will overflow. For example, the expression Long MillsPerYear = 365 * 24 * 60 * 60 * 1000; results in an incorrect result because the products of Integers on the right hand side are larger than the maximum Integer value and they overflow. As a result, the final product isn't the expected one. You can avoid this by ensuring that the type of numeric values or variables you are using in arithmetic operations are large enough to hold the results. In this example, append L to numeric values to make them Long so the intermediate products will be Long as well and no overflow occurs. The following example shows how to correctly compute the amount of milliseconds in a year by multiplying Long numeric values. Long MillsPerYear = 365L * 24L * 60L * 60L * 1000L; Long ExpectedValue = 31536000000L; System.assertEquals(MillsPerYear, ExpectedValue); Loss of Fractions in Divisions When dividing numeric Integer or Long values, the fractional portion of the result, if any, is removed before performing any implicit conversions to a Double or Decimal. For example, Double d = 5/3; returns 1.0 because the actual result (1.666...) is an Integer and is rounded to 1 before being implicitly converted to a Double. To preserve the fractional value, ensure that you are using Double or Decimal numeric values in the division. For example, Double d = 5.0/3.0; returns 1.6666666666666667 because 5.0 and 3.0 represent Double values, which results in the quotient being a Double as well and no fractional value is lost. Variables Local variables are declared with Java-style syntax. For example: Integer i = 0; String str; Account a; Account[] accts; Set<String> s; Map<ID, Account> m; As with Java, multiple variables can be declared and initialized in a single statement, using comma separation. For example: Integer i, j, k; All variables allow null as a value and are initialized to null if they are not assigned another value. For instance, in the following example, i, and k are assigned values, while j is set to null because it is not assigned: Integer i = 0, j, k = 1; Variables can be defined at any point in a block, and take on scope from that point forward. Sub-blocks cannot redefine a variable name that has already been used in a parent block, but parallel blocks can reuse a variable name. For example: Integer i; { 57
- 60. Language Constructs Case Sensitivity // Integer i; This declaration is not allowed } for (Integer j = 0; j < 10; j++); for (Integer j = 0; j < 10; j++); Case Sensitivity To avoid confusion with case-insensitive SOQL and SOSL queries, Apex is also case-insensitive. This means: • Variable and method names are case insensitive. For example: Integer I; //Integer i; This would be an error. • References to object and field names are case insensitive. For example: Account a1; ACCOUNT a2; • SOQL and SOSL statements are case insensitive. For example: Account[] accts = [sELect ID From ACCouNT where nAme = 'fred']; Also note that Apex uses the same filtering semantics as SOQL, which is the basis for comparisons in the SOAP API and the Salesforce user interface. The use of these semantics can lead to some interesting behavior. For example, if an end user generates a report based on a filter for values that come before 'm' in the alphabet (that is, values < 'm'), null fields are returned in the result. The rationale for this behavior is that users typically think of a field without a value as just a “space” character, rather than its actual “null” value. Consequently, in Apex, the following expressions all evaluate to true: String s; System.assert('a' == 'A'); System.assert(s < 'b'); System.assert(!(s > 'b')); Note: Although s < 'b' evaluates to true in the example above, 'b.'compareTo(s) generates an error because you are trying to compare a letter to a null value. Constants Constants can be defined using the final keyword, which means that the variable can be assigned at most once, either in the declaration itself, or with a static initializer method if the constant is defined in a class. For example: public class myCls { static final Integer PRIVATE_INT_CONST; static final Integer PRIVATE_INT_CONST2 = 200; public static Integer calculate() { return 2 + 7; } static { 58
- 61. Language Constructs Expressions PRIVATE_INT_CONST = calculate(); } } For more information, see Using the final Keyword on page 131. Expressions An expression is a construct made up of variables, operators, and method invocations that evaluates to a single value. This section provides an overview of expressions in Apex and contains the following: • Understanding Expressions • Understanding Expression Operators • Understanding Operator Precedence • Extending sObject and List Expressions • Using Comments Understanding Expressions An expression is a construct made up of variables, operators, and method invocations that evaluates to a single value. In Apex, an expression is always one of the following types: • A literal expression. For example: 1 + 1 • A new sObject, Apex object, list, set, or map. For example: new Account(<field_initializers>) new Integer[<n>] new Account[]{<elements>} new List<Account>() new Set<String>{} new Map<String, Integer>() new myRenamingClass(string oldName, string newName) • Any value that can act as the left-hand of an assignment operator (L-values), including variables, one-dimensional list positions, and most sObject or Apex object field references. For example: Integer i myList[3] myContact.name myRenamingClass.oldName • Any sObject field reference that is not an L-value, including: ◊ The ID of an sObject in a list (see Lists) ◊ A set of child records associated with an sObject (for example, the set of contacts associated with a particular account). This type of expression yields a query result, much like SOQL and SOSL queries. 59
- 62. Language Constructs Understanding Expression Operators • A SOQL or SOSL query surrounded by square brackets, allowing for on-the-fly evaluation in Apex. For example: Account[] aa = [SELECT Id, Name FROM Account WHERE Name ='Acme']; Integer i = [SELECT COUNT() FROM Contact WHERE LastName ='Weissman']; List<List<SObject>> searchList = [FIND 'map*' IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity, Lead]; For information, see SOQL and SOSL Queries on page 73. • A static or instance method invocation. For example: System.assert(true) myRenamingClass.replaceNames() changePoint(new Point(x, y)); Understanding Expression Operators Expressions can also be joined to one another with operators to create compound expressions. Apex supports the following operators: Operator Syntax Description = x = y Assignment operator (Right associative). Assigns the value of y to the L-value x. Note that the data type of x must match the data type of y, and cannot be null. += x += y Addition assignment operator (Right associative). Adds the value of y to the original value of x and then reassigns the new value to x. See + for additional information. x and y cannot be null. *= x *= y Multiplication assignment operator (Right associative). Multiplies the value of y with the original value of x and then reassigns the new value to x. Note that x and y must be Integers or Doubles, or a combination. x and y cannot be null. -= x -= y Subtraction assignment operator (Right associative). Subtracts the value of y from the original value of x and then reassigns the new value to x. Note that x and y must be Integers or Doubles, or a combination. x and y cannot be null. /= x /= y Division assignment operator (Right associative). Divides the original value of x with the value of y and then reassigns the new value to x. Note that x and y must be Integers or Doubles, or a combination. x and y cannot be null. |= x |= y OR assignment operator (Right associative). If x, a Boolean, and y, a Boolean, are both false, then x remains false. Otherwise, x is assigned the value of true. Note: • This operator exhibits “short-circuiting” behavior, which means y is evaluated only if x is false. • x and y cannot be null. 60
- 63. Language Constructs Understanding Expression Operators Operator Syntax Description &= x &= y AND assignment operator (Right associative). If x, a Boolean, and y, a Boolean, are both true, then x remains true. Otherwise, x is assigned the value of false. Note: • This operator exhibits “short-circuiting” behavior, which means y is evaluated only if x is true. • x and y cannot be null. <<= x <<= y Bitwise shift left assignment operator. Shifts each bit in x to the left by y bits so that the high order bits are lost, and the new right bits are set to 0. This value is then reassigned to x. >>= x >>= y Bitwise shift right signed assignment operator. Shifts each bit in x to the right by y bits so that the low order bits are lost, and the new left bits are set to 0 for positive values of y and 1 for negative values of y. This value is then reassigned to x. >>>= x >>>= y Bitwise shift right unsigned assignment operator. Shifts each bit in x to the right by y bits so that the low order bits are lost, and the new left bits are set to 0 for all values of y. This value is then reassigned to x. ? : x ? y : z Ternary operator (Right associative). This operator acts as a short-hand for if-then-else statements. If x, a Boolean, is true, y is the result. Otherwise z is the result. Note that x cannot be null. && x && y AND logical operator (Left associative). If x, a Boolean, and y, a Boolean, are both true, then the expression evaluates to true. Otherwise the expression evaluates to false. Note: • && has precedence over || • This operator exhibits “short-circuiting” behavior, which means y is evaluated only if x is true. • x and y cannot be null. || x || y OR logical operator (Left associative). If x, a Boolean, and y, a Boolean, are both false, then the expression evaluates to false. Otherwise the expression evaluates to true. Note: • && has precedence over || • This operator exhibits “short-circuiting” behavior, which means y is evaluated only if x is false. • x and y cannot be null. 61
- 64. Language Constructs Understanding Expression Operators Operator Syntax Description == x == y Equality operator. If the value of x equals the value of y, the expression evaluates to true. Otherwise, the expression evaluates to false. Note: • Unlike Java, == in Apex compares object value equality, not reference equality. Consequently: ◊ String comparison using == is case insensitive ◊ ID comparison using == is case sensitive, and does not distinguish between 15-character and 18-character formats • For sObjects and sObject arrays, == performs a deep check of all sObject field values before returning its result. Likewise for collections, built-in Apex types, and user-defined types. • For records, every field must have the same value for == to evaluate to true. • x or y can be the literal null. • The comparison of any two values can never result in null. • SOQL and SOSL use = for their equality operator, and not ==. Although Apex and SOQL and SOSL are strongly linked, this unfortunate syntax discrepancy exists because most modern languages use = for assignment and == for equality. The designers of Apex deemed it more valuable to maintain this paradigm than to force developers to learn a new assignment operator. The result is that Apex developers must use == for equality tests in the main body of the Apex code, and = for equality in SOQL and SOSL queries. === x === y Exact equality operator. If x and y reference the exact same location in memory, the expression evaluates to true. Otherwise, the expression evaluates to false. Note that this operator only works for sObjects or collections (such as a Map or list). For an Apex object (such as an Exception or instantiation of a class) the exact equality operator is the same as the equality operator. < x < y Less than operator. If x is less than y, the expression evaluates to true. Otherwise, the expression evaluates to false. Note: • Unlike other database stored procedures, Apex does not support tri-state Boolean logic, and the comparison of any two values can never result in null. • If x or y equal null and are Integers, Doubles, Dates, or Datetimes, the expression is false. • A non-null String or ID value is always greater than a null value. • If x and y are IDs, they must reference the same type of object. Otherwise, a runtime error results. • If x or y is an ID and the other value is a String, the String value is validated and treated as an ID. 62
- 65. Language Constructs Understanding Expression Operators Operator Syntax Description • x and y cannot be Booleans. • The comparison of two strings is performed according to the locale of the context user. > x > y Greater than operator. If x is greater than y, the expression evaluates to true. Otherwise, the expression evaluates to false. Note: • The comparison of any two values can never result in null. • If x or y equal null and are Integers, Doubles, Dates, or Datetimes, the expression is false. • A non-null String or ID value is always greater than a null value. • If x and y are IDs, they must reference the same type of object. Otherwise, a runtime error results. • If x or y is an ID and the other value is a String, the String value is validated and treated as an ID. • x and y cannot be Booleans. • The comparison of two strings is performed according to the locale of the context user. <= x <= y Less than or equal to operator. If x is less than or equal to y, the expression evaluates to true. Otherwise, the expression evaluates to false. Note: • The comparison of any two values can never result in null. • If x or y equal null and are Integers, Doubles, Dates, or Datetimes, the expression is false. • A non-null String or ID value is always greater than a null value. • If x and y are IDs, they must reference the same type of object. Otherwise, a runtime error results. • If x or y is an ID and the other value is a String, the String value is validated and treated as an ID. • x and y cannot be Booleans. • The comparison of two strings is performed according to the locale of the context user. >= x >= y Greater than or equal to operator. If x is greater than or equal to y, the expression evaluates to true. Otherwise, the expression evaluates to false. Note: • The comparison of any two values can never result in null. • If x or y equal null and are Integers, Doubles, Dates, or Datetimes, the expression is false. • A non-null String or ID value is always greater than a null value. 63
- 66. Language Constructs Understanding Expression Operators Operator Syntax Description • If x and y are IDs, they must reference the same type of object. Otherwise, a runtime error results. • If x or y is an ID and the other value is a String, the String value is validated and treated as an ID. • x and y cannot be Booleans. • The comparison of two strings is performed according to the locale of the context user. != x != y Inequality operator. If the value of x does not equal the value of y, the expression evaluates to true. Otherwise, the expression evaluates to false. Note: • Unlike Java, != in Apex compares object value equality, not reference equality. • For sObjects and sObject arrays, != performs a deep check of all sObject field values before returning its result. • For records, != evaluates to true if the records have different values for any field. • x or y can be the literal null. • The comparison of any two values can never result in null. !== x !== y Exact inequality operator. If x and y do not reference the exact same location in memory, the expression evaluates to true. Otherwise, the expression evaluates to false. Note that this operator only works for sObjects, collections (such as a Map or list), or an Apex object (such as an Exception or instantiation of a class). + x + y Addition operator. Adds the value of x to the value of y according to the following rules: • If x and y are Integers or Doubles, adds the value of x to the value of y. If a Double is used, the result is a Double. • If x is a Date and y is an Integer, returns a new Date that is incremented by the specified number of days. • If x is a Datetime and y is an Integer or Double, returns a new Date that is incremented by the specified number of days, with the fractional portion corresponding to a portion of a day. • If x is a String and y is a String or any other type of non-null argument, concatenates y to the end of x. - x - y Subtraction operator. Subtracts the value of y from the value of x according to the following rules: • If x and y are Integers or Doubles, subtracts the value of x from the value of y. If a Double is used, the result is a Double. • If x is a Date and y is an Integer, returns a new Date that is decremented by the specified number of days. 64
- 67. Language Constructs Understanding Expression Operators Operator Syntax Description • If x is a Datetime and y is an Integer or Double, returns a new Date that is decremented by the specified number of days, with the fractional portion corresponding to a portion of a day. * x * y Multiplication operator. Multiplies x, an Integer or Double, with y, another Integer or Double. Note that if a double is used, the result is a Double. / x / y Division operator. Divides x, an Integer or Double, by y, another Integer or Double. Note that if a double is used, the result is a Double. ! !x Logical complement operator. Inverts the value of a Boolean, so that true becomes false, and false becomes true. - -x Unary negation operator. Multiplies the value of x, an Integer or Double, by -1. Note that the positive equivalent + is also syntactically valid, but does not have a mathematical effect. ++ x++ Increment operator. Adds 1 to the value of x, a variable of a numeric type. If prefixed (++x), the expression evaluates to the value of x after the increment. ++x If postfixed (x++), the expression evaluates to the value of x before the increment. -- x-- Decrement operator. Subtracts 1 from the value of x, a variable of a numeric type. If prefixed (--x), the expression evaluates to the value of x after the --x decrement. If postfixed (x--), the expression evaluates to the value of x before the decrement. & x & y Bitwise AND operator. ANDs each bit in x with the corresponding bit in y so that the result bit is set to 1 if both of the bits are set to 1. This operator is not valid for types Long or Integer. | x | y Bitwise OR operator. ORs each bit in x with the corresponding bit in y so that the result bit is set to 1 if at least one of the bits is set to 1. This operator is not valid for types Long or Integer. ^ x ^ y Bitwise exclusive OR operator. Exclusive ORs each bit in x with the corresponding bit in y so that the result bit is set to 1 if exactly one of the bits is set to 1 and the other bit is set to 0. ^= x ^= y Bitwise exclusive OR operator. Exclusive ORs each bit in x with the corresponding bit in y so that the result bit is set to 1 if exactly one of the bits is set to 1 and the other bit is set to 0. << x << y Bitwise shift left operator. Shifts each bit in x to the left by y bits so that the high order bits are lost, and the new right bits are set to 0. >> x >> y Bitwise shift right signed operator. Shifts each bit in x to the right by y bits so that the low order bits are lost, and the new left bits are set to 0 for positive values of y and 1 for negative values of y. >>> x >>> y Bitwise shift right unsigned operator. Shifts each bit in x to the right by y bits so that the low order bits are lost, and the new left bits are set to 0 for all values of y. 65
- 68. Language Constructs Understanding Operator Precedence Operator Syntax Description () (x) Parentheses. Elevates the precedence of an expression x so that it is evaluated first in a compound expression. Understanding Operator Precedence Apex uses the following operator precedence rules: Precedence Operators Description 1 {} () ++ -- Grouping and prefix increments and decrements 2 ! -x +x (type) new Unary negation, type cast and object creation 3 * / Multiplication and division 4 + - Addition and subtraction 5 < <= > >= instanceof Greater-than and less-than comparisons, reference tests 6 == != Comparisons: equal and not-equal 7 && Logical AND 8 || Logical OR 9 = += -= *= /= &= Assignment operators Extending sObject and List Expressions As in Java, sObject and list expressions can be extended with method references and list expressions, respectively, to form new expressions. In the following example, a new variable containing the length of the new account name is assigned to acctNameLength. Integer acctNameLength = new Account[]{new Account(Name='Acme')}[0].Name.length(); In the above, new Account[] generates a list. The list is populated by the SOQL statement {new Account(name='Acme')}. Item 0, the first item in the list, is then accessed by the next part of the string [0]. The name of the sObject in the list is accessed, followed by the method returning the length name.length(). In the following example, a name that has been shifted to lower case is returned. String nameChange = [SELECT Name FROM Account][0].Name.toLowerCase(); 66
- 69. Language Constructs Using Comments Using Comments Both single and multiline comments are supported in Apex code: • To create a single line comment, use //. All characters on the same line to the right of the // are ignored by the parser. For example: Integer i = 1; // This comment is ignored by the parser • To create a multiline comment, use /* and */ to demarcate the beginning and end of the comment block. For example: Integer i = 1; /* This comment can wrap over multiple lines without getting interpreted by the parser. */ Assignment Statements An assignment statement is any statement that places a value into a variable, generally in one of the following two forms: [LValue] = [new_value_expression]; [LValue] = [[inline_soql_query]]; In the forms above, [LValue] stands for any expression that can be placed on the left side of an assignment operator. These include: • A simple variable. For example: Integer i = 1; Account a = new Account(); Account[] accts = [SELECT Id FROM Account]; • A de-referenced list element. For example: ints[0] = 1; accts[0].Name = 'Acme'; • An sObject field reference that the context user has permission to edit. For example: Account a = new Account(Name = 'Acme', BillingCity = 'San Francisco'); // IDs cannot be set manually // a.Id = '00300000003T2PGAA0'; This code is invalid! // Instead, insert the record. The system automatically assigns it an ID. insert a; // Fields also must be writeable for the context user // a.CreatedDate = System.today(); This code is invalid because // createdDate is read-only! // Since the account a has been inserted, it is now possible to // create a new contact that is related to it 67
- 70. Language Constructs Conditional (If-Else) Statements Contact c = new Contact(LastName = 'Roth', Account = a); // Notice that you can write to the account name directly through the contact c.Account.Name = 'salesforce.com'; Assignment is always done by reference. For example: Account a = new Account(); Account b; Account[] c = new Account[]{}; a.Name = 'Acme'; b = a; c.add(a); // These asserts should now be true. You can reference the data // originally allocated to account a through account b and account list c. System.assertEquals(b.Name, 'Acme'); System.assertEquals(c[0].Name, 'Acme'); Similarly, two lists can point at the same value in memory. For example: Account[] a = new Account[]{new Account()}; Account[] b = a; a[0].Name = 'Acme'; System.assert(b[0].Name == 'Acme'); In addition to =, other valid assignment operators include +=, *=, /=, |=, &=, ++, and --. See Understanding Expression Operators on page 60. Conditional (If-Else) Statements The conditional statement in Apex works similarly to Java: if ([Boolean_condition]) // Statement 1 else // Statement 2 The else portion is always optional, and always groups with the closest if. For example: Integer x, sign; // Your code if (x <= 0) if (x == 0) sign = 0; else sign = -1; is equivalent to: Integer x, sign; // Your code if (x <= 0) { if (x == 0) { sign = 0; } else { sign = -1; } } 68
- 71. Language Constructs Loops Repeated else if statements are also allowed. For example: if (place == 1) { medal_color = 'gold'; } else if (place == 2) { medal_color = 'silver'; } else if (place == 3) { medal_color = 'bronze'; } else { medal_color = null; } Loops Apex supports the following five types of procedural loops: • do {statement} while (Boolean_condition); • while (Boolean_condition) statement; • for (initialization; Boolean_exit_condition; increment) statement; • for (variable : array_or_set) statement; • for (variable : [inline_soql_query]) statement; All loops allow for loop control structures: • break; exits the entire loop • continue; skips to the next iteration of the loop Do-While Loops The Apex do-while loop repeatedly executes a block of code as long as a particular Boolean condition remains true. Its syntax is: do { code_block } while (condition); Note: Curly braces ({}) are always required around a code_block. As in Java, the Apex do-while loop does not check the Boolean condition statement until after the first loop is executed. Consequently, the code block always runs at least once. As an example, the following code outputs the numbers 1 - 10 into the debug log: Integer count = 1; do { System.debug(count); count++; } while (count < 11); 69
- 72. Language Constructs While Loops While Loops The Apex while loop repeatedly executes a block of code as long as a particular Boolean condition remains true. Its syntax is: while (condition) { code_block } Note: Curly braces ({}) are required around a code_block only if the block contains more than one statement. Unlike do-while, the while loop checks the Boolean condition statement before the first loop is executed. Consequently, it is possible for the code block to never execute. As an example, the following code outputs the numbers 1 - 10 into the debug log: Integer count = 1; while (count < 11) { System.debug(count); count++; } For Loops Apex supports three variations of the for loop: • The traditional for loop: for (init_stmt; exit_condition; increment_stmt) { code_block } • The list or set iteration for loop: for (variable : list_or_set) { code_block } where variable must be of the same primitive or sObject type as list_or_set. • The SOQL for loop: for (variable : [soql_query]) { code_block } or for (variable_list : [soql_query]) { code_block } 70
- 73. Language Constructs For Loops Both variable and variable_list must be of the same sObject type as is returned by the soql_query. Note: Curly braces ({}) are required around a code_block only if the block contains more than one statement. Each is discussed further in the sections that follow. Traditional For Loops The traditional for loop in Apex corresponds to the traditional syntax used in Java and other languages. Its syntax is: for (init_stmt; exit_condition; increment_stmt) { code_block } When executing this type of for loop, the Apex runtime engine performs the following steps, in order: 1. Execute the init_stmt component of the loop. Note that multiple variables can be declared and/or initialized in this statement. 2. Perform the exit_condition check. If true, the loop continues. If false, the loop exits. 3. Execute the code_block. 4. Execute the increment_stmt statement. 5. Return to Step 2. As an example, the following code outputs the numbers 1 - 10 into the debug log. Note that an additional initialization variable, j, is included to demonstrate the syntax: for (Integer i = 0, j = 0; i < 10; i++) { System.debug(i+1); } List or Set Iteration For Loops The list or set iteration for loop iterates over all the elements in a list or set. Its syntax is: for (variable : list_or_set) { code_block } where variable must be of the same primitive or sObject type as list_or_set. When executing this type of for loop, the Apex runtime engine assigns variable to each element in list_or_set, and runs the code_block for each value. For example, the following code outputs the numbers 1 - 10 to the debug log: Integer[] myInts = new Integer[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; for (Integer i : myInts) { System.debug(i); } 71
- 74. Language Constructs For Loops SOQL For Loops SOQL for loops iterate over all of the sObject records returned by a SOQL query. The syntax of a SOQL for loop is either: for (variable : [soql_query]) { code_block } or for (variable_list : [soql_query]) { code_block } Both variable and variable_list must be of the same type as the sObjects that are returned by the soql_query. As in standard SOQL queries, the [soql_query] statement can refer to code expressions in their WHERE clauses using the : syntax. For example: String s = 'Acme'; for (Account a : [SELECT Id, Name from Account where Name LIKE :(s+'%')]) { // Your code } The following example combines creating a list from a SOQL query, with the DML update method. // Create a list of account records from a SOQL query List<Account> accs = [SELECT Id, Name FROM Account WHERE Name = 'Siebel']; // Loop through the list and update the Name field for(Account a : accs){ a.Name = 'Oracle'; } // Update the database update accs; SOQL For Loops Versus Standard SOQL Queries SOQL for loops differ from standard SOQL statements because of the method they use to retrieve sObjects. While the standard queries discussed in SOQL and SOSL Queries can retrieve either the count of a query or a number of object records, SOQL for loops retrieve all sObjects, using efficient chunking with calls to the query and queryMore methods of the SOAP API. Developers should always use a SOQL for loop to process query results that return many records, to avoid the limit on heap size. Note that queries including an aggregate function don't support queryMore. A runtime exception occurs if you use a query containing an aggregate function that returns more than 2000 rows in a for loop. SOQL For Loop Formats SOQL for loops can process records one at a time using a single sObject variable, or in batches of 200 sObjects at a time using an sObject list: • The single sObject format executes the for loop's <code_block> once per sObject record. Consequently, it is easy to understand and use, but is grossly inefficient if you want to use data manipulation language (DML) statements within the for loop body. Each DML statement ends up processing only one sObject at a time. 72
- 75. Language Constructs SOQL and SOSL Queries • The sObject list format executes the for loop's <code_block> once per list of 200 sObjects. Consequently, it is a little more difficult to understand and use, but is the optimal choice if you need to use DML statements within the for loop body. Each DML statement can bulk process a list of sObjects at a time. For example, the following code illustrates the difference between the two types of SOQL query for loops: // Create a savepoint because the data should not be committed to the database Savepoint sp = Database.setSavepoint(); insert new Account[]{new Account(Name = 'yyy'), new Account(Name = 'yyy'), new Account(Name = 'yyy')}; // The single sObject format executes the for loop once per returned record Integer i = 0; for (Account tmp : [SELECT Id FROM Account WHERE Name = 'yyy']) { i++; } System.assert(i == 3); // Since there were three accounts named 'yyy' in the // database, the loop executed three times // The sObject list format executes the for loop once per returned batch // of records i = 0; Integer j; for (Account[] tmp : [SELECT Id FROM Account WHERE Name = 'yyy']) { j = tmp.size(); i++; } System.assert(j == 3); // The list should have contained the three accounts // named 'yyy' System.assert(i == 1); // Since a single batch can hold up to 100 records and, // only three records should have been returned, the // loop should have executed only once // Revert the database to the original state Database.rollback(sp); Note: • The break and continue keywords can be used in both types of inline query for loop formats. When using the sObject list format, continue skips to the next list of sObjects. • DML statements can only process up to 10,000 records at a time, and sObject list for loops process records in batches of 200. Consequently, if you are inserting, updating, or deleting more than one record per returned record in an sObject list for loop, it is possible to encounter runtime limit errors. See Understanding Execution Governors and Limits on page 225. SOQL and SOSL Queries You can evaluate Salesforce Object Query Language (SOQL) or Salesforce Object Search Language (SOSL) statements on-the-fly in Apex by surrounding the statement in square brackets. SOQL Statements SOQL statements evaluate to a list of sObjects, a single sObject, or an Integer for count method queries. 73
- 76. Language Constructs SOQL and SOSL Queries For example, you could retrieve a list of accounts that are named Acme: List<Account> aa = [SELECT Id, Name FROM Account WHERE Name = 'Acme']; From this list, you can access individual elements: if (!aa.isEmpty()) { // Execute commands } You can also create new objects from SOQL queries on existing ones. The following example creates a new contact for the first account with the number of employees greater than 10: Contact c = new Contact(Account = [SELECT Name FROM Account WHERE NumberOfEmployees > 10 LIMIT 1]); c.FirstName = 'James'; c.LastName = 'Yoyce'; Note that the newly created object contains null values for its fields, which will need to be set. The count method can be used to return the number of rows returned by a query. The following example returns the total number of contacts with the last name of Weissman: Integer i = [SELECT COUNT() FROM Contact WHERE LastName = 'Weissman']; You can also operate on the results using standard arithmetic: Integer j = 5 * [SELECT COUNT() FROM Account]; For a full description of SOQL query syntax, see the Salesforce SOQL and SOSL Reference Guide. SOSL Statements SOSL statements evaluate to a list of lists of sObjects, where each list contains the search results for a particular sObject type. The result lists are always returned in the same order as they were specified in the SOSL query. If a SOSL query does not return any records for a specified sObject type, the search results include an empty list for that sObject. For example, you can return a list of accounts, contacts, opportunities, and leads that begin with the phrase map: List<List<SObject>> searchList = [FIND 'map*' IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity, Lead]; Note: The syntax of the FIND clause in Apex differs from the syntax of the FIND clause in the SOAP API: • In Apex, the value of the FIND clause is demarcated with single quotes. For example: FIND 'map*' IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity, Lead • In the Force.com API, the value of the FIND clause is demarcated with braces. For example: FIND {map*} IN ALL FIELDS RETURNING Account (Id, Name), Contact, Opportunity, Lead 74
- 77. Language Constructs Working with SOQL and SOSL Query Results From searchList, you can create arrays for each object returned: Account [] accounts = ((List<Account>)searchList[0]); Contact [] contacts = ((List<Contact>)searchList[1]); Opportunity [] opportunities = ((List<Opportunity>)searchList[2]); Lead [] leads = ((List<Lead>)searchList[3]); For a full description of SOSL query syntax, see the Salesforce SOQL and SOSL Reference Guide. Working with SOQL and SOSL Query Results SOQL and SOSL queries only return data for sObject fields that are selected in the original query. If you try to access a field that was not selected in the SOQL or SOSL query (other than ID), you receive a runtime error, even if the field contains a value in the database. The following code example causes a runtime error: insert new Account(Name = 'Singha'); Account acc = [SELECT Id FROM Account WHERE Name = 'Singha' LIMIT 1]; // Note that name is not selected String name = [SELECT Id FROM Account WHERE Name = 'Singha' LIMIT 1].Name; The following is the same code example rewritten so it does not produce a runtime error. Note that Name has been added as part of the select statement, after Id. insert new Account(Name = 'Singha'); Account acc = [SELECT Id FROM Account WHERE Name = 'Singha' LIMIT 1]; // Note that name is now selected String name = [SELECT Id, Name FROM Account WHERE Name = 'Singha' LIMIT 1].Name; Even if only one sObject field is selected, a SOQL or SOSL query always returns data as complete records. Consequently, you must dereference the field in order to access it. For example, this code retrieves an sObject list from the database with a SOQL query, accesses the first account record in the list, and then dereferences the record's AnnualRevenue field: Double rev = [SELECT AnnualRevenue FROM Account WHERE Name = 'Acme'][0].AnnualRevenue; // When only one result is returned in a SOQL query, it is not necessary // to include the list's index. Double rev2 = [SELECT AnnualRevenue FROM Account WHERE Name = 'Acme' LIMIT 1].AnnualRevenue; The only situation in which it is not necessary to dereference an sObject field in the result of an SOQL query, is when the query returns an Integer as the result of a COUNT operation: Integer i = [SELECT COUNT() FROM Account]; Fields in records returned by SOSL queries must always be dereferenced. Also note that sObject fields that contain formulas return the value of the field at the time the SOQL or SOSL query was issued. Any changes to other fields that are used within the formula are not reflected in the formula field value until the record has been saved and re-queried in Apex. Like other read-only sObject fields, the values of the formula fields themselves cannot be changed in Apex. 75
- 78. Language Constructs Working with SOQL Aggregate Functions Working with SOQL Aggregate Functions Aggregate functions in SOQL, such as SUM() and MAX(), allow you to roll up and summarize your data in a query. For more information on aggregate functions, see ”Aggregate Functions” in the Salesforce SOQL and SOSL Reference Guide. You can use aggregate functions without using a GROUP BY clause. For example, you could use the AVG() aggregate function to find the average Amount for all your opportunities. AggregateResult[] groupedResults = [SELECT AVG(Amount)aver FROM Opportunity]; Object avgAmount = groupedResults[0].get('aver'); Note that any query that includes an aggregate function returns its results in an array of AggregateResult objects. AggregateResult is a read-only sObject and is only used for query results. Aggregate functions become a more powerful tool to generate reports when you use them with a GROUP BY clause. For example, you could find the average Amount for all your opportunities by campaign. AggregateResult[] groupedResults = [SELECT CampaignId, AVG(Amount) FROM Opportunity GROUP BY CampaignId]; for (AggregateResult ar : groupedResults) { System.debug('Campaign ID' + ar.get('CampaignId')); System.debug('Average amount' + ar.get('expr0')); } Any aggregated field in a SELECT list that does not have an alias automatically gets an implied alias with a format expri, where i denotes the order of the aggregated fields with no explicit aliases. The value of i starts at 0 and increments for every aggregated field with no explicit alias. For more information, see ”Using Aliases with GROUP BY” in the Salesforce SOQL and SOSL Reference Guide. Note: Queries that include aggregate functions are subject to the same governor limits as other SOQL queries for the total number of records returned. This limit includes any records included in the aggregation, not just the number of rows returned by the query. If you encounter this limit, you should add a condition to the WHERE clause to reduce the amount of records processed by the query. Working with Very Large SOQL Queries Your SOQL query may return so many sObjects that the limit on heap size is exceeded and an error occurs. To resolve, use a SOQL query for loop instead, since it can process multiple batches of records through the use of internal calls to query and queryMore. For example, if the results are too large, the syntax below causes a runtime exception: Account[] accts = [SELECT Id FROM Account]; Instead, use a SOQL query for loop as in one of the following examples: // Use this format if you are not executing DML statements // within the for loop for (Account a : [SELECT Id, Name FROM Account WHERE Name LIKE 'Acme%']) { 76
- 79. Language Constructs Working with Very Large SOQL Queries // Your code without DML statements here } // Use this format for efficiency if you are executing DML statements // within the for loop for (List<Account> accts : [SELECT Id, Name FROM Account WHERE Name LIKE 'Acme%']) { // Your code here update accts; } The following example demonstrates a SOQL query for loop used to mass update records. Suppose you want to change the last name of a contact across all records for contacts whose first and last names match a specified criteria: public void massUpdate() { for (List<Contact> contacts: [SELECT FirstName, LastName FROM Contact]) { for(Contact c : contacts) { if (c.FirstName == 'Barbara' && c.LastName == 'Gordon') { c.LastName = 'Wayne'; } } update contacts; } } Instead of using a SOQL query in a for loop, the preferred method of mass updating records is to use batch Apex, which minimizes the risk of hitting governor limits. For more information, see SOQL For Loops on page 72. More Efficient SOQL Queries For best performance, SOQL queries must be selective, particularly for queries inside of triggers. To avoid long execution times, non-selective SOQL queries may be terminated by the system. Developers will receive an error message when a non-selective query in a trigger executes against an object that contains more than 100,000 records. To avoid this error, ensure that the query is selective. Selective SOQL Query Criteria • A query is selective when one of the query filters is on an indexed field and the query filter reduces the resulting number of rows below a system-defined threshold. The performance of the SOQL query improves when two or more filters used in the WHERE clause meet the mentioned conditions. • The selectivity threshold is 10% of the records for the first million records and less than 5% of the records after the first million records, up to a maximum of 333,000 records. In some circumstances, for example with a query filter that is an indexed standard field, the threshold may be higher. Also, the selectivity threshold is subject to change. Custom Index Considerations for Selective SOQL Queries • The following fields are indexed by default: primary keys (Id, Name and Owner fields), foreign keys (lookup or master-detail relationship fields), audit dates (such as LastModifiedDate), and custom fields marked as External ID or Unique. • Salesforce.com Support can add custom indexes on request for customers. • A custom index can't be created on these types of fields: formula fields, multi-select picklists, currency fields in a multicurrency organization, long text fields, and binary fields (fields of type blob, file, or encrypted text.) Note that 77
- 80. Language Constructs Working with Very Large SOQL Queries new data types, typically complex ones, may be added to Salesforce and fields of these types may not allow custom indexing. • Typically, a custom index won't be used in these cases: ◊ The value(s) queried for exceeds the system-defined threshold mentioned above ◊ The filter operator is a negative operator such as NOT EQUAL TO (or !=), NOT CONTAINS, and NOT STARTS WITH ◊ The CONTAINS operator is used in the filter and the number of rows to be scanned exceeds 333,000. This is because the CONTAINS operator requires a full scan of the index. Note that this threshold is subject to change. ◊ When comparing with an empty value (Name != '') However, there are other complex scenarios in which custom indexes won't be used. Contact your salesforce.com representative if your scenario isn't covered by these cases or if you need further assistance with non-selective queries. Examples of Selective SOQL Queries To better understand whether a query on a large object is selective or not, let's analyze some queries. For these queries, we will assume there are more than 100,000 records (including soft-deleted records, that is, deleted records that are still in the Recycle Bin) for the Account sObject. Query 1: SELECT Id FROM Account WHERE Id IN (<list of account IDs>) The WHERE clause is on an indexed field (Id). If SELECT COUNT() FROM Account WHERE Id IN (<list of account IDs>) returns fewer records than the selectivity threshold, the index on Id is used. This will typically be the case since the list of IDs only contains a small amount of records. Query 2: SELECT Id FROM Account WHERE Name != '' Since Account is a large object even though Name is indexed (primary key), this filter returns most of the records, making the query non-selective. Query 3: SELECT Id FROM Account WHERE Name != '' AND CustomField__c = 'ValueA' Here we have to see if each filter, when considered individually, is selective. As we saw in the previous example the first filter isn't selective. So let's focus on the second one. If the count of records returned by SELECT COUNT() FROM Account WHERE CustomField__c = 'ValueA' is lower than the selectivity threshold, and CustomField__c is indexed, the query is selective. Query 4: SELECT Id FROM Account WHERE FormulaField__c = 'ValueA' Since a formula field can't be custom indexed, the query won't be selective, regardless of how many records have actually 'ValueA'. Remember that filtering on a formula field should be avoided, especially when querying on large objects, since the formula needs to be evaluated for every Account record on the fly. 78
- 81. Language Constructs Using SOQL Queries That Return One Record Using SOQL Queries That Return One Record SOQL queries can be used to assign a single sObject value when the result list contains only one element. When the L-value of an expression is a single sObject type, Apex automatically assigns the single sObject record in the query result list to the L-value. A runtime exception results if zero sObjects or more than one sObject is found in the list. For example: List<Account> accts = [SELECT Id FROM Account]; // These lines of code are only valid if one row is returned from // the query. Notice that the second line dereferences the field from the // query without assigning it to an intermediary sObject variable. Account acct = [SELECT Id FROM Account]; String name = [SELECT Name FROM Account].Name; Improving Performance by Not Searching on Null Values In your SOQL and SOSL queries, avoid searching records that contain null values. Filter out null values first to improve performance. In the following example, any records where the treadID value is null are filtered out of the returned values. Public class TagWS { /* getThreadTags * * a quick method to pull tags not in the existing list * */ public static webservice List<String> getThreadTags(String threadId, List<String> tags) { system.debug(LoggingLevel.Debug,tags); List<String> retVals = new List<String>(); Set<String> tagSet = new Set<String>(); Set<String> origTagSet = new Set<String>(); origTagSet.addAll(tags); // Note WHERE clause verifies that threadId is not null for(CSO_CaseThread_Tag__c t : [SELECT Name FROM CSO_CaseThread_Tag__c WHERE Thread__c = :threadId AND WHERE threadID != null]) { tagSet.add(t.Name); } for(String x : origTagSet) { // return a minus version of it so the UI knows to clear it if(!tagSet.contains(x)) retVals.add('-' + x); } for(String x : tagSet) { // return a plus version so the UI knows it's new if(!origTagSet.contains(x)) retvals.add('+' + x); } return retVals; } 79
- 82. Language Constructs Understanding Foreign Key and Parent-Child Relationship SOQL Queries Understanding Foreign Key and Parent-Child Relationship SOQL Queries The SELECT statement of a SOQL query can be any valid SOQL statement, including foreign key and parent-child record joins. If foreign key joins are included, the resulting sObjects can be referenced using normal field notation. For example: System.debug([SELECT Account.Name FROM Contact WHERE FirstName = 'Caroline'].Account.Name); Additionally, parent-child relationships in sObjects act as SOQL queries as well. For example: for (Account a : [SELECT Id, Name, (SELECT LastName FROM Contacts) FROM Account WHERE Name = 'Acme']) { Contact[] cons = a.Contacts; } //The following example also works because we limit to only 1 contact for (Account a : [SELECT Id, Name, (SELECT LastName FROM Contacts LIMIT 1) FROM Account WHERE Name = 'testAgg']) { Contact c = a.Contacts; } Working with Polymorphic Relationships in SOQL Queries A polymorphic relationship is a relationship between objects where a referenced object can be one of several different types. For example, the What relationship field of an Event could be an Account, or a Campaign, or an Opportunity. The following describes how to use SOQL queries with polymorphic relationships in Apex. If you want more general information on polymorphic relationships, see Understanding Polymorphic Keys and Relationships in the Force.com SOQL and SOSL Reference. You can use SOQL queries that reference polymorphic fields in Apex to get results that depend on the object type referenced by the polymorphic field. One approach is to filter your results using the Type qualifier. This example queries Events that are related to an Account or Opportunity via the What field. List<Event> = [SELECT Description FROM Event WHERE What.Type IN ('Account', 'Opportunity')]; Another approach would be to use the TYPEOF clause in the SOQL SELECT statement. This example also queries Events that are related to an Account or Opportunity via the What field. List<Event> = [SELECT TYPEOF What WHEN Account THEN Phone WHEN Opportunity THEN Amount END FROM Event]; Note: TYPEOF is currently available as a Developer Preview as part of the SOQL Polymorphism feature. For more information on enabling TYPEOF for your organization, contact salesforce.com. These queries will return a list of sObjects where the relationship field references the desired object types. 80
- 83. Language Constructs Using Apex Variables in SOQL and SOSL Queries If you need to access the referenced object in a polymorphic relationship, you can use the instanceof keyword to determine the object type. The following example uses instanceof to determine whether an Account or Opportunity is related to an Event. Event myEvent = eventFromQuery; if (myEvent.What instanceof Account) { // myEvent.What references an Account, so process accordingly } else if (myEvent.What instanceof Opportunity) { // myEvent.What references an Opportunity, so process accordingly } Note that you must assign the referenced sObject that the query returns to a variable of the appropriate type before you can pass it to another method. The following example queries for User or Group owners of Merchandise__c custom objects using a SOQL query with a TYPEOF clause, uses instanceof to determine the owner type, and then assigns the owner objects to User or Group type variables before passing them to utility methods. public class PolymorphismExampleClass { // Utility method for a User public static void processUser(User theUser) { System.debug('Processed User'); } // Utility method for a Group public static void processGroup(Group theGroup) { System.debug('Processed Group'); } public static void processOwnersOfMerchandise() { // Select records based on the Owner polymorphic relationship field List<Merchandise__c> merchandiseList = [SELECT TYPEOF Owner WHEN User THEN LastName WHEN Group THEN Email END FROM Merchandise__c]; // We now have a list of Merchandise__c records owned by either a User or Group for (Merchandise__c merch: merchandiseList) { // We can use instanceof to check the polymorphic relationship type // Note that we have to assign the polymorphic reference to the appropriate // sObject type before passing to a method if (merch.Owner instanceof User) { User userOwner = merch.Owner; processUser(userOwner); } else if (merch.Owner instanceof Group) { Group groupOwner = merch.Owner; processGroup(groupOwner); } } } } Using Apex Variables in SOQL and SOSL Queries SOQL and SOSL statements in Apex can reference Apex code variables and expressions if they are preceded by a colon (:). This use of a local code variable within a SOQL or SOSL statement is called a bind. The Apex parser first evaluates the local variable in code context before executing the SOQL or SOSL statement. Bind expressions can be used as: • The search string in FIND clauses. • The filter literals in WHERE clauses. • The value of the IN or NOT IN operator in WHERE clauses, allowing filtering on a dynamic set of values. Note that this is of particular use with a list of IDs or Strings, though it works with lists of any type. 81
- 84. Language Constructs Using Apex Variables in SOQL and SOSL Queries • The division names in WITH DIVISION clauses. • The numeric value in LIMIT clauses. Bind expressions can't be used with other clauses, such as INCLUDES. For example: Account A = new Account(Name='xxx'); insert A; Account B; // A simple bind B = [SELECT Id FROM Account WHERE Id = :A.Id]; // A bind with arithmetic B = [SELECT Id FROM Account WHERE Name = :('x' + 'xx')]; String s = 'XXX'; // A bind with expressions B = [SELECT Id FROM Account WHERE Name = :'XXXX'.substring(0,3)]; // A bind with an expression that is itself a query result B = [SELECT Id FROM Account WHERE Name = :[SELECT Name FROM Account WHERE Id = :A.Id].Name]; Contact C = new Contact(LastName='xxx', AccountId=A.Id); insert new Contact[]{C, new Contact(LastName='yyy', accountId=A.id)}; // Binds in both the parent and aggregate queries B = [SELECT Id, (SELECT Id FROM Contacts WHERE Id = :C.Id) FROM Account WHERE Id = :A.Id]; // One contact returned Contact D = B.Contacts; // A limit bind Integer i = 1; B = [SELECT Id FROM Account LIMIT :i]; // An IN-bind with an Id list. Note that a list of sObjects // can also be used--the Ids of the objects are used for // the bind Contact[] cc = [SELECT Id FROM Contact LIMIT 2]; Task[] tt = [SELECT Id FROM Task WHERE WhoId IN :cc]; // An IN-bind with a String list String[] ss = new String[]{'a', 'b'}; Account[] aa = [SELECT Id FROM Account WHERE AccountNumber IN :ss]; // A SOSL query with binds in all possible clauses String myString1 = 'aaa'; String myString2 = 'bbb'; Integer myInt3 = 11; String myString4 = 'ccc'; Integer myInt5 = 22; 82
- 85. Language Constructs Querying All Records with a SOQL Statement List<List<SObject>> searchList = [FIND :myString1 IN ALL FIELDS RETURNING Account (Id, Name WHERE Name LIKE :myString2 LIMIT :myInt3), Contact, Opportunity, Lead WITH DIVISION =:myString4 LIMIT :myInt5]; Querying All Records with a SOQL Statement SOQL statements can use the ALL ROWS keywords to query all records in an organization, including deleted records and archived activities. For example: System.assertEquals(2, [SELECT COUNT() FROM Contact WHERE AccountId = a.Id ALL ROWS]); You can use ALL ROWS to query records in your organization's Recycle Bin. You cannot use the ALL ROWS keywords with the FOR UPDATE keywords. Locking Statements Apex allows developers to lock sObject records while they are being updated in order to prevent race conditions and other thread safety problems. While an sObject record is locked, no other program or user is allowed to make updates. To lock a set of sObject records in Apex, embed the keywords FOR UPDATE after any inline SOQL statement. For example, the following statement, in addition to querying for two accounts, also locks the accounts that are returned: Account [] accts = [SELECT Id FROM Account LIMIT 2 FOR UPDATE]; Note: You cannot use the ORDER BY keywords in any SOQL query that uses locking. However, query results are automatically ordered by ID. While the accounts are locked by this call, data manipulation language (DML) statements can modify their field values in the database in the transaction. Warning: Use care when setting locks in your Apex code. See Avoiding Deadlocks, below. Locking in a SOQL For Loop The FOR UPDATE keywords can also be used within SOQL for loops. For example: for (Account[] accts : [SELECT Id FROM Account FOR UPDATE]) { // Your code } 83
- 86. Language Constructs Avoiding Deadlocks As discussed in SOQL For Loops, the example above corresponds internally to calls to the query() and queryMore() methods in the SOAP API. Note that there is no commit statement. If your Apex trigger completes successfully, any database changes are automatically committed. If your Apex trigger does not complete successfully, any changes made to the database are rolled back. Avoiding Deadlocks Note that Apex has the possibility of deadlocks, as does any other procedural logic language involving updates to multiple database tables or rows. To avoid such deadlocks, the Apex runtime engine: 1. First locks sObject parent records, then children. 2. Locks sObject records in order of ID when multiple records of the same type are being edited. As a developer, use care when locking rows to ensure that you are not introducing deadlocks. Verify that you are using standard deadlock avoidance techniques by accessing tables and rows in the same order from all locations in an application. Transaction Control All requests are delimited by the trigger, class method, Web Service, Visualforce page or anonymous block that executes the Apex code. If the entire request completes successfully, all changes are committed to the database. For example, suppose a Visualforce page called an Apex controller, which in turn called an additional Apex class. Only when all the Apex code has finished running and the Visualforce page has finished running, are the changes committed to the database. If the request does not complete successfully, all database changes are rolled back. However, sometimes during the processing of records, your business rules require that partial work (already executed DML statements) be “rolled back” so that the processing can continue in another direction. Apex gives you the ability to generate a savepoint, that is, a point in the request that specifies the state of the database at that time. Any DML statement that occurs after the savepoint can be discarded, and the database can be restored to the same condition it was in at the time you generated the savepoint. The following limitations apply to generating savepoint variables and rolling back the database: • If you set more than one savepoint, then roll back to a savepoint that is not the last savepoint you generated, the later savepoint variables become invalid. For example, if you generated savepoint SP1 first, savepoint SP2 after that, and then you rolled back to SP1, the variable SP2 would no longer be valid. You will receive a runtime error if you try to use it. • References to savepoints cannot cross trigger invocations, because each trigger invocation is a new execution context. If you declare a savepoint as a static variable then try to use it across trigger contexts you will receive a runtime error. • Each savepoint you set counts against the governor limit for DML statements. • Static variables are not reverted during a rollback. If you try to run the trigger again, the static variables retain the values from the first run. • Each rollback counts against the governor limit for DML statements. You will receive a runtime error if you try to rollback the database additional times. • The ID on an sObject inserted after setting a savepoint is not cleared after a rollback. Create new a sObject to insert after a rollback. Attempting to insert the sObject using the variable created before the rollback fails because the sObject variable has an ID. Updating or upserting the sObject using the same variable also fails because the sObject is not in the database and, thus, cannot be updated. 84
- 87. Language Constructs Exception Statements The following is an example using the setSavepoint and rollback Database methods. Account a = new Account(Name = 'xxx'); insert a; System.assertEquals(null, [SELECT AccountNumber FROM Account WHERE Id = :a.Id]. AccountNumber); // Create a savepoint while AccountNumber is null Savepoint sp = Database.setSavepoint(); // Change the account number a.AccountNumber = '123'; update a; System.assertEquals('123', [SELECT AccountNumber FROM Account WHERE Id = :a.Id]. AccountNumber); // Rollback to the previous null value Database.rollback(sp); System.assertEquals(null, [SELECT AccountNumber FROM Account WHERE Id = :a.Id]. AccountNumber); Exception Statements Apex uses exceptions to note errors and other events that disrupt the normal flow of code execution. throw statements can be used to generate exceptions, while try, catch, and finally can be used to gracefully recover from an exception. You can also create your own exceptions using the Exception class. For more information, see Exception Class on page 474. Throw Statements A throw statement allows you to signal that an error has occurred. To throw an exception, use the throw statement and provide it with an exception object to provide information about the specific error. For example: throw exceptionObject; Try-Catch-Finally Statements The try, catch, and finally statements can be used to gracefully recover from a thrown exception: • The try statement identifies a block of code in which an exception can occur. • The catch statement identifies a block of code that can handle a particular type of exception. A single try statement can have multiple associated catch statements, however, each catch statement must have a unique exception type. • The finally statement optionally identifies a block of code that is guaranteed to execute and allows you to clean up after the code enclosed in the try block. A single try statement can have only one associated finally statement. Syntax The syntax of these statements is as follows: try { code_block } catch (exceptionType) { 85
- 88. Language Constructs Try-Catch-Finally Statements code_block } // Optional catch statements for other exception types. // Note that the general exception type, 'Exception', // must be the last catch block when it is used. } catch (Exception e) { code_block } // Optional finally statement } finally { code_block } Example For example: try { // Your code here } catch (ListException e) { // List Exception handling code here } catch (Exception e) { // Generic exception handling code here } Note: Limit exceptions caused by an execution governor cannot be caught. See Understanding Execution Governors and Limits on page 225. 86
- 89. Chapter 3 Invoking Apex In this chapter ... You can invoke your Apex code using one of several mechanisms. You can write an Apex trigger and have your trigger code invoked for the events your trigger • Triggers specifies—before or after a certain operation for a specified sObject type. You • Apex Scheduler can also write an Apex class and schedule it to run at specified intervals, or run • Anonymous Blocks code snippets in an anonymous block. Finally, you can use the Ajax toolkit to • Apex in AJAX invoke Web service methods implemented in Apex. This chapter includes the following: • Triggers • Apex scheduler (for Apex classes only) • Anonymous Blocks • AJAX Toolkit 87
- 90. Invoking Apex Triggers Triggers Apex can be invoked through the use of triggers. A trigger is Apex code that executes before or after the following types of operations: • insert • update • delete • merge • upsert • undelete For example, you can have a trigger run before an object's records are inserted into the database, after records have been deleted, or even after a record is restored from the Recycle Bin. You can define triggers for any top-level standard object, such as a Contact or an Account, but not for standard child objects, such as a ContactRole. • For case comments, click Your Name > Setup > Customize > Cases > Case Comments > Triggers. • For email messages, click Your Name > Setup > Customize > Cases > Email Messages > Triggers. Triggers can be divided into two types: • Before triggers can be used to update or validate record values before they are saved to the database. • After triggers can be used to access field values that are set by the database (such as a record's Id or lastUpdated field), and to affect changes in other records, such as logging into an audit table or firing asynchronous events with a queue. Triggers can also modify other records of the same type as the records that initially fired the trigger. For example, if a trigger fires after an update of contact A, the trigger can also modify contacts B, C, and D. Because triggers can cause other records to change, and because these changes can, in turn, fire more triggers, the Apex runtime engine considers all such operations a single unit of work and sets limits on the number of operations that can be performed to prevent infinite recursion. See Understanding Execution Governors and Limits on page 225. Additionally, if you update or delete a record in its before trigger, or delete a record in its after trigger, you will receive a runtime error. This includes both direct and indirect operations. For example, if you update account A, and the before update trigger of account A inserts contact B, and the after insert trigger of contact B queries for account A and updates it using the DML update statement or database method, then you are indirectly updating account A in its before trigger, and you will receive a runtime error. Implementation Considerations Before creating triggers, consider the following: • upsert triggers fire both before and after insert or before and after update triggers as appropriate. • merge triggers fire both before and after delete triggers for the losing records and before update triggers for the winning record only. See Triggers and Merge Statements on page 96. • Triggers that execute after a record has been undeleted only work with specific objects. See Triggers and Recovered Records on page 97. • Field history is not recorded until the end of a trigger. If you query field history in a trigger, you will not see any history for the current transaction. 88
- 91. Invoking Apex Bulk Triggers • For Apex saved using Salesforce.com API version 20.0 or earlier, if an API call causes a trigger to fire, the batch of 200 records to process is further split into batches of 100 records. For Apex saved using Salesforce.com API version 21.0 and later, no further splits of API batches occur. Note that static variable values are reset between batches, but governor limits are not. Do not use static variables to track state information between batches. Bulk Triggers All triggers are bulk triggers by default, and can process multiple records at a time. You should always plan on processing more than one record at a time. Note: An Event object that is defined as recurring is not processed in bulk for insert, delete, or update triggers. Bulk triggers can handle both single record updates and bulk operations like: • Data import • Force.com Bulk API calls • Mass actions, such as record owner changes and deletes • Recursive Apex methods and triggers that invoke bulk DML statements Trigger Syntax To define a trigger, use the following syntax: trigger triggerName on ObjectName (trigger_events) { code_block } where trigger_events can be a comma-separated list of one or more of the following events: • before insert • before update • before delete • after insert • after update • after delete • after undelete Note: • You can only use the webService keyword in a trigger when it is in a method defined as asynchronous; that is, when the method is defined with the @future keyword. • A trigger invoked by an insert, delete, or update of a recurring event or recurring task results in a runtime error when the trigger is called in bulk from the Force.com API. 89
- 92. Invoking Apex Trigger Context Variables For example, the following code defines a trigger for the before insert and before update events on the Account object: trigger myAccountTrigger on Account (before insert, before update) { // Your code here } The code block of a trigger cannot contain the static keyword. Triggers can only contain keywords applicable to an inner class. In addition, you do not have to manually commit any database changes made by a trigger. If your Apex trigger completes successfully, any database changes are automatically committed. If your Apex trigger does not complete successfully, any changes made to the database are rolled back. Trigger Context Variables All triggers define implicit variables that allow developers to access runtime context. These variables are contained in the System.Trigger class: Variable Usage isExecuting Returns true if the current context for the Apex code is a trigger, not a Visualforce page, a Web service, or an executeanonymous() API call. isInsert Returns true if this trigger was fired due to an insert operation, from the Salesforce user interface, Apex, or the API. isUpdate Returns true if this trigger was fired due to an update operation, from the Salesforce user interface, Apex, or the API. isDelete Returns true if this trigger was fired due to a delete operation, from the Salesforce user interface, Apex, or the API. isBefore Returns true if this trigger was fired before any record was saved. isAfter Returns true if this trigger was fired after all records were saved. isUndelete Returns true if this trigger was fired after a record is recovered from the Recycle Bin (that is, after an undelete operation from the Salesforce user interface, Apex, or the API.) new Returns a list of the new versions of the sObject records. Note that this sObject list is only available in insert and update triggers, and the records can only be modified in before triggers. newMap A map of IDs to the new versions of the sObject records. Note that this map is only available in before update, after insert, and after update triggers. old Returns a list of the old versions of the sObject records. Note that this sObject list is only available in update and delete triggers. oldMap A map of IDs to the old versions of the sObject records. Note that this map is only available in update and delete triggers. 90
- 93. Invoking Apex Trigger Context Variables Variable Usage size The total number of records in a trigger invocation, both old and new. Note: If any record that fires a trigger includes an invalid field value (for example, a formula that divides by zero), that value is set to null in the new, newMap, old, and oldMap trigger context variables. For example, in this simple trigger, Trigger.new is a list of sObjects and can be iterated over in a for loop, or used as a bind variable in the IN clause of a SOQL query: Trigger t on Account (after insert) { for (Account a : Trigger.new) { // Iterate over each sObject } // This single query finds every contact that is associated with any of the // triggering accounts. Note that although Trigger.new is a collection of // records, when used as a bind variable in a SOQL query, Apex automatically // transforms the list of records into a list of corresponding Ids. Contact[] cons = [SELECT LastName FROM Contact WHERE AccountId IN :Trigger.new]; } This trigger uses Boolean context variables like Trigger.isBefore and Trigger.isDelete to define code that only executes for specific trigger conditions: trigger myAccountTrigger on Account(before delete, before insert, before update, after delete, after insert, after update) { if (Trigger.isBefore) { if (Trigger.isDelete) { // In a before delete trigger, the trigger accesses the records that will be // deleted with the Trigger.old list. for (Account a : Trigger.old) { if (a.name != 'okToDelete') { a.addError('You can't delete this record!'); } } } else { // In before insert or before update triggers, the trigger accesses the new records // with the Trigger.new list. for (Account a : Trigger.new) { if (a.name == 'bad') { a.name.addError('Bad name'); } } if (Trigger.isInsert) { for (Account a : Trigger.new) { System.assertEquals('xxx', a.accountNumber); System.assertEquals('industry', a.industry); System.assertEquals(100, a.numberofemployees); System.assertEquals(100.0, a.annualrevenue); a.accountNumber = 'yyy'; } // If the trigger is not a before trigger, it must be an after trigger. } else { if (Trigger.isInsert) { List<Contact> contacts = new List<Contact>(); 91
- 94. Invoking Apex Context Variable Considerations for (Account a : Trigger.new) { if(a.Name == 'makeContact') { contacts.add(new Contact (LastName = a.Name, AccountId = a.Id)); } } insert contacts; } } }}} Context Variable Considerations Be aware of the following considerations for trigger context variables: • trigger.new and trigger.old cannot be used in Apex DML operations. • You can use an object to change its own field values using trigger.new, but only in before triggers. In all after triggers, trigger.new is not saved, so a runtime exception is thrown. • trigger.old is always read-only. • You cannot delete trigger.new. The following table lists considerations about certain actions in different trigger events: Trigger Event Can change fields using Can update original object Can delete original object trigger.new using an update DML using a delete DML operation operation before insert Allowed. Not applicable. The original Not applicable. The original object has not been created; object has not been created; nothing can reference it, so nothing can reference it, so nothing can update it. nothing can update it. after insert Not allowed. A runtime error Allowed. Allowed, but unnecessary. The is thrown, as trigger.new object is deleted immediately is already saved. after being inserted. before update Allowed. Not allowed. A runtime error Not allowed. A runtime error is thrown. is thrown. after update Not allowed. A runtime error Allowed. Even though bad Allowed. The updates are is thrown, as trigger.new code could cause an infinite saved before the object is is already saved. recursion doing this deleted, so if the object is incorrectly, the error would be undeleted, the updates become found by the governor limits. visible. before delete Not allowed. A runtime error Allowed. The updates are Not allowed. A runtime error is thrown. trigger.new is saved before the object is is thrown. The deletion is not available in before delete deleted, so if the object is already in progress. triggers. undeleted, the updates become visible. 92
- 95. Invoking Apex Common Bulk Trigger Idioms Trigger Event Can change fields using Can update original object Can delete original object trigger.new using an update DML using a delete DML operation operation after delete Not allowed. A runtime error Not applicable. The object has Not applicable. The object has is thrown. trigger.new is already been deleted. already been deleted. not available in after delete triggers. after undelete Not allowed. A runtime error Allowed. Allowed, but unnecessary. The is thrown. trigger.old is object is deleted immediately not available in after undelete after being inserted. triggers. Common Bulk Trigger Idioms Although bulk triggers allow developers to process more records without exceeding execution governor limits, they can be more difficult for developers to understand and code because they involve processing batches of several records at a time. The following sections provide examples of idioms that should be used frequently when writing in bulk. Using Maps and Sets in Bulk Triggers Set and map data structures are critical for successful coding of bulk triggers. Sets can be used to isolate distinct records, while maps can be used to hold query results organized by record ID. For example, this bulk trigger from the sample quoting application first adds each pricebook entry associated with the OpportunityLineItem records in Trigger.new to a set, ensuring that the set contains only distinct elements. It then queries the PricebookEntries for their associated product color, and places the results in a map. Once the map is created, the trigger iterates through the OpportunityLineItems in Trigger.new and uses the map to assign the appropriate color. // When a new line item is added to an opportunity, this trigger copies the value of the // associated product's color to the new record. trigger oppLineTrigger on OpportunityLineItem (before insert) { // For every OpportunityLineItem record, add its associated pricebook entry // to a set so there are no duplicates. Set<Id> pbeIds = new Set<Id>(); for (OpportunityLineItem oli : Trigger.new) pbeIds.add(oli.pricebookentryid); // Query the PricebookEntries for their associated product color and place the results // in a map. Map<Id, PricebookEntry> entries = new Map<Id, PricebookEntry>( [select product2.color__c from pricebookentry where id in :pbeIds]); // Now use the map to set the appropriate color on every OpportunityLineItem processed // by the trigger. for (OpportunityLineItem oli : Trigger.new) oli.color__c = entries.get(oli.pricebookEntryId).product2.color__c; } 93
- 96. Invoking Apex Defining Triggers Correlating Records with Query Results in Bulk Triggers Use the Trigger.newMap and Trigger.oldMap ID-to-sObject maps to correlate records with query results. For example, this trigger from the sample quoting app uses Trigger.oldMap to create a set of unique IDs (Trigger.oldMap.keySet()). The set is then used as part of a query to create a list of quotes associated with the opportunities being processed by the trigger. For every quote returned by the query, the related opportunity is retrieved from Trigger.oldMap and prevented from being deleted: trigger oppTrigger on Opportunity (before delete) { for (Quote__c q : [SELECT opportunity__c FROM quote__c WHERE opportunity__c IN :Trigger.oldMap.keySet()]) { Trigger.oldMap.get(q.opportunity__c).addError('Cannot delete opportunity with a quote'); } } Using Triggers to Insert or Update Records with Unique Fields When an insert or upsert event causes a record to duplicate the value of a unique field in another new record in that batch, the error message for the duplicate record includes the ID of the first record. However, it is possible that the error message may not be correct by the time the request is finished. When there are triggers present, the retry logic in bulk operations causes a rollback/retry cycle to occur. That retry cycle assigns new keys to the new records. For example, if two records are inserted with the same value for a unique field, and you also have an insert event defined for a trigger, the second duplicate record fails, reporting the ID of the first record. However, once the system rolls back the changes and re-inserts the first record by itself, the record receives a new ID. That means the error message reported by the second record is no longer valid. Defining Triggers Trigger code is stored as metadata under the object with which they are associated. To define a trigger in Salesforce: 1. For a standard object, click Your Name > Setup > Customize, click the name of the object, then click Triggers. For a custom object, click Your Name > Setup > Create > Objects and click the name of the object. For campaign members, click Your Name > Setup > Customize > Campaigns > Campaign Member > Triggers. For case comments, click Your Name > Setup > Customize > Cases > Case Comments > Triggers. For email messages, click Your Name > Setup > Customize > Cases > Email Messages > Triggers. For the Attachment, ContentDocument, and Note standard objects, you can’t create a trigger in the Salesforce user interface. For these objects, create a trigger using development tools, such as the Developer Console or the Force.com IDE. Alternatively, you can also use the Metadata API. 2. In the Triggers related list, click New. 3. Click Version Settings to specify the version of Apex and the API used with this trigger. If your organization has installed managed packages from the AppExchange, you can also specify which version of each managed package to use with this trigger. Use the default values for all versions. This associates the trigger with the most recent version of Apex and the API, as well as each managed package. You can specify an older version of a managed package if you want to access components or functionality that differs from the most recent package version. 4. Click Apex Trigger and select the Is Active checkbox if the trigger should be compiled and enabled. Leave this checkbox deselected if you only want to store the code in your organization's metadata. This checkbox is selected by default. 94
- 97. Invoking Apex Defining Triggers 5. In the Body text box, enter the Apex for the trigger. A single trigger can be up to 1 million characters in length. To define a trigger, use the following syntax: trigger triggerName on ObjectName (trigger_events) { code_block } where trigger_events can be a comma-separated list of one or more of the following events: • before insert • before update • before delete • after insert • after update • after delete • after undelete Note: • You can only use the webService keyword in a trigger when it is in a method defined as asynchronous; that is, when the method is defined with the @future keyword. • A trigger invoked by an insert, delete, or update of a recurring event or recurring task results in a runtime error when the trigger is called in bulk from the Force.com API. 6. Click Save. Note: Triggers are stored with an isValid flag that is set to true as long as dependent metadata has not changed since the trigger was last compiled. If any changes are made to object names or fields that are used in the trigger, including superficial changes such as edits to an object or field description, the isValid flag is set to false until the Apex compiler reprocesses the code. Recompiling occurs when the trigger is next executed, or when a user re-saves the trigger in metadata. If a lookup field references a record that has been deleted, Salesforce clears the value of the lookup field by default. Alternatively, you can choose to prevent records from being deleted if they’re in a lookup relationship. The Apex Trigger Editor When editing Visualforce or Apex, either in the Visualforce development mode footer or from Setup, an editor is available with the following functionality: Syntax highlighting The editor automatically applies syntax highlighting for keywords and all functions and operators. Search ( ) Search enables you to search for text within the current page, class, or trigger. To use search, enter a string in the Search textbox and click Find Next. • To replace a found search string with another string, enter the new string in the Replace textbox and click replace to replace just that instance, or Replace All to replace that instance and all other instances of the search string that occur in the page, class, or trigger. 95
- 98. Invoking Apex Triggers and Merge Statements • To make the search operation case sensitive, select the Match Case option. • To use a regular expression as your search string, select the Regular Expressions option. The regular expressions follow JavaScript's regular expression rules. A search using regular expressions can find strings that wrap over more than one line. If you use the replace operation with a string found by a regular expression, the replace operation can also bind regular expression group variables ($1, $2, and so on) from the found search string. For example, to replace an <h1> tag with an <h2> tag and keep all the attributes on the original <h1> intact, search for <h1(s+)(.*)> and replace it with <h2$1$2>. Go to line ( ) This button allows you to highlight a specified line number. If the line is not currently visible, the editor scrolls to that line. Undo ( ) and Redo ( ) Use undo to reverse an editing action and redo to recreate an editing action that was undone. Font size Select a font size from the drop-down list to control the size of the characters displayed in the editor. Line and column position The line and column position of the cursor is displayed in the status bar at the bottom of the editor. This can be used with go to line ( ) to quickly navigate through the editor. Line and character count The total number of lines and characters is displayed in the status bar at the bottom of the editor. Triggers and Merge Statements Merge events do not fire their own trigger events. Instead, they fire delete and update events as follows: Deletion of losing records A single merge operation fires a single delete event for all records that are deleted in the merge. To determine which records were deleted as a result of a merge operation use the MasterRecordId field in Trigger.old. When a record is deleted after losing a merge operation, its MasterRecordId field is set to the ID of the winning record. The MasterRecordId field is only set in after delete trigger events. If your application requires special handling for deleted records that occur as a result of a merge, you need to use the after delete trigger event. Update of the winning record A single merge operation fires a single update event for the winning record only. Any child records that are reparented as a result of the merge operation do not fire triggers. For example, if two contacts are merged, only the delete and update contact triggers fire. No triggers for records related to the contacts, such as accounts or opportunities, fire. The following is the order of events when a merge occurs: 1. The before delete trigger fires. 2. The system deletes the necessary records due to the merge, assigns new parent records to the child records, and sets the MasterRecordId field on the deleted records. 96
- 99. Invoking Apex Triggers and Recovered Records 3. The after delete trigger fires. 4. The system does the specific updates required for the master record. Normal update triggers apply. Triggers and Recovered Records The after undelete trigger event only works with recovered records—that is, records that were deleted and then recovered from the Recycle Bin through the undelete DML statement. These are also called undeleted records. The after undelete trigger events only run on top-level objects. For example, if you delete an Account, an Opportunity may also be deleted. When you recover the Account from the Recycle Bin, the Opportunity is also recovered. If there is an after undelete trigger event associated with both the Account and the Opportunity, only the Account after undelete trigger event executes. The after undelete trigger event only fires for the following objects: • Account • Asset • Campaign • Case • Contact • ContentDocument • Contract • Custom objects • Event • Lead • Opportunity • Product • Solution • Task Triggers and Order of Execution When you save a record with an insert, update, or upsert statement, Salesforce performs the following events in order. Note: Before Salesforce executes these events on the server, the browser runs JavaScript validation if the record contains any dependent picklist fields. The validation limits each dependent picklist field to its available values. No other validation occurs on the client side. On the server, Salesforce: 1. Loads the original record from the database or initializes the record for an upsert statement. 2. Loads the new record field values from the request and overwrites the old values. If the request came from a standard UI edit page, Salesforce runs system validation to check the record for: • Compliance with layout-specific rules • Required values at the layout level and field-definition level • Valid field formats • Maximum field length 97
- 100. Invoking Apex Triggers and Order of Execution Salesforce doesn't perform system validation in this step when the request comes from other sources, such as an Apex application or a SOAP API call. 3. Executes all before triggers. 4. Runs most system validation steps again, such as verifying that all required fields have a non-null value, and runs any user-defined validation rules. The only system validation that Salesforce doesn't run a second time (when the request comes from a standard UI edit page) is the enforcement of layout-specific rules. 5. Saves the record to the database, but doesn't commit yet. 6. Executes all after triggers. 7. Executes assignment rules. 8. Executes auto-response rules. 9. Executes workflow rules. 10. If there are workflow field updates, updates the record again. 11. If the record was updated with workflow field updates, fires before and after triggers one more time (and only one more time), in addition to standard validations. Custom validation rules are not run again. Note: The before and after triggers fire one more time only if something needs to be updated. If the fields have already been set to a value, the triggers are not fired again. 12. Executes escalation rules. 13. If the record contains a roll-up summary field or is part of a cross-object workflow, performs calculations and updates the roll-up summary field in the parent record. Parent record goes through save procedure. 14. If the parent record is updated, and a grand-parent record contains a roll-up summary field or is part of a cross-object workflow, performs calculations and updates the roll-up summary field in the parent record. Grand-parent record goes through save procedure. 15. Executes Criteria Based Sharing evaluation. 16. Commits all DML operations to the database. 17. Executes post-commit logic, such as sending email. Note: During a recursive save, Salesforce skips steps 7 through 14. Additional Considerations Please note the following when working with triggers: • When Enable Validation and Triggers from Lead Convert is selected, if the lead conversion creates an opportunity and the opportunity has Apex before triggers associated with it, the triggers run immediately after the opportunity is created, before the opportunity contact role is created. For more information, see “Customizing Lead Settings” in the Salesforce online help. • If you are using before triggers to set Stage and Forecast Category for an opportunity record, the behavior is as follows: ◊ If you set Stage and Forecast Category, the opportunity record contains those exact values. ◊ If you set Stage but not Forecast Category, the Forecast Category value on the opportunity record defaults to the one associated with trigger Stage. ◊ If you reset Stage to a value specified in an API call or incoming from the user interface, the Forecast Category value should also come from the API call or user interface. If no value for Forecast Category is specified and the incoming Stage is different than the trigger Stage, the Forecast Category defaults to the one associated with trigger Stage. If the trigger Stage and incoming Stage are the same, the Forecast Category is not defaulted. 98
- 101. Invoking Apex Operations that Don't Invoke Triggers • If you are cloning an opportunity with products, the following events occur in order: 1. The parent opportunity is saved according to the list of events shown above. 2. The opportunity products are saved according to the list of events shown above. Note: If errors occur on an opportunity product, you must return to the opportunity and fix the errors before cloning. If any opportunity products contain unique custom fields, you must null them out before cloning the opportunity. • Trigger.old contains a version of the objects before the specific update that fired the trigger. However, there is an exception. When a record is updated and subsequently triggers a workflow rule field update, Trigger.old in the last update trigger won’t contain the version of the object immediately prior to the workflow update, but the object before the initial update was made. For example, suppose an existing record has a number field with an initial value of 1. A user updates this field to 10, and a workflow rule field update fires and increments it to 11. In the update trigger that fires after the workflow field update, the field value of the object obtained from Trigger.old is the original value of 1, rather than 10, as would typically be the case. Operations that Don't Invoke Triggers Triggers are only invoked for data manipulation language (DML) operations that are initiated or processed by the Java application server. Consequently, some system bulk operations don't currently invoke triggers. Some examples include: • Cascading delete operations. Records that did not initiate a delete don't cause trigger evaluation. • Cascading updates of child records that are reparented as a result of a merge operation • Mass campaign status changes • Mass division transfers • Mass address updates • Mass approval request transfers • Mass email actions • Modifying custom field data types • Renaming or replacing picklists • Managing price books • Changing a user's default division with the transfer division option checked • Changes to the following objects: ◊ BrandTemplate ◊ MassEmailTemplate ◊ Folder • Update account triggers don't fire before or after a business account record type is changed to person account (or a person account record type is changed to business account.) Note: Inserts, updates, and deletes on person accounts fire account triggers, not contact triggers. Before triggers associated with the following operations are only fired during lead conversion if validation and triggers for lead conversion are enabled in the organization: • insert of accounts, contacts, and opportunities 99
- 102. Invoking Apex Operations that Don't Invoke Triggers • update of accounts and contacts Opportunity triggers are not fired when the account owner changes as a result of the associated opportunity's owner changing. When you modify an opportunity product on an opportunity, or when an opportunity product schedule changes an opportunity product, even if the opportunity product changes the opportunity, the before and after triggers and the validation rules don't fire for the opportunity. However, roll-up summary fields do get updated, and workflow rules associated with the opportunity do run. The getContent and getContentAsPDF PageReference methods aren't allowed in triggers. Note the following for the ContentVersion object: • Content pack operations involving the ContentVersion object, including slides and slide autorevision, don't invoke triggers. Note: Content packs are revised when a slide inside of the pack is revised. • Values for the TagCsv and VersionData fields are only available in triggers if the request to create or update ContentVersion records originates from the API. • You can't use before or after delete triggers with the ContentVersion object. Things to consider about FeedItem and FeedComment triggers: • FeedItem and FeedComment objects don't support updates. Don't use before update or after update triggers. • FeedItem and FeedComment objects can't be undeleted. Don't use the after undelete trigger. • Only FeedItems of Type TextPost, LinkPost, and ContentPost can be inserted, and therefore invoke the before or after insert trigger. User status updates don't cause the FeedItem triggers to fire. • While FeedPost objects were supported for API versions 18.0, 19.0, and 20.0, don't use any insert or delete triggers saved against versions prior to 21.0. • For FeedItem the following fields are not available in the before insert trigger: ◊ ContentSize ◊ ContentType In addition, the ContentData field is not available in any delete trigger. • For FeedComment before insert and after insert triggers, the fields of a ContentVersion associated with the FeedComment (obtained through FeedComment.RelatedRecordId) are not available. • Apex code uses additional security when executing in a Chatter context. To post to a private group, the user running the code must be a member of that group. If the running user isn't a member, you can set the CreatedById field to be a member of the group in the FeedItem record. 100
- 103. Invoking Apex Entity and Field Limitations in Triggers Entity and Field Limitations in Triggers QuestionDataCategorySelection Entity Not Available in After Insert Triggers The after insert trigger that fires after inserting one ore more Question records doesn’t have access to the QuestionDataCategorySelection records that are associated with the inserted Questions. For example, the following query doesn’t return any results in an after insert trigger: QuestionDataCategorySelection[] dcList = [select Id,DataCategoryName from QuestionDataCategorySelection where ParentId IN :questions]; Fields Not Updateable in Before Triggers Some field values are set during the system save operation, which occurs after before triggers have fired. As a result, these fields cannot be modified or accurately detected in before insert or before update triggers. Some examples include: • Task.isClosed • Opportunity.amount* • Opportunity.ForecastCategory • Opportunity.isWon • Opportunity.isClosed • Contract.activatedDate • Contract.activatedById • Case.isClosed • Solution.isReviewed • Id (for all records)** • createdDate (for all records)** • lastUpdated (for all records) * When Opportunity has no lineitems, Amount can be modified by a before trigger. ** Id and createdDate can be detected in before update triggers, but cannot be modified. Trigger Exceptions Triggers can be used to prevent DML operations from occurring by calling the addError() method on a record or field. When used on Trigger.new records in insert and update triggers, and on Trigger.old records in delete triggers, the custom error message is displayed in the application interface and logged. Note: Users experience less of a delay in response time if errors are added to before triggers. A subset of the records being processed can be marked with the addError() method: • If the trigger was spawned by a DML statement in Apex, any one error results in the entire operation rolling back. However, the runtime engine still processes every record in the operation to compile a comprehensive list of errors. • If the trigger was spawned by a bulk DML call in the Force.com API, the runtime engine sets aside the bad records and attempts to do a partial save of the records that did not generate errors. See Bulk DML Exception Handling on page 289. If a trigger ever throws an unhandled exception, all records are marked with an error and no further processing takes place. 101
- 104. Invoking Apex Trigger and Bulk Request Best Practices Trigger and Bulk Request Best Practices A common development pitfall is the assumption that trigger invocations never include more than one record. Apex triggers are optimized to operate in bulk, which, by definition, requires developers to write logic that supports bulk operations. This is an example of a flawed programming pattern. It assumes that only one record is pulled in during a trigger invocation. While this might support most user interface events, it does not support bulk operations invoked through the SOAP API or Visualforce. trigger MileageTrigger on Mileage__c (before insert, before update) { User c = [SELECT Id FROM User WHERE mileageid__c = Trigger.new[0].id]; } This is another example of a flawed programming pattern. It assumes that less than 100 records are pulled in during a trigger invocation. If more than 20 records are pulled into this request, the trigger would exceed the SOQL query limit of 100 SELECT statements: trigger MileageTrigger on Mileage__c (before insert, before update) { for(mileage__c m : Trigger.new){ User c = [SELECT Id FROM user WHERE mileageid__c = m.Id]; } } For more information on governor limits, see Understanding Execution Governors and Limits on page 225. This example demonstrates the correct pattern to support the bulk nature of triggers while respecting the governor limits: Trigger MileageTrigger on Mileage__c (before insert, before update) { Set<ID> ids = Trigger.new.keySet(); List<User> c = [SELECT Id FROM user WHERE mileageid__c in :ids]; } This pattern respects the bulk nature of the trigger by passing the Trigger.new collection to a set, then using the set in a single SOQL query. This pattern captures all incoming records within the request while limiting the number of SOQL queries. Best Practices for Designing Bulk Programs The following are the best practices for this design pattern: • Minimize the number of data manipulation language (DML) operations by adding records to collections and performing DML operations against these collections. • Minimize the number of SOQL statements by preprocessing records and generating sets, which can be placed in single SOQL statement used with the IN clause. See Also: What are the Limitations of Apex? 102
- 105. Invoking Apex Apex Scheduler Apex Scheduler To invoke Apex classes to run at specific times, first implement the Schedulable interface for the class, then specify the schedule using either the Schedule Apex page in the Salesforce user interface, or the System.schedule method. For more information about the Schedule Apex page, see “Scheduling Apex” in the Salesforce online help. Important: Salesforce only adds the process to the queue at the scheduled time. Actual execution may be delayed based on service availability. You can only have 25 classes scheduled at one time. You can evaluate your current count by viewing the Scheduled Jobs page in Salesforce or programmatically using SOAP API to query the CronTrigger object. Use extreme care if you are planning to schedule a class from a trigger. You must be able to guarantee that the trigger will not add more scheduled classes than the 25 that are allowed. In particular, consider API bulk updates, import wizards, mass record changes through the user interface, and all cases where more than one record can be updated at a time. You cannot update an Apex class if there are one or more active scheduled jobs for that class. Implementing the Schedulable Interface To schedule an Apex class to run at regular intervals, first write an Apex class that implements the Salesforce-provided interface Schedulable. The scheduler runs as system: all classes are executed, whether the user has permission to execute the class or not. For more information on setting class permissions, see “Apex Class Security Overview” in the Salesforce online help. To monitor or stop the execution of a scheduled Apex job using the Salesforce user interface, click Your Name > Setup > Monitoring > Scheduled Jobs. For more information, see “Monitoring Scheduled Jobs” in the Salesforce online help. The Schedulable interface contains one method that must be implemented, execute. global void execute(SchedulableContext sc){} The implemented method must be declared as global or public. Use this method to instantiate the class you want to schedule. Tip: Though it's possible to do additional processing in the execute method, we recommend that all processing take place in a separate class. The following example implements the Schedulable interface for a class called mergeNumbers: global class scheduledMerge implements Schedulable{ global void execute(SchedulableContext SC) { mergeNumbers M = new mergeNumbers(); } } The following example uses the System.Schedule method to implement the above class. scheduledMerge m = new scheduledMerge(); String sch = '20 30 8 10 2 ?'; system.schedule('Merge Job', sch, m); 103
- 106. Invoking Apex Apex Scheduler You can also use the Schedulable interface with batch Apex classes. The following example implements the Schedulable interface for a batch Apex class called batchable: global class scheduledBatchable implements Schedulable{ global void execute(SchedulableContext sc) { batchable b = new batchable(); database.executebatch(b); } } Use the SchedulableContext object to keep track of the scheduled job once it's scheduled. The SchedulableContext method getTriggerID returns the Id of the CronTrigger object associated with this scheduled job as a string. Use this method to track the progress of the scheduled job. To stop execution of a job that was scheduled, use the System.abortJob method with the ID returned by the.getTriggerID method. Testing the Apex Scheduler The following is an example of how to test using the Apex scheduler. The System.schedule method starts an asynchronous process. This means that when you test scheduled Apex, you must ensure that the scheduled job is finished before testing against the results. Use the Test methods startTest and stopTest around the System.schedule method to ensure it finishes before continuing your test. All asynchronous calls made after the startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run synchronously. If you don’t include the System.schedule method within the startTest and stopTest methods, the scheduled job executes at the end of your test method for Apex saved using Salesforce.com API version 25.0 and later, but not in earlier versions. This is the class to be tested. global class TestScheduledApexFromTestMethod implements Schedulable { // This test runs a scheduled job at midnight Sept. 3rd. 2022 public static String CRON_EXP = '0 0 0 3 9 ? 2022'; global void execute(SchedulableContext ctx) { CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered, NextFireTime FROM CronTrigger WHERE Id = :ctx.getTriggerId()]; System.assertEquals(CRON_EXP, ct.CronExpression); System.assertEquals(0, ct.TimesTriggered); System.assertEquals('2022-09-03 00:00:00', String.valueOf(ct.NextFireTime)); Account a = [SELECT Id, Name FROM Account WHERE Name = 'testScheduledApexFromTestMethod']; a.name = 'testScheduledApexFromTestMethodUpdated'; update a; } } The following tests the above class: @istest class TestClass { static testmethod void test() { Test.startTest(); 104
- 107. Invoking Apex Apex Scheduler Account a = new Account(); a.Name = 'testScheduledApexFromTestMethod'; insert a; // Schedule the test job String jobId = System.schedule('testBasicScheduledApex', TestScheduledApexFromTestMethod.CRON_EXP, new TestScheduledApexFromTestMethod()); // Get the information from the CronTrigger API object CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered, NextFireTime FROM CronTrigger WHERE id = :jobId]; // Verify the expressions are the same System.assertEquals(TestScheduledApexFromTestMethod.CRON_EXP, ct.CronExpression); // Verify the job has not run System.assertEquals(0, ct.TimesTriggered); // Verify the next time the job will run System.assertEquals('2022-09-03 00:00:00', String.valueOf(ct.NextFireTime)); System.assertNotEquals('testScheduledApexFromTestMethodUpdated', [SELECT id, name FROM account WHERE id = :a.id].name); Test.stopTest(); System.assertEquals('testScheduledApexFromTestMethodUpdated', [SELECT Id, Name FROM Account WHERE Id = :a.Id].Name); } } Using the System.Schedule Method After you implement a class with the Schedulable interface, use the System.Schedule method to execute it. The scheduler runs as system: all classes are executed, whether the user has permission to execute the class or not. Note: Use extreme care if you are planning to schedule a class from a trigger. You must be able to guarantee that the trigger will not add more scheduled classes than the 25 that are allowed. In particular, consider API bulk updates, import wizards, mass record changes through the user interface, and all cases where more than one record can be updated at a time. The System.Schedule method takes three arguments: a name for the job, an expression used to represent the time and date the job is scheduled to run, and the name of the class. This expression has the following syntax: Seconds Minutes Hours Day_of_month Month Day_of_week optional_year Note: Salesforce only adds the process to the queue at the scheduled time. Actual execution may be delayed based on service availability. The System.Schedule method uses the user's timezone for the basis of all schedules. The following are the values for the expression: Name Values Special Characters Seconds 0–59 None 105
- 108. Invoking Apex Apex Scheduler Name Values Special Characters Minutes 0–59 None Hours 0–23 , - * / Day_of_month 1–31 , - * ? / L W Month 1–12 or the following: , - * / • JAN • FEB • MAR • APR • MAY • JUN • JUL • AUG • SEP • OCT • NOV • DEC Day_of_week 1–7 or the following: , - * ? / L # • SUN • MON • TUE • WED • THU • FRI • SAT optional_year null or 1970–2099 , - * / The special characters are defined as follows: Special Character Description , Delimits values. For example, use JAN, MAR, APR to specify more than one month. - Specifies a range. For example, use JAN-MAR to specify more than one month. * Specifies all values. For example, if Month is specified as *, the job is scheduled for every month. ? Specifies no specific value. This is only available for Day_of_month and Day_of_week, and is generally used when specifying a value for one and not the other. / Specifies increments. The number before the slash specifies when the intervals will begin, and the number after the slash is the interval amount. For example, 106
- 109. Invoking Apex Apex Scheduler Special Character Description if you specify 1/5 for Day_of_month, the Apex class runs every fifth day of the month, starting on the first of the month. L Specifies the end of a range (last). This is only available for Day_of_month and Day_of_week. When used with Day of month, L always means the last day of the month, such as January 31, February 28 for leap years, and so on. When used with Day_of_week by itself, it always means 7 or SAT. When used with a Day_of_week value, it means the last of that type of day in the month. For example, if you specify 2L, you are specifying the last Monday of the month. Do not use a range of values with L as the results might be unexpected. W Specifies the nearest weekday (Monday-Friday) of the given day. This is only available for Day_of_month. For example, if you specify 20W, and the 20th is a Saturday, the class runs on the 19th. If you specify 1W, and the first is a Saturday, the class does not run in the previous month, but on the third, which is the following Monday. Tip: Use the L and W together to specify the last weekday of the month. # Specifies the nth day of the month, in the format weekday#day_of_month. This is only available for Day_of_week. The number before the # specifies weekday (SUN-SAT). The number after the # specifies the day of the month. For example, specifying 2#2 means the class runs on the second Monday of every month. The following are some examples of how to use the expression. Expression Description 0 0 13 * * ? Class runs every day at 1 PM. 0 0 22 ? * 6L Class runs the last Friday of every month at 10 PM. 0 0 10 ? * MON-FRI Class runs Monday through Friday at 10 AM. 0 0 20 * * ? 2010 Class runs every day at 8 PM during the year 2010. In the following example, the class proschedule implements the Schedulable interface. The class is scheduled to run at 8 AM, on the 13th of February. proschedule p = new proschedule(); String sch = '0 0 8 13 2 ?'; system.schedule('One Time Pro', sch, p); Apex Scheduler Best Practices and Limits • Salesforce only adds the process to the queue at the scheduled time. Actual execution may be delayed based on service availability. 107
- 110. Invoking Apex Anonymous Blocks • Use extreme care if you are planning to schedule a class from a trigger. You must be able to guarantee that the trigger will not add more scheduled classes than the 25 that are allowed. In particular, consider API bulk updates, import wizards, mass record changes through the user interface, and all cases where more than one record can be updated at a time. • Though it's possible to do additional processing in the execute method, we recommend that all processing take place in a separate class. • You can only have 25 classes scheduled at one time. You can evaluate your current count by viewing the Scheduled Jobs page in Salesforce or programmatically using SOAP API to query the CronTrigger object. • You can't use the getContent and getContentAsPDF PageReference methods in scheduled Apex. • Synchronous Web service callouts are not supported from scheduled Apex. To be able to make callouts, make an asynchronous callout by placing the callout in a method annotated with @future(callout=true) and call this method from scheduled Apex. However, if your scheduled Apex executes a batch job, callouts are supported from the batch class. See Using Batch Apex. Anonymous Blocks An anonymous block is Apex code that does not get stored in the metadata, but that can be compiled and executed using one of the following: • Developer Console • Force.com IDE • The executeAnonymous SOAP API call: ExecuteAnonymousResult executeAnonymous(String code) You can use anonymous blocks to quickly evaluate Apex on the fly, such as in the Developer Console or the Force.com IDE, or to write code that changes dynamically at runtime. For example, you might write a client Web application that takes input from a user, such as a name and address, and then uses an anonymous block of Apex to insert a contact with that name and address into the database. Note the following about the content of an anonymous block (for executeAnonymous, the code String): • Can include user-defined methods and exceptions. • User-defined methods cannot include the keyword static. • You do not have to manually commit any database changes. • If your Apex trigger completes successfully, any database changes are automatically committed. If your Apex trigger does not complete successfully, any changes made to the database are rolled back. • Unlike classes and triggers, anonymous blocks execute as the current user and can fail to compile if the code violates the user's object- and field-level permissions. • Do not have a scope other than local. For example, though it is legal to use the global access modifier, it has no meaning. The scope of the method is limited to the anonymous block. Even though a user-defined method can refer to itself or later methods without the need for forward declarations, variables cannot be referenced before their actual declaration. In the following example, the Integer int must be declared while myProcedure1 does not: Integer int1 = 0; void myProcedure1() { 108
- 111. Invoking Apex Apex in AJAX myProcedure2(); } void myProcedure2() { int1++; } myProcedure1(); The return result for anonymous blocks includes: • Status information for the compile and execute phases of the call, including any errors that occur • The debug log content, including the output of any calls to the System.debug method (see Understanding the Debug Log on page 210) • The Apex stack trace of any uncaught code execution exceptions, including the class, method, and line number for each call stack element For more information on executeAnonymous(), see SOAP API and SOAP Headers for Apex. See also Working with Logs in the Developer Console and the Force.com IDE. Apex in AJAX The AJAX toolkit includes built-in support for invoking Apex through anonymous blocks or public webService methods. To do so, include the following lines in your AJAX code: <script src="/soap/ajax/15.0/connection.js" type="text/javascript"></script> <script src="/soap/ajax/15.0/apex.js" type="text/javascript"></script> Note: For AJAX buttons, use the alternate forms of these includes. To invoke Apex, use one of the following two methods: • Execute anonymously via sforce.apex.executeAnonymous (script). This method returns a result similar to the API's result type, but as a JavaScript structure. • Use a class WSDL. For example, you can call the following Apex class: global class myClass { webService static Id makeContact(String lastName, Account a) { Contact c = new Contact(LastName = lastName, AccountId = a.Id); return c.id; } } By using the following JavaScript code: var account = sforce.sObject("Account"); var id = sforce.apex.execute("myClass","makeContact", {lastName:"Smith", a:account}); The execute method takes primitive data types, sObjects, and lists of primitives or sObjects. 109
- 112. Invoking Apex Apex in AJAX To call a webService method with no parameters, use {} as the third parameter for sforce.apex.execute. For example, to call the following Apex class: global class myClass{ webService static String getContextUserName() { return UserInfo.getFirstName(); } } Use the following JavaScript code: var contextUser = sforce.apex.execute("myClass", "getContextUserName", {}); Note: If a namespace has been defined for your organization, you must include it in the JavaScript code when you invoke the class. For example, to call the above class, the JavaScript code from above would be rewritten as follows: var contextUser = sforce.apex.execute("myNamespace.myClass", "getContextUserName", {}); To verify whether your organization has a namespace, log in to your Salesforce organization and navigate to Your Name > Setup > Create > Packages. If a namespace is defined, it is listed under Developer Settings. Both examples result in native JavaScript values that represent the return type of the methods. Use the following line to display a popup window with debugging information: sforce.debug.trace=true; 110
- 113. Chapter 4 Classes, Objects, and Interfaces In this chapter ... A class is a template or blueprint from which Apex objects are created. Classes consist of other classes, user-defined methods, variables, exception types, and • Understanding Classes static initialization code. They are stored in the application under Your Name • Interfaces and Extending Classes > Setup > Develop > Apex Classes. • Keywords Once successfully saved, class methods or variables can be invoked by other Apex • Annotations code, or through the SOAP API (or AJAX Toolkit) for methods that have been • Classes and Casting designated with the webService keyword. • Differences Between Apex Classes In most cases, the class concepts described here are modeled on their counterparts and Java Classes in Java, and can be quickly understood by those who are familiar with them. • Class Definition Creation • Understanding Classes—more about creating classes in Apex • Class Security • Interfaces and Extending Classes—information about interfaces • Enforcing Object and Field • Keywords and Annotations—additional modifiers for classes, methods or Permissions variables • Namespace Prefix • Classes and Casting—assigning a class of one data type to another • Version Settings • Differences Between Apex Classes and Java Classes—how Apex and Java differ • Class Definition Creation and Class Security—creating a class in the Salesforce user interface as well as enabling users to access a class • Namespace Prefix and Version Settings—using a namespace prefix and versioning Apex classes 111
- 114. Classes, Objects, and Interfaces Understanding Classes Understanding Classes As in Java, you can create classes in Apex. A class is a template or blueprint from which objects are created. An object is an instance of a class. For example, the PurchaseOrder class describes an entire purchase order, and everything that you can do with a purchase order. An instance of the PurchaseOrder class is a specific purchase order that you send or receive. All objects have state and behavior, that is, things that an object knows about itself, and things that an object can do. The state of a PurchaseOrder object—what it knows—includes the user who sent it, the date and time it was created, and whether it was flagged as important. The behavior of a PurchaseOrder object—what it can do—includes checking inventory, shipping a product, or notifying a customer. A class can contain variables and methods. Variables are used to specify the state of an object, such as the object's Name or Type. Since these variables are associated with a class and are members of it, they are commonly referred to as member variables. Methods are used to control behavior, such as getOtherQuotes or copyLineItems. An interface is like a class in which none of the methods have been implemented—the method signatures are there, but the body of each method is empty. To use an interface, another class must implement it by providing a body for all of the methods contained in the interface. For more general information on classes, objects, and interfaces, see http://java.sun.com/docs/books/tutorial/java/concepts/index.html Defining Apex Classes In Apex, you can define top-level classes (also called outer classes) as well as inner classes, that is, a class defined within another class. You can only have inner classes one level deep. For example: public class myOuterClass { // Additional myOuterClass code here class myInnerClass { // myInnerClass code here } } To define a class, specify the following: 1. Access modifiers: • You must use one of the access modifiers (such as public or global) in the declaration of a top-level class. • You do not have to use an access modifier in the declaration of an inner class. 2. Optional definition modifiers (such as virtual, abstract, and so on) 3. Required: The keyword class followed by the name of the class 4. Optional extensions and/or implementations Use the following syntax for defining classes: private | public | global [virtual | abstract | with sharing | without sharing | (none)] class ClassName [implements InterfaceNameList | (none)] [extends ClassName | (none)] { // The body of the class } 112
- 115. Classes, Objects, and Interfaces Extended Class Example • The private access modifier declares that this class is only known locally, that is, only by this section of code. This is the default access for inner classes—that is, if you don't specify an access modifier for an inner class, it is considered private. This keyword can only be used with inner classes. • The public access modifier declares that this class is visible in your application or namespace. • The global access modifier declares that this class is known by all Apex code everywhere. All classes that contain methods defined with the webService keyword must be declared as global. If a method or inner class is declared as global, the outer, top-level class must also be defined as global. • The with sharing and without sharing keywords specify the sharing mode for this class. For more information, see Using the with sharing or without sharing Keywords on page 134. • The virtual definition modifier declares that this class allows extension and overrides. You cannot override a method with the override keyword unless the class has been defined as virtual. • The abstract definition modifier declares that this class contains abstract methods, that is, methods that only have their signature declared and no body defined. Note: • You cannot add an abstract method to a global class after the class has been uploaded in a Managed - Released package version. • If the class in the Managed - Released package is virtual, the method that you can add to it must also be virtual and must have an implementation. • You cannot override a public or protected virtual method of a global class of an installed managed package. For more information about managed packages, see Developing Apex in Managed Packages on page 231. A class can implement multiple interfaces, but only extend one existing class. This restriction means that Apex does not support multiple inheritance. The interface names in the list are separated by commas. For more information about interfaces, see Interfaces and Extending Classes on page 127. For more information about method and variable access modifiers, see Access Modifiers on page 121. Extended Class Example The following is an extended example of a class, showing all the features of Apex classes. The keywords and concepts introduced in the example are explained in more detail throughout this chapter. // Top-level (outer) class must be public or global (usually public unless they contain // a Web Service, then they must be global) public class OuterClass { // Static final variable (constant) – outer class level only private static final Integer MY_INT; // Non-final static variable - use this to communicate state across triggers // within a single request) public static String sharedState; // Static method - outer class level only public static Integer getInt() { return MY_INT; } // Static initialization (can be included where the variable is defined) static { MY_INT = 2; } // Member variable for outer class 113
- 116. Classes, Objects, and Interfaces Extended Class Example private final String m; // Instance initialization block - can be done where the variable is declared, // or in a constructor { m = 'a'; } // Because no constructor is explicitly defined in this outer class, an implicit, // no-argument, public constructor exists // Inner interface public virtual interface MyInterface { // No access modifier is necessary for interface methods - these are always // public or global depending on the interface visibility void myMethod(); } // Interface extension interface MySecondInterface extends MyInterface { Integer method2(Integer i); } // Inner class - because it is virtual it can be extended. // This class implements an interface that, in turn, extends another interface. // Consequently the class must implement all methods. public virtual class InnerClass implements MySecondInterface { // Inner member variables private final String s; private final String s2; // Inner instance initialization block (this code could be located above) { this.s = 'x'; } // Inline initialization (happens after the block above executes) private final Integer i = s.length(); // Explicit no argument constructor InnerClass() { // This invokes another constructor that is defined later this('none'); } // Constructor that assigns a final variable value public InnerClass(String s2) { this.s2 = s2; } // Instance method that implements a method from MyInterface. // Because it is declared virtual it can be overridden by a subclass. public virtual void myMethod() { /* does nothing */ } // Implementation of the second interface method above. // This method references member variables (with and without the "this" prefix) public Integer method2(Integer i) { return this.i + s.length(); } } // Abstract class (that subclasses the class above). No constructor is needed since // parent class has a no-argument constructor public abstract class AbstractChildClass extends InnerClass { // Override the parent class method with this signature. // Must use the override keyword 114
- 117. Classes, Objects, and Interfaces Extended Class Example public override void myMethod() { /* do something else */ } // Same name as parent class method, but different signature. // This is a different method (displaying polymorphism) so it does not need // to use the override keyword protected void method2() {} // Abstract method - subclasses of this class must implement this method abstract Integer abstractMethod(); } // Complete the abstract class by implementing its abstract method public class ConcreteChildClass extends AbstractChildClass { // Here we expand the visibility of the parent method - note that visibility // cannot be restricted by a sub-class public override Integer abstractMethod() { return 5; } } // A second sub-class of the original InnerClass public class AnotherChildClass extends InnerClass { AnotherChildClass(String s) { // Explicitly invoke a different super constructor than one with no arguments super(s); } } // Exception inner class public virtual class MyException extends Exception { // Exception class member variable public Double d; // Exception class constructor MyException(Double d) { this.d = d; } // Exception class method, marked as protected protected void doIt() {} } // Exception classes can be abstract and implement interfaces public abstract class MySecondException extends Exception implements MyInterface { } } This code example illustrates: • A top-level class definition (also called an outer class) • Static variables and static methods in the top-level class, as well as static initialization code blocks • Member variables and methods for the top-level class • Classes with no user-defined constructor — these have an implicit, no-argument constructor • An interface definition in the top-level class • An interface that extends another interface • Inner class definitions (one level deep) within a top-level class • A class that implements an interface (and, therefore, its associated sub-interface) by implementing public versions of the method signatures • An inner class constructor definition and invocation • An inner class member variable and a reference to it using the this keyword (with no arguments) • An inner class constructor that uses the this keyword (with arguments) to invoke a different constructor 115
- 118. Classes, Objects, and Interfaces Declaring Class Variables • Initialization code outside of constructors — both where variables are defined, as well as with anonymous blocks in curly braces ({}). Note that these execute with every construction in the order they appear in the file, as with Java. • Class extension and an abstract class • Methods that override base class methods (which must be declared virtual) • The override keyword for methods that override subclass methods • Abstract methods and their implementation by concrete sub-classes • The protected access modifier • Exceptions as first class objects with members, methods, and constructors This example shows how the class above can be called by other Apex code: // Construct an instance of an inner concrete class, with a user-defined constructor OuterClass.InnerClass ic = new OuterClass.InnerClass('x'); // Call user-defined methods in the class System.assertEquals(2, ic.method2(1)); // Define a variable with an interface data type, and assign it a value that is of // a type that implements that interface OuterClass.MyInterface mi = ic; // Use instanceof and casting as usual OuterClass.InnerClass ic2 = mi instanceof OuterClass.InnerClass ? (OuterClass.InnerClass)mi : null; System.assert(ic2 != null); // Construct the outer type OuterClass o = new OuterClass(); System.assertEquals(2, OuterClass.getInt()); // Construct instances of abstract class children System.assertEquals(5, new OuterClass.ConcreteChildClass().abstractMethod()); // Illegal - cannot construct an abstract class // new OuterClass.AbstractChildClass(); // Illegal – cannot access a static method through an instance // o.getInt(); // Illegal - cannot call protected method externally // new OuterClass.ConcreteChildClass().method2(); This code example illustrates: • Construction of the outer class • Construction of an inner class and the declaration of an inner interface type • A variable declared as an interface type can be assigned an instance of a class that implements that interface • Casting an interface variable to be a class type that implements that interface (after verifying this using the instanceof operator) Declaring Class Variables To declare a variable, specify the following: • Optional: Modifiers, such as public or final, as well as static. • Required: The data type of the variable, such as String or Boolean. 116
- 119. Classes, Objects, and Interfaces Defining Class Methods • Required: The name of the variable. • Optional: The value of the variable. Use the following syntax when defining a variable: [public | private | protected | global | final] [static] data_type variable_name [= value] For example: private static final Integer MY_INT; private final Integer i = 1; Defining Class Methods To define a method, specify the following: • Optional: Modifiers, such as public or protected. • Required: The data type of the value returned by the method, such as String or Integer. Use void if the method does not return a value. • Required: A list of input parameters for the method, separated by commas, each preceded by its data type, and enclosed in parentheses (). If there are no parameters, use a set of empty parentheses. A method can only have 32 input parameters. • Required: The body of the method, enclosed in braces {}. All the code for the method, including any local variable declarations, is contained here. Use the following syntax when defining a method: (public | private | protected | global ) [override] [static] data_type method_name (input parameters) { // The body of the method } Note: You can only use override to override methods in classes that have been defined as virtual. For example: public static Integer getInt() { return MY_INT; } As in Java, methods that return values can also be run as a statement if their results are not assigned to another variable. Note that user-defined methods: • Can be used anywhere that system methods are used. • Can be recursive. • Can have side effects, such as DML insert statements that initialize sObject record IDs. See Apex Data Manipulation Language (DML) Operations on page 268. • Can refer to themselves or to methods defined later in the same class or anonymous block. Apex parses methods in two phases, so forward declarations are not needed. 117
- 120. Classes, Objects, and Interfaces Defining Class Methods • Can be polymorphic. For example, a method named foo can be implemented in two ways, one with a single Integer parameter and one with two Integer parameters. Depending on whether the method is called with one or two Integers, the Apex parser selects the appropriate implementation to execute. If the parser cannot find an exact match, it then seeks an approximate match using type coercion rules. For more information on data conversion, see Understanding Rules of Conversion on page 56. Note: If the parser finds multiple approximate matches, a parse-time exception is generated. • When using void methods that have side effects, user-defined methods are typically executed as stand-alone procedure statements in Apex code. For example: System.debug('Here is a note for the log.'); • Can have statements where the return values are run as a statement if their results are not assigned to another variable. This is the same as in Java. Passing Method Arguments By Value In Apex, all primitive data type arguments, such as Integer or String, are passed into methods by value. This means that any changes to the arguments exist only within the scope of the method. When the method returns, the changes to the arguments are lost. Non-primitive data type arguments, such as sObjects, are also passed into methods by value. This means that when the method returns, the passed-in argument still references the same object as before the method call and can't be changed to point to another object. However, the values of the object's fields can be changed in the method. The following are examples of passing primitive and non-primitive data type arguments into methods. Example: Passing Primitive Data Type Arguments This example shows how a primitive argument of type String is passed by value into another method. The debugStatusMessage method in this example creates a String variable, msg, and assigns it a value. It then passes this variable as an argument to another method, which modifies the value of this String. However, since String is a primitive type, it is passed by value, and when the method returns, the value of the original variable, msg, is unchanged. An assert statement verifies that the value of msg is still the old value. public class PassPrimitiveTypeExample { public static void debugStatusMessage() { String msg = 'Original value'; processString(msg); // The value of the msg variable didn't // change; it is still the old value. System.assertEquals(msg, 'Original value'); } public static void processString(String s) { s = 'Modified value'; } } Example: Passing Non-Primitive Data Type Arguments This example shows how a List argument is passed by value into another method and can be modified. It also shows that the List argument can’t be modified to point to another List object. First, the createTemperatureHistory method creates a variable, fillMe, that is a List of Integers and passes it to a method. The called method fills this list with Integer values representing rounded temperature values. When the method returns, an assert verifies that the contents of the original List 118
- 121. Classes, Objects, and Interfaces Using Constructors variable has changed and now contains five values. Next, the example creates a second List variable, createMe, and passes it to another method. The called method assigns the passed-in argument to a newly created List that contains new Integer values. When the method returns, the original createMe variable doesn’t point to the new List but still points to the original List, which is empty. An assert verifies that createMe contains no values. public class PassNonPrimitiveTypeExample { public static void createTemperatureHistory() { List<Integer> fillMe = new List<Integer>(); reference(fillMe); // The list is modified and contains five items // as expected. System.assertEquals(fillMe.size(),5); List<Integer> createMe = new List<Integer>(); referenceNew(createMe); // The list is not modified because it still points // to the original list, not the new list // that the method created. System.assertEquals(createMe.size(),0); } public static void reference(List<Integer> m) { // Add rounded temperatures for the last five days. m.add(70); m.add(68); m.add(75); m.add(80); m.add(82); } public static void referenceNew(List<Integer> m) { // Assign argument to a new List of // five temperature values. m = new List<Integer>{55, 59, 62, 60, 63}; } } Using Constructors A constructor is code that is invoked when an object is created from the class blueprint. You do not need to write a constructor for every class. If a class does not have a user-defined constructor, an implicit, no-argument, public one is used. The syntax for a constructor is similar to a method, but it differs from a method definition in that it never has an explicit return type and it is not inherited by the object created from it. After you write the constructor for a class, you must use the new keyword in order to instantiate an object from that class, using that constructor. For example, using the following class: public class TestObject { // The no argument constructor public TestObject() { // more code here } } A new object of this type can be instantiated with the following code: TestObject myTest = new TestObject(); 119
- 122. Classes, Objects, and Interfaces Using Constructors If you write a constructor that takes arguments, you can then use that constructor to create an object using those arguments. If you create a constructor that takes arguments, and you still want to use a no-argument constructor, you must include one in your code. Once you create a constructor for a class, you no longer have access to the default, no-argument public constructor. You must create your own. In Apex, a constructor can be overloaded, that is, there can be more than one constructor for a class, each having different parameters. The following example illustrates a class with two constructors: one with no arguments and one that takes a simple Integer argument. It also illustrates how one constructor calls another constructor using the this(...) syntax, also know as constructor chaining. public class TestObject2 { private static final Integer DEFAULT_SIZE = 10; Integer size; //Constructor with no arguments public TestObject2() { this(DEFAULT_SIZE); // Using this(...) calls the one argument constructor } // Constructor with one argument public TestObject2(Integer ObjectSize) { size = ObjectSize; } } New objects of this type can be instantiated with the following code: TestObject2 myObject1 = new TestObject2(42); TestObject2 myObject2 = new TestObject2(); Every constructor that you create for a class must have a different argument list. In the following example, all of the constructors are possible: public class Leads { // First a no-argument constructor public Leads () {} // A constructor with one argument public Leads (Boolean call) {} // A constructor with two arguments public Leads (String email, Boolean call) {} // Though this constructor has the same arguments as the // one above, they are in a different order, so this is legal public Leads (Boolean call, String email) {} } When you define a new class, you are defining a new data type. You can use class name in any place you can use other data type names, such as String, Boolean, or Account. If you define a variable whose type is a class, any object you assign to it must be an instance of that class or subclass. 120
- 123. Classes, Objects, and Interfaces Access Modifiers Access Modifiers Apex allows you to use the private, protected, public, and global access modifiers when defining methods and variables. While triggers and anonymous blocks can also use these access modifiers, they are not as useful in smaller portions of Apex. For example, declaring a method as global in an anonymous block does not enable you to call it from outside of that code. For more information on class access modifiers, see Defining Apex Classes on page 112. Note: Interface methods have no access modifiers. They are always global. For more information, see Interfaces and Extending Classes on page 127. By default, a method or variable is visible only to the Apex code within the defining class. You must explicitly specify a method or variable as public in order for it to be available to other classes in the same application namespace (see Namespace Prefix). You can change the level of visibility by using the following access modifiers: private This is the default, and means that the method or variable is accessible only within the Apex class in which it is defined. If you do not specify an access modifier, the method or variable is private. protected This means that the method or variable is visible to any inner classes in the defining Apex class. You can only use this access modifier for instance methods and member variables. Note that it is strictly more permissive than the default (private) setting, just like Java. public This means the method or variable can be used by any Apex in this application or namespace. Note: In Apex, the public access modifier is not the same as it is in Java. This was done to discourage joining applications, to keep the code for each application separate. In Apex, if you want to make something public like it is in Java, you need to use the global access modifier. global This means the method or variable can be used by any Apex code that has access to the class, not just the Apex code in the same application. This access modifier should be used for any method that needs to be referenced outside of the application, either in the SOAP API or by other Apex code. If you declare a method or variable as global, you must also declare the class that contains it as global. Note: We recommend using the global access modifier rarely, if at all. Cross-application dependencies are difficult to maintain. To use the private, protected, public, or global access modifiers, use the following syntax: [(none)|private|protected|public|global] declaration 121
- 124. Classes, Objects, and Interfaces Static and Instance For example: private string s1 = '1'; public string gets1() { return this.s1; } Static and Instance In Apex, you can have static methods, variables, and initialization code. Apex classes can’t be static. You can also have instance methods, member variables, and initialization code (which have no modifier), and local variables: • Static methods, variables, or initialization code are associated with a class, and are only allowed in outer classes. When you declare a method or variable as static, it's initialized only once when a class is loaded. Static variables aren't transmitted as part of the view state for a Visualforce page. • Instance methods, member variables, and initialization code are associated with a particular object and have no definition modifier. When you declare instance methods, member variables, or initialization code, an instance of that item is created with every object instantiated from the class. • Local variables are associated with the block of code in which they are declared. All local variables should be initialized before they are used. The following is an example of a local variable whose scope is the duration of the if code block: Boolean myCondition = true; if (myCondition) { integer localVariable = 10; } Using Static Methods and Variables You can only use static methods and variables with outer classes. Inner classes have no static methods or variables. A static method or variable does not require an instance of the class in order to run. All static member variables in a class are initialized before any object of the class is created. This includes any static initialization code blocks. All of these are run in the order in which they appear in the class. Static methods are generally used as utility methods and never depend on a particular instance member variable value. Because a static method is only associated with a class, it cannot access any instance member variable values of its class. Static variables are only static within the scope of the request. They are not static across the server, or across the entire organization. Use static variables to store information that is shared within the confines of the class. All instances of the same class share a single copy of the static variables. For example, all triggers that are spawned by the same request can communicate with each other by viewing and updating static variables in a related class. A recursive trigger might use the value of a class variable to determine when to exit the recursion. Suppose you had the following class: public class p { public static boolean firstRun = true; } 122
- 125. Classes, Objects, and Interfaces Static and Instance A trigger that uses this class could then selectively fail the first run of the trigger: trigger t1 on Account (before delete, after delete, after undelete) { if(Trigger.isBefore){ if(Trigger.isDelete){ if(p.firstRun){ Trigger.old[0].addError('Before Account Delete Error'); p.firstRun=false; } } } } Class static variables cannot be accessed through an instance of that class. So if class C has a static variable S, and x is an instance of C, then x.S is not a legal expression. The same is true for instance methods: if M() is a static method then x.M() is not legal. Instead, your code should refer to those static identifiers using the class: C.S and C.M(). If a local variable is named the same as the class name, these static methods and variables are hidden. Inner classes behave like static Java inner classes, but do not require the static keyword. Inner classes can have instance member variables like outer classes, but there is no implicit pointer to an instance of the outer class (using the this keyword). Note: For Apex saved using Salesforce.com API version 20.0 or earlier, if an API call causes a trigger to fire, the batch of 200 records to process is further split into batches of 100 records. For Apex saved using Salesforce.com API version 21.0 and later, no further splits of API batches occur. Note that static variable values are reset between batches, but governor limits are not. Do not use static variables to track state information between batches. Using Instance Methods and Variables Instance methods and member variables are used by an instance of a class, that is, by an object. Instance member variables are declared inside a class, but not within a method. Instance methods usually use instance member variables to affect the behavior of the method. Suppose you wanted to have a class that collects two dimensional points and plot them on a graph. The following skeleton class illustrates this, making use of member variables to hold the list of points and an inner class to manage the two-dimensional list of points. public class Plotter { // This inner class manages the points class Point { Double x; Double y; Point(Double x, Double y) { this.x = x; this.y = y; } Double getXCoordinate() { return x; } Double getYCoordinate() { return y; } } 123
- 126. Classes, Objects, and Interfaces Static and Instance List<Point> points = new List<Point>(); public void plot(Double x, Double y) { points.add(new Point(x, y)); } // The following method takes the list of points and does something with them public void render() { } } Using Initialization Code Instance initialization code is a block of code in the following form that is defined in a class: { //code body } The instance initialization code in a class is executed every time an object is instantiated from that class. These code blocks run before the constructor. If you do not want to write your own constructor for a class, you can use an instance initialization code block to initialize instance variables. However, most of the time you should either give the variable a default value or use the body of a constructor to do initialization and not use instance initialization code. Static initialization code is a block of code preceded with the keyword static: static { //code body } Similar to other static code, a static initialization code block is only initialized once on the first use of the class. A class can have any number of either static or instance initialization code blocks. They can appear anywhere in the code body. The code blocks are executed in the order in which they appear in the file, the same as in Java. You can use static initialization code to initialize static final variables and to declare any information that is static, such as a map of values. For example: public class MyClass { class RGB { Integer red; Integer green; Integer blue; RGB(Integer red, Integer green, Integer blue) { this.red = red; this.green = green; this.blue = blue; } } static Map<String, RGB> colorMap = new Map<String, RGB>(); 124
- 127. Classes, Objects, and Interfaces Apex Properties static { colorMap.put('red', new RGB(255, 0, 0)); colorMap.put('cyan', new RGB(0, 255, 255)); colorMap.put('magenta', new RGB(255, 0, 255)); } } Apex Properties An Apex property is similar to a variable, however, you can do additional things in your code to a property value before it is accessed or returned. Properties can be used in many different ways: they can validate data before a change is made; they can prompt an action when data is changed, such as altering the value of other member variables; or they can expose data that is retrieved from some other source, such as another class. Property definitions include one or two code blocks, representing a get accessor and a set accessor: • The code in a get accessor executes when the property is read. • The code in a set accessor executes when the property is assigned a new value. A property with only a get accessor is considered read-only. A property with only a set accessor is considered write-only. A property with both accessors is read-write. To declare a property, use the following syntax in the body of a class: Public class BasicClass { // Property declaration access_modifier return_type property_name { get { //Get accessor code block } set { //Set accessor code block } } } Where: • access_modifier is the access modifier for the property. All modifiers that can be applied to variables can also be applied to properties. These include: public, private, global, protected, static, virtual, abstract, override and transient. For more information on access modifiers, see Access Modifiers on page 121. • return_type is the type of the property, such as Integer, Double, sObject, and so on. For more information, see Data Types on page 36. • property_name is the name of the property For example, the following class defines a property named prop. The property is public. The property returns an integer data type. public class BasicProperty { public integer prop { get { return prop; } set { prop = value; } } } 125
- 128. Classes, Objects, and Interfaces Apex Properties The following code segment calls the class above, exercising the get and set accessors: BasicProperty bp = new BasicProperty(); bp.prop = 5; // Calls set accessor System.assert(bp.prop == 5); // Calls get accessor Note the following: • The body of the get accessor is similar to that of a method. It must return a value of the property type. Executing the get accessor is the same as reading the value of the variable. • The get accessor must end in a return statement. • We recommend that your get accessor should not change the state of the object that it is defined on. • The set accessor is similar to a method whose return type is void. • When you assign a value to the property, the set accessor is invoked with an argument that provides the new value. • When the set accessor is invoked, the system passes an implicit argument to the setter called value of the same data type as the property. • Properties cannot be defined on interface. • Apex properties are based on their counterparts in C#, with the following differences: ◊ Properties provide storage for values directly. You do not need to create supporting members for storing values. ◊ It is possible to create automatic properties in Apex. For more information, see Using Automatic Properties on page 126. Using Automatic Properties Properties do not require additional code in their get or set accessor code blocks. Instead, you can leave get and set accessor code blocks empty to define an automatic property. Automatic properties allow you to write more compact code that is easier to debug and maintain. They can be declared as read-only, read-write, or write-only. The following example creates three automatic properties: public class AutomaticProperty { public integer MyReadOnlyProp { get; } public double MyReadWriteProp { get; set; } public string MyWriteOnlyProp { set; } } The following code segment exercises these properties: AutomaticProperty ap = new AutomaticProperty(); ap.MyReadOnlyProp = 5; // This produces a compile error: not writable ap.MyReadWriteProp = 5; // No error System.assert(MyWriteOnlyProp == 5); // This produces a compile error: not readable Using Static Properties When a property is declared as static, the property's accessor methods execute in a static context. This means that the accessors do not have access to non-static member variables defined in the class. The following example creates a class with both static and instance properties: public class StaticProperty { public static integer StaticMember; public integer NonStaticMember; public static integer MyGoodStaticProp { get{return MyGoodStaticProp;} 126
- 129. Classes, Objects, and Interfaces Interfaces and Extending Classes } // The following produces a system error // public static integer MyBadStaticProp { return NonStaticMember; } public integer MyGoodNonStaticProp { get{return NonStaticMember;} } } The following code segment calls the static and instance properties: StaticProperty sp = new StaticProperty(); // The following produces a system error: a static variable cannot be // accessed through an object instance // sp.MyGoodStaticProp = 5; // The following does not produce an error StaticProperty.MyGoodStaticProp = 5; Using Access Modifiers on Property Accessors Property accessors can be defined with their own access modifiers. If an accessor includes its own access modifier, this modifier overrides the access modifier of the property. The access modifier of an individual accessor must be more restrictive than the access modifier on the property itself. For example, if the property has been defined as public, the individual accessor cannot be defined as global. The following class definition shows additional examples: global virtual class PropertyVisibility { // X is private for read and public for write public integer X { private get; set; } // Y can be globally read but only written within a class global integer Y { get; public set; } // Z can be read within the class but only subclasses can set it public integer Z { get; protected set; } } Interfaces and Extending Classes An interface is like a class in which none of the methods have been implemented—the method signatures are there, but the body of each method is empty. To use an interface, another class must implement it by providing a body for all of the methods contained in the interface. Interfaces can provide a layer of abstraction to your code. They separate the specific implementation of a method from the declaration for that method. This way you can have different implementations of a method based on your specific application. Defining an interface is similar to defining a new class. For example, a company might have two types of purchase orders, ones that come from customers, and others that come from their employees. Both are a type of purchase order. Suppose you needed a method to provide a discount. The amount of the discount can depend on the type of purchase order. You can model the general concept of a purchase order as an interface and have specific implementations for customers and employees. In the following example the focus is only on the discount aspect of a purchase order. public class PurchaseOrders { // An interface that defines what a purchase order looks like in general public interface PurchaseOrder { // All other functionality excluded 127
- 130. Classes, Objects, and Interfaces Custom Iterators Double discount(); } // One implementation of the interface for customers public virtual class CustomerPurchaseOrder implements PurchaseOrder { public virtual Double discount() { return .05; // Flat 5% discount } } // Employee purchase order extends Customer purchase order, but with a // different discount public class EmployeePurchaseOrder extends CustomerPurchaseOrder{ public override Double discount() { return .10; // It’s worth it being an employee! 10% discount } } } Note the following about the above example: • The interface PurchaseOrder is defined as a general prototype. Methods defined within an interface have no access modifiers and contain just their signature. • The CustomerPurchaseOrder class implements this interface; therefore, it must provide a definition for the discount method. As with Java, any class that implements an interface must define all of the methods contained in the interface. • The employee version of the purchase order extends the customer version. A class extends another class using the keyword extends. A class can only extend one other class, but it can implement more than one interface. When you define a new interface, you are defining a new data type. You can use an interface name in any place you can use another data type name. If you define a variable whose type is an interface, any object you assign to it must be an instance of a class that implements the interface, or a sub-interface data type. An interface can extend another interface. As with classes, when an interface extends another interface, all the methods and properties of the extended interface are available to the extending interface. See also Classes and Casting on page 144. Note: You cannot add a method to a global interface after the class has been uploaded in a Managed - Released package version. Custom Iterators An iterator traverses through every item in a collection. For example, in a while loop in Apex, you define a condition for exiting the loop, and you must provide some means of traversing the collection, that is, an iterator. In the following example, count is incremented by 1 every time the loop is executed (count++) : while (count < 11) { System.debug(count); count++; } Using the Iterator interface you can create a custom set of instructions for traversing a List through a loop. This is useful for data that exists in sources outside of Salesforce that you would normally define the scope of using a SELECT statement. Iterators can also be used if you have multiple SELECT statements. 128
- 131. Classes, Objects, and Interfaces Custom Iterators Using Custom Iterators To use custom iterators, you must create an Apex class that implements the Iterator interface. The Iterator interface has the following instance methods: Name Arguments Returns Description hasNext Boolean Returns true if there is another item in the collection being traversed, false otherwise. next Any type Returns the next item in the collection. All methods in the Iterator interface must be declared as global or public. You can only use a custom iterator in a while loop. For example: IterableString x = new IterableString('This is a really cool test.'); while(x.hasNext()){ system.debug(x.next()); } Iterators are not currently supported in for loops. Using Custom Iterators with Iterable If you do not want to use a custom iterator with a list, but instead want to create your own data structure, you can use the Iterable interface to generate the data structure. The Iterable interface has the following method: Name Arguments Returns Description iterator Iterator class Returns a reference to the iterator for this interface. The iterator method must be declared as global or public. It creates a reference to the iterator that you can then use to traverse the data structure. In the following example a custom iterator iterates through a collection: global class CustomIterable implements Iterator<Account>{ List<Account> accs {get; set;} Integer i {get; set;} public CustomIterable(){ accs = [SELECT Id, Name, NumberOfEmployees FROM Account WHERE Name = 'false']; i = 0; } global boolean hasNext(){ if(i >= accs.size()) { return false; 129
- 132. Classes, Objects, and Interfaces Keywords } else { return true; } } global Account next(){ // 8 is an arbitrary // constant in this example // that represents the // maximum size of the list. if(i == 8){return null;} i++; return accs[i-1]; } } The following calls the above code: global class foo implements iterable<Account>{ global Iterator<Account> Iterator(){ return new CustomIterable(); } } The following is a batch job that uses an iterator: global class batchClass implements Database.batchable<Account>{ global Iterable<Account> start(Database.batchableContext info){ return new foo(); } global void execute(Database.batchableContext info, List<Account> scope){ List<Account> accsToUpdate = new List<Account>(); for(Account a : scope){ a.Name = 'true'; a.NumberOfEmployees = 69; accsToUpdate.add(a); } update accsToUpdate; } global void finish(Database.batchableContext info){ } } Keywords Apex has the following keywords available: • final • instanceof • super • this • transient • with sharing and without sharing 130
- 133. Classes, Objects, and Interfaces Using the final Keyword Using the final Keyword You can use the final keyword to modify variables. • Final variables can only be assigned a value once, either when you declare a variable or in initialization code. You must assign a value to it in one of these two places. • Static final variables can be changed in static initialization code or where defined. • Member final variables can be changed in initialization code blocks, constructors, or with other variable declarations. • To define a constant, mark a variable as both static and final (see Constants on page 58). • Non-final static variables are used to communicate state at the class level (such as state between triggers). However, they are not shared across requests. • Methods and classes are final by default. You cannot use the final keyword in the declaration of a class or method. This means they cannot be overridden. Use the virtual keyword if you need to override a method or class. Using the instanceof Keyword If you need to verify at runtime whether an object is actually an instance of a particular class, use the instanceof keyword. The instanceof keyword can only be used to verify if the target type in the expression on the right of the keyword is a viable alternative for the declared type of the expression on the left. You could add the following check to the Report class in the classes and casting example before you cast the item back into a CustomReport object. If (Reports.get(0) instanceof CustomReport) { // Can safely cast it back to a custom report object CustomReport c = (CustomReport) Reports.get(0); } Else { // Do something with the non-custom-report. } Using the super Keyword The super keyword can be used by classes that are extended from virtual or abstract classes. By using super, you can override constructors and methods from the parent class. For example, if you have the following virtual class: public virtual class SuperClass { public String mySalutation; public String myFirstName; public String myLastName; public SuperClass() { mySalutation = 'Mr.'; myFirstName = 'Carl'; myLastName = 'Vonderburg'; } public SuperClass(String salutation, String firstName, String lastName) { mySalutation = salutation; myFirstName = firstName; 131
- 134. Classes, Objects, and Interfaces Using the this Keyword myLastName = lastName; } public virtual void printName() { System.debug('My name is ' + mySalutation + myLastName); } public virtual String getFirstName() { return myFirstName; } } You can create the following class that extends Superclass and overrides its printName method: public class Subclass extends Superclass { public override void printName() { super.printName(); System.debug('But you can call me ' + super.getFirstName()); } } The expected output when calling Subclass.printName is My name is Mr. Vonderburg. But you can call me Carl. You can also use super to call constructors. Add the following constructor to SubClass: public Subclass() { super('Madam', 'Brenda', 'Clapentrap'); } Now, the expected output of Subclass.printName is My name is Madam Clapentrap. But you can call me Brenda. Best Practices for Using the super Keyword • Only classes that are extending from virtual or abstract classes can use super. • You can only use super in methods that are designated with the override keyword. Using the this Keyword There are two different ways of using the this keyword. You can use the this keyword in dot notation, without parenthesis, to represent the current instance of the class in which it appears. Use this form of the this keyword to access instance variables and methods. For example: public class myTestThis { string s; { this.s = 'TestString'; } } 132
- 135. Classes, Objects, and Interfaces Using the transient Keyword In the above example, the class myTestThis declares an instance variable s. The initialization code populates the variable using the this keyword. Or you can use the this keyword to do constructor chaining, that is, in one constructor, call another constructor. In this format, use the this keyword with parentheses. For example: public class testThis { // First constructor for the class. It requires a string parameter. public testThis(string s2) { } // Second constructor for the class. It does not require a parameter. // This constructor calls the first constructor using the this keyword. public testThis() { this('None'); } } When you use the this keyword in a constructor to do constructor chaining, it must be the first statement in the constructor. Using the transient Keyword Use the transient keyword to declare instance variables that can't be saved, and shouldn't be transmitted as part of the view state for a Visualforce page. For example: Transient Integer currentTotal; You can also use the transient keyword in Apex classes that are serializable, namely in controllers, controller extensions, or classes that implement the Batchable or Schedulable interface. In addition, you can use transient in classes that define the types of fields declared in the serializable classes. Declaring variables as transient reduces view state size. A common use case for the transient keyword is a field on a Visualforce page that is needed only for the duration of a page request, but should not be part of the page's view state and would use too many system resources to be recomputed many times during a request. Some Apex objects are automatically considered transient, that is, their value does not get saved as part of the page's view state. These objects include the following: • PageReferences • XmlStream classes • Collections automatically marked as transient only if the type of object that they hold is automatically marked as transient, such as a collection of Savepoints • Most of the objects generated by system methods, such as Schema.getGlobalDescribe. • JSONParser class instances. For more information, see JSON Support on page 396. Static variables also don't get transmitted through the view state. The following example contains both a Visualforce page and a custom controller. Clicking the refresh button on the page causes the transient date to be updated because it is being recreated each time the page is refreshed. The non-transient date continues to have its original value, which has been deserialized from the view state, so it remains the same. <apex:page controller="ExampleController"> T1: {!t1} <br/> T2: {!t2} <br/> 133
- 136. Classes, Objects, and Interfaces Using the with sharing or without sharing Keywords <apex:form> <apex:commandLink value="refresh"/> </apex:form> </apex:page> public class ExampleController { DateTime t1; transient DateTime t2; public String getT1() { if (t1 == null) t1 = System.now(); return '' + t1; } public String getT2() { if (t2 == null) t2 = System.now(); return '' + t2; } } Using the with sharing or without sharing Keywords Apex generally runs in system context; that is, the current user's permissions, field-level security, and sharing rules aren’t taken into account during code execution. Note: The only exceptions to this rule are Apex code that is executed with the executeAnonymous call. executeAnonymous always executes using the full permissions of the current user. For more information on executeAnonymous, see Anonymous Blocks on page 108. Because these rules aren't enforced, developers who use Apex must take care that they don't inadvertently expose sensitive data that would normally be hidden from users by user permissions, field-level security, or organization-wide defaults. They should be particularly careful with Web services, which can be restricted by permissions, but execute in system context once they are initiated. Most of the time, system context provides the correct behavior for system-level operations such as triggers and Web services that need access to all data in an organization. However, you can also specify that particular Apex classes should enforce the sharing rules that apply to the current user. (For more information on sharing rules, see the Salesforce.com online help.) Note: A user's permissions and field-level security are always ignored to ensure that Apex code can view all fields and objects in an organization. If particular fields or objects are hidden for a user, the code would fail to compile at runtime. Use the with sharing keywords when declaring a class to enforce the sharing rules that apply to the current user. For example: public with sharing class sharingClass { // Code here } Use the without sharing keywords when declaring a class to ensure that the sharing rules for the current user are not enforced. For example: public without sharing class noSharing { 134
- 137. Classes, Objects, and Interfaces Using the with sharing or without sharing Keywords // Code here } If a class is not declared as either with or without sharing, the current sharing rules remain in effect. This means that if the class is called by a class that has sharing enforced, then sharing is enforced for the called class. Both inner classes and outer classes can be declared as with sharing. The sharing setting applies to all code contained in the class, including initialization code, constructors, and methods. Classes inherit this setting from a parent class when one class extends or implements another, but inner classes do not inherit the sharing setting from their container class. For example: public with sharing class CWith { // All code in this class operates with enforced sharing rules. Account a = [SELECT . . . ]; public static void m() { . . . } static { . . . } { . . . } public c() { . . . } } public without sharing class CWithout { // All code in this class ignores sharing rules and operates // as if the context user has the Modify All Data permission. Account a = [SELECT . . . ]; . . . public static void m() { . . . // This call into CWith operates with enforced sharing rules // for the context user. When the call finishes, the code execution // returns to without sharing mode. CWith.m(); } public class CInner { // All code in this class executes with the same sharing context // as the code that calls it. // Inner classes are separate from outer classes. . . . // Again, this call into CWith operates with enforced sharing rules // for the context user, regardless of the class that initially called this inner class. // When the call finishes, the code execution returns to the sharing mode that was used to call this inner class. CWith.m(); } public class CInnerWithOut exends CWithout { // All code in this class ignores sharing rules because 135
- 138. Classes, Objects, and Interfaces Annotations // this class extends a parent class that ignores sharing rules. } } Warning: There is no guarantee that a class declared as with sharing doesn't call code that operates as without sharing. Class-level security is always still necessary. In addition, all SOQL or SOSL queries that use PriceBook2 ignore the with sharing keyword. All PriceBook records are returned, regardless of the applied sharing rules. Enforcing the current user's sharing rules can impact: • SOQL and SOSL queries. A query may return fewer rows than it would operating in system context. • DML operations. An operation may fail because the current user doesn't have the correct permissions. For example, if the user specifies a foreign key value that exists in the organization, but which the current user does not have access to. Annotations An Apex annotation modifies the way a method or class is used, similar to annotations in Java. Annotations are defined with an initial @ symbol, followed by the appropriate keyword. To add an annotation to a method, specify it immediately before the method or class definition. For example: global class MyClass { @future Public static void myMethod(String a) { //long-running Apex code } } Apex supports the following annotations: • @Deprecated • @Future • @IsTest • @ReadOnly • @RemoteAction • Apex REST annotations: ◊ @RestResource(urlMapping='/yourUrl') ◊ @HttpDelete ◊ @HttpGet ◊ @HttpPatch ◊ @HttpPost ◊ @HttpPut 136
- 139. Classes, Objects, and Interfaces Deprecated Annotation Deprecated Annotation Use the deprecated annotation to identify methods, classes, exceptions, enums, interfaces, or variables that can no longer be referenced in subsequent releases of the managed package in which they reside. This is useful when you are refactoring code in managed packages as the requirements evolve. New subscribers cannot see the deprecated elements, while the elements continue to function for existing subscribers and API integrations. The following code snippet shows a deprecated method. The same syntax can be used to deprecate classes, exceptions, enums, interfaces, or variables. @deprecated // This method is deprecated. Use myOptimizedMethod(String a, String b) instead. global void myMethod(String a) { } Note the following rules when deprecating Apex identifiers: • Unmanaged packages cannot contain code that uses the deprecated keyword. • When an Apex item is deprecated, all global access modifiers that reference the deprecated identifier must also be deprecated. Any global method that uses the deprecated type in its signature, either in an input argument or the method return type, must also be deprecated. A deprecated item, such as a method or a class, can still be referenced internally by the package developer. • webService methods and variables cannot be deprecated. • You can deprecate an enum but you cannot deprecate individual enum values. • You can deprecate an interface but you cannot deprecate individual methods in an interface. • You can deprecate an abstract class but you cannot deprecate individual abstract methods in an abstract class. • You cannot remove the deprecated annotation to undeprecate something in Apex after you have released a package version where that item in Apex is deprecated. For more information about package versions, see Developing Apex in Managed Packages on page 231. Future Annotation Use the future annotation to identify methods that are executed asynchronously. When you specify future, the method executes when Salesforce has available resources. For example, you can use the future annotation when making an asynchronous Web service callout to an external service. Without the annotation, the Web service callout is made from the same thread that is executing the Apex code, and no additional processing can occur until the callout is complete (synchronous processing). Methods with the future annotation must be static methods, and can only return a void type. To make a method in a class execute asynchronously, define the method with the future annotation. For example: global class MyFutureClass { @future static void myMethod(String a, Integer i) { System.debug('Method called with: ' + a + ' and ' + i); //do callout, other long running code } } 137
- 140. Classes, Objects, and Interfaces IsTest Annotation The following snippet shows how to specify that a method executes a callout: @future (callout=true) public static void doCalloutFromFuture() { //Add code to perform callout } You can specify (callout=false) to prevent a method from making callouts. To test methods defined with the future annotation, call the class containing the method in a startTest, stopTest code block. All asynchronous calls made after the startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run synchronously. Methods with the future annotation have the following limits: • No more than 10 method calls per Apex invocation Note: Asynchronous calls, such as @future or executeBatch, called in a startTest, stopTest block, do not count against your limits for the number of queued jobs. • Salesforce also imposes a limit on the number of future method invocations: 200 method calls per full Salesforce user license, Salesforce Platform user license, or Force.com - One App user license, per 24 hours. This is an organization-wide limit. Chatter Only, Chatter customer users, Customer Portal User, and partner portal User licenses aren’t included in this limit calculation. For example, suppose your organization has three full Salesforce licenses, two Salesforce Platform licenses, and 100 Customer Portal User licenses. Your entire organization is limited to only 1,000 method calls every 24 hours, calculated as 200 * (3+2), not 200 * (3+2+100). • The specified parameters must be primitive data types, arrays of primitive data types, or collections of primitive data types. • Methods with the future annotation cannot take sObjects or objects as arguments. • Methods with the future annotation cannot be used in Visualforce controllers in either getMethodName or setMethodName methods, nor in the constructor. Remember that any method using the future annotation requires special consideration because the method does not necessarily execute in the same order it is called. You cannot call a method annotated with future from a method that also has the future annotation. Nor can you call a trigger from an annotated method that calls another annotated method. The getContent and getContentAsPDF PageReference methods cannot be used in methods with the future annotation. For more information about callouts, see Invoking Callouts Using Apex on page 251. See Also: Understanding Execution Governors and Limits IsTest Annotation Use the isTest annotation to define classes or individual methods that only contain code used for testing your application. The isTest annotation is similar to creating methods declared as testMethod. Note: Classes defined with the isTest annotation don't count against your organization limit of 3 MB for all Apex code. Individual test methods in a class not annotated with isTest do count against your organization code size limit. See Understanding Execution Governors and Limits on page 225. 138
- 141. Classes, Objects, and Interfaces IsTest Annotation Starting with Apex code saved using Salesforce.com API version 24.0, test methods don’t have access by default to pre-existing data in the organization. However, test code saved against Salesforce.com API version 23.0 or earlier continues to have access to all data in the organization and its data access is unchanged. See Isolation of Test Data from Organization Data in Unit Tests on page 159. Classes and methods defined as isTest can be either private or public. Classes defined as isTest must be top-level classes. This is an example of a private test class that contains two test methods. @isTest private class MyTestClass { // Methods for testing @isTest static void test1() { // Implement test code } @isTest static void test2() { // Implement test code } } This is an example of a public test class that contains utility methods for test data creation: @isTest public class TestUtil { public static void createTestAccounts() { // Create some test accounts } public static void createTestContacts() { // Create some test contacts } } Classes defined as isTest can't be interfaces or enums. Methods of a public test class can only be called from a running test, that is, a test method or code invoked by a test method, and can't be called by a non-test request. In addition, test class methods can be invoked using the Salesforce user interface or the API. For more information, see Running Unit Test Methods. IsTest(SeeAllData=true) Annotation For Apex code saved using Salesforce.com API version 24.0 and later, use the isTest(SeeAllData=true) annotation to grant test classes and individual test methods access to all data in the organization, including pre-existing data that the test didn’t create. Starting with Apex code saved using Salesforce.com API version 24.0, test methods don’t have access by default to pre-existing data in the organization. However, test code saved against Salesforce.com API version 23.0 or earlier continues to have access to all data in the organization and its data access is unchanged. See Isolation of Test Data from Organization Data in Unit Tests on page 159. Considerations of the IsTest(SeeAllData=true) Annotation • If a test class is defined with the isTest(SeeAllData=true) annotation, this annotation applies to all its test methods whether the test methods are defined with the @isTest annotation or the testmethod keyword. 139
- 142. Classes, Objects, and Interfaces IsTest Annotation • The isTest(SeeAllData=true) annotation is used to open up data access when applied at the class or method level. However, using isTest(SeeAllData=false) on a method doesn’t restrict organization data access for that method if the containing class has already been defined with the isTest(SeeAllData=true) annotation. In this case, the method will still have access to all the data in the organization. This example shows how to define a test class with the isTest(SeeAllData=true) annotation. All the test methods in this class have access to all data in the organization. // All test methods in this class can access all data. @isTest(SeeAllData=true) public class TestDataAccessClass { // This test accesses an existing account. // It also creates and accesses a new test account. static testmethod void myTestMethod1() { // Query an existing account in the organization. Account a = [SELECT Id, Name FROM Account WHERE Name='Acme' LIMIT 1]; System.assert(a != null); // Create a test account based on the queried account. Account testAccount = a.clone(); testAccount.Name = 'Acme Test'; insert testAccount; // Query the test account that was inserted. Account testAccount2 = [SELECT Id, Name FROM Account WHERE Name='Acme Test' LIMIT 1]; System.assert(testAccount2 != null); } // Like the previous method, this test method can also access all data // because the containing class is annotated with @isTest(SeeAllData=true). @isTest static void myTestMethod2() { // Can access all data in the organization. } } This second example shows how to apply the isTest(SeeAllData=true) annotation on a test method. Because the class that the test method is contained in isn’t defined with this annotation, you have to apply this annotation on the test method to enable access to all data for that test method. The second test method doesn’t have this annotation, so it can access only the data it creates in addition to objects that are used to manage your organization, such as users. // This class contains test methods with different data access levels. @isTest private class ClassWithDifferentDataAccess { // Test method that has access to all data. @isTest(SeeAllData=true) static void testWithAllDataAccess() { // Can query all data in the organization. } // Test method that has access to only the data it creates // and organization setup and metadata objects. @isTest static void testWithOwnDataAccess() { // This method can still access the User object. // This query returns the first user object. User u = [SELECT UserName,Email FROM User LIMIT 1]; System.debug('UserName: ' + u.UserName); System.debug('Email: ' + u.Email); 140
- 143. Classes, Objects, and Interfaces ReadOnly Annotation // Can access the test account that is created here. Account a = new Account(Name='Test Account'); insert a; // Access the account that was just created. Account insertedAcct = [SELECT Id,Name FROM Account WHERE Name='Test Account']; System.assert(insertedAcct != null); } } IsTest(OnInstall=true) Annotation Use the IsTest(OnInstall=true) annotation to specify which Apex tests are executed during package installation. This annotation is used for tests in managed or unmanaged packages. Only test methods with this annotation, or methods that are part of a test class that has this annotation, will be executed during package installation. Tests annotated to run during package installation must pass in order for the package installation to succeed. It is no longer possible to bypass a failing test during package installation. A test method or a class that doesn't have this annotation, or that is annotated with isTest(OnInstall=false) or isTest, won't be executed during installation. This example shows how to annotate a test method that will be executed during package installation. In this example, test1 will be executed but test2 and test3 won't. public class OnInstallClass { // Implement logic for the class. public void method1(){ // Some code } // This test method will be executed // during the installation of the package. @isTest(OnInstall=true) static void test1() { // Some test code } // Tests excluded from running during the // the installation of a package. @isTest static void test2() { // Some test code } static testmethod void test3() { // Some test code } } ReadOnly Annotation The @ReadOnly annotation allows you to perform unrestricted queries against the Force.com database. All other limits still apply. It's important to note that this annotation, while removing the limit of the number of returned rows for a request, blocks you from performing the following operations within the request: DML operations, calls to System.schedule, calls to methods annotated with @future, and sending emails. The @ReadOnly annotation is available for Web services and the Schedulable interface. To use the @ReadOnly annotation, the top level request must be in the schedule execution or the Web service invocation. For example, if a Visualforce page calls 141
- 144. Classes, Objects, and Interfaces RemoteAction Annotation a Web service that contains the @ReadOnly annotation, the request fails because Visualforce is the top level request, not the Web service. Visualforce pages can call controller methods with the @ReadOnly annotation, and those methods will run with the same relaxed restrictions. To increase other Visualforce-specific limits, such as the size of a collection that can be used by an iteration component like <apex:pageBlockTable>, you can set the readonly attribute on the <apex:page> tag to true. For more information, see Working with Large Sets of Data in the Visualforce Developer's Guide. RemoteAction Annotation The RemoteAction annotation provides support for Apex methods used in Visualforce to be called via JavaScript. This process is often referred to as JavaScript remoting. Note: Methods with the RemoteAction annotation must be static and either global or public. To use JavaScript remoting in a Visualforce page, add the request as a JavaScript invocation with the following form: [namespace.]controller.method( [parameters...,] callbackFunction, [configuration] ); • namespace is the namespace of the controller class. This is required if your organization has a namespace defined, or if the class comes from an installed package. • controller is the name of your Apex controller. • method is the name of the Apex method you’re calling. • parameters is the comma-separated list of parameters that your method takes. • callbackFunction is the name of the JavaScript function that will handle the response from the controller. You can also declare an anonymous function inline. callbackFunction receives the status of the method call and the result as parameters. • configuration configures the handling of the remote call and response. Use this to specify whether or not to escape the Apex method’s response. The default value is {escape: true}. In your controller, your Apex method declaration is preceded with the @RemoteAction annotation like this: @RemoteAction global static String getItemId(String objectName) { ... } Your method can take Apex primitives, collections, typed and generic sObjects, and user-defined Apex classes and interfaces as arguments. Generic sObjects must have an ID or sobjectType value to identify actual type. Interface parameters must have an apexType to identify actual type. Your method can return Apex primitives, sObjects, collections, user-defined Apex classes and enums, SaveResult, UpsertResult, DeleteResult, SelectOption, or PageReference. For more information, see JavaScript Remoting for Apex Controllers in the Visualforce Developer's Guide. Apex REST Annotations Six new annotations have been added that enable you to expose an Apex class as a RESTful Web service. 142
- 145. Classes, Objects, and Interfaces Apex REST Annotations • @RestResource(urlMapping='/yourUrl') • @HttpDelete • @HttpGet • @HttpPatch • @HttpPost • @HttpPut See Also: Apex REST Basic Code Sample RestResource Annotation The @RestResource annotation is used at the class level and enables you to expose an Apex class as a REST resource. These are some considerations when using this annotation: • The URL mapping is relative to https://instance.salesforce.com/services/apexrest/. • A wildcard character (*) may be used. • The URL mapping is case-sensitive. A URL mapping for my_url will only match a REST resource containing my_url and not My_Url. • To use this annotation, your Apex class must be defined as global. URL Guidelines URL path mappings are as follows: • The path must begin with a '/' • If an '*' appears, it must be preceded by '/' and followed by '/', unless the '*' is the last character, in which case it need not be followed by '/' The rules for mapping URLs are: • An exact match always wins. • If no exact match is found, find all the patterns with wildcards that match, and then select the longest (by string length) of those. • If no wildcard match is found, an HTTP response status code 404 is returned. The URL for a namespaced classes contains the namespace. For example, if your class is in namespace abc and the class is mapped to your_url, then the API URL is modified as follows: https://instance.salesforce.com/services/apexrest/abc/your_url/. In the case of a URL collision, the namespaced class is always used. HttpDelete Annotation The @HttpDelete annotation is used at the method level and enables you to expose an Apex method as a REST resource. This method is called when an HTTP DELETE request is sent, and deletes the specified resource. To use this annotation, your Apex method must be defined as global static. 143
- 146. Classes, Objects, and Interfaces Classes and Casting HttpGet Annotation The @HttpGet annotation is used at the method level and enables you to expose an Apex method as a REST resource. This method is called when an HTTP GET request is sent, and returns the specified resource. These are some considerations when using this annotation: • To use this annotation, your Apex method must be defined as global static. • Methods annotated with @HttpGet are also called if the HTTP request uses the HEAD request method. HttpPatch Annotation The @HttpPatch annotation is used at the method level and enables you to expose an Apex method as a REST resource. This method is called when an HTTP PATCH request is sent, and updates the specified resource. To use this annotation, your Apex method must be defined as global static. HttpPost Annotation The @HttpPost annotation is used at the method level and enables you to expose an Apex method as a REST resource. This method is called when an HTTP POST request is sent, and creates a new resource. To use this annotation, your Apex method must be defined as global static. HttpPut Annotation The @HttpPut annotation is used at the method level and enables you to expose an Apex method as a REST resource. This method is called when an HTTP PUT request is sent, and creates or updates the specified resource. To use this annotation, your Apex method must be defined as global static. Classes and Casting In general, all type information is available at runtime. This means that Apex enables casting, that is, a data type of one class can be assigned to a data type of another class, but only if one class is a child of the other class. Use casting when you want to convert an object from one data type to another. In the following example, CustomReport extends the class Report. Therefore, it is a child of that class. This means that you can use casting to assign objects with the parent data type (Report) to the objects of the child data type (CustomReport). In the following code block, first, a custom report object is added to a list of report objects. After that, the custom report object is returned as a report object, then is cast back into a custom report object. Public virtual class Report { Public class CustomReport extends Report { // Create a list of report objects Report[] Reports = new Report[5]; // Create a custom report object CustomReport a = new CustomReport(); // Because the custom report is a sub class of the Report class, 144
- 147. Classes, Objects, and Interfaces Classes and Casting // you can add the custom report object a to the list of report objects Reports.add(a); // The following is not legal, because the compiler does not know that what you are // returning is a custom report. You must use cast to tell it that you know what // type you are returning // CustomReport c = Reports.get(0); // Instead, get the first item in the list by casting it back to a custom report object CustomReport c = (CustomReport) Reports.get(0); } } Figure 4: Casting Example In addition, an interface type can be cast to a sub-interface or a class type that implements that interface. Tip: To verify if a class is a specific type of class, use the instanceOf keyword. For more information, see Using the instanceof Keyword on page 131. 145
- 148. Classes, Objects, and Interfaces Classes and Collections Classes and Collections Lists and maps can be used with classes and interfaces, in the same ways that lists and maps can be used with sObjects. This means, for example, that you can use a user-defined data type only for the value of a map, not for the key. Likewise, you cannot create a set of user-defined objects. If you create a map or list of interfaces, any child type of the interface can be put into that collection. For instance, if the List contains an interface i1, and MyC implements i1, then MyC can be placed in the list. Collection Casting Because collections in Apex have a declared type at runtime, Apex allows collection casting. Collections can be cast in a similar manner that arrays can be cast in Java. For example, a list of CustomerPurchaseOrder objects can be assigned to a list of PurchaseOrder objects if class CustomerPurchaseOrder is a child of class PurchaseOrder. public virtual class PurchaseOrder { Public class CustomerPurchaseOrder extends PurchaseOrder { } { List<PurchaseOrder> POs = new PurchaseOrder[] {}; List<CustomerPurchaseOrder> CPOs = new CustomerPurchaseOrder[]{}; POs = CPOs;} } Once the CustomerPurchaseOrder list is assigned to the PurchaseOrder list variable, it can be cast back to a list of CustomerPurchaseOrder objects, but only because that instance was originally instantiated as a list of CustomerPurchaseOrder. A list of PurchaseOrder objects that is instantiated as such cannot be cast to a list of CustomerPurchaseOrder objects, even if the list of PurchaseOrder objects contains only CustomerPurchaseOrder objects. If the user of a PurchaseOrder list that only includes CustomerPurchaseOrders objects tries to insert a non-CustomerPurchaseOrder subclass of PurchaseOrder (such as InternalPurchaseOrder), a runtime exception results. This is because Apex collections have a declared type at runtime. Note: Maps behave in the same way as lists with regards to the value side of the Map—if the value side of map A can be cast to the value side of map B, and they have the same key type, then map A can be cast to map B. A runtime error results if the casting is not valid with the particular map at runtime. Differences Between Apex Classes and Java Classes The following is a list of the major differences between Apex classes and Java classes: • Inner classes and interfaces can only be declared one level deep inside an outer class. • Static methods and variables can only be declared in a top-level class definition, not in an inner class. • Inner classes behave like static Java inner classes, but do not require the static keyword. Inner classes can have instance member variables like outer classes, but there is no implicit pointer to an instance of the outer class (using the this keyword). 146
- 149. Classes, Objects, and Interfaces Class Definition Creation • The private access modifier is the default, and means that the method or variable is accessible only within the Apex class in which it is defined. If you do not specify an access modifier, the method or variable is private. • Specifying no access modifier for a method or variable and the private access modifier are synonymous. • The public access modifier means the method or variable can be used by any Apex in this application or namespace. • The global access modifier means the method or variable can be used by any Apex code that has access to the class, not just the Apex code in the same application. This access modifier should be used for any method that needs to be referenced outside of the application, either in the SOAP API or by other Apex code. If you declare a method or variable as global, you must also declare the class that contains it as global. • Methods and classes are final by default. ◊ The virtual definition modifier allows extension and overrides. ◊ The override keyword must be used explicitly on methods that override base class methods. • Interface methods have no modifiers—they are always global. • Exception classes must extend either exception or another user-defined exception. ◊ Their names must end with the word exception. ◊ Exception classes have four implicit constructors that are built-in, although you can add others. For more information, see Exception Class on page 474. • Classes and interfaces can be defined in triggers and anonymous blocks, but only as local. Class Definition Creation To create a class in Salesforce: 1. Click Your Name > Setup > Develop > Apex Classes. 2. Click New. 3. Click Version Settings to specify the version of Apex and the API used with this class. If your organization has installed managed packages from the AppExchange, you can also specify which version of each managed package to use with this class. Use the default values for all versions. This associates the class with the most recent version of Apex and the API, as well as each managed package. You can specify an older version of a managed package if you want to access components or functionality that differs from the most recent package version. You can specify an older version of Apex and the API to maintain specific behavior. 4. In the class editor, enter the Apex code for the class. A single class can be up to 1 million characters in length, not including comments, test methods, or classes defined using @isTest. 5. Click Save to save your changes and return to the class detail screen, or click Quick Save to save your changes and continue editing your class. Your Apex class must compile correctly before you can save your class. Classes can also be automatically generated from a WSDL by clicking Generate from WSDL. See SOAP Services: Defining a Class from a WSDL Document on page 252. Once saved, classes can be invoked through class methods or variables by other Apex code, such as a trigger. Note: To aid backwards-compatibility, classes are stored with the version settings for a specified version of Apex and the API. If the Apex class references components, such as a custom object, in installed managed packages, the version settings for each managed package referenced by the class is saved too. Additionally, classes are stored with an isValid flag that is set to true as long as dependent metadata has not changed since the class was last compiled. If any changes 147
- 150. Classes, Objects, and Interfaces Class Definition Creation are made to object names or fields that are used in the class, including superficial changes such as edits to an object or field description, or if changes are made to a class that calls this class, the isValid flag is set to false. When a trigger or Web service call invokes the class, the code is recompiled and the user is notified if there are any errors. If there are no errors, the isValid flag is reset to true. The Apex Class Editor When editing Visualforce or Apex, either in the Visualforce development mode footer or from Setup, an editor is available with the following functionality: Syntax highlighting The editor automatically applies syntax highlighting for keywords and all functions and operators. Search ( ) Search enables you to search for text within the current page, class, or trigger. To use search, enter a string in the Search textbox and click Find Next. • To replace a found search string with another string, enter the new string in the Replace textbox and click replace to replace just that instance, or Replace All to replace that instance and all other instances of the search string that occur in the page, class, or trigger. • To make the search operation case sensitive, select the Match Case option. • To use a regular expression as your search string, select the Regular Expressions option. The regular expressions follow JavaScript's regular expression rules. A search using regular expressions can find strings that wrap over more than one line. If you use the replace operation with a string found by a regular expression, the replace operation can also bind regular expression group variables ($1, $2, and so on) from the found search string. For example, to replace an <h1> tag with an <h2> tag and keep all the attributes on the original <h1> intact, search for <h1(s+)(.*)> and replace it with <h2$1$2>. Go to line ( ) This button allows you to highlight a specified line number. If the line is not currently visible, the editor scrolls to that line. Undo ( ) and Redo ( ) Use undo to reverse an editing action and redo to recreate an editing action that was undone. Font size Select a font size from the drop-down list to control the size of the characters displayed in the editor. Line and column position The line and column position of the cursor is displayed in the status bar at the bottom of the editor. This can be used with go to line ( ) to quickly navigate through the editor. Line and character count The total number of lines and characters is displayed in the status bar at the bottom of the editor. 148
- 151. Classes, Objects, and Interfaces Naming Conventions Naming Conventions We recommend following Java standards for naming, that is, classes start with a capital letter, methods start with a lowercase verb, and variable names should be meaningful. It is not legal to define a class and interface with the same name in the same class. It is also not legal for an inner class to have the same name as its outer class. However, methods and variables have their own namespaces within the class so these three types of names do not clash with each other. In particular it is legal for a variable, method, and a class within a class to have the same name. Name Shadowing Member variables can be shadowed by local variables—in particular function arguments. This allows methods and constructors of the standard Java form: Public Class Shadow { String s; Shadow(String s) { this.s = s; } // Same name ok setS(String s) { this.s = s; } // Same name ok } Member variables in one class can shadow member variables with the same name in a parent classes. This can be useful if the two classes are in different top-level classes and written by different teams. For example, if one has a reference to a class C and wants to gain access to a member variable M in parent class P (with the same name as a member variable in C) the reference should be assigned to a reference to P first. Static variables can be shadowed across the class hierarchy—so if P defines a static S, a subclass C can also declare a static S. References to S inside C refer to that static—in order to reference the one in P, the syntax P.S must be used. Static class variables cannot be referenced through a class instance. They must be referenced using the raw variable name by itself (inside that top-level class file) or prefixed with the class name. For example: public class p1 { public static final Integer CLASS_INT = 1; public class c { }; } p1.c c = new p1.c(); // This is illegal // Integer i = c.CLASS_INT; // This is correct Integer i = p1.CLASS_INT; Class Security You can specify which users can execute methods in a particular top-level class based on their user profile or permission sets. You can only set security on Apex classes, not on triggers. To set Apex class security from the class list page: 1. Click Your Name > Setup > Develop > Apex Classes. 2. Next to the name of the class that you want to restrict, click Security. 149
- 152. Classes, Objects, and Interfaces Enforcing Object and Field Permissions 3. Select the profiles that you want to enable from the Available Profiles list and click Add, or select the profiles that you want to disable from the Enabled Profiles list and click Remove. 4. Click Save. To set Apex class security from the class detail page: 1. Click Your Name > Setup > Develop > Apex Classes. 2. Click the name of the class that you want to restrict. 3. Click Security. 4. Select the profiles that you want to enable from the Available Profiles list and click Add, or select the profiles that you want to disable from the Enabled Profiles list and click Remove. 5. Click Save. To set Apex class security from a permission set: 1. Click Your Name > Setup > Manage Users > Permission Sets. 2. Select a permission set. 3. Click Apex Class Access. 4. Click Edit. 5. Select the Apex classes that you want to enable from the Available Apex Classes list and click Add, or select the Apex classes that you want to disable from the Enabled Apex Classes list and click Remove. 6. Click Save. To set Apex class security from a profile: 1. Click Your Name > Setup > Manage Users > Profiles. 2. Select a profile. 3. In the Apex Class Access page or related list, click Edit. 4. Select the Apex classes that you want to enable from the Available Apex Classes list and click Add, or select the Apex classes that you want to disable from the Enabled Apex Classes list and click Remove. 5. Click Save. Enforcing Object and Field Permissions Apex generally runs in system context; that is, the current user's permissions, field-level security, and sharing rules aren’t taken into account during code execution. The only exceptions to this rule are Apex code that is executed with the executeAnonymous call. executeAnonymous always executes using the full permissions of the current user. For more information on executeAnonymous, see Anonymous Blocks on page 108. Although Apex doesn't enforce object-level and field-level permissions by default, you can enforce these permissions in your code by explicitly calling the sObject describe result methods (of Schema.DescribeSObjectResult) and the field describe result methods (of Schema.DescribeFieldResult) that check the current user's access permission levels. In this way, you can verify if the current user has the necessary permissions, and only if he or she has sufficient permissions, you can then perform a specific DML operation or a query. For example, you can call the isAccessible, isCreateable, or isUpdateable methods of Schema.DescribeSObjectResult to verify whether the current user has read, create, or update access to an sObject, respectively. Similarly, Schema.DescribeFieldResult exposes these access control methods that you can call to check 150
- 153. Classes, Objects, and Interfaces Namespace Prefix the current user's read, create, or update access for a field. In addition, you can call the isDeletable method provided by Schema.DescribeSObjectResult to check if the current user has permission to delete a specific sObject. These are some examples of how to call the access control methods. To check the field-level update permission of the contact's email field before updating it: if (Schema.sObjectType.Contact.fields.Email.isUpdateable()) { // Update contact phone number } To check the field-level create permission of the contact's email field before creating a new contact: if (Schema.sObjectType.Contact.fields.Email.isCreateable()) { // Create new contact } To check the field-level read permission of the contact's email field before querying for this field: if (Schema.sObjectType.Contact.fields.Email.isAccessible()) { Contact c = [SELECT Email FROM Contact WHERE Id= :Id]; } To check the object-level permission for the contact before deleting the contact. if (Schema.sObjectType.Contact.isDeletable()) { // Delete contact } Sharing rules are distinct from object-level and field-level permissions. They can coexist. If sharing rules are defined in Salesforce, you can enforce them at the class level by declaring the class with the with sharing keyword. For more information, see Using the with sharing or without sharing Keywords. If you call the sObject describe result and field describe result access control methods, the verification of object and field-level permissions is performed in addition to the sharing rules that are in effect. Sometimes, the access level granted by a sharing rule could conflict with an object-level or field-level permission. Namespace Prefix The application supports the use of namespace prefixes. Namespace prefixes are used in managed Force.com AppExchange packages to differentiate custom object and field names from those in use by other organizations. After a developer registers a globally unique namespace prefix and registers it with AppExchange registry, external references to custom object and field names in the developer's managed packages take on the following long format: namespace_prefix__obj_or_field_name__c Because these fully-qualified names can be onerous to update in working SOQL statements, SOSL statements, and Apex once a class is marked as “managed,” Apex supports a default namespace for schema names. When looking at identifiers, the parser considers the namespace of the current object and then assumes that it is the namespace of all other objects and fields unless otherwise specified. Consequently, a stored class should refer to custom object and field names directly (using obj_or_field_name__c) for those objects that are defined within its same application namespace. 151
- 154. Classes, Objects, and Interfaces Using Namespaces When Invoking Methods Tip: Only use namespace prefixes when referring to custom objects and fields in managed packages that have been installed to your organization from theAppExchange. Using Namespaces When Invoking Methods To invoke a method that is defined in a managed package, Apex allows fully-qualified identifiers of the form: namespace_prefix.class.method(args) Use the special namespace System to disambiguate the built-in static classes from any user-defined ones (for example, System.System.debug()). Without the System namespace prefix, system static class names such as Math and System can be overridden by user-defined classes with the same name, as outlined below. Tip: Only use namespace prefixes when invoking methods in managed packages that have been installed to your organization from theAppExchange. Namespace, Class, and Variable Name Precedence Because local variables, class names, and namespaces can all hypothetically use the same identifiers, the Apex parser evaluates expressions in the form of name1.name2.[...].nameN as follows: 1. The parser first assumes that name1 is a local variable with name2 - nameN as field references. 2. If the first assumption does not hold true, the parser then assumes that name1 is a class name and name2 is a static variable name with name3 - nameN as field references. 3. If the second assumption does not hold true, the parser then assumes that name1 is a namespace name, name2 is a class name, name3 is a static variable name, and name4 - nameN are field references. 4. If the third assumption does not hold true, the parser reports an error. If the expression ends with a set of parentheses (for example, name1.name2.[...].nameM.nameN()), the Apex parser evaluates the expression as follows: 1. The parser first assumes that name1 is a local variable with name2 - nameM as field references, and nameN as a method invocation. 2. If the first assumption does not hold true: • If the expression contains only two identifiers (name1.name2()), the parser then assumes that name1 is a class name and name2 is a method invocation. • If the expression contains more than two identifiers, the parser then assumes that name1 is a class name, name2 is a static variable name with name3 - nameM as field references, and nameN is a method invocation. 3. If the second assumption does not hold true, the parser then assumes that name1 is a namespace name, name2 is a class name, name3 is a static variable name, name4 - nameM are field references, and nameN is a method invocation. 4. If the third assumption does not hold true, the parser reports an error. However, with class variables Apex also uses dot notation to reference member variables. Those member variables might refer to other class instances, or they might refer to an sObject which has its own dot notation rules to refer to field names (possibly navigating foreign keys). 152
- 155. Classes, Objects, and Interfaces Type Resolution and System Namespace for Types Once you enter an sObject field in the expression, the remainder of the expression stays within the sObject domain, that is, sObject fields cannot refer back to Apex expressions. For instance, if you have the following class: public class c { c1 c1 = new c1(); class c1 { c2 c2; } class c2 { Account a; } } Then the following expressions are all legal: c.c1.c2.a.name c.c1.c2.a.owner.lastName.toLowerCase() c.c1.c2.a.tasks c.c1.c2.a.contacts.size() Type Resolution and System Namespace for Types Because the type system must resolve user-defined types defined locally or in other classes, the Apex parser evaluates types as follows: 1. For a type reference TypeN, the parser first looks up that type as a scalar type. 2. If TypeN is not found, the parser looks up locally defined types. 3. If TypeN still is not found, the parser looks up a class of that name. 4. If TypeN still is not found, the parser looks up system types such as sObjects. For the type T1.T2 this could mean an inner type T2 in a top-level class T1, or it could mean a top-level class T2 in the namespace T1 (in that order of precedence). Version Settings To aid backwards-compatibility, classes and triggers are stored with the version settings for a specific Salesforce.com API version. If an Apex class or trigger references components, such as a custom object, in installed managed packages, the version settings for each managed package referenced by the class are saved too. This ensures that as Apex, the API, and the components in managed packages evolve in subsequent released versions, a class or trigger is still bound to versions with specific, known behavior. Setting a version for an installed package determines the exposed interface and behavior of any Apex code in the installed package. This allows you to continue to reference Apex that may be deprecated in the latest version of an installed package, if you installed a version of the package before the code was deprecated. Typically, you reference the latest Salesforce.com API version and each installed package version. If you save an Apex class or trigger without specifying the Salesforce.com API version, the class or trigger is associated with the latest installed version by default. If you save an Apex class or trigger that references a managed package without specifying a version of the managed package, the class or trigger is associated with the latest installed version of the managed package by default. 153
- 156. Classes, Objects, and Interfaces Setting the Salesforce API Version for Classes and Triggers Setting the Salesforce API Version for Classes and Triggers To set the Salesforce.com API and Apex version for a class or trigger: 1. Edit either a class or trigger, and click Version Settings. 2. Select the Version of the Salesforce.com API. This is also the version of Apex associated with the class or trigger. 3. Click Save. If you pass an object as a parameter in a method call from one Apex class, C1, to another class, C2, and C2 has different fields exposed due to the Salesforce.com API version setting, the fields in the objects are controlled by the version settings of C2. Using the following example, the Categories field is set to null after calling the insertIdea method in class C2 from a method in the test class C1, because the Categories field is not available in version 13.0 of the API. The first class is saved using Salesforce.com API version 13.0: // This class is saved using Salesforce API version 13.0 // Version 13.0 does not include the Idea.categories field global class C2 { global Idea insertIdea(Idea a) { insert a; // category field set to null on insert // retrieve the new idea Idea insertedIdea = [SELECT title FROM Idea WHERE Id =:a.Id]; return insertedIdea; } } The following class is saved using Salesforce.com API version 16.0: @isTest // This class is bound to API version 16.0 by Version Settings private class C1 { static testMethod void testC2Method() { Idea i = new Idea(); i.CommunityId = '09aD000000004YCIAY'; i.Title = 'Testing Version Settings'; i.Body = 'Categories field is included in API version 16.0'; i.Categories = 'test'; C2 c2 = new C2(); Idea returnedIdea = c2.insertIdea(i); // retrieve the new idea Idea ideaMoreFields = [SELECT title, categories FROM Idea WHERE Id = :returnedIdea.Id]; // assert that the categories field from the object created // in this class is not null System.assert(i.Categories != null); // assert that the categories field created in C2 is null System.assert(ideaMoreFields.Categories == null); } } 154
- 157. Classes, Objects, and Interfaces Setting Package Versions for Apex Classes and Triggers Setting Package Versions for Apex Classes and Triggers To configure the package version settings for a class or trigger: 1. Edit either a class or trigger, and click Version Settings. 2. Select a Version for each managed package referenced by the class or trigger. This version of the managed package will continue to be used by the class or trigger if later versions of the managed package are installed, unless you manually update the version setting. To add an installed managed package to the settings list, select a package from the list of available packages. The list is only displayed if you have an installed managed package that is not already associated with the class or trigger. 3. Click Save. Note the following when working with package version settings: • If you save an Apex class or trigger that references a managed package without specifying a version of the managed package, the Apex class or trigger is associated with the latest installed version of the managed package by default. • You cannot Remove a class or trigger's version setting for a managed package if the package is referenced in the class or trigger. Use Show Dependencies to find where a managed package is referenced by a class or trigger. 155
- 158. Chapter 5 Testing Apex In this chapter ... Apex provides a testing framework that allows you to write unit tests, run your tests, check test results, and have code coverage results. • Understanding Testing in Apex This chapter provides an overview of unit tests, data visibility for tests, as well as • Unit Testing Apex the tools that are available on the Force.com platform for testing Apex. • Running Unit Test Methods • Testing Best Practices • Understanding Testing in Apex • Testing Example • Unit Testing Apex • Running Unit Test Methods • Testing Best Practices • Testing Example 156
- 159. Testing Apex Understanding Testing in Apex Understanding Testing in Apex Testing is the key to successful long term development, and is a critical component of the development process. We strongly recommend that you use a test-driven development process, that is, test development that occurs at the same time as code development. Why Test Apex? Testing is key to the success of your application, particularly if your application is to be deployed to customers. If you validate that your application works as expected, that there are no unexpected behaviors, your customers are going to trust you more. There are two ways of testing an application. One is through the Salesforce user interface, important, but merely testing through the user interface will not catch all of the use cases for your application. The other way is to test for bulk functionality: up to 200 records can be passed through your code if it's invoked using SOAP API or by a Visualforce standard set controller. An application is seldom finished. You will have additional releases of it, where you change and extend functionality. If you have written comprehensive tests, you can ensure that a regression is not introduced with any new functionality. Before you can deploy your code or package it for the Force.com AppExchange, the following must be true: • 75% of your Apex code must be covered by unit tests, and all of those tests must complete successfully. Note the following: ◊ When deploying to a production organization, every unit test in your organization namespace is executed. ◊ Calls to System.debug are not counted as part of Apex code coverage. ◊ Test methods and test classes are not counted as part of Apex code coverage. ◊ While only 75% of your Apex code must be covered by tests, your focus shouldn't be on the percentage of code that is covered. Instead, you should make sure that every use case of your application is covered, including positive and negative cases, as well as bulk and single record. This should lead to 75% or more of your code being covered by unit tests. • Every trigger has some test coverage. • All classes and triggers compile successfully. Salesforce runs all tests in all organizations that have Apex code to verify that no behavior has been altered as a result of any service upgrades. What to Test in Apex Salesforce.com recommends that you write tests for the following: Single action Test to verify that a single record produces the correct, expected result. Bulk actions Any Apex code, whether a trigger, a class or an extension, may be invoked for 1 to 200 records. You must test not only the single record case, but the bulk cases as well. Positive behavior Test to verify that the expected behavior occurs through every expected permutation, that is, that the user filled out everything correctly and did not go past the limits. 157
- 160. Testing Apex Unit Testing Apex Negative behavior There are likely limits to your applications, such as not being able to add a future date, not being able to specify a negative amount, and so on. You must test for the negative case and verify that the error messages are correctly produced as well as for the positive, within the limits cases. Restricted user Test whether a user with restricted access to the sObjects used in your code sees the expected behavior. That is, whether they can run the code or receive error messages. Note: Conditional and ternary operators are not considered executed unless both the positive and negative branches are executed. For examples of these types of tests, see Testing Example on page 168. Unit Testing Apex To facilitate the development of robust, error-free code, Apex supports the creation and execution of unit tests. Unit tests are class methods that verify whether a particular piece of code is working properly. Unit test methods take no arguments, commit no data to the database, send no emails, and are flagged with the testMethod keyword in the method definition. For example: public class myClass { static testMethod void myTest() { code_block } } Use the isTest annotation to define classes or individual methods that only contain code used for testing your application. The isTest annotation is similar to creating methods declared as testMethod. Note: Classes defined with the isTest annotation don't count against your organization limit of 3 MB for all Apex code. Individual test methods in a class not annotated with isTest do count against your organization code size limit. See Understanding Execution Governors and Limits on page 225. This is an example of a test class that contains two test methods. @isTest private class MyTestClass { // Methods for testing @isTest static void test1() { // Implement test code } @isTest static void test2() { // Implement test code } } 158
- 161. Testing Apex Isolation of Test Data from Organization Data in Unit Tests Unit Test Considerations Here are some things to note about unit tests. • Test methods can’t be used to test Web service callouts. Web service callouts are asynchronous, while unit tests are synchronous. • You can’t send email messages from a test method. • Since test methods don’t commit data created in the test, you don’t have to delete test data upon completion. • For some sObjects that have fields with unique constraints, inserting duplicate sObject records results in an error. For example, inserting CollaborationGroup sObjects with the same name results in an error because CollaborationGroup records must have unique names. • Tracked changes for a record (FeedTrackedChange records) in Chatter feeds aren't available when test methods modify the associated record. FeedTrackedChange records require the change to the parent record they're associated with to be committed to the database before they're created. Since test methods don't commit data, they don't result in the creation of FeedTrackedChange records. See Also: IsTest Annotation Isolation of Test Data from Organization Data in Unit Tests Starting with Apex code saved using Salesforce.com API version 24.0 and later, test methods don’t have access by default to pre-existing data in the organization, such as standard objects, custom objects, and custom settings data, and can only access data that they create. However, objects that are used to manage your organization or metadata objects can still be accessed in your tests such as: • User • Profile • Organization • RecordType • ApexClass • ApexTrigger • ApexComponent • ApexPage Whenever possible, you should create test data for each test. You can disable this restriction by annotating your test class or test method with the IsTest(SeeAllData=true) annotation. For more information, see IsTest(SeeAllData=true) Annotation. Test code saved using Salesforce.com API version 23.0 or earlier continues to have access to all data in the organization and its data access is unchanged. Data Access Considerations • If a new test method saved using Salesforce.com API version 24.0 or later calls a method in another class saved using version 23.0 or earlier, the data access restrictions of the caller are enforced in the called method; that is, the called method won’t have access to organization data because the caller doesn’t, even though it was saved in an earlier version. 159
- 162. Testing Apex Using the runAs Method • This access restriction to test data applies to all code running in test context. For example, if a test method causes a trigger to execute and the test can’t access organization data, the trigger won’t be able to either. • If a test makes a Visualforce request, the executing test stays in test context but runs in a different thread, so test data isolation is no longer enforced. In this case, the test will be able to access all data in the organization after initiating the Visualforce request. However, if the Visualforce request performs a callback, such as a JavaScript remoting call, any data inserted by the callback won't be visible to the test. • There might be some cases where you can’t create certain types of data from your test method because of specific limitations. Here are some examples of such limitations. ◊ Inserting a pricebook entry for a product isn’t feasible from a test since the standard pricebook isn’t accessible and can’t be created in a running test. Also, inserting a pricebook entry for a custom pricebook isn’t supported since this requires defining a standard pricebook. For such situations, annotate your test method with IsTest(SeeAllData=true) so that your test can access organization data. ◊ Some standard objects aren’t createable. For more information on these objects, see the Object Reference for Salesforce and Force.com. ◊ For some sObjects that have fields with unique constraints, inserting duplicate sObject records results in an error. For example, inserting CollaborationGroup sObjects with the same name results in an error because CollaborationGroup records must have unique names. This happens whether or not your test is annotated with IsTest(SeeAllData=true). ◊ Records that are created only after related records are committed to the database, like tracked changes in Chatter. Tracked changes for a record (FeedTrackedChange records) in Chatter feeds aren't available when test methods modify the associated record. FeedTrackedChange records require the change to the parent record they're associated with to be committed to the database before they're created. Since test methods don't commit data, they don't result in the creation of FeedTrackedChange records. Using the runAs Method Generally, all Apex code runs in system mode, and the permissions and record sharing of the current user are not taken into account. The system method runAs enables you to write test methods that change either the user contexts to an existing user or a new user, or to run using the code from a specific version of a managed package. When running as a user, all of that user's record sharing is then enforced. You can only use runAs in a test method. The original system context is started again after all runAs test methods complete. For information on using the runAs method and specifying a package version context, see Testing Behavior in Package Versions on page 235. Note: Every call to runAs counts against the total number of DML statements issued in the process. In the following example, a new test user is created, then code is run as that user, with that user's permissions and record access: public class TestRunAs { public static testMethod void testRunAs() { // Setup test data // This code runs as the system user Profile p = [SELECT Id FROM Profile WHERE Name='Standard User']; User u = new User(Alias = 'standt', Email='standarduser@testorg.com', EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US', LocaleSidKey='en_US', ProfileId = p.Id, TimeZoneSidKey='America/Los_Angeles', UserName='standarduser@testorg.com'); 160
- 163. Testing Apex Using Limits, startTest, and stopTest System.runAs(u) { // The following code runs as user 'u' System.debug('Current User: ' + UserInfo.getUserName()); System.debug('Current Profile: ' + UserInfo.getProfileId()); } } } You can nest more than one runAs method. For example: public class TestRunAs2 { public static testMethod void test2() { Profile p = [SELECT Id FROM Profile WHERE Name='Standard User']; User u2 = new User(Alias = 'newUser', Email='newuser@testorg.com', EmailEncodingKey='UTF-8', LastName='Testing', LanguageLocaleKey='en_US', LocaleSidKey='en_US', ProfileId = p.Id, TimeZoneSidKey='America/Los_Angeles', UserName='newuser@testorg.com'); System.runAs(u2) { // The following code runs as user u2. System.debug('Current User: ' + UserInfo.getUserName()); System.debug('Current Profile: ' + UserInfo.getProfileId()); // The following code runs as user u3. User u3 = [SELECT Id FROM User WHERE UserName='newuser@testorg.com']; System.runAs(u3) { System.debug('Current User: ' + UserInfo.getUserName()); System.debug('Current Profile: ' + UserInfo.getProfileId()); } // Any additional code here would run as user u2. } } } Best Practices for Using runAs The following items use the permissions granted by the user specified with runAs running as a specific user: • Dynamic Apex • Methods using with sharing or without sharing • Shared records The original permissions are reset after runAs completes. The runAs method ignores user license limits. You can create new users with runAs even if your organization has no additional user licenses. Using Limits, startTest, and stopTest The Limits methods return the specific limit for the particular governor, such as the number of calls of a method or the amount of heap size remaining. There are two versions of every method: the first returns the amount of the resource that has been used in the current context, while the second version contains the word “limit” and returns the total amount of the resource that is available for that context. For example, getCallouts returns the number of callouts to an external service that have already been processed in the current context, while getLimitCallouts returns the total number of callouts available in the given context. 161
- 164. Testing Apex Adding SOSL Queries to Unit Tests In addition to the Limits methods, use the startTest and stopTest methods to validate how close the code is to reaching governor limits. The startTest method marks the point in your test code when your test actually begins. Each testMethod is allowed to call this method only once. All of the code before this method should be used to initialize variables, populate data structures, and so on, allowing you to set up everything you need to run your test. Any code that executes after the call to startTest and before stopTest is assigned a new set of governor limits. The startTest method does not refresh the context of the test: it adds a context to your test. For example, if your class makes 98 SOQL queries before it calls startTest, and the first significant statement after startTest is a DML statement, the program can now make an additional 100 queries. Once stopTest is called, however, the program goes back into the original context, and can only make 2 additional SOQL queries before reaching the limit of 100. The stopTest method marks the point in your test code when your test ends. Use this method in conjunction with the startTest method. Each testMethod is allowed to call this method only once. Any code that executes after the stopTest method is assigned the original limits that were in effect before startTest was called. All asynchronous calls made after the startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run synchronously. Adding SOSL Queries to Unit Tests To ensure that test methods always behave in a predictable way, any Salesforce Object Search Language (SOSL) query that is added to an Apex test method returns an empty set of search results when the test method executes. If you do not want the query to return an empty list of results, you can use the Test.setFixedSearchResults system method to define a list of record IDs that are returned by the search. All SOSL queries that take place later in the test method return the list of record IDs that were specified by the Test.setFixedSearchResults method. Additionally, the test method can call Test.setFixedSearchResults multiple times to define different result sets for different SOSL queries. If you do not call the Test.setFixedSearchResults method in a test method, or if you call this method without specifying a list of record IDs, any SOSL queries that take place later in the test method return an empty list of results. The list of record IDs specified by the Test.setFixedSearchResults method replaces the results that would normally be returned by the SOSL query if it were not subject to any WHERE or LIMIT clauses. If these clauses exist in the SOSL query, they are applied to the list of fixed search results. For example: public class SoslFixedResultsTest1 { public static testMethod void testSoslFixedResults() { Id [] fixedSearchResults= new Id[1]; fixedSearchResults[0] = '001x0000003G89h'; Test.setFixedSearchResults(fixedSearchResults); List<List<SObject>> searchList = [FIND 'test' IN ALL FIELDS RETURNING Account(id, name WHERE name = 'test' LIMIT 1)]; } } Although the account record with an ID of 001x0000003G89h may not match the query string in the FIND clause ('test'), the record is passed into the RETURNING clause of the SOSL statement. If the record with ID 001x0000003G89h matches the WHERE clause filter, the record is returned. If it does not match the WHERE clause, no record is returned. 162
- 165. Testing Apex Running Unit Test Methods Running Unit Test Methods You can run unit tests for: • A specific class • A subset of classes • All unit tests in your organization To run a test, use any of the following: • The Salesforce user interface • The Force.com IDE • The API Running Tests Through the Salesforce User Interface You can run unit tests on the Apex Test Execution page. Tests started on this page run asynchronously, that is, you don't have to wait for a test class execution to finish. The Apex Test Execution page refreshes the status of a test and displays the results after the test completes. To use the Apex Test Execution page: 1. Click Your Name > Setup > Develop > Apex Test Execution. 2. Click Select Tests.... Note: If you have Apex classes that are installed from a managed package, you must compile these classes first by clicking Compile all classes on the Apex Classes page so that they appear in the list. See “Managing Apex Classes” in the online help. 3. Select the tests to run. The list of tests contains classes that contain test methods. • To select tests from an installed managed package, select its corresponding namespace from the drop-down list. Only the classes of the managed package with the selected namespace appear in the list. • To select tests that exist locally in your organization, select [My Namespace] from the drop-down list. Only local classes that aren't from managed packages appear in the list. • To select any test, select [All Namespaces] from the drop-down list. All the classes in the organization appear, whether or not they are from a managed package. 163
- 166. Testing Apex Running Unit Test Methods Note: Classes whose tests are still running don't appear in the list. 4. Click Run. After you run tests using the Apex Test Execution page, you can display the percentage of code covered by those tests on the list of Apex classes. Click Your Name > Setup > Develop > Apex Classes, then click Calculate your organization's code coverage. Note: The code coverage value computed by Calculate your organization's code coverage might differ from the code coverage value computed after running all unit tests using Run All Tests. This is because Calculate your organization's code coverage excludes classes that are part of installed managed packages while Run All Tests doesn't. You can also verify which lines of code are covered by tests for an individual class. Click Your Name > Setup > Develop > Apex Classes, then click the percentage number in the Code Coverage column for a class. Click Your Name > Setup > Develop > Apex Test Execution > View Test History to view all test results for your organization, not just tests that you have run. Test results are retained for 30 days after they finish running, unless cleared. Alternatively, use the Apex classes page to run tests. To use the Apex Classes page to generate test results, click Your Name > Setup > Develop > Apex Classes, then either click Run All Tests or click the name of a specific class that contains tests and click Run Test. After you use the Apex Classes page to generate test results, the test result page contains the following sections. Each section can be expanded or collapsed. • A summary section that details the number of tests run, the number of failures, the percentage of Apex code that is covered by unit tests, the total execution time in milliseconds, and a link to a downloadable debug log file. The debug log is automatically set to specific log levels and categories, which can't be changed. Category Level Database INFO Apex Code FINE Apex Profiling FINE Workflow FINEST Validation INFO Important: Before you can deploy Apex or package it for the Force.com AppExchange, the following must be true: ◊ 75% of your Apex code must be covered by unit tests, and all of those tests must complete successfully. Note the following: - When deploying to a production organization, every unit test in your organization namespace is executed. - Calls to System.debug are not counted as part of Apex code coverage. - Test methods and test classes are not counted as part of Apex code coverage. - While only 75% of your Apex code must be covered by tests, your focus shouldn't be on the percentage of code that is covered. Instead, you should make sure that every use case of your application is covered, including positive and negative cases, as well as bulk and single record. This should lead to 75% or more of your code being covered by unit tests. 164
- 167. Testing Apex Running Unit Test Methods ◊ Every trigger has some test coverage. ◊ All classes and triggers compile successfully. • Test successes, if any. • Test failures, if any. • A code coverage section. This section lists all the classes and triggers in your organization, and the percentage of lines of code in each class and trigger that are covered by tests. If you click the coverage percent number, a page displays, highlighting all the lines of code for that class or trigger that are covered by tests in blue, as well as highlighting all the lines of code that are not covered by tests in red. It also lists how many times a particular line in the class or trigger was executed by the test • Test coverage warnings, if any. Running Tests Using the Force.com IDE In addition, you can execute tests with the Force.com IDE (see https://wiki.developerforce.com/index.php/Apex_Toolkit_for_Eclipse). Running Tests Using the API Note: The API for asynchronous test runs is a Beta release. Using objects and Apex code to insert and query those objects, you can add tests to the Apex job queue for execution and check the results of completed test runs. This enables you to not only start tests asynchronously but also schedule your tests to execute at specific times by using the Apex scheduler. See Apex Scheduler for more information. To start an asynchronous execution of unit tests and check their results, use these objects: • ApexTestQueueItem: Represents a single Apex class in the Apex job queue. • ApexTestResult: Represents the result of an Apex test method execution. Insert an ApexTestQueueItem object to place its corresponding Apex class in the Apex job queue for execution. The Apex job executes the test methods in the class. After the job executes, ApexTestResult contains the result for each single test method executed as part of the test. To abort a class that is in the Apex job queue, perform an update operation on the ApexTestQueueItem object and set its Status field to Aborted. If you insert multiple Apex test queue items in a single bulk operation, the queue items will share the same parent job. This means that a test run can consist of the execution of the tests of several classes if all the test queue items are inserted in the same bulk operation. The maximum number of test queue items, and hence classes, that you can insert in the Apex job queue is the greater of 500 or 10 multiplied by the number of test classes in the organization. This example shows how to use DML operations to insert and query the ApexTestQueueItem and ApexTestResult objects. The enqueueTests method inserts queue items for all classes that end with Test. It then returns the parent job ID of one queue item, which is the same for all queue items because they were inserted in bulk. The checkClassStatus method retrieves all the queue items that correspond to the specified job ID. It then queries and outputs the name, job status, and pass rate for each class. The checkMethodStatus method gets information of each test method that was executed as part of the job. public class TestUtil { 165
- 168. Testing Apex Running Unit Test Methods // Enqueue all classes ending in "Test". public static ID enqueueTests() { ApexClass[] testClasses = [SELECT Id FROM ApexClass WHERE Name LIKE '%Test']; if (testClasses.size() > 0) { ApexTestQueueItem[] queueItems = new List<ApexTestQueueItem>(); for (ApexClass cls : testClasses) { queueItems.add(new ApexTestQueueItem(ApexClassId=cls.Id)); } insert queueItems; // Get the job ID of the first queue item returned. ApexTestQueueItem item = [SELECT ParentJobId FROM ApexTestQueueItem WHERE Id=:queueItems[0].Id LIMIT 1]; return item.parentjobid; } return null; } // Get the status and pass rate for each class // whose tests were run by the job. // that correspond to the specified job ID. public static void checkClassStatus(ID jobId) { ApexTestQueueItem[] items = [SELECT ApexClass.Name, Status, ExtendedStatus FROM ApexTestQueueItem WHERE ParentJobId=:jobId]; for (ApexTestQueueItem item : items) { String extStatus = item.extendedstatus == null ? '' : item.extendedStatus; System.debug(item.ApexClass.Name + ': ' + item.Status + extStatus); } } // Get the result for each test method that was executed. public static void checkMethodStatus(ID jobId) { ApexTestResult[] results = [SELECT Outcome, ApexClass.Name, MethodName, Message, StackTrace FROM ApexTestResult WHERE AsyncApexJobId=:jobId]; for (ApexTestResult atr : results) { System.debug(atr.ApexClass.Name + '.' + atr.MethodName + ': ' + atr.Outcome); if (atr.message != null) { System.debug(atr.Message + 'n at ' + atr.StackTrace); } } } } You can also use the runTests() call from the SOAP API to run tests synchronously: RunTestsResult[] runTests(RunTestsRequest ri) This call allows you to run all tests in all classes, all tests in a specific namespace, or all tests in a subset of classes in a specific namespace, as specified in the RunTestsRequest object. It returns the following: • Total number of tests that ran • Code coverage statistics (described below) • Error information for each failed test • Information for each test that succeeds • Time it took to run the test 166
- 169. Testing Apex Testing Best Practices For more information on runTests(), see the WSDL located at https://your_salesforce_server/services/wsdl/apex, where your_salesforce_server is equivalent to the server on which your organization is located, such as na1.salesforce.com. Though administrators in a Salesforce production organization cannot make changes to Apex code using the Salesforce user interface, it is still important to use runTests() to verify that the existing unit tests run to completion after a change is made, such as adding a unique constraint to an existing field. Salesforce production organizations must use the compileAndTest SOAP API call to make changes to Apex code. For more information, see Deploying Apex on page 599. For more information on runTests(), see SOAP API and SOAP Headers for Apex on page 629. Testing Best Practices Good tests should do the following: • Cover as many lines of code as possible. Before you can deploy Apex or package it for the Force.com AppExchange, the following must be true: Important: ◊ 75% of your Apex code must be covered by unit tests, and all of those tests must complete successfully. Note the following: - When deploying to a production organization, every unit test in your organization namespace is executed. - Calls to System.debug are not counted as part of Apex code coverage. - Test methods and test classes are not counted as part of Apex code coverage. - While only 75% of your Apex code must be covered by tests, your focus shouldn't be on the percentage of code that is covered. Instead, you should make sure that every use case of your application is covered, including positive and negative cases, as well as bulk and single record. This should lead to 75% or more of your code being covered by unit tests. ◊ Every trigger has some test coverage. ◊ All classes and triggers compile successfully. • In the case of conditional logic (including ternary operators), execute each branch of code logic. • Make calls to methods using both valid and invalid inputs. • Complete successfully without throwing any exceptions, unless those errors are expected and caught in a try…catch block. • Always handle all exceptions that are caught, instead of merely catching the exceptions. • Use System.assert methods to prove that code behaves properly. • Use the runAs method to test your application in different user contexts. • Use the isTest annotation. Classes defined with the isTest annotation do not count against your organization limit of 3 MB for all Apex code. See IsTest Annotation on page 138. • Exercise bulk trigger functionality—use at least 20 records in your tests. • Use the ORDER BY keywords to ensure that the records are returned in the expected order. • Not assume that record IDs are in sequential order. 167
- 170. Testing Apex Testing Example Record IDs are not created in ascending order unless you insert multiple records with the same request. For example, if you create an account A, and receive the ID 001D000000IEEmT, then create account B, the ID of account B may or may not be sequentially higher. • On the list of Apex classes, there is a Code Coverage column. If you click the coverage percent number, a page displays, highlighting all the lines of code for that class or trigger that are covered by tests in blue, as well as highlighting all the lines of code that are not covered by tests in red. It also lists how many times a particular line in the class or trigger was executed by the test • Set up test data: ◊ Create the necessary data in test classes, so the tests do not have to rely on data in a particular organization. ◊ Create all test data before calling the starttest method. ◊ Since tests don't commit, you won't need to delete any data. • Write comments stating not only what is supposed to be tested, but the assumptions the tester made about the data, the expected outcome, and so on. • Test the classes in your application individually. Never test your entire application in a single test. If you are running many tests, consider the following: • In the Force.com IDE, you may need to increase the Read timeout value for your Apex project. See https://wiki.developerforce.com/index.php/Apex_Toolkit_for_Eclipse for details. • In the Salesforce user interface, you may need to test the classes in your organization individually, instead of trying to run all of the tests at the same time using the Run All Tests button. Testing Example The following example includes cases for the following types of tests: • Positive case with single and multiple records • Negative case with single and multiple records • Testing with other users The test is used with a simple mileage tracking application. The existing code for the application verifies that not more than 500 miles are entered in a single day. The primary object is a custom object named Mileage__c. Here is the entire test class. The following sections step through specific portions of the code. @isTest private class MileageTrackerTestSuite { static testMethod void runPositiveTestCases() { Double totalMiles = 0; final Double maxtotalMiles = 500; final Double singletotalMiles = 300; final Double u2Miles = 100; //Set up user User u1 = [SELECT Id FROM User WHERE Alias='auser']; //Run As U1 System.RunAs(u1){ 168
- 171. Testing Apex Testing Example System.debug('Inserting 300 miles... (single record validation)'); Mileage__c testMiles1 = new Mileage__c(Miles__c = 300, Date__c = System.today()); insert testMiles1; //Validate single insert for(Mileage__c m:[SELECT miles__c FROM Mileage__c WHERE CreatedDate = TODAY and CreatedById = :u1.id and miles__c != null]) { totalMiles += m.miles__c; } System.assertEquals(singletotalMiles, totalMiles); //Bulk validation totalMiles = 0; System.debug('Inserting 200 mileage records... (bulk validation)'); List<Mileage__c> testMiles2 = new List<Mileage__c>(); for(integer i=0; i<200; i++) { testMiles2.add( new Mileage__c(Miles__c = 1, Date__c = System.today()) ); } insert testMiles2; for(Mileage__c m:[SELECT miles__c FROM Mileage__c WHERE CreatedDate = TODAY and CreatedById = :u1.Id and miles__c != null]) { totalMiles += m.miles__c; } System.assertEquals(maxtotalMiles, totalMiles); }//end RunAs(u1) //Validate additional user: totalMiles = 0; //Setup RunAs User u2 = [SELECT Id FROM User WHERE Alias='tuser']; System.RunAs(u2){ Mileage__c testMiles3 = new Mileage__c(Miles__c = 100, Date__c = System.today()); insert testMiles3; for(Mileage__c m:[SELECT miles__c FROM Mileage__c WHERE CreatedDate = TODAY and CreatedById = :u2.Id and miles__c != null]) { totalMiles += m.miles__c; } //Validate System.assertEquals(u2Miles, totalMiles); } //System.RunAs(u2) } // runPositiveTestCases() static testMethod void runNegativeTestCases() { User u3 = [SELECT Id FROM User WHERE Alias='tuser']; System.RunAs(u3){ 169
- 172. Testing Apex Testing Example System.debug('Inserting a record with 501 miles... (negative test case)'); Mileage__c testMiles3 = new Mileage__c( Miles__c = 501, Date__c = System.today() ); try { insert testMiles3; } catch (DmlException e) { //Assert Error Message System.assert( e.getMessage().contains('Insert failed. First exception on ' + 'row 0; first error: FIELD_CUSTOM_VALIDATION_EXCEPTION, ' + 'Mileage request exceeds daily limit(500): [Miles__c]'), e.getMessage() ); //Assert field System.assertEquals(Mileage__c.Miles__c, e.getDmlFields(0)[0]); //Assert Status Code System.assertEquals('FIELD_CUSTOM_VALIDATION_EXCEPTION' , e.getDmlStatusCode(0) ); } //catch } //RunAs(u3) } // runNegativeTestCases() } // class MileageTrackerTestSuite Positive Test Case The following steps through the above code, in particular, the positive test case for single and multiple records. 1. Add text to the debug log, indicating the next step of the code: System.debug('Inserting 300 more miles...single record validation'); 2. Create a Mileage__c object and insert it into the database. Mileage__c testMiles1 = new Mileage__c(Miles__c = 300, Date__c = System.today() ); insert testMiles1; 3. Validate the code by returning the inserted records: for(Mileage__c m:[SELECT miles__c FROM Mileage__c WHERE CreatedDate = TODAY and CreatedById = :createdbyId and miles__c != null]) { totalMiles += m.miles__c; } 4. Use the system.assertEquals method to verify that the expected result is returned: System.assertEquals(singletotalMiles, totalMiles); 5. Before moving to the next test, set the number of total miles back to 0: totalMiles = 0; 6. Validate the code by creating a bulk insert of 200 records. 170
- 173. Testing Apex Testing Example First, add text to the debug log, indicating the next step of the code: System.debug('Inserting 200 Mileage records...bulk validation'); 7. Then insert 200 Mileage__c records: List<Mileage__c> testMiles2 = new List<Mileage__c>(); for(Integer i=0; i<200; i++){ testMiles2.add( new Mileage__c(Miles__c = 1, Date__c = System.today()) ); } insert testMiles2; 8. Use System.assertEquals to verify that the expected result is returned: for(Mileage__c m:[SELECT miles__c FROM Mileage__c WHERE CreatedDate = TODAY and CreatedById = :CreatedbyId and miles__c != null]) { totalMiles += m.miles__c; } System.assertEquals(maxtotalMiles, totalMiles); Negative Test Case The following steps through the above code, in particular, the negative test case. 1. Create a static test method called runNegativeTestCases: static testMethod void runNegativeTestCases(){ 2. Add text to the debug log, indicating the next step of the code: System.debug('Inserting 501 miles... negative test case'); 3. Create a Mileage__c record with 501 miles. Mileage__c testMiles3 = new Mileage__c(Miles__c = 501, Date__c = System.today()); 4. Place the insert statement within a try/catch block. This allows you to catch the validation exception and assert the generated error message. try { insert testMiles3; } catch (DmlException e) { 5. Now use the System.assert and System.assertEquals to do the testing. Add the following code to the catch block you previously created: //Assert Error Message System.assert(e.getMessage().contains('Insert failed. First exception '+ 'on row 0; first error: FIELD_CUSTOM_VALIDATION_EXCEPTION, '+ 'Mileage request exceeds daily limit(500): [Miles__c]'), e.getMessage()); //Assert Field 171
- 174. Testing Apex Testing Example System.assertEquals(Mileage__c.Miles__c, e.getDmlFields(0)[0]); //Assert Status Code System.assertEquals('FIELD_CUSTOM_VALIDATION_EXCEPTION' , e.getDmlStatusCode(0)); } } } Testing as a Second User The following steps through the above code, in particular, running as a second user. 1. Before moving to the next test, set the number of total miles back to 0: totalMiles = 0; 2. Set up the next user. User u2 = [SELECT Id FROM User WHERE Alias='tuser']; System.RunAs(u2){ 3. Add text to the debug log, indicating the next step of the code: System.debug('Setting up testing - deleting any mileage records for ' + UserInfo.getUserName() + ' from today'); 4. Then insert one Mileage__c record: Mileage__c testMiles3 = new Mileage__c(Miles__c = 100, Date__c = System.today()); insert testMiles3; 5. Validate the code by returning the inserted records: for(Mileage__c m:[SELECT miles__c FROM Mileage__c WHERE CreatedDate = TODAY and CreatedById = :u2.Id and miles__c != null]) { totalMiles += m.miles__c; } 6. Use the system.assertEquals method to verify that the expected result is returned: System.assertEquals(u2Miles, totalMiles); 172
- 175. Chapter 6 Dynamic Apex In this chapter ... Dynamic Apex enables developers to create more flexible applications by providing them with the ability to: • Understanding Apex Describe Information • Access sObject and field describe information • Dynamic SOQL Describe information provides information about sObject and field properties. • Dynamic SOSL For example, the describe information for an sObject includes whether that • Dynamic DML type of sObject supports operations like create or undelete, the sObject's name and label, the sObject's fields and child objects, and so on. The describe information for a field includes whether the field has a default value, whether it is a calculated field, the type of the field, and so on. Note that describe information provides information about objects in an organization, not individual records. • Write dynamic SOQL queries, dynamic SOSL queries and dynamic DML Dynamic SOQL and SOSL queries provide the ability to execute SOQL or SOSL as a string at runtime, while dynamic DML provides the ability to create a record dynamically and then insert it into the database using DML. Using dynamic SOQL, SOSL, and DML, an application can be tailored precisely to the organization as well as the user's permissions. This can be useful for applications that are installed from Force.com AppExchange. 173
- 176. Dynamic Apex Understanding Apex Describe Information Understanding Apex Describe Information Apex provides two data structures for sObject and field describe information: • Token—a lightweight, serializable reference to an sObject or a field that is validated at compile time. • Describe result—an object that contains all the describe properties for the sObject or field. Describe result objects are not serializable, and are validated at runtime. It is easy to move from a token to its describe result, and vice versa. Both sObject and field tokens have the method getDescribe which returns the describe result for that token. On the describe result, the getSObjectType and getSObjectField methods return the tokens for sObject and field, respectively. Because tokens are lightweight, using them can make your code faster and more efficient. For example, use the token version of an sObject or field when you are determining the type of an sObject or field that your code needs to use. The token can be compared using the equality operator (==) to determine whether an sObject is the Account object, for example, or whether a field is the Name field or a custom calculated field. The following code provides a general example of how to use tokens and describe results to access information about sObject and field properties: // Create a new account as the generic type sObject sObject s = new Account(); // Verify that the generic sObject is an Account sObject System.assert(s.getsObjectType() == Account.sObjectType); // Get the sObject describe result for the Account object Schema.DescribeSObjectResult r = Account.sObjectType.getDescribe(); // Get the field describe result for the Name field on the Account object Schema.DescribeFieldResult f = Schema.sObjectType.Account.fields.Name; // Verify that the field token is the token for the Name field on an Account object System.assert(f.getSObjectField() == Account.Name); // Get the field describe result from the token f = f.getSObjectField().getDescribe(); The following algorithm shows how you can work with describe information in Apex: 1. Generate a list or map of tokens for the sObjects in your organization (see Accessing All sObjects on page 177.) 2. Determine the sObject you need to access. 3. Generate the describe result for the sObject. 4. If necessary, generate a map of field tokens for the sObject (see Accessing All Field Describe Results for an sObject on page 178.) 5. Generate the describe result for the field the code needs to access. Understanding Describe Information Permissions Apex generally runs in system mode. All classes and triggers that are not included in a package, that is, are native to your organization, have no restrictions on the sObjects that they can look up dynamically. This means that with native code, you can generate a map of all the sObjects for your organization, regardless of the current user's permission. Dynamic Apex, contained in managed packages created by salesforce.com ISV partners that are installed from Force.com AppExchange, have restricted access to any sObject outside the managed package. Partners can set the API Access value 174
- 177. Dynamic Apex Understanding Apex Describe Information within the package to grant access to standard sObjects not included as part of the managed package. While Partners can request access to standard objects, custom objects are not included as part of the managed package and can never be referenced or accessed by dynamic Apex that is packaged. For more information, see “About API and Dynamic Apex Access in Packages” in the Salesforce online help. Using sObject Tokens SObjects, such as Account and MyCustomObject__c, act as static classes with special static methods and member variables for accessing token and describe result information. You must explicitly reference an sObject and field name at compile time to gain access to the describe result. To access the token for an sObject, use one of the following methods: • Access the sObjectType member variable on an sObject type, such as Account. • Call the getSObjectType method on an sObject describe result, an sObject variable, a list, or a map. Schema.SObjectType is the data type for an sObject token. In the following example, the token for the Account sObject is returned: Schema.sObjectType t = Account.sObjectType; The following also returns a token for the Account sObject: Account A = new Account(); Schema.sObjectType T = A.getSObjectType(); This example can be used to determine whether an sObject or a list of sObjects is of a particular type: public class sObjectTest { { // Create a generic sObject variable s SObject s = Database.query('SELECT Id FROM Account LIMIT 1'); // Verify if that sObject variable is an Account token System.assertEquals(s.getSObjectType(), Account.sObjectType); // Create a list of generic sObjects List<sObject> l = new Account[]{}; // Verify if the list of sObjects contains Account tokens System.assertEquals(l.getSObjectType(), Account.sObjectType); } } Some standard sObjects have a field called sObjectType, for example, AssignmentRule, QueueSObject, and RecordType. For these types of sObjects, always use the getSObjectType method for retrieving the token. If you use the property, for example, RecordType.sObjectType, the field is returned. Using sObject Describe Results To access the describe result for an sObject, use one of the following methods: • Call the getDescribe method on an sObject token. • Use the Schema sObjectType static variable with the name of the sObject. For example, Schema.sObjectType.Lead. Schema.DescribeSObjectResult is the data type for an sObject describe result. 175
- 178. Dynamic Apex Understanding Apex Describe Information The following example uses the getDescribe method on an sObject token: Schema.DescribeSObjectResult D = Account.sObjectType.getDescribe(); The following example uses the Schema sObjectType static member variable: Schema.DescribeSObjectResult D = Schema.SObjectType.Account; For more information about the methods available with the sObject describe result, see sObject Describe Result Methods on page 357. Using Field Tokens To access the token for a field, use one of the following methods: • Access the static member variable name of an sObject static type, for example, Account.Name. • Call the getSObjectField method on a field describe result. The field token uses the data type Schema.SObjectField. In the following example, the field token is returned for the Account object's AccountNumber field: Schema.SObjectField F = Account.AccountNumber; In the following example, the field token is returned from the field describe result: // Get the describe result for the Name field on the Account object Schema.DescribeFieldResult f = Schema.sObjectType.Account.fields.Name; // Verify that the field token is the token for the Name field on an Account object System.assert(f.getSObjectField() == Account.Name); // Get the describe result from the token f = f.getSObjectField().getDescribe(); Using Field Describe Results To access the describe result for a field, use one of the following methods: • Call the getDescribe method on a field token. • Access the fields member variable of an sObject token with a field member variable (such as Name, BillingCity, and so on.) The field describe result uses the data type Schema.DescribeFieldResult. The following example uses the getDescribe method: Schema.DescribeFieldResult F = Account.AccountNumber.getDescribe(); This example uses the fields member variable method: Schema.DescribeFieldResult F = Schema.SObjectType.Account.fields.Name; In the example above, the system uses special parsing to validate that the final member variable (Name) is valid for the specified sObject at compile time. When the parser finds the fields member variable, it looks backwards to find the name of the sObject (Account) and validates that the field name following the fields member variable is legitimate. The fields member variable only works when used in this manner. 176
- 179. Dynamic Apex Understanding Apex Describe Information You can only have 100 fields member variable statements in an Apex class or trigger. Note: You should not use the fields member variable without also using either a field member variable name or the getMap method. For more information on getMap, see Accessing All Field Describe Results for an sObject on page 178. For more information about the methods available with a field describe result, see Describe Field Result Methods on page 361. Accessing All sObjects Use the Schema getGlobalDescribe method to return a map that represents the relationship between all sObject names (keys) to sObject tokens (values). For example: Map<String, Schema.SObjectType> gd = Schema.getGlobalDescribe(); The map has the following characteristics: • It is dynamic, that is, it is generated at runtime on the sObjects currently available for the organization, based on permissions. • The sObject names are case insensitive. • The keys use namespaces as required. • The keys reflect whether the sObject is a custom object. For example, if the code block that generates the map is in namespace N1, and an sObject is also in N1, the key in the map is represented as MyObject__c. However, if the code block is in namespace N1, and the sObject is in namespace N2, the key is N2__MyObject__c. In addition, standard sObjects have no namespace prefix. Creating sObjects Dynamically You can create sObjects whose types are determined at run time by calling the newSObject method of the Schema.sObjectType sObject token class. The following example shows how to get an sObject token that corresponds to an sObject type name using the Schema.getGlobalDescribe method. Then, an instance of the sObject is created through the newSObject method of Schema.sObjectType. This example also contains a test method that verifies the dynamic creation of an account. public class DynamicSObjectCreation { public static sObject createObject(String typeName) { Schema.SObjectType targetType = Schema.getGlobalDescribe().get(typeName); if (targetType == null) { // throw an exception } // Instantiate an sObject with the type passed in as an argument // at run time. return targetType.newSObject(); } static testmethod void testObjectCreation() { String typeName = 'Account'; String acctName = 'Acme'; // Create a new sObject by passing the sObject type as an argument. Account a = (Account)createObject(typeName); System.assertEquals(typeName, String.valueOf(a.getSobjectType())); // Set the account name and insert the account. a.Name = acctName; insert a; 177
- 180. Dynamic Apex Understanding Apex Describe Information // Verify the new sObject got inserted. Account[] b = [SELECT Name from Account WHERE Name = :acctName]; system.assert(b.size() > 0); } } Accessing All Field Describe Results for an sObject Use the field describe result's getMap method to return a map that represents the relationship between all the field names (keys) and the field tokens (values) for an sObject. The following example generates a map that can be used to access a field by name: Map<String, Schema.SObjectField> M = Schema.SObjectType.Account.fields.getMap(); Note: The value type of this map is not a field describe result. Using the describe results would take too many system resources. Instead, it is a map of tokens that you can use to find the appropriate field. After you determine the field, generate the describe result for it. The map has the following characteristics: • It is dynamic, that is, it is generated at runtime on the fields for that sObject. • All field names are case insensitive. • The keys use namespaces as required. • The keys reflect whether the field is a custom object. For example, if the code block that generates the map is in namespace N1, and a field is also in N1, the key in the map is represented as MyField__c. However, if the code block is in namespace N1, and the field is in namespace N2, the key is N2__MyField__c. In addition, standard fields have no namespace prefix. Accessing All Data Categories Associated with an sObject Use the describeDataCategory Groups and describeDataCategory GroupStructures methods to return the categories associated with a specific object: 1. Return all the category groups associated with the objects of your choice (see describeDataCategory Groups on page 349). 2. From the returned map, get the category group name and sObject name you want to further interrogate (see Schema.Describe DataCategoryGroupResult on page 350). 3. Specify the category group and associated object, then retrieve the categories available to this object (see describeDataCategory GroupStructures on page 349). The describeDataCategory GroupStructures method returns the categories available for the object in the category group you specified. For additional information about data categories, see “What are Data Categories?” in the Salesforce online help. In the following example, the describeDataCategoryGroupSample method returns all the category groups associated with the Article and Question objects. The describeDataCategoryGroupStructures method returns all the categories available for articles and questions in the Regions category group. For additional information about articles and questions, see “Managing Articles and Translations” and “Answers Overview” in the Salesforce online help. To use the following example, you must: • Enable Salesforce Knowledge. • Enable the answers feature. 178
- 181. Dynamic Apex Understanding Apex Describe Information • Create a data category group called Regions. • Assign Regions as the data category group to be used by Answers. • Make sure the Regions data category group is assigned to Salesforce Knowledge. For more information on creating data category groups, see “Creating and Modifying Category Groups” in the Salesforce online help. For more information on answers, see “Answers Overview” in the Salesforce online help. public class DescribeDataCategoryGroupSample { public static List<DescribeDataCategoryGroupResult> describeDataCategoryGroupSample(){ List<DescribeDataCategoryGroupResult> describeCategoryResult; try { //Creating the list of sobjects to use for the describe //call List<String> objType = new List<String>(); objType.add('KnowledgeArticleVersion'); objType.add('Question'); //Describe Call describeCategoryResult = Schema.describeDataCategoryGroups(objType); //Using the results and retrieving the information for(DescribeDataCategoryGroupResult singleResult : describeCategoryResult){ //Getting the name of the category singleResult.getName(); //Getting the name of label singleResult.getLabel(); //Getting description singleResult.getDescription(); //Getting the sobject singleResult.getSobject(); } } catch(Exception e){ } return describeCategoryResult; } } public class DescribeDataCategoryGroupStructures { public static List<DescribeDataCategoryGroupStructureResult> getDescribeDataCategoryGroupStructureResults(){ List<DescribeDataCategoryGroupResult> describeCategoryResult; List<DescribeDataCategoryGroupStructureResult> describeCategoryStructureResult; try { //Making the call to the describeDataCategoryGroups to //get the list of category groups associated List<String> objType = new List<String>(); objType.add('KnowledgeArticleVersion'); objType.add('Question'); describeCategoryResult = Schema.describeDataCategoryGroups(objType); //Creating a list of pair objects to use as a parameter //for the describe call List<DataCategoryGroupSobjectTypePair> pairs = new List<DataCategoryGroupSobjectTypePair>(); //Looping throught the first describe result to create //the list of pairs for the second describe call 179
- 182. Dynamic Apex Understanding Apex Describe Information for(DescribeDataCategoryGroupResult singleResult : describeCategoryResult){ DataCategoryGroupSobjectTypePair p = new DataCategoryGroupSobjectTypePair(); p.setSobject(singleResult.getSobject()); p.setDataCategoryGroupName(singleResult.getName()); pairs.add(p); } //describeDataCategoryGroupStructures() describeCategoryStructureResult = Schema.describeDataCategoryGroupStructures(pairs, false); //Getting data from the result for(DescribeDataCategoryGroupStructureResult singleResult : describeCategoryStructureResult){ //Get name of the associated Sobject singleResult.getSobject(); //Get the name of the data category group singleResult.getName(); //Get the name of the data category group singleResult.getLabel(); //Get the description of the data category group singleResult.getDescription(); //Get the top level categories DataCategory [] toplevelCategories = singleResult.getTopCategories(); //Recursively get all the categories List<DataCategory> allCategories = getAllCategories(toplevelCategories); for(DataCategory category : allCategories) { //Get the name of the category category.getName(); //Get the label of the category category.getLabel(); //Get the list of sub categories in the category DataCategory [] childCategories = category.getChildCategories(); } } } catch (Exception e){ } return describeCategoryStructureResult; } private static DataCategory[] getAllCategories(DataCategory [] categories){ if(categories.isEmpty()){ return new DataCategory[]{}; } else { DataCategory [] categoriesClone = categories.clone(); DataCategory category = categoriesClone[0]; DataCategory[] allCategories = new DataCategory[]{category}; categoriesClone.remove(0); categoriesClone.addAll(category.getChildCategories()); allCategories.addAll(getAllCategories(categoriesClone)); return allCategories; } } 180
- 183. Dynamic Apex Understanding Apex Describe Information } Testing Access to All Data Categories Associated with an sObject The following example tests the describeDataCategoryGroupSample method shown in Accessing All Data Categories Associated with an sObject. It ensures that the returned category group and associated objects are correct. @isTest private class DescribeDataCategoryGroupSampleTest { public static testMethod void describeDataCategoryGroupSampleTest(){ List<DescribeDataCategoryGroupResult>describeResult = DescribeDataCategoryGroupSample.describeDataCategoryGroupSample(); //Assuming that you have KnowledgeArticleVersion and Questions //associated with only one category group 'Regions'. System.assert(describeResult.size() == 2, 'The results should only contain two results: ' + describeResult.size()); for(DescribeDataCategoryGroupResult result : describeResult) { //Storing the results String name = result.getName(); String label = result.getLabel(); String description = result.getDescription(); String objectNames = result.getSobject(); //asserting the values to make sure System.assert(name == 'Regions', 'Incorrect name was returned: ' + name); System.assert(label == 'Regions of the World', 'Incorrect label was returned: ' + label); System.assert(description == 'This is the category group for all the regions', 'Incorrect description was returned: ' + description); System.assert(objectNames.contains('KnowledgeArticleVersion') || objectNames.contains('Question'), 'Incorrect sObject was returned: ' + objectNames); } } } This example tests the describeDataCategoryGroupStructures method shown in Accessing All Data Categories Associated with an sObject. It ensures that the returned category group, categories and associated objects are correct. @isTest private class DescribeDataCategoryGroupStructuresTest { public static testMethod void getDescribeDataCategoryGroupStructureResultsTest(){ List<Schema.DescribeDataCategoryGroupStructureResult> describeResult = DescribeDataCategoryGroupStructures.getDescribeDataCategoryGroupStructureResults(); System.assert(describeResult.size() == 2, 'The results should only contain 2 results: ' + describeResult.size()); //Creating category info CategoryInfo world = new CategoryInfo('World', 'World'); CategoryInfo asia = new CategoryInfo('Asia', 'Asia'); CategoryInfo northAmerica = new CategoryInfo('NorthAmerica', 'North America'); CategoryInfo southAmerica = new CategoryInfo('SouthAmerica', 'South America'); CategoryInfo europe = new CategoryInfo('Europe', 'Europe'); List<CategoryInfo> info = new CategoryInfo[] { asia, northAmerica, southAmerica, europe 181
- 184. Dynamic Apex Understanding Apex Describe Information }; for (Schema.DescribeDataCategoryGroupStructureResult result : describeResult) { String name = result.getName(); String label = result.getLabel(); String description = result.getDescription(); String objectNames = result.getSobject(); //asserting the values to make sure System.assert(name == 'Regions', 'Incorrect name was returned: ' + name); System.assert(label == 'Regions of the World', 'Incorrect label was returned: ' + label); System.assert(description == 'This is the category group for all the regions', 'Incorrect description was returned: ' + description); System.assert(objectNames.contains('KnowledgeArticleVersion') || objectNames.contains('Question'), 'Incorrect sObject was returned: ' + objectNames); DataCategory [] topLevelCategories = result.getTopCategories(); System.assert(topLevelCategories.size() == 1, 'Incorrect number of top level categories returned: ' + topLevelCategories.size()); System.assert(topLevelCategories[0].getLabel() == world.getLabel() && topLevelCategories[0].getName() == world.getName()); //checking if the correct children are returned DataCategory [] children = topLevelCategories[0].getChildCategories(); System.assert(children.size() == 4, 'Incorrect number of children returned: ' + children.size()); for(Integer i=0; i < children.size(); i++){ System.assert(children[i].getLabel() == info[i].getLabel() && children[i].getName() == info[i].getName()); } } } private class CategoryInfo { private final String name; private final String label; private CategoryInfo(String n, String l){ this.name = n; this.label = l; } public String getName(){ return this.name; } public String getLabel(){ return this.label; } } } 182
- 185. Dynamic Apex Dynamic SOQL Dynamic SOQL Dynamic SOQL refers to the creation of a SOQL string at runtime with Apex code. Dynamic SOQL enables you to create more flexible applications. For example, you can create a search based on input from an end user, or update records with varying field names. To create a dynamic SOQL query at runtime, use the database query method, in one of the following ways: • Return a single sObject when the query returns a single record: sObject S = Database.query(string_limit_1); • Return a list of sObjects when the query returns more than a single record: List<sObject> L = Database.query(string); The database query method can be used wherever an inline SOQL query can be used, such as in regular assignment statements and for loops. The results are processed in much the same way as static SOQL queries are processed. Dynamic SOQL results can be specified as concrete sObjects, such as Account or MyCustomObject__c, or as the generic sObject data type. At runtime, the system validates that the type of the query matches the declared type of the variable. If the query does not return the correct sObject type, a runtime error is thrown. This means you do not need to cast from a generic sObject to a concrete sObject. Dynamic SOQL queries have the same governor limits as static queries. For more information on governor limits, see Understanding Execution Governors and Limits on page 225. For a full description of SOQL query syntax, see Salesforce Object Query Language (SOQL) in the Force.com SOQL and SOSL Reference. SOQL Injection SOQL injection is a technique by which a user causes your application to execute database methods you did not intend by passing SOQL statements into your code. This can occur in Apex code whenever your application relies on end user input to construct a dynamic SOQL statement and you do not handle the input properly. To prevent SOQL injection, use the escapeSingleQuotes method. This method adds the escape character () to all single quotation marks in a string that is passed in from a user. The method ensures that all single quotation marks are treated as enclosing strings, instead of database commands. Dynamic SOSL Dynamic SOSL refers to the creation of a SOSL string at runtime with Apex code. Dynamic SOSL enables you to create more flexible applications. For example, you can create a search based on input from an end user, or update records with varying field names. To create a dynamic SOSL query at runtime, use the search query method. For example: List<List <sObject>> myQuery = search.query(SOSL_search_string); 183
- 186. Dynamic Apex Dynamic DML The following example exercises a simple SOSL query string. String searchquery='FIND'Edge*'IN ALL FIELDS RETURNING Account(id,name),Contact, Lead'; List<List<SObject>>searchList=search.query(searchquery); Dynamic SOSL statements evaluate to a list of lists of sObjects, where each list contains the search results for a particular sObject type. The result lists are always returned in the same order as they were specified in the dynamic SOSL query. From the example above, the results from Account are first, then Contact, then Lead. The search query method can be used wherever an inline SOSL query can be used, such as in regular assignment statements and for loops. The results are processed in much the same way as static SOSL queries are processed. Dynamic SOSL queries have the same governor limits as static queries. For more information on governor limits, see Understanding Execution Governors and Limits on page 225. For a full description of SOSL query syntax, see Salesforce Object Search Language (SOSL) in the Force.com SOQL and SOSL Reference. SOSL Injection SOSL injection is a technique by which a user causes your application to execute database methods you did not intend by passing SOSL statements into your code. This can occur in Apex code whenever your application relies on end user input to construct a dynamic SOSL statement and you do not handle the input properly. To prevent SOSL injection, use the escapeSingleQuotes method. This method adds the escape character () to all single quotation marks in a string that is passed in from a user. The method ensures that all single quotation marks are treated as enclosing strings, instead of database commands. Dynamic DML In addition to querying describe information and building SOQL queries at runtime, you can also create sObjects dynamically, and insert them into the database using DML. To create a new sObject of a given type, use the newSObject method on an sObject token. Note that the token must be cast into a concrete sObject type (such as Account). For example: // Get a new account Account A = new Account(); // Get the token for the account Schema.sObjectType tokenA = A.getSObjectType(); // The following produces an error because the token is a generic sObject, not an Account // Account B = tokenA.newSObject(); // The following works because the token is cast back into an Account Account B = (Account)tokenA.newSObject(); Though the sObject token tokenA is a token of Account, it is considered an sObject because it is accessed separately. It must be cast back into the concrete sObject type Account to use the newSObject method. For more information on casting, see Classes and Casting on page 144. 184
- 187. Dynamic Apex Dynamic DML This is another example that shows how to obtain the sObject token through the Schema.getGlobalDescribe method and then creates a new sObject using the newSObject method on the token. This example also contains a test method that verifies the dynamic creation of an account. public class DynamicSObjectCreation { public static sObject createObject(String typeName) { Schema.SObjectType targetType = Schema.getGlobalDescribe().get(typeName); if (targetType == null) { // throw an exception } // Instantiate an sObject with the type passed in as an argument // at run time. return targetType.newSObject(); } static testmethod void testObjectCreation() { String typeName = 'Account'; String acctName = 'Acme'; // Create a new sObject by passing the sObject type as an argument. Account a = (Account)createObject(typeName); System.assertEquals(typeName, String.valueOf(a.getSobjectType())); // Set the account name and insert the account. a.Name = acctName; insert a; // Verify the new sObject got inserted. Account[] b = [SELECT Name from Account WHERE Name = :acctName]; system.assert(b.size() > 0); } } You can also specify an ID with newSObject to create an sObject that references an existing record that you can update later. For example: SObject s = Database.query('SELECT Id FROM account LIMIT 1')[0].getSObjectType(). newSObject([SELECT Id FROM Account LIMIT 1][0].Id); See Schema.sObjectType on page 366. Setting and Retrieving Field Values Use the get and put methods on an object to set or retrieve values for fields using either the API name of the field expressed as a String, or the field's token. In the following example, the API name of the field AccountNumber is used: SObject s = [SELECT AccountNumber FROM Account LIMIT 1]; Object o = s.get('AccountNumber'); s.put('AccountNumber', 'abc'); The following example uses the AccountNumber field's token instead: Schema.DescribeFieldResult f = Schema.sObjectType.Account.fields.AccountNumber; Sobject s = Database.query('SELECT AccountNumber FROM Account LIMIT 1'); s.put(f.getsObjectField(), '12345'); The Object scalar data type can be used as a generic data type to set or retrieve field values on an sObject. This is equivalent to the anyType field type. Note that the Object data type is different from the sObject data type, which can be used as a generic type for any sObject. 185
- 188. Dynamic Apex Dynamic DML Note: Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String value that is too long for the field. Setting and Retrieving Foreign Keys Apex supports populating foreign keys by name (or external ID) in the same way as the API. To set or retrieve the scalar ID value of a foreign key, use the get or put methods. To set or retrieve the record associated with a foreign key, use the getSObject and putSObject methods. Note that these methods must be used with the sObject data type, not Object. For example: SObject c = Database.query('SELECT Id, FirstName, AccountId, Account.Name FROM Contact LIMIT 1'); SObject a = c.getSObject('Account'); There is no need to specify the external ID for a parent sObject value while working with child sObjects. If you provide an ID in the parent sObject, it is ignored by the DML operation. Apex assumes the foreign key is populated through a relationship SOQL query, which always returns a parent object with a populated ID. If you have an ID, use it with the child object. For example, suppose that custom object C1 has a foreign key c2__c that links to a child custom object C2. You want to create a C1 object and have it associated with a C2 record named 'xxx' (assigned to the value c2__r). You do not need the ID of the 'xxx' record, as it is populated through the relationship of parent to child. For example: insert new C1__c(name = 'x', c2__r = new C2__c(name = 'xxx')); If you had assigned a value to the ID for c2__r, it would be ignored. If you do have the ID, assign it to the object (c2__c), not the record. You can also access foreign keys using dynamic Apex. The following example shows how to get the values from a subquery in a parent-to-child relationship using dynamic Apex: String queryString = 'SELECT Id, Name, ' + '(SELECT FirstName, LastName FROM Contacts LIMIT 1) FROM Account'; SObject[] queryParentObject = Database.query(queryString); for (SObject parentRecord : queryParentObject){ Object ParentFieldValue = parentRecord.get('Name'); // Prevent a null relationship from being accessed SObject[] childRecordsFromParent = parentRecord.getSObjects('Contacts'); if (childRecordsFromParent != null) { for (SObject childRecord : childRecordsFromParent){ Object ChildFieldValue1 = childRecord.get('FirstName'); Object ChildFieldValue2 = childRecord.get('LastName'); System.debug('Account Name: ' + ParentFieldValue + '. Contact Name: '+ ChildFieldValue1 + ' ' + ChildFieldValue2); } } } 186
- 189. Chapter 7 Batch Apex In this chapter ... A developer can now employ batch Apex to build complex, long-running processes on the Force.com platform. For example, a developer could build an archiving • Using Batch Apex solution that runs on a nightly basis, looking for records past a certain date and • Understanding Apex Managed adding them to an archive. Or a developer could build a data cleansing operation Sharing that goes through all Accounts and Opportunities on a nightly basis and updates them if necessary, based on custom criteria. Batch Apex is exposed as an interface that must be implemented by the developer. Batch jobs can be programmatically invoked at runtime using Apex. You can only have five queued or active batch jobs at one time. You can evaluate your current count by viewing the Scheduled Jobs page in Salesforce or programmatically using SOAP API to query the AsyncapexJob object. Warning: Use extreme care if you are planning to invoke a batch job from a trigger. You must be able to guarantee that the trigger will not add more batch jobs than the five that are allowed. In particular, consider API bulk updates, import wizards, mass record changes through the user interface, and all cases where more than one record can be updated at a time. Batch jobs can also be programmatically scheduled to run at specific times using the Apex scheduler, or scheduled using the Schedule Apex page in the Salesforce user interface. For more information on the Schedule Apex page, see “Scheduling Apex” in the Salesforce online help. The batch Apex interface is also used for Apex managed sharing recalculations. For more information on batch jobs, continue to Using Batch Apex on page 188. For more information on Apex managed sharing, see Understanding Apex Managed Sharing on page 197. 187
- 190. Batch Apex Using Batch Apex Using Batch Apex To use batch Apex, you must write an Apex class that implements the Salesforce-provided interface Database.Batchable, and then invoke the class programmatically. To monitor or stop the execution of the batch Apex job, click Your Name > Setup > Monitoring > Apex Jobs. For more information, see Monitoring the Apex Job Queue in the Salesforce online help. Implementing the Database.Batchable Interface The Database.Batchable interface contains three methods that must be implemented: • start method global (Database.QueryLocator | Iterable<sObject>) start(Database.BatchableContext bc) {} The start method is called at the beginning of a batch Apex job. Use the start method to collect the records or objects to be passed to the interface method execute. This method returns either a Database.QueryLocator object or an iterable that contains the records or objects being passed into the job. Use the Database.QueryLocator object when you are using a simple query (SELECT) to generate the scope of objects used in the batch job. If you use a querylocator object, the governor limit for the total number of records retrieved by SOQL queries is bypassed. For example, a batch Apex job for the Account object can return a QueryLocator for all account records (up to 50 million records) in an organization. Another example is a sharing recalculation for the Contact object that returns a QueryLocator for all account records in an organization. Use the iterable when you need to create a complex scope for the batch job. You can also use the iterable to create your own custom process for iterating through the list. Important: If you use an iterable, the governor limit for the total number of records retrieved by SOQL queries is still enforced. • execute method: global void execute(Database.BatchableContext BC, list<P>){} The execute method is called for each batch of records passed to the method. Use this method to do all required processing for each chunk of data. This method takes the following: ◊ A reference to the Database.BatchableContext object. ◊ A list of sObjects, such as List<sObject>, or a list of parameterized types. If you are using a Database.QueryLocator, the returned list should be used. Batches of records are not guaranteed to execute in the order they are received from the start method. • finish method global void finish(Database.BatchableContext BC){} The finish method is called after all batches are processed. Use this method to send confirmation emails or execute post-processing operations. 188
- 191. Batch Apex Using Batch Apex Each execution of a batch Apex job is considered a discrete transaction. For example, a batch Apex job that contains 1,000 records and is executed without the optional scope parameter from Database.executeBatch is considered five transactions of 200 records each. The Apex governor limits are reset for each transaction. If the first transaction succeeds but the second fails, the database updates made in the first transaction are not rolled back. Using Database.BatchableContext All of the methods in the Database.Batchable interface require a reference to a Database.BatchableContext object. Use this object to track the progress of the batch job. The following is the instance method with the Database.BatchableContext object: Name Arguments Returns Description getJobID ID Returns the ID of the AsyncApexJob object associated with this batch job as a string. Use this method to track the progress of records in the batch job. You can also use this ID with the System.abortJob method. The following example uses the Database.BatchableContext to query the AsyncApexJob associated with the batch job. global void finish(Database.BatchableContext BC){ // Get the ID of the AsyncApexJob representing this batch job // from Database.BatchableContext. // Query the AsyncApexJob object to retrieve the current job's information. AsyncApexJob a = [SELECT Id, Status, NumberOfErrors, JobItemsProcessed, TotalJobItems, CreatedBy.Email FROM AsyncApexJob WHERE Id = :BC.getJobId()]; // Send an email to the Apex job's submitter notifying of job completion. Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); String[] toAddresses = new String[] {a.CreatedBy.Email}; mail.setToAddresses(toAddresses); mail.setSubject('Apex Sharing Recalculation ' + a.Status); mail.setPlainTextBody ('The batch Apex job processed ' + a.TotalJobItems + ' batches with '+ a.NumberOfErrors + ' failures.'); Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); } Using Database.QueryLocator to Define Scope The start method can return either a Database.QueryLocator object that contains the records to be used in the batch job or an iterable. The following example uses a Database.QueryLocator: global class SearchAndReplace implements Database.Batchable<sObject>{ global final String Query; global final String Entity; global final String Field; global final String Value; global SearchAndReplace(String q, String e, String f, String v){ Query=q; Entity=e; Field=f;Value=v; } 189
- 192. Batch Apex Using Batch Apex global Database.QueryLocator start(Database.BatchableContext BC){ return Database.getQueryLocator(query); } global void execute(Database.BatchableContext BC, List<sObject> scope){ for(sobject s : scope){ s.put(Field,Value); } update scope; } global void finish(Database.BatchableContext BC){ } } Using an Iterable in Batch Apex to Define Scope The start method can return either a Database.QueryLocator object that contains the records to be used in the batch job, or an iterable. Use an iterable to step through the returned items more easily. global class batchClass implements Database.batchable{ global Iterable start(Database.BatchableContext info){ return new CustomAccountIterable(); } global void execute(Database.BatchableContext info, List<Account> scope){ List<Account> accsToUpdate = new List<Account>(); for(Account a : scope){ a.Name = 'true'; a.NumberOfEmployees = 70; accsToUpdate.add(a); } update accsToUpdate; } global void finish(Database.BatchableContext info){ } } Using the Database.executeBatch Method You can use the Database.executeBatch method to programmatically begin a batch job. Important: When you call Database.executeBatch, Salesforce only adds the process to the queue at the scheduled time. Actual execution may be delayed based on service availability. The Database.executeBatch method takes two parameters: • The class that implements Database.Batchable. • The Database.executeBatch method takes an optional parameter scope. This parameter specifies the number of records that should be passed into the execute method. Use this parameter when you have many operations for each record being passed in and are running into governor limits. By limiting the number of records, you are thereby limiting the operations per transaction. This value must be greater than zero. If the start method returns a QueryLocator, the optional scope parameter of Database.executeBatch can have a maximum value of 2,000. If set to a higher value, Salesforce chunks the records returned by the QueryLocator into smaller batches of up to 2,000 records. If the start method returns an iterable, the scope parameter value has no upper limit; however, if you use a very high number, you may run into other limits. 190
- 193. Batch Apex Using Batch Apex The Database.executeBatch method returns the ID of the AsyncApexJob object, which can then be used to track the progress of the job. For example: ID batchprocessid = Database.executeBatch(reassign); AsyncApexJob aaj = [SELECT Id, Status, JobItemsProcessed, TotalJobItems, NumberOfErrors FROM AsyncApexJob WHERE ID =: batchprocessid ]; For more information about the AsyncApexJob object, see AsyncApexJob in the Object Reference for Salesforce and Force.com. You can also use this ID with the System.abortJob method. Batch Apex Examples The following example uses a Database.QueryLocator: global class UpdateAccountFields implements Database.Batchable<sObject>{ global final String Query; global final String Entity; global final String Field; global final String Value; global UpdateAccountFields(String q, String e, String f, String v){ Query=q; Entity=e; Field=f;Value=v; } global Database.QueryLocator start(Database.BatchableContext BC){ return Database.getQueryLocator(query); } global void execute(Database.BatchableContext BC, List<sObject> scope){ for(Sobject s : scope){s.put(Field,Value); } update scope; } global void finish(Database.BatchableContext BC){ } } The following code can be used to call the above class: Id batchInstanceId = Database.executeBatch(new UpdateAccountFields(q,e,f,v), 5); The following class uses batch Apex to reassign all accounts owned by a specific user to a different user. global class OwnerReassignment implements Database.Batchable<sObject>{ String query; String email; Id toUserId; Id fromUserId; global Database.querylocator start(Database.BatchableContext BC){ return Database.getQueryLocator(query);} global void execute(Database.BatchableContext BC, List<sObject> scope){ List<Account> accns = new List<Account>(); for(sObject s : scope){Account a = (Account)s; 191
- 194. Batch Apex Using Batch Apex if(a.OwnerId==fromUserId){ a.OwnerId=toUserId; accns.add(a); } } update accns; } global void finish(Database.BatchableContext BC){ Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); mail.setToAddresses(new String[] {email}); mail.setReplyTo('batch@acme.com'); mail.setSenderDisplayName('Batch Processing'); mail.setSubject('Batch Process Completed'); mail.setPlainTextBody('Batch Process has completed'); Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); } } Use the following to execute the OwnerReassignment class in the previous example: OwnerReassignment reassign = new OwnerReassignment(); reassign.query = 'SELECT Id, Name, Ownerid FROM Account ' + 'WHERE ownerid='' + u.id + '''; reassign.email='admin@acme.com'; reassign.fromUserId = u; reassign.toUserId = u2; ID batchprocessid = Database.executeBatch(reassign); The following is an example of a batch Apex class for deleting records. global class BatchDelete implements Database.Batchable<sObject> { public String query; global Database.QueryLocator start(Database.BatchableContext BC){ return Database.getQueryLocator(query); } global void execute(Database.BatchableContext BC, List<sObject> scope){ delete scope; DataBase.emptyRecycleBin(scope); } global void finish(Database.BatchableContext BC){ } } This code calls the BatchDelete batch Apex class to delete old documents. The specified query selects documents to delete for all documents that are in a specified folder and that are older than a specified date. Next, the sample invokes the batch job. BatchDelete BDel = new BatchDelete(); Datetime d = Datetime.now(); d = d.addDays(-1); // Replace this value with the folder ID that contains // the documents to delete. String folderId = '00lD000000116lD'; // Query for selecting the documents to delete BDel.query = 'SELECT Id FROM Document WHERE FolderId='' + folderId + '' AND CreatedDate < '+d.format('yyyy-MM-dd')+'T'+ d.format('HH:mm')+':00.000Z'; 192
- 195. Batch Apex Using Batch Apex // Invoke the batch job. ID batchprocessid = Database.executeBatch(BDel); System.debug('Returned batch process ID: ' + batchProcessId); Using Callouts in Batch Apex To use a callout in batch Apex, you must specify Database.AllowsCallouts in the class definition. For example: global class SearchAndReplace implements Database.Batchable<sObject>, Database.AllowsCallouts{ } Callouts include HTTP requests as well as methods defined with the webService keyword. Using State in Batch Apex Each execution of a batch Apex job is considered a discrete transaction. For example, a batch Apex job that contains 1,000 records and is executed without the optional scope parameter is considered five transactions of 200 records each. If you specify Database.Stateful in the class definition, you can maintain state across these transactions. When using Database.Stateful, only instance member variables retain their values between transactions. Static member variables don’t and are reset between transactions. Maintaining state is useful for counting or summarizing records as they're processed. For example, suppose your job processed opportunity records. You could define a method in execute to aggregate totals of the opportunity amounts as they were processed. If you don't specify Database.Stateful, all static and instance member variables are set back to their original values. The following example summarizes a custom field total__c as the records are processed: global class SummarizeAccountTotal implements Database.Batchable<sObject>, Database.Stateful{ global final String Query; global integer Summary; global SummarizeAccountTotal(String q){Query=q; Summary = 0; } global Database.QueryLocator start(Database.BatchableContext BC){ return Database.getQueryLocator(query); } global void execute( Database.BatchableContext BC, List<sObject> scope){ for(sObject s : scope){ Summary = Integer.valueOf(s.get('total__c'))+Summary; } } global void finish(Database.BatchableContext BC){ } } In addition, you can specify a variable to access the initial state of the class. You can use this variable to share the initial state with all instances of the Database.Batchable methods. For example: // Implement the interface using a list of Account sObjects // Note that the initialState variable is declared as final 193
- 196. Batch Apex Using Batch Apex global class MyBatchable implements Database.Batchable<sObject> { private final String initialState; String query; global MyBatchable(String intialState) { this.initialState = initialState; } global Database.QueryLocator start(Database.BatchableContext BC) { // Access initialState here return Database.getQueryLocator(query); } global void execute(Database.BatchableContext BC, List<sObject> batch) { // Access initialState here } global void finish(Database.BatchableContext BC) { // Access initialState here } } Note that initialState is the initial state of the class. You cannot use it to pass information between instances of the class during execution of the batch job. For example, if you changed the value of initialState in execute, the second chunk of processed records would not be able to access the new value: only the initial value would be accessible. Testing Batch Apex When testing your batch Apex, you can test only one execution of the execute method. You can use the scope parameter of the executeBatch method to limit the number of records passed into the execute method to ensure that you aren't running into governor limits. The executeBatch method starts an asynchronous process. This means that when you test batch Apex, you must make certain that the batch job is finished before testing against the results. Use the Test methods startTest and stopTest around the executeBatch method to ensure it finishes before continuing your test. All asynchronous calls made after the startTest method are collected by the system. When stopTest is executed, all asynchronous processes are run synchronously. If you don’t include the executeBatch method within the startTest and stopTest methods, the batch job executes at the end of your test method for Apex saved using Salesforce.com API version 25.0 and later, but not in earlier versions. Starting with Apex saved using Salesforce.com API version 22.0, exceptions that occur during the execution of a batch Apex job that is invoked by a test method are now passed to the calling test method, and as a result, causes the test method to fail. If you want to handle exceptions in the test method, enclose the code in try and catch statements. You must place the catch block after the stopTest method. Note however that with Apex saved using Salesforce.com API version 21.0 and earlier, such exceptions don't get passed to the test method and don't cause test methods to fail. Note: Asynchronous calls, such as @future or executeBatch, called in a startTest, stopTest block, do not count against your limits for the number of queued jobs. The example below tests the OwnerReassignment class. public static testMethod void testBatch() { user u = [SELECT ID, UserName FROM User WHERE username='testuser1@acme.com']; user u2 = [SELECT ID, UserName FROM User WHERE username='testuser2@acme.com']; String u2id = u2.id; 194
- 197. Batch Apex Using Batch Apex // Create 200 test accounts - this simulates one execute. // Important - the Salesforce.com test framework only allows you to // test one execute. List <Account> accns = new List<Account>(); for(integer i = 0; i<200; i++){ Account a = new Account(Name='testAccount'+'i', Ownerid = u.ID); accns.add(a); } insert accns; Test.StartTest(); OwnerReassignment reassign = new OwnerReassignment(); reassign.query='SELECT ID, Name, Ownerid ' + 'FROM Account ' + 'WHERE OwnerId='' + u.Id + ''' + ' LIMIT 200'; reassign.email='admin@acme.com'; reassign.fromUserId = u.Id; reassign.toUserId = u2.Id; ID batchprocessid = Database.executeBatch(reassign); Test.StopTest(); System.AssertEquals( database.countquery('SELECT COUNT()' +' FROM Account WHERE OwnerId='' + u2.Id + '''), 200); } } Batch Apex Governor Limits Keep in mind the following governor limits for batch Apex: • Up to five queued or active batch jobs are allowed for Apex. • A user can have up to 50 query cursors open at a time. For example, if 50 cursors are open and a client application still logged in as the same user attempts to open a new one, the oldest of the 50 cursors is released. Note that this limit is different for the batch Apex start method, which can have up to five query cursors open at a time per user. The other batch Apex methods have the higher limit of 50 cursors. Cursor limits for different Force.com features are tracked separately. For example, you can have 50 Apex query cursors, 50 batch cursors, and 50 Visualforce cursors open at the same time. • A maximum of 50 million records can be returned in the Database.QueryLocator object. If more than 50 million records are returned, the batch job is immediately terminated and marked as Failed. • If the start method returns a QueryLocator, the optional scope parameter of Database.executeBatch can have a maximum value of 2,000. If set to a higher value, Salesforce chunks the records returned by the QueryLocator into smaller batches of up to 2,000 records. If the start method returns an iterable, the scope parameter value has no upper limit; however, if you use a very high number, you may run into other limits. • If no size is specified with the optional scope parameter of Database.executeBatch, Salesforce chunks the records returned by the start method into batches of 200, and then passes each batch to the execute method. Apex governor limits are reset for each execution of execute. • The start, execute, and finish methods can implement up to 10 callouts each. • Batch executions are limited to 10 callouts per method execution. • The maximum number of batch executions is 250,000 per 24 hours. 195
- 198. Batch Apex Using Batch Apex • Only one batch Apex job's start method can run at a time in an organization. Batch jobs that haven’t started yet remain in the queue until they're started. Note that this limit doesn’t cause any batch job to fail and execute methods of batch Apex jobs still run in parallel if more than one job is running. Batch Apex Best Practices • Use extreme care if you are planning to invoke a batch job from a trigger. You must be able to guarantee that the trigger will not add more batch jobs than the five that are allowed. In particular, consider API bulk updates, import wizards, mass record changes through the user interface, and all cases where more than one record can be updated at a time. • When you call Database.executeBatch, Salesforce only places the job in the queue at the scheduled time. Actual execution may be delayed based on service availability. • When testing your batch Apex, you can test only one execution of the execute method. You can use the scope parameter of the executeBatch method to limit the number of records passed into the execute method to ensure that you aren't running into governor limits. • The executeBatch method starts an asynchronous process. This means that when you test batch Apex, you must make certain that the batch job is finished before testing against the results. Use the Test methods startTest and stopTest around the executeBatch method to ensure it finishes before continuing your test. • Use Database.Stateful with the class definition if you want to share instance member variables or data across job transactions. Otherwise, all member variables are reset to their initial state at the start of each transaction. • Methods declared as future aren't allowed in classes that implement the Database.Batchable interface. • Methods declared as future can't be called from a batch Apex class. • For a batch Apex class saved using Salesforce.com API version 25.0 and earlier, you cannot call the Database.executeBatch method from within any batch Apex method. Starting with Apex saved using Salesforce.com API version 26.0, you can call Database.executeBatch from the finish method only. The version used is the version of the running batch class that starts another batch job. If the finish method in the running batch class calls a method in a helper class to start the batch job, the Salesforce.com API version of the helper class doesn’t matter. • You cannot use the getContent and getContentAsPDF PageReference methods in a batch job. • In the event of a catastrophic failure such as a service outage, any operations in progress are marked as Failed. You should run the batch job again to correct any errors. • When a batch Apex job is run, email notifications are sent either to the user who submitted the batch job, or, if the code is included in a managed package and the subscribing organization is running the batch job, the email is sent to the recipient listed in the Apex Exception Notification Recipient field. • Each method execution uses the standard governor limits anonymous block, Visualforce controller, or WSDL method. • Each batch Apex invocation creates an AsyncApexJob record. Use the ID of this record to construct a SOQL query to retrieve the job’s status, number of errors, progress, and submitter. For more information about the AsyncApexJob object, see AsyncApexJob in the Object Reference for Salesforce and Force.com. • For each 10,000 AsyncApexJob records, Apex creates one additional AsyncApexJob record of type BatchApexWorker for internal use. When querying for all AsyncApexJob records, we recommend that you filter out records of type BatchApexWorker using the JobType field. Otherwise, the query will return one more record for every 10,000 AsyncApexJob records. For more information about the AsyncApexJob object, see AsyncApexJob in the Object Reference for Salesforce and Force.com. • All methods in the class must be defined as global or public. • For a sharing recalculation, we recommend that the execute method delete and then re-create all Apex managed sharing for the records in the batch. This ensures the sharing is accurate and complete. See Also: Exception Statements Understanding Execution Governors and Limits Understanding Sharing 196
- 199. Batch Apex Understanding Apex Managed Sharing Understanding Apex Managed Sharing Sharing is the act of granting a user or group of users permission to perform a set of actions on a record or set of records. Sharing access can be granted using the Salesforce user interface and Force.com, or programmatically using Apex. This section provides an overview of sharing using Apex: • Understanding Sharing • Sharing a Record Using Apex • Recalculating Apex Managed Sharing For more information on sharing, see “Setting Your Organization-Wide Sharing Defaults” in the Salesforce online help. Understanding Sharing Sharing enables record-level access control for all custom objects, as well as many standard objects (such as Account, Contact, Opportunity and Case). Administrators first set an object’s organization-wide default sharing access level, and then grant additional access based on record ownership, the role hierarchy, sharing rules, and manual sharing. Developers can then use Apex managed sharing to grant additional access programmatically with Apex. Most sharing for a record is maintained in a related sharing object, similar to an access control list (ACL) found in other platforms. Types of Sharing Salesforce has the following types of sharing: Force.com Managed Sharing Force.com managed sharing involves sharing access granted by Force.com based on record ownership, the role hierarchy, and sharing rules: Record Ownership Each record is owned by a user or optionally a queue for custom objects, cases and leads. The record owner is automatically granted Full Access, allowing them to view, edit, transfer, share, and delete the record. Role Hierarchy The role hierarchy enables users above another user in the hierarchy to have the same level of access to records owned by or shared with users below. Consequently, users above a record owner in the role hierarchy are also implicitly granted Full Access to the record, though this behavior can be disabled for specific custom objects. The role hierarchy is not maintained with sharing records. Instead, role hierarchy access is derived at runtime. For more information, see “Controlling Access Using Hierarchies” in the Salesforce online help. Sharing Rules Sharing rules are used by administrators to automatically grant users within a given group or role access to records owned by a specific group of users. Sharing rules cannot be added to a package and cannot be used to support sharing logic for apps installed from Force.com AppExchange. Sharing rules can be based on record ownership or other criteria. You can't use Apex to create criteria-based sharing rules. Also, criteria-based sharing cannot be tested using Apex. All implicit sharing added by Force.com managed sharing cannot be altered directly using the Salesforce user interface, SOAP API, or Apex. 197
- 200. Batch Apex Understanding Sharing User Managed Sharing, also known as Manual Sharing User managed sharing allows the record owner or any user with Full Access to a record to share the record with a user or group of users. This is generally done by an end-user, for a single record. Only the record owner and users above the owner in the role hierarchy are granted Full Access to the record. It is not possible to grant other users Full Access. Users with the “Modify All” object-level permission for the given object or the “Modify All Data” permission can also manually share a record. User managed sharing is removed when the record owner changes or when the access granted in the sharing does not grant additional access beyond the object's organization-wide sharing default access level. Apex Managed Sharing Apex managed sharing provides developers with the ability to support an application’s particular sharing requirements programmatically through Apex or the SOAP API. This type of sharing is similar to Force.com managed sharing. Only users with “Modify All Data” permission can add or change Apex managed sharing on a record. Apex managed sharing is maintained across record owner changes. Note: Apex sharing reasons and Apex managed sharing recalculation are only available for custom objects. The Sharing Reason Field In the Salesforce user interface, the Reason field on a custom object specifies the type of sharing used for a record. This field is called rowCause in Apex or the Force.com API. Each of the following list items is a type of sharing used for records. The tables show Reason field value, and the related rowCause value. • Force.com Managed Sharing Reason Field Value rowCause Value (Used in Apex or the Force.com API) Account Sharing ImplicitChild Associated record owner or sharing ImplicitParent Owner Owner Opportunity Team Team Sharing Rule Rule Territory Assignment Rule TerritoryRule • User Managed Sharing Reason Field Value rowCause Value (Used in Apex or the Force.com API) Manual Sharing Manual Territory Manual TerritoryManual • Apex Managed Sharing 198
- 201. Batch Apex Sharing a Record Using Apex Reason Field Value rowCause Value (Used in Apex or the Force.com API) Defined by developer Defined by developer The displayed reason for Apex managed sharing is defined by the developer. Access Levels When determining a user’s access to a record, the most permissive level of access is used. Most share objects support the following access levels: Access Level API Name Description Private None Only the record owner and users above the record owner in the role hierarchy can view and edit the record. This access level only applies to the AccountShare object. Read Only Read The specified user or group can view the record only. Read/Write Edit The specified user or group can view and edit the record. Full Access All The specified user or group can view, edit, transfer, share, and delete the record. Note: This access level can only be granted with Force.com managed sharing. Sharing a Record Using Apex To access sharing programmatically, you must use the share object associated with the standard or custom object for which you want to share. For example, AccountShare is the sharing object for the Account object, ContactShare is the sharing object for the Contact object, and so on. In addition, all custom object sharing objects are named as follows, where MyCustomObject is the name of the custom object: MyCustomObject__Share Objects on the detail side of a master-detail relationship do not have an associated sharing object. The detail record’s access is determined by the master’s sharing object and the relationship’s sharing setting. For more information, see “Custom Object Security” in the Salesforce online help. A share object includes records supporting all three types of sharing: Force.com managed sharing, user managed sharing, and Apex managed sharing. Sharing granted to users implicitly through organization-wide defaults, the role hierarchy, and permissions such as the “View All” and “Modify All” permissions for the given object, “View All Data,” and “Modify All Data” are not tracked with this object. Every share object has the following properties: 199
- 202. Batch Apex Sharing a Record Using Apex Property Name Description objectNameAccessLevel The level of access that the specified user or group has been granted for a share sObject. The name of the property is AccessLevel appended to the object name. For example, the property name for LeadShare object is LeadShareAccessLevel. Valid values are: • Edit • Read • All Note: The All access level can only be used by Force.com managed sharing. This field must be set to an access level that is higher than the organization’s default access level for the parent object. For more information, see Access Levels on page 199. ParentID The ID of the object. This field cannot be updated. RowCause The reason why the user or group is being granted access. The reason determines the type of sharing, which controls who can alter the sharing record. This field cannot be updated. UserOrGroupId The user or group IDs to which you are granting access. A group can be a public group, role, or territory. This field cannot be updated. You can share a standard or custom object with users or groups. For more information about the types of users and groups you can share an object with, see User and Group in the Object Reference for Salesforce and Force.com. Creating User Managed Sharing Using Apex It is possible to manually share a record to a user or a group using Apex or the SOAP API. If the owner of the record changes, the sharing is automatically deleted. The following example class contains a method that shares the job specified by the job ID with the specified user or group ID with read access. It also includes a test method that validates this method. Before you save this example class, create a custom object called Job. public class JobSharing { static boolean manualShareRead(Id recordId, Id userOrGroupId){ // Create new sharing object for the custom object Job. Job__Share jobShr = new Job__Share(); // Set the ID of record being shared. jobShr.ParentId = recordId; // Set the ID of user or group being granted access. jobShr.UserOrGroupId = userOrGroupId; // Set the access level. jobShr.AccessLevel = 'Read'; // Set rowCause to 'manual' for manual sharing. // This line can be omitted as 'manual' is the default value for sharing objects. jobShr.RowCause = Schema.Job__Share.RowCause.Manual; // Insert the sharing record and capture the save result. // The false parameter allows for partial processing if multiple records passed // into the operation. Database.SaveResult sr = Database.insert(jobShr,false); 200
- 203. Batch Apex Sharing a Record Using Apex // Process the save results. if(sr.isSuccess()){ // Indicates success return true; } else { // Get first save result error. Database.Error err = sr.getErrors()[0]; // Check if the error is related to trival access level. // Access levels equal or more permissive than the object's default // access level are not allowed. // These sharing records are not required and thus an insert exception is acceptable. if(err.getStatusCode() == StatusCode.FIELD_FILTER_VALIDATION_EXCEPTION && err.getMessage().contains('AccessLevel')){ // Indicates success. return true; } else{ // Indicates failure. return false; } } } // Test for the manualShareRead method static testMethod void testManualShareRead(){ // Select users for the test. List<User> users = [SELECT Id FROM User WHERE IsActive = true LIMIT 2]; Id User1Id = users[0].Id; Id User2Id = users[1].Id; // Create new job. Job__c j = new Job__c(); j.Name = 'Test Job'; j.OwnerId = user1Id; insert j; // Insert manual share for user who is not record owner. System.assertEquals(manualShareRead(j.Id, user2Id), true); // Query job sharing records. List<Job__Share> jShrs = [SELECT Id, UserOrGroupId, AccessLevel, RowCause FROM job__share WHERE ParentId = :j.Id AND UserOrGroupId= :user2Id]; // Test for only one manual share on job. System.assertEquals(jShrs.size(), 1, 'Set the object's sharing model to Private.'); // Test attributes of manual share. System.assertEquals(jShrs[0].AccessLevel, 'Read'); System.assertEquals(jShrs[0].RowCause, 'Manual'); System.assertEquals(jShrs[0].UserOrGroupId, user2Id); // Test invalid job Id. delete j; // Insert manual share for deleted job id. System.assertEquals(manualShareRead(j.Id, user2Id), false); } } 201
- 204. Batch Apex Sharing a Record Using Apex Important: The object’s organization-wide default access level must not be set to the most permissive access level. For custom objects, this is Public Read/Write. For more information, see Access Levels on page 199. Creating Apex Managed Sharing Apex managed sharing enables developers to programmatically manipulate sharing to support their application’s behavior through Apex or the SOAP API. This type of sharing is similar to Force.com managed sharing. Only users with “Modify All Data” permission can add or change Apex managed sharing on a record. Apex managed sharing is maintained across record owner changes. Apex managed sharing must use an Apex sharing reason. Apex sharing reasons are a way for developers to track why they shared a record with a user or group of users. Using multiple Apex sharing reasons simplifies the coding required to make updates and deletions of sharing records. They also enable developers to share with the same user or group multiple times using different reasons. Apex sharing reasons are defined on an object's detail page. Each Apex sharing reason has a label and a name: • The label displays in the Reason column when viewing the sharing for a record in the user interface. This allows users and administrators to understand the source of the sharing. The label is also enabled for translation through the Translation Workbench. • The name is used when referencing the reason in the API and Apex. All Apex sharing reason names have the following format: MyReasonName__c Apex sharing reasons can be referenced programmatically as follows: Schema.CustomObject__Share.rowCause.SharingReason__c For example, an Apex sharing reason called Recruiter for an object called Job can be referenced as follows: Schema.Job__Share.rowCause.Recruiter__c For more information, see Schema Methods on page 348. To create an Apex sharing reason: 1. Click Your Name > Setup > Create > Objects. 2. Select the custom object. 3. Click New in the Apex Sharing Reasons related list. 4. Enter a label for the Apex sharing reason. The label displays in the Reason column when viewing the sharing for a record in the user interface. The label is also enabled for translation through the Translation Workbench. 5. Enter a name for the Apex sharing reason. The name is used when referencing the reason in the API and Apex. This name can contain only underscores and alphanumeric characters, and must be unique in your organization. It must begin with a letter, not include spaces, not end with an underscore, and not contain two consecutive underscores. 6. Click Save. Note: Apex sharing reasons and Apex managed sharing recalculation are only available for custom objects. 202
- 205. Batch Apex Sharing a Record Using Apex Apex Managed Sharing Example For this example, suppose you are building a recruiting application and have an object called Job. You want to validate that the recruiter and hiring manager listed on the job have access to the record. The following trigger grants the recruiter and hiring manager access when the job record is created. This example requires a custom object called Job, with two lookup fields associated with User records called Hiring_Manager and Recruiter. Also, the Job custom object should have two sharing reasons added called Hiring_Manager and Recruiter. trigger JobApexSharing on Job__c (after insert) { if(trigger.isInsert){ // Create a new list of sharing objects for Job List<Job__Share> jobShrs = new List<Job__Share>(); // Declare variables for recruiting and hiring manager sharing Job__Share recruiterShr; Job__Share hmShr; for(Job__c job : trigger.new){ // Instantiate the sharing objects recruiterShr = new Job__Share(); hmShr = new Job__Share(); // Set the ID of record being shared recruiterShr.ParentId = job.Id; hmShr.ParentId = job.Id; // Set the ID of user or group being granted access recruiterShr.UserOrGroupId = job.Recruiter__c; hmShr.UserOrGroupId = job.Hiring_Manager__c; // Set the access level recruiterShr.AccessLevel = 'edit'; hmShr.AccessLevel = 'read'; // Set the Apex sharing reason for hiring manager and recruiter recruiterShr.RowCause = Schema.Job__Share.RowCause.Recruiter__c; hmShr.RowCause = Schema.Job__Share.RowCause.Hiring_Manager__c; // Add objects to list for insert jobShrs.add(recruiterShr); jobShrs.add(hmShr); } // Insert sharing records and capture save result // The false parameter allows for partial processing if multiple records are passed // into the operation Database.SaveResult[] lsr = Database.insert(jobShrs,false); // Create counter Integer i=0; // Process the save results for(Database.SaveResult sr : lsr){ if(!sr.isSuccess()){ // Get the first save result error Database.Error err = sr.getErrors()[0]; // Check if the error is related to a trivial access level // Access levels equal or more permissive than the object's default // access level are not allowed. // These sharing records are not required and thus an insert exception is // acceptable. if(!(err.getStatusCode() == StatusCode.FIELD_FILTER_VALIDATION_EXCEPTION 203
- 206. Batch Apex Recalculating Apex Managed Sharing && err.getMessage().contains('AccessLevel'))){ // Throw an error when the error is not related to trivial access level. trigger.newMap.get(jobShrs[i].ParentId). addError( 'Unable to grant sharing access due to following exception: ' + err.getMessage()); } } i++; } } } Under certain circumstances, inserting a share row results in an update of an existing share row. Consider these examples: • If a manual share access level is set to Read and you insert a new one that’s set to Write, the original share rows are updated to Write, indicating the higher level of access. • If users can access an account because they can access its child records (contact, case, opportunity, and so on), and an account sharing rule is created, the row cause of the parent implicit share is replaced by the sharing rule row cause, indicating the higher level of access. Important: The object’s organization-wide default access level must not be set to the most permissive access level. For custom objects, this is Public Read/Write. For more information, see Access Levels on page 199. Recalculating Apex Managed Sharing Salesforce automatically recalculates sharing for all records on an object when its organization-wide sharing default access level changes. The recalculation adds Force.com managed sharing when appropriate. In addition, all types of sharing are removed if the access they grant is considered redundant. For example, manual sharing, which grants Read Only access to a user, is deleted when the object’s sharing model changes from Private to Public Read Only. To recalculate Apex managed sharing, you must write an Apex class that implements a Salesforce-provided interface to do the recalculation. You must then associate the class with the custom object, on the custom object's detail page, in the Apex Sharing Recalculation related list. Note: Apex sharing reasons and Apex managed sharing recalculation are only available for custom objects. You can execute this class from the custom object detail page where the Apex sharing reason is specified. An administrator might need to recalculate the Apex managed sharing for an object if a locking issue prevented Apex code from granting access to a user as defined by the application’s logic. You can also use the Database.executeBatch method to programmatically invoke an Apex managed sharing recalculation. Note: Every time a custom object's organization-wide sharing default access level is updated, any Apex recalculation classes defined for associated custom object are also executed. To monitor or stop the execution of the Apex recalculation, click Your Name > Setup > Monitoring > Apex Jobs. For more information, see “Monitoring the Apex Job Queue” in the Salesforce online help. 204
- 207. Batch Apex Recalculating Apex Managed Sharing Creating an Apex Class for Recalculating Sharing To recalculate Apex managed sharing, you must write an Apex class to do the recalculation. This class must implement the Salesforce-provided interface Database.Batchable. The Database.Batchable interface is used for all batch Apex processes, including recalculating Apex managed sharing. You can implement this interface more than once in your organization. For more information on the methods that must be implemented, see Using Batch Apex on page 188. Before creating an Apex managed sharing recalculation class, also consider the best practices. Important: The object’s organization-wide default access level must not be set to the most permissive access level. For custom objects, this is Public Read/Write. For more information, see Access Levels on page 199. Apex Managed Sharing Recalculation Example For this example, suppose you are building a recruiting application and have an object called Job. You want to validate that the recruiter and hiring manager listed on the job have access to the record. The following Apex class performs this validation. This example requires a custom object called Job, with two lookup fields associated with User records called Hiring_Manager and Recruiter. Also, the Job custom object should have two sharing reasons added called Hiring_Manager and Recruiter. Before you run this sample, replace the email address with a valid email address that you want to to send error notifications and job completion notifications to. global class JobSharingRecalc implements Database.Batchable<sObject> { // String to hold email address that emails will be sent to. // Replace its value with a valid email address. static String emailAddress = 'admin@yourcompany.com'; // The start method is called at the beginning of a sharing recalculation. // This method returns a SOQL query locator containing the records // to be recalculated. global Database.QueryLocator start(Database.BatchableContext BC){ return Database.getQueryLocator([SELECT Id, Hiring_Manager__c, Recruiter__c FROM Job__c]); } // The executeBatch method is called for each chunk of records returned from start. global void execute(Database.BatchableContext BC, List<sObject> scope){ // Create a map for the chunk of records passed into method. Map<ID, Job__c> jobMap = new Map<ID, Job__c>((List<Job__c>)scope); // Create a list of Job__Share objects to be inserted. List<Job__Share> newJobShrs = new List<Job__Share>(); // Locate all existing sharing records for the Job records in the batch. // Only records using an Apex sharing reason for this app should be returned. List<Job__Share> oldJobShrs = [SELECT Id FROM Job__Share WHERE Id IN :jobMap.keySet() AND (RowCause = :Schema.Job__Share.rowCause.Recruiter__c OR RowCause = :Schema.Job__Share.rowCause.Hiring_Manager__c)]; // Construct new sharing records for the hiring manager and recruiter // on each Job record. for(Job__c job : jobMap.values()){ Job__Share jobHMShr = new Job__Share(); Job__Share jobRecShr = new Job__Share(); // Set the ID of user (hiring manager) on the Job record being granted access. jobHMShr.UserOrGroupId = job.Hiring_Manager__c; // The hiring manager on the job should always have 'Read Only' access. 205
- 208. Batch Apex Recalculating Apex Managed Sharing jobHMShr.AccessLevel = 'Read'; // The ID of the record being shared jobHMShr.ParentId = job.Id; // Set the rowCause to the Apex sharing reason for hiring manager. // This establishes the sharing record as Apex managed sharing. jobHMShr.RowCause = Schema.Job__Share.RowCause.Hiring_Manager__c; // Add sharing record to list for insertion. newJobShrs.add(jobHMShr); // Set the ID of user (recruiter) on the Job record being granted access. jobRecShr.UserOrGroupId = job.Recruiter__c; // The recruiter on the job should always have 'Read/Write' access. jobRecShr.AccessLevel = 'Edit'; // The ID of the record being shared jobRecShr.ParentId = job.Id; // Set the rowCause to the Apex sharing reason for recruiter. // This establishes the sharing record as Apex managed sharing. jobRecShr.RowCause = Schema.Job__Share.RowCause.Recruiter__c; // Add the sharing record to the list for insertion. newJobShrs.add(jobRecShr); } try { // Delete the existing sharing records. // This allows new sharing records to be written from scratch. Delete oldJobShrs; // Insert the new sharing records and capture the save result. // The false parameter allows for partial processing if multiple records are // passed into operation. Database.SaveResult[] lsr = Database.insert(newJobShrs,false); // Process the save results for insert. for(Database.SaveResult sr : lsr){ if(!sr.isSuccess()){ // Get the first save result error. Database.Error err = sr.getErrors()[0]; // Check if the error is related to trivial access level. // Access levels equal or more permissive than the object's default // access level are not allowed. // These sharing records are not required and thus an insert exception // is acceptable. if(!(err.getStatusCode() == StatusCode.FIELD_FILTER_VALIDATION_EXCEPTION && err.getMessage().contains('AccessLevel'))){ // Error is not related to trivial access level. // Send an email to the Apex job's submitter. Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); String[] toAddresses = new String[] {emailAddress}; mail.setToAddresses(toAddresses); mail.setSubject('Apex Sharing Recalculation Exception'); mail.setPlainTextBody( 'The Apex sharing recalculation threw the following exception: ' + err.getMessage()); Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); } } } 206
- 209. Batch Apex Recalculating Apex Managed Sharing } catch(DmlException e) { // Send an email to the Apex job's submitter on failure. Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); String[] toAddresses = new String[] {emailAddress}; mail.setToAddresses(toAddresses); mail.setSubject('Apex Sharing Recalculation Exception'); mail.setPlainTextBody( 'The Apex sharing recalculation threw the following exception: ' + e.getMessage()); Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); } } // The finish method is called at the end of a sharing recalculation. global void finish(Database.BatchableContext BC){ // Send an email to the Apex job's submitter notifying of job completion. Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); String[] toAddresses = new String[] {emailAddress}; mail.setToAddresses(toAddresses); mail.setSubject('Apex Sharing Recalculation Completed.'); mail.setPlainTextBody ('The Apex sharing recalculation finished processing'); Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); } } Testing Apex Managed Sharing Recalculations This example inserts five Job records and invokes the batch job that is implemented in the batch class of the previous example. This example requires a custom object called Job, with two lookup fields associated with User records called Hiring_Manager and Recruiter. Also, the Job custom object should have two sharing reasons added called Hiring_Manager and Recruiter. Before you run this test, set the organization-wide default sharing for Job to Private. Note that since email messages aren’t sent from tests, and because the batch class is invoked by a test method, the email notifications won’t be sent in this case. @isTest private class JobSharingTester { // Test for the JobSharingRecalc class static testMethod void testApexSharing(){ // Instantiate the class implementing the Database.Batchable interface. JobSharingRecalc recalc = new JobSharingRecalc(); // Select users for the test. List<User> users = [SELECT Id FROM User WHERE IsActive = true LIMIT 2]; ID User1Id = users[0].Id; ID User2Id = users[1].Id; // Insert some test job records. List<Job__c> testJobs = new List<Job__c>(); for (Integer i=0;i<5;i++) { Job__c j = new Job__c(); j.Name = 'Test Job ' + i; j.Recruiter__c = User1Id; j.Hiring_Manager__c = User2Id; testJobs.add(j); } insert testJobs; Test.startTest(); // Invoke the Batch class. String jobId = Database.executeBatch(recalc); Test.stopTest(); 207
- 210. Batch Apex Recalculating Apex Managed Sharing // Get the Apex job and verify there are no errors. AsyncApexJob aaj = [Select JobType, TotalJobItems, JobItemsProcessed, Status, CompletedDate, CreatedDate, NumberOfErrors from AsyncApexJob where Id = :jobId]; System.assertEquals(0, aaj.NumberOfErrors); // This query returns jobs and related sharing records that were inserted // by the batch job's execute method. List<Job__c> jobs = [SELECT Id, Hiring_Manager__c, Recruiter__c, (SELECT Id, ParentId, UserOrGroupId, AccessLevel, RowCause FROM Shares WHERE (RowCause = :Schema.Job__Share.rowCause.Recruiter__c OR RowCause = :Schema.Job__Share.rowCause.Hiring_Manager__c)) FROM Job__c]; // Validate that Apex managed sharing exists on jobs. for(Job__c job : jobs){ // Two Apex managed sharing records should exist for each job // when using the Private org-wide default. System.assert(job.Shares.size() == 2); for(Job__Share jobShr : job.Shares){ // Test the sharing record for hiring manager on job. if(jobShr.RowCause == Schema.Job__Share.RowCause.Hiring_Manager__c){ System.assertEquals(jobShr.UserOrGroupId,job.Hiring_Manager__c); System.assertEquals(jobShr.AccessLevel,'Read'); } // Test the sharing record for recruiter on job. else if(jobShr.RowCause == Schema.Job__Share.RowCause.Recruiter__c){ System.assertEquals(jobShr.UserOrGroupId,job.Recruiter__c); System.assertEquals(jobShr.AccessLevel,'Edit'); } } } } } Associating an Apex Class Used for Recalculation An Apex class used for recalculation must be associated with a custom object. To associate an Apex managed sharing recalculation class with a custom object: 1. Click Your Name > Setup > Create > Objects. 2. Select the custom object. 3. Click New in the Apex Sharing Recalculations related list. 4. Choose the Apex class that recalculates the Apex sharing for this object. The class you choose must implement the Database.Batchable interface. You cannot associate the same Apex class multiple times with the same custom object. 5. Click Save. 208
- 211. Chapter 8 Debugging Apex In this chapter ... Apex provides debugging support. You can debug your Apex code using the Developer Console and debug logs. To further aid debugging, Apex sends emails • Understanding the Debug Log to developers for unhandled exceptions. Furthermore, Apex enforces a certain • Handling Uncaught Exceptions set of governor limits for your running code to ensure shared resources aren’t • Understanding Execution Governors monopolized in a multi-tenant environment. Last but not least, you can select and Limits to have emails sent to end-users who are running code that surpasses a certain • Using Governor Limit Email percentage of any governor limit. Warnings This chapter covers the following: • Understanding the Debug Log • Handling Uncaught Exceptions • Understanding Execution Governors and Limits • Using Governor Limit Email Warnings 209
- 212. Debugging Apex Understanding the Debug Log Understanding the Debug Log A debug log records database operations, system processes, and errors that occur when executing a transaction or while running unit tests. The system generates a debug log for a user every time that user executes a transaction that is included in the filter criteria. You can retain and manage the debug logs for specific users. To view saved debug logs, click Your Name > Setup > Monitoring > Debug Logs. The following are the limits for debug logs: • Once a user is added, that user can record up to 20 debug logs. After a user reaches this limit, debug logs stop being recorded for that user. Click Reset on the Monitoring Debug logs page to reset the number of logs for that user back to 20. Any existing logs are not overwritten. • Each debug log can only be 2 MB. Debug logs that are larger than 2 MB in size are truncated. • Each organization can retain up to 50 MB of debug logs. Once your organization has reached 50 MB of debug logs, the oldest debug logs start being overwritten. Inspecting the Debug Log Sections After you generate a debug log, the type and amount of information listed depends on the filter values you set for the user. However, the format for a debug log is always the same. A debug log has the following sections: Header The header contains the following information: • The version of the API used during the transaction. • The log category and level used to generate the log. For example: The following is an example of a header: 25.0 APEX_CODE,DEBUG;APEX_PROFILING,INFO;CALLOUT,INFO;DB,INFO;SYSTEM,DEBUG;VALIDATION,INFO;VISUALFORCE,INFO; WORKFLOW,INFO In this example, the API version is 25.0, and the following debug log categories and levels have been set: Apex Code DEBUG Apex Profiling INFO Callout INFO Database INFO System DEBUG Validation INFO Visualforce INFO Workflow INFO 210
- 213. Debugging Apex Understanding the Debug Log Execution Units An execution unit is equivalent to a transaction. It contains everything that occurred within the transaction. The execution is delimited by EXECUTION_STARTED and EXECUTION_FINISHED. Code Units A code unit is a discrete unit of work within a transaction. For example, a trigger is one unit of code, as is a webService method, or a validation rule. Note: A class is not a discrete unit of code. Units of code are indicated by CODE_UNIT_STARTED and CODE_UNIT_FINISHED. Units of work can embed other units of work. For example: EXECUTION_STARTED CODE_UNIT_STARTED|[EXTERNAL]execute_anonymous_apex CODE_UNIT_STARTED|[EXTERNAL]MyTrigger on Account trigger event BeforeInsert for [new] CODE_UNIT_FINISHED <-- The trigger ends CODE_UNIT_FINISHED <-- The executeAnonymous ends EXECUTION_FINISHED Units of code include, but are not limited to, the following: • Triggers • Workflow invocations and time-based workflow • Validation rules • Approval processes • Apex lead convert • @future method invocations • Web service invocations • executeAnonymous calls • Visualforce property accesses on Apex controllers • Visualforce actions on Apex controllers • Execution of the batch Apex start and finish methods, as well as each execution of the execute method • Execution of the Apex System.Schedule execute method • Incoming email handling Log Lines Included inside the units of code. These indicate what code or rules are being executed, or messages being specifically written to the debug log. For example: Figure 5: Debug Log Line Example 211
- 214. Debugging Apex Understanding the Debug Log Log lines are made up of a set of fields, delimited by a pipe (|). The format is: • timestamp: consists of the time when the event occurred and a value between parentheses. The time is in the user's time zone and in the format HH:mm:ss.SSS. The value represents the time elapsed in nanoseconds since the start of the request. The elapsed time value is excluded from logs reviewed in the Developer Console. • event identifier: consists of the specific event that triggered the debug log being written to, such as SAVEPOINT_RESET or VALIDATION_RULE, and any additional information logged with that event, such as the method name or the line and character number where the code was executed. Additional Log Data In addition, the log contains the following information: • Cumulative resource usage—Logged at the end of many code units, such as triggers, executeAnonymous, batch Apex message processing, @future methods, Apex test methods, Apex web service methods, and Apex lead convert. • Cumulative profiling information—Logged once at the end of the transaction. Contains information about the most expensive queries (that used the most resources), DML invocations, and so on. The following is an example debug log: 22.0 APEX_CODE,DEBUG;APEX_PROFILING,INFO;CALLOUT,INFO;DB,INFO;SYSTEM,DEBUG;VALIDATION,INFO;VISUALFORCE,INFO; WORKFLOW,INFO 11:47:46.030 (30064000)|EXECUTION_STARTED 11:47:46.030 (30159000)|CODE_UNIT_STARTED|[EXTERNAL]|TRIGGERS 11:47:46.030 (30271000)|CODE_UNIT_STARTED|[EXTERNAL]|01qD00000004JvP|myAccountTrigger on Account trigger event BeforeUpdate for [001D000000IzMaE] 11:47:46.038 (38296000)|SYSTEM_METHOD_ENTRY|[2]|System.debug(ANY) 11:47:46.038 (38450000)|USER_DEBUG|[2]|DEBUG|Hello World! 11:47:46.038 (38520000)|SYSTEM_METHOD_EXIT|[2]|System.debug(ANY) 11:47:46.546 (38587000)|CUMULATIVE_LIMIT_USAGE 11:47:46.546|LIMIT_USAGE_FOR_NS|(default)| Number of SOQL queries: 0 out of 100 Number of query rows: 0 out of 50000 Number of SOSL queries: 0 out of 20 Number of DML statements: 0 out of 150 Number of DML rows: 0 out of 10000 Number of script statements: 1 out of 200000 Maximum heap size: 0 out of 6000000 Number of callouts: 0 out of 10 Number of Email Invocations: 0 out of 10 Number of fields describes: 0 out of 100 Number of record type describes: 0 out of 100 Number of child relationships describes: 0 out of 100 Number of picklist describes: 0 out of 100 Number of future calls: 0 out of 10 11:47:46.546|CUMULATIVE_LIMIT_USAGE_END 11:47:46.038 (38715000)|CODE_UNIT_FINISHED|myAccountTrigger on Account trigger event BeforeUpdate for [001D000000IzMaE] 11:47:47.154 (1154831000)|CODE_UNIT_FINISHED|TRIGGERS 11:47:47.154 (1154881000)|EXECUTION_FINISHED Setting Debug Log Filters for Apex Classes and Triggers Debug log filtering provides a mechanism for fine-tuning the log verbosity at the trigger and class level. This is especially helpful when debugging Apex logic. For example, to evaluate the output of a complex process, you can raise the log verbosity for a given class while turning off logging for other classes or triggers within a single request. 212
- 215. Debugging Apex Understanding the Debug Log When you override the debug log levels for a class or trigger, these debug levels also apply to the class methods that your class or trigger calls and the triggers that get executed as a result. All class methods and triggers in the execution path inherit the debug log settings from their caller, unless they have these settings overridden. The following diagram illustrates overriding debug log levels at the class and trigger level. For this scenario, suppose Class1 is causing some issues that you would like to take a closer look at. To this end, the debug log levels of Class1 are raised to the finest granularity. Class3 doesn't override these log levels, and therefore inherits the granular log filters of Class1. However, UtilityClass has already been tested and is known to work properly, so it has its log filters turned off. Similarly, Class2 isn't in the code path that causes a problem, therefore it has its logging minimized to log only errors for the Apex Code category. Trigger2 inherits these log settings from Class2. Figure 6: Fine-tuning debug logging for classes and triggers The following is a pseudo-code example that the diagram is based on. 1. Trigger1 calls a method of Class1 and another method of Class2. For example: trigger Trigger1 on Account (before insert) { Class1.someMethod(); Class2.anotherMethod(); } 2. Class1 calls a method of Class3, which in turn calls a method of a utility class. For example: public class Class1 { public static void someMethod() { Class3.thirdMethod(); } } public class Class3 { public static void thirdMethod() { UtilityClass.doSomething(); } } 3. Class2 causes a trigger, Trigger2, to be executed. For example: public class Class2 { public static void anotherMethod() { // Some code that causes Trigger2 to be fired. } } 213
- 216. Debugging Apex Working with Logs in the Developer Console To set log filters: 1. From a class or trigger detail page, click Log Filters. 2. Click Override Log Filters. The log filters are set to the default log levels. 3. Choose the log level desired for each log category. To learn more about debug log categories, debug log levels, and debug log events, see Setting Debug Log Filters. See Also: Working with Logs in the Developer Console Debugging Apex API Calls Working with Logs in the Developer Console Use the logs tab in the Developer Console to open debug logs. 1. Click Open to open the selected log in a new System Log view. 2. Click Open Raw Log to open the selected log in a plain text view that displays the unformatted contents of the debug log. 3. Click Download Log to download the selected log. 4. Click Auto Hide Logs to automatically hide all existing logs the next time the page is refreshed. This button is a toggle: click the button a second time to display all logs. 5. Click Clear to remove all logs from the list. Tip: If you are monitoring debug logs for a user, those logs are still accessible from the Debug Log page. Click Your Name > Setup > Monitoring > Debug Logs. 6. Select This Session Only to display only logs generated by you since opening the Developer Console. Deselect to see all debug logs currently saved for your organization, including those created by monitoring users. 7. Click Filter and type text to filter the visible logs. For example, if you want to see debug logs from a specific user, type that user's name. The filter is case-sensitive. Logs open in a System Log view. System Log view is a context-sensitive execution viewer that shows the source of an operation, what triggered that operation, and what occurred afterward. You can use this view to inspect debug logs that include database events, Apex processing, workflow, and validation logic. To learn more about working with logs in a System Log view in the Developer Console, see “System Log View” in the online help. When using the Developer Console or monitoring a debug log, you can specify the level of information that gets included in the log. 214
- 217. Debugging Apex Working with Logs in the Developer Console Log category The type of information logged, such as information from Apex or workflow rules. Log level The amount of information logged. Event type The combination of log category and log level that specify which events get logged. Each event can log additional information, such as the line and character number where the event started, fields associated with the event, duration of the event in milliseconds, and so on. Debug Log Categories You can specify the following log categories. The amount of information logged for each category depends on the log level: Log Category Description Database Includes information about database activity, including every data manipulation language (DML) statement or inline SOQL or SOSL query. Workflow Includes information for workflow rules, such as the rule name, the actions taken, and so on. Validation Includes information about validation rules, such as the name of the rule, whether the rule evaluated true or false, and so on. Callout Includes the request-response XML that the server is sending and receiving from an external Web service. This is useful when debugging issues related to using Force.com Web services API calls. Apex Code Includes information about Apex code and can include information such as log messages generated by DML statements, inline SOQL or SOSL queries, the start and completion of any triggers, and the start and completion of any test method, and so on. Apex Profiling Includes cumulative profiling information, such as the limits for your namespace, the number of emails sent, and so on. Visualforce Includes information about Visualforce events including serialization and deserialization of the view state or the evaluation of a formula field in a Visualforce page. System Includes information about calls to all system methods such as the System.debug method. Debug Log Levels You can specify the following log levels. The levels are listed from lowest to highest. Specific events are logged based on the combination of category and levels. Most events start being logged at the INFO level. The level is cumulative, that is, if you select FINE, the log will also include all events logged at DEBUG, INFO, WARN and ERROR levels. Note: Not all levels are available for all categories. Only the levels that correspond to one or more events are available. • ERROR • WARN 215
- 218. Debugging Apex Working with Logs in the Developer Console • INFO • DEBUG • FINE • FINER • FINEST Important: Before running a deployment, verify that the Apex Code log level is not set to FINEST. If the Apex Code log level is set to FINEST, the deployment might take longer than expected. If the Developer Console is open, the log levels in the Developer Console affect all logs, including logs created during a deployment. Debug Event Types The following is an example of what is written to the debug log. The event is USER_DEBUG. The format is timestamp | event identifier: • timestamp: consists of the time when the event occurred and a value between parentheses. The time is in the user's time zone and in the format HH:mm:ss.SSS. The value represents the time elapsed in nanoseconds since the start of the request. The elapsed time value is excluded from logs reviewed in the Developer Console. • event identifier: consists of the specific event that triggered the debug log being written to, such as SAVEPOINT_RESET or VALIDATION_RULE, and any additional information logged with that event, such as the method name or the line and character number where the code was executed. The following is an example of a debug log line. Figure 7: Debug Log Line Example In this example, the event identifier is made up of the following: • Event name: USER_DEBUG • Line number of the event in the code: [2] • Logging level the System.Debug method was set to: DEBUG • User-supplied string for the System.Debug method: Hello world! The following example of a log line is triggered by this code snippet. 216
- 219. Debugging Apex Working with Logs in the Developer Console Figure 8: Debug Log Line Code Snippet The following log line is recorded when the test reaches line 5 in the code: 15:51:01.071 (55856000)|DML_BEGIN|[5]|Op:Insert|Type:Invoice_Statement__c|Rows:1 In this example, the event identifier is made up of the following: • Event name: DML_BEGIN • Line number of the event in the code: [5] • DML operation type—Insert: Op:Insert • Object name: Type:Invoice_Statement__c • Number of rows passed into the DML operation: Rows:1 The following table lists the event types that are logged, what fields or other information get logged with each event, as well as what combination of log level and category cause an event to be logged. Event Name Fields or Information Logged With Event Category Logged Level Logged BULK_HEAP_ALLOCATE Number of bytes allocated Apex Code FINEST CALLOUT_REQUEST Line number, request headers Callout INFO and above CALLOUT_RESPONSE Line number, response body Callout INFO and above CODE_UNIT_FINISHED None Apex Code ERROR and above CODE_UNIT_STARTED Line number, code unit name, such as Apex Code ERROR and above MyTrigger on Account trigger event BeforeInsert for [new] 217
- 220. Debugging Apex Working with Logs in the Developer Console Event Name Fields or Information Logged With Event Category Logged Level Logged CONSTRUCTOR_ENTRY Line number, Apex class ID, the sring Apex Code DEBUG and above <init>() with the types of parameters, if any, between the parentheses CONSTRUCTOR_EXIT Line number, the string <init>() with the Apex Code DEBUG and above types of parameters, if any, between the parentheses CUMULATIVE_LIMIT_USAGE None Apex Profiling INFO and above CUMULATIVE_LIMIT_USAGE_END None Apex Profiling INFO and above CUMULATIVE_PROFILING None Apex Profiling FINE and above CUMULATIVE_PROFILING_BEGIN None Apex Profiling FINE and above CUMULATIVE_PROFILING_END None Apex Profiling FINE and above DML_BEGIN Line number, operation (such as Insert, Apex Code INFO and above Update, and so on), record name or type, number of rows passed into DML operation DML_END Line number Apex Code INFO and above EMAIL_QUEUE Line number Apex Code INFO and above ENTERING_MANAGED_PKG Package namespace Apex Code INFO and above EXCEPTION_THROWN Line number, exception type, message Apex Code INFO and above EXECUTION_FINISHED None Apex Code ERROR and above EXECUTION_STARTED None Apex Code ERROR and above FATAL_ERROR Exception type, message, stack trace Apex Code ERROR and above HEAP_ALLOCATE Line number, number of bytes Apex Code FINER and above HEAP_DEALLOCATE Line number, number of bytes deallocated Apex Code FINER and above IDEAS_QUERY_EXECUTE Line number DB FINEST LIMIT_USAGE_FOR_NS Namespace, following limits: Apex Profiling FINEST Number of SOQL queries Number of query rows Number of SOSL queries Number of DML statements Number of DML rows Number of code statements Maximum heap size Number of callouts Number of Email Invocations Number of fields describes 218
- 221. Debugging Apex Working with Logs in the Developer Console Event Name Fields or Information Logged With Event Category Logged Level Logged Number of record type describes Number of child relationships describes Number of picklist describes Number of future calls Number of find similar calls Number of System.runAs() invocations METHOD_ENTRY Line number, the Force.com ID of the class, Apex Code DEBUG and above method signature METHOD_EXIT Line number, the Force.com ID of the class, Apex Code DEBUG and above method signature. For constructors, the following information is logged: Line number, class name. POP_TRACE_FLAGS Line number, the Force.com ID of the class System INFO and above or trigger that has its log filters set and that is going into scope, the name of this class or trigger, the log filter settings that are now in effect after leaving this scope PUSH_TRACE_FLAGS Line number, the Force.com ID of the class System INFO and above or trigger that has its log filters set and that is going out of scope, the name of this class or trigger, the log filter settings that are now in effect after entering this scope QUERY_MORE_ITERATIONS Line number, number of queryMore DB INFO and above iterations SAVEPOINT_ROLLBACK Line number, Savepoint name DB INFO and above SAVEPOINT_SET Line number, Savepoint name DB INFO and above SLA_END Number of cases, load time, processing time, Workflow INFO and above number of case milestones to insert/update/delete, new trigger SLA_EVAL_MILESTONE Milestone ID Workflow INFO and above SLA_NULL_START_DATE None Workflow INFO and above SLA_PROCESS_CASE Case ID Workflow INFO and above SOQL_EXECUTE_BEGIN Line number, number of aggregations, query DB INFO and above source 219
- 222. Debugging Apex Working with Logs in the Developer Console Event Name Fields or Information Logged With Event Category Logged Level Logged SOQL_EXECUTE_END Line number, number of rows, duration in DB INFO and above milliseconds SOSL_EXECUTE_BEGIN Line number, query source DB INFO and above SOSL_EXECUTE_END Line number, number of rows, duration in DB INFO and above milliseconds STACK_FRAME_VARIABLE_LIST Frame number, variable list of the form: Apex Profiling FINE and above Variable number | Value. For example: var1:50 var2:'Hello World' STATEMENT_EXECUTE Line number Apex Code FINER and above STATIC_VARIABLE_LIST Variable list of the form: Variable number Apex Profiling FINE and above | Value. For example: var1:50 var2:'Hello World' SYSTEM_CONSTRUCTOR_ENTRY Line number, the string <init>() with the System DEBUG types of parameters, if any, between the parentheses SYSTEM_CONSTRUCTOR_EXIT Line number, the string <init>() with the System DEBUG types of parameters, if any, between the parentheses SYSTEM_METHOD_ENTRY Line number, method signature System DEBUG SYSTEM_METHOD_EXIT Line number, method signature System DEBUG SYSTEM_MODE_ENTER Mode name System INFO and above SYSTEM_MODE_EXIT Mode name System INFO and above TESTING_LIMITS None Apex Profiling INFO and above TOTAL_EMAIL_RECIPIENTS_QUEUED Number of emails sent Apex Profiling FINE and above USER_DEBUG Line number, logging level, user-supplied Apex Code DEBUG and above string by default. If the user sets the log level for the System.Debug method, the event is logged at that level instead. VALIDATION_ERROR Error message Validation INFO and above VALIDATION_FAIL None Validation INFO and above 220
- 223. Debugging Apex Working with Logs in the Developer Console Event Name Fields or Information Logged With Event Category Logged Level Logged VALIDATION_FORMULA Formula source, values Validation INFO and above VALIDATION_PASS None Validation INFO and above VALIDATION_RULE Rule name Validation INFO and above VARIABLE_ASSIGNMENT Line number, variable name, a string Apex Code FINEST representation of the variable's value, the variable's address VARIABLE_SCOPE_BEGIN Line number, variable name, type, a value Apex Code FINEST that indicates if the variable can be referenced, a value that indicates if the variable is static VARIABLE_SCOPE_END None Apex Code FINEST VF_APEX_CALL Element name, method name, return type Apex Code INFO and above VF_DESERIALIZE_VIEWSTATE_BEGIN View state ID Visualforce INFO and above VF_DESERIALIZE_VIEWSTATE_END None Visualforce INFO and above VF_EVALUATE_FORMULA_BEGIN View state ID, formula Visualforce FINER and above VF_EVALUATE_FORMULA_END None Visualforce FINER and above VF_PAGE_MESSAGE Message text Apex Code INFO and above VF_SERIALIZE_VIEWSTATE_BEGIN View state ID Visualforce INFO and above VF_SERIALIZE_VIEWSTATE_END None Visualforce INFO and above WF_ACTION Action description Workflow INFO and above WF_ACTION_TASK Task subject, action ID, rule, owner, due date Workflow INFO and above WF_ACTIONS_END Summer of actions performed Workflow INFO and above WF_APPROVAL Transition type, EntityName: NameField Workflow INFO and above Id, process node name WF_APPROVAL_REMOVE EntityName: NameField Id Workflow INFO and above WF_APPROVAL_SUBMIT EntityName: NameField Id Workflow INFO and above WF_ASSIGN Owner, assignee template ID Workflow INFO and above WF_CRITERIA_BEGIN EntityName: NameField Id, rule name, Workflow INFO and above rule ID, trigger type (if rule respects trigger types) WF_CRITERIA_END Boolean value indicating success (true or false) Workflow INFO and above WF_EMAIL_ALERT Action ID, rule Workflow INFO and above WF_EMAIL_SENT Email template ID, recipients, CC emails Workflow INFO and above WF_ENQUEUE_ACTIONS Summary of actions enqueued Workflow INFO and above WF_ESCALATION_ACTION Case ID, business hours Workflow INFO and above WF_ESCALATION_RULE None Workflow INFO and above 221
- 224. Debugging Apex Working with Logs in the Developer Console Event Name Fields or Information Logged With Event Category Logged Level Logged WF_EVAL_ENTRY_CRITERIA Process name, email template ID, Boolean Workflow INFO and above value indicating result (true or false) WF_FIELD_UPDATE EntityName: NameField Id, object or Workflow INFO and above field name WF_FORMULA Formula source, values Workflow INFO and above WF_HARD_REJECT None Workflow INFO and above WF_NEXT_APPROVER Owner, next owner type, field Workflow INFO and above WF_NO_PROCESS_FOUND None Workflow INFO and above WF_OUTBOUND_MSG EntityName: NameField Id, action ID, Workflow INFO and above rule WF_PROCESS_NODE Process name Workflow INFO and above WF_REASSIGN_RECORD EntityName: NameField Id, owner Workflow INFO and above WF_RESPONSE_NOTIFY Notifier name, notifier email, notifier Workflow INFO and above template ID WF_RULE_ENTRY_ORDER Integer, indicating order Workflow INFO and above WF_RULE_EVAL_BEGIN Rule type Workflow INFO and above WF_RULE_EVAL_END None Workflow INFO and above WF_RULE_EVAL_VALUE Value Workflow INFO and above WF_RULE_FILTER Filter criteria Workflow INFO and above WF_RULE_INVOCATION EntityName: NameField Id Workflow INFO and above WF_RULE_NOT_EVALUATED None Workflow INFO and above WF_SOFT_REJECT Process name Workflow INFO and above WF_SPOOL_ACTION_BEGIN Node type Workflow INFO and above WF_TIME_TRIGGER EntityName: NameField Id, time action, Workflow INFO and above time action container, evaluation Datetime 222
- 225. Debugging Apex Debugging Apex API Calls Event Name Fields or Information Logged With Event Category Logged Level Logged WF_TIME_TRIGGERS_BEGIN None Workflow INFO and above See Also: Understanding the Debug Log Debugging Apex API Calls Debugging Apex API Calls All API calls that invoke Apex support a debug facility that allows access to detailed information about the execution of the code, including any calls to System.debug(). In addition to the Developer Console, a SOAP input header called DebuggingHeader allows you to set the logging granularity according to the levels outlined in the following table. Element Name Type Description LogCategory string Specify the type of information returned in the debug log. Valid values are: • Db • Workflow • Validation • Callout • Apex_code • Apex_profiling • All LogCategoryLevel string Specifies the amount of information returned in the debug log. Only the Apex_code LogCategory uses the log category levels. Valid log levels are (listed from lowest to highest): • ERROR • WARN • INFO • DEBUG • FINE • FINER • FINEST In addition, the following log levels are still supported as part of the DebuggingHeader for backwards compatibility. Log Level Description NONE Does not include any log messages. 223
- 226. Debugging Apex Handling Uncaught Exceptions Log Level Description DEBUGONLY Includes lower level messages, as well as messages generated by calls to the System.debug method. DB Includes log messages generated by calls to the System.debug method, as well as every data manipulation language (DML) statement or inline SOQL or SOSL query. PROFILE Includes log messages generated by calls to the System.debug method, every DML statement or inline SOQL or SOSL query, and the entrance and exit of every user-defined method. In addition, the end of the debug log contains overall profiling information for the portions of the request that used the most resources, in terms of SOQL and SOSL statements, DML operations, and Apex method invocations. These three sections list the locations in the code that consumed the most time, in descending order of total cumulative time, along with the number of times they were executed. CALLOUT Includes the request-response XML that the server is sending and receiving from an external Web service. This is useful when debugging issues related to using Force.com Web services API calls. DETAIL Includes all messages generated by the PROFILE level as well as the following: • Variable declaration statements • Start of loop executions • All loop controls, such as break and continue • Thrown exceptions * • Static and class initialization code * • Any changes in the with sharing context The corresponding output header, DebuggingInfo, contains the resulting debug log. For more information, see DebuggingHeader on page 646. See Also: Understanding the Debug Log Working with Logs in the Developer Console Handling Uncaught Exceptions If some Apex code has a bug or does not catch a code-level exception: • The end user sees a simple explanation of the problem in the application interface. This error message includes the Apex stack trace. • The developer specified in the LastModifiedBy field receives the error via email with the Apex stack trace and the customer’s organization and user ID. No other customer data is returned with the report. Note that for Apex code that runs synchronously, some error emails may get suppressed for duplicate exception errors. For Apex code that runs asynchronously—batch Apex, scheduled Apex, or future methods (methods annotated with @future)—error emails for duplicate exceptions don’t get suppressed. 224
- 227. Debugging Apex Understanding Execution Governors and Limits Understanding Execution Governors and Limits Because Apex runs in a multitenant environment, the Apex runtime engine strictly enforces a number of limits to ensure that runaway Apex does not monopolize shared resources. These limits, or governors, track and enforce the statistics outlined in the following table. If some Apex code ever exceeds a limit, the associated governor issues a runtime exception that cannot be handled. Governor limits apply to an entire organization, as well as to specific namespaces. For example, if you install a managed package created by a salesforce.com ISV Partner from Force.com AppExchange, the components in the package belong to a namespace unique from other components in your organization. Consequently, any Apex code in that package can issue up to 150 DML statements while executing. In addition, any Apex code that is native to your organization can also issue up to 150 DML statements, meaning more than 150 DML statements might execute during a single request if code from the managed package and your native organization both execute. Conversely, if you install a package from AppExchange that is not created by a salesforce.com ISV Partner, the code from that package does not have its own separate governor limit count. Any resources it uses counts against the total for your organization. Cumulative resource messages and warning emails are also generated based on managed package namespaces as well. For more information on salesforce.com ISV Partner packages, see salesforce.com Partner Programs. Description Limit 1 Total number of SOQL queries issued 100 1 Total number of SOQL queries issued for Batch Apex and future methods 200 Total number of records retrieved by SOQL queries 50,000 Total number of records retrieved by Database.getQueryLocator 10,000 Total number of SOSL queries issued 20 Total number of records retrieved by a single SOSL query 200 Total number of DML statements issued2 150 Total number of records processed as a result of DML statements, Approval.process, or 10,000 database.emptyRecycleBin Total number of executed code statements 200,000 Total number of executed code statements for Batch Apex and future methods 1,000,000 3 Total heap size 6 MB Total heap size for Batch Apex and future methods 12 MB Total stack depth for any Apex invocation that recursively fires triggers due to insert, 16 update, or delete statements4 For loop list batch size 200 Total number of callouts (HTTP requests or Web services calls) in a request 10 Maximum timeout for all callouts (HTTP requests or Web services calls) in a request 120 seconds Default timeout of callouts (HTTP requests or Web services calls) in a request 10 seconds Total number of methods with the future annotation allowed per Apex invocation5 10 225
- 228. Debugging Apex Understanding Execution Governors and Limits Description Limit 6 Maximum size of callout request or response (HTTP request or Web services call) 3 MB Total number of sendEmail methods allowed 10 Total number of describes allowed7 100 Total number of classes that can be scheduled concurrently 25 Total number of test classes that can be queued per a 24–hour period8 The greater of 500 or 10 multiplied by the number of test classes in the organization 1 In a SOQL query with parent-child relationship sub-queries, each parent-child relationship counts as an additional query. These types of queries have a limit of three times the number for top-level queries. The row counts from these relationship queries contribute to the row counts of the overall code execution. In addition to static SOQL statements, calls to the following methods count against the number of SOQL statements issued in a request. • Database.countQuery • Database.getQueryLocator • Database.query 2 Calls to the following methods count against the number of DML queries issued in a request. • Approval.process • Database.convertLead • Database.emptyRecycleBin • Database.rollback • Database.setSavePoint • delete and Database.delete • insert and Database.insert • merge • undelete and Database.undelete • update and Database.update • upsert and Database.upsert • System.runAs 3 Email services heap size is 36 MB. 4 Recursive Apex that does not fire any triggers with insert, update, or delete statements exists in a single invocation, with a single stack. Conversely, recursive Apex that fires a trigger spawns the trigger in a new Apex invocation, separate from the invocation of the code that caused it to fire. Because spawning a new invocation of Apex is a more expensive operation than a recursive call in a single invocation, there are tighter restrictions on the stack depth of these types of recursive calls. 5 Salesforce also imposes a limit on the number of future method invocations: 200 method calls per full Salesforce user license, Salesforce Platform user license, or Force.com - One App user license, per 24 hours. This is an organization-wide limit. Chatter Only, Chatter customer users, Customer Portal User, and partner portal User licenses aren’t included in this limit calculation. For example, suppose your organization has three full Salesforce licenses, two Salesforce Platform licenses, and 100 Customer Portal User licenses. Your entire organization is limited to only 1,000 method calls every 24 hours, calculated as 200 * (3+2), not 200 * (3+2+100). 226
- 229. Debugging Apex Understanding Execution Governors and Limits 6 The HTTP request and response sizes count towards the total heap size. 7 Describes include the following methods and objects. • ChildRelationship objects • RecordTypeInfo objects • PicklistEntry objects • fields calls • fieldsets calls 8 This limit applies when you start tests asynchronously by selecting test classes for execution through the Apex Test Execution page or by inserting ApexTestQueueItem objects using SOAP API. Limits apply individually to each testMethod. Use the Limits methods to determine the code execution limits for your code while it is running. For example, you can use the getDMLStatements method to determine the number of DML statements that have already been called by your program, or the getLimitDMLStatements method to determine the total number of DML statements available to your code. For best performance, SOQL queries must be selective, particularly for queries inside of triggers. To avoid long execution times, non-selective SOQL queries may be terminated by the system. Developers will receive an error message when a non-selective query in a trigger executes against an object that contains more than 100,000 records. To avoid this error, ensure that the query is selective. See More Efficient SOQL Queries. For Apex saved using Salesforce.com API version 20.0 or earlier, if an API call causes a trigger to fire, the batch of 200 records to process is further split into batches of 100 records. For Apex saved using Salesforce.com API version 21.0 and later, no further splits of API batches occur. Note that static variable values are reset between batches, but governor limits are not. Do not use static variables to track state information between batches. In addition to the execution governor limits, Apex has the following limits. • The maximum number of characters for a class is 1 million. • The maximum number of characters for a trigger is 1 million. • The maximum amount of code used by all Apex code in an organization is 3 MB. Note: This limit does not apply to certified managed packages installed from AppExchange, (that is, an app that has been marked AppExchange Certified). The code in those types of packages belong to a namespace unique from the code in your organization. For more information on AppExchange Certified packages, see the Force.com AppExchange online help. This limit also does not apply to any code included in a class defined with the @isTest annotation. • There is a limit on the method size. Large methods that exceed the allowed limit cause an exception to be thrown during the execution of your code. Like in Java, the method size limit in Apex is 65,535 bytecode instructions in compiled form. • If a SOQL query runs more than 120 seconds, the request can be canceled by Salesforce. • Each Apex request is limited to 10 minutes of execution. • A callout request is limited to a maximum of 20 simultaneous requests to URLs with the same host. The host is defined by the unique subdomain for the URL, for example, www.mysite.com and extra.mysite.com are two different hosts. This limit is calculated across all organizations that access the same host. If this limit is exceeded, a CalloutException will be thrown. • The maximum number of records that an event report returns for a user who is not a system administrator is 20,000, for system administrators, 100,000. 227
- 230. Debugging Apex Understanding Execution Governors and Limits • Each organization is allowed 10 synchronous concurrent requests for long-running requests that last longer than 5 seconds. If additional requests are made while the 10 long-running requests are still running, they are denied. • A user can have up to 50 query cursors open at a time. For example, if 50 cursors are open and a client application still logged in as the same user attempts to open a new one, the oldest of the 50 cursors is released. Note that this limit is different for the batch Apex start method, which can have up to five query cursors open at a time per user. The other batch Apex methods have the higher limit of 50 cursors. Cursor limits for different Force.com features are tracked separately. For example, you can have 50 Apex query cursors, 50 batch cursors, and 50 Visualforce cursors open at the same time. • In a single transaction, you can only reference 10 unique namespaces. For example, suppose you have an object that executes a class in a managed package when the object is updated. Then that class updates a second object, which in turn executes a different class in a different package. Even though the second package wasn't accessed directly by the first, because it occurs in the same transaction, it's included in the number of namespaces being accessed in a single transaction. • Any deployment of Apex is limited to 5,000 code units of classes and triggers. • If you use the Data.com Clean product and its automated jobs, and you have set up Apex triggers with SOQL queries to run when account, contact, or lead records, the queries may interfere with Clean jobs for those objects. Your Apex triggers (combined) should not exceed 200 SOQL queries per batch. If they do, your Clean job for that object will fail. In addition, if your triggers call future methods, they will be subject to a limit of 10 future calls per batch. Email Limits Inbound Email Limits Email Services: Maximum Number of Email Messages Processed Number of user licenses multiplied by 1,000, up to a daily maximum of (Includes limit for On-Demand Email-to-Case) 1,000,000 Email Services: Maximum Size of Email Message (Body and Attachments) 10 MB1 On-Demand Email-to-Case: Maximum Email Attachment Size 10 MB On-Demand Email-to-Case: Maximum Number of Email Messages Processed Number of user licenses multiplied by 1,000, up to a daily maximum of (Counts toward limit for Email Services) 1,000,000 1 The maximum size of email messages for Email Services varies depending on language and character set. When defining email services, note the following: • An email service only processes messages it receives at one of its addresses. • Salesforce limits the total number of messages that all email services combined, including On-Demand Email-to-Case, can process daily. Messages that exceed this limit are bounced, discarded, or queued for processing the next day, depending on how you configure the failure response settings for each email service. Salesforce calculates the limit by multiplying the number of user licenses by 1,000, up to a daily maximum of 1,000,000. For example, if you have ten licenses, your organization can process up to 10,000 email messages a day. • Email service addresses that you create in your sandbox cannot be copied to your production organization. • For each email service, you can tell Salesforce to send error email messages to a specified address instead of the sender's email address. • Email services rejects email messages and notifies the sender if the email (combined body text, body HTML and attachments) exceeds approximately 10 MB (varies depending on language and character set). 228
- 231. Debugging Apex Understanding Execution Governors and Limits Outbound Email: Limits for Single and Mass Email Sent Using Apex You can send single emails to a maximum of 1,000 external email addresses per day based on Greenwich Mean Time (GMT). Single emails sent using the application don't count towards this limit. You can send mass email to a total of 1,000 external email addresses per day per organization based on Greenwich Mean Time (GMT). The maximum number of external addresses you can include in each mass email depends on the Edition of Salesforce you are using: Edition Address Limit per Mass Email Professional 250 Enterprise Edition 500 Unlimited Edition 1,000 Note: Note the following about email limits: • The single and mass email limits don't take unique addresses into account. For example, if you have johndoe@example.com in your email 10 times, that counts as 10 against the limit. • You can send an unlimited amount of email to your internal users. These limits also apply to emails sent using the API and Apex. • In Developer Edition organizations and organizations evaluating Salesforce during a trial period, your organization can send mass email to no more than 10 external email addresses per day. This lower limit does not apply if your organization was created before the Winter '12 release and already had mass email enabled with a higher limit. Batch Apex Governor Limits Keep in mind the following governor limits for batch Apex: • Up to five queued or active batch jobs are allowed for Apex. • A user can have up to 50 query cursors open at a time. For example, if 50 cursors are open and a client application still logged in as the same user attempts to open a new one, the oldest of the 50 cursors is released. Note that this limit is different for the batch Apex start method, which can have up to five query cursors open at a time per user. The other batch Apex methods have the higher limit of 50 cursors. Cursor limits for different Force.com features are tracked separately. For example, you can have 50 Apex query cursors, 50 batch cursors, and 50 Visualforce cursors open at the same time. • A maximum of 50 million records can be returned in the Database.QueryLocator object. If more than 50 million records are returned, the batch job is immediately terminated and marked as Failed. • If the start method returns a QueryLocator, the optional scope parameter of Database.executeBatch can have a maximum value of 2,000. If set to a higher value, Salesforce chunks the records returned by the QueryLocator into smaller batches of up to 2,000 records. If the start method returns an iterable, the scope parameter value has no upper limit; however, if you use a very high number, you may run into other limits. • If no size is specified with the optional scope parameter of Database.executeBatch, Salesforce chunks the records returned by the start method into batches of 200, and then passes each batch to the execute method. Apex governor limits are reset for each execution of execute. • The start, execute, and finish methods can implement up to 10 callouts each. • Batch executions are limited to 10 callouts per method execution. • The maximum number of batch executions is 250,000 per 24 hours. 229
- 232. Debugging Apex Using Governor Limit Email Warnings • Only one batch Apex job's start method can run at a time in an organization. Batch jobs that haven’t started yet remain in the queue until they're started. Note that this limit doesn’t cause any batch job to fail and execute methods of batch Apex jobs still run in parallel if more than one job is running. See Also: What are the Limitations of Apex? Future Annotation Scheduling Data.com Clean Jobs (Data.com Clean Only) Using Governor Limit Email Warnings When an end-user invokes Apex code that surpasses more than 50% of any governor limit, you can specify a user in your organization to receive an email notification of the event with additional details. To enable email warnings: 1. Log in to Salesforce as an administrator user. 2. Click Your Name > Setup > Manage Users > Users. 3. Click Edit next to the name of the user who should receive the email notifications. 4. Select the Send Apex Warning Emails option. 5. Click Save. 230
- 233. Chapter 9 Developing Apex in Managed Packages In this chapter ... A package is a container for something as small as an individual component or as large as a set of related apps. After creating a package, you can distribute it to • Package Versions other Salesforce users and organizations, including those outside your company. • Deprecating Apex An organization can create a single managed package that can be downloaded • Behavior in Package Versions and installed by many different organizations. Managed packages differ from unmanaged packages by having some locked components, allowing the managed package to be upgraded later. Unmanaged packages do not include locked components and cannot be upgraded. This section includes the following topics related to developing Apex in managed packages: • Package Versions • Deprecating Apex • Behavior in Package Versions 231
- 234. Developing Apex in Managed Packages Package Versions Package Versions A package version is a number that identifies the set of components uploaded in a package. The version number has the format majorNumber.minorNumber.patchNumber (for example, 2.1.3). The major and minor numbers increase to a chosen value during every major release. The patchNumber is generated and updated only for a patch release. Unmanaged packages are not upgradeable, so each package version is simply a set of components for distribution. A package version has more significance for managed packages. Packages can exhibit different behavior for different versions. Publishers can use package versions to evolve the components in their managed packages gracefully by releasing subsequent package versions without breaking existing customer integrations using the package. When an existing subscriber installs a new package version, there is still only one instance of each component in the package, but the components can emulate older versions. For example, a subscriber may be using a managed package that contains an Apex class. If the publisher decides to deprecate a method in the Apex class and release a new package version, the subscriber still sees only one instance of the Apex class after installing the new version. However, this Apex class can still emulate the previous version for any code that references the deprecated method in the older version. Note the following when developing Apex in managed packages: • The code contained in an Apex class or trigger that is part of a managed package is automatically obfuscated and cannot be viewed in an installing organization. The only exceptions are methods declared as global, meaning that the method signatures can be viewed in an installing organization. • Managed packages receive a unique namespace. This namespace is automatically prepended to your class names, methods, variables, and so on, which helps prevent duplicate names in the installer's organization. • In a single transaction, you can only reference 10 unique namespaces. For example, suppose you have an object that executes a class in a managed package when the object is updated. Then that class updates a second object, which in turn executes a different class in a different package. Even though the second package wasn't accessed directly by the first, because it occurs in the same transaction, it's included in the number of namespaces being accessed in a single transaction. • The code contained in Apex that is part of a managed package is automatically obfuscated and cannot be viewed in an installing organization. The only exceptions are methods declared as global, meaning that the method signatures can be viewed in an installing organization. • Package developers can use the deprecated annotation to identify methods, classes, exceptions, enums, interfaces, and variables that can no longer be referenced in subsequent releases of the managed package in which they reside. This is useful when you are refactoring code in managed packages as the requirements evolve. • You can write test methods that change the package version context to a different package version by using the system method runAs. • You cannot add a method to a global interface or an abstract method to a global class after the interface or class has been uploaded in a Managed - Released package version. If the class in the Managed - Released package is virtual, the method that you can add to it must also be virtual and must have an implementation. • Apex code contained in an unmanaged package that explicitly references a namespace cannot be uploaded. Deprecating Apex Package developers can use the deprecated annotation to identify methods, classes, exceptions, enums, interfaces, and variables that can no longer be referenced in subsequent releases of the managed package in which they reside. This is useful when you are refactoring code in managed packages as the requirements evolve. After you upload another package version as Managed - Released, new subscribers that install the latest package version cannot see the deprecated elements, while the 232
- 235. Developing Apex in Managed Packages Behavior in Package Versions elements continue to function for existing subscribers and API integrations. A deprecated item, such as a method or a class, can still be referenced internally by the package developer. Note: You cannot use the deprecated annotation in Apex classes or triggers in unmanaged packages. Package developers can use Managed - Beta package versions for evaluation and feedback with a pilot set of users in different Salesforce organizations. If a developer deprecates an Apex identifier and then uploads a version of the package as Managed - Beta, subscribers that install the package version still see the deprecated identifier in that package version. If the package developer subsequently uploads a Managed - Released package version, subscribers will no longer see the deprecated identifier in the package version after they install it. Behavior in Package Versions A package component can exhibit different behavior in different package versions. This behavior versioning allows you to add new components to your package and refine your existing components, while still ensuring that your code continues to work seamlessly for existing subscribers. If a package developer adds a new component to a package and uploads a new package version, the new component is available to subscribers that install the new package version. Versioning Apex Code Behavior Package developers can use conditional logic in Apex classes and triggers to exhibit different behavior for different versions. This allows the package developer to continue to support existing behavior in classes and triggers in previous package versions while continuing to evolve the code. When subscribers install multiple versions of your package and write code that references Apex classes or triggers in your package, they must select the version they are referencing. Within the Apex code that is being referenced in your package, you can conditionally execute different code paths based on the version setting of the calling Apex code that is making the reference. The package version setting of the calling code can be determined within the package code by calling the System.requestVersion method. In this way, package developers can determine the request context and specify different behavior for different versions of the package. The following sample uses the System.requestVersion method and instantiates the System.Version class to define different behaviors in an Apex trigger for different package versions. trigger oppValidation on Opportunity (before insert, before update) { for (Opportunity o : Trigger.new){ // Add a new validation to the package // Applies to versions of the managed package greater than 1.0 if (System.requestVersion().compareTo(new Version(1,0)) > 0) { if (o.Probability >= 50 && o.Description == null) { o.addError('All deals over 50% require a description'); } } // Validation applies to all versions of the managed package. if (o.IsWon == true && o.LeadSource == null) { o.addError('A lead source must be provided for all Closed Won deals'); } 233
- 236. Developing Apex in Managed Packages Apex Code Items that Are Not Versioned } } For a full list of methods that work with package versions, see Version Methods and the System.requestVersion method in System Methods. The request context is persisted if a class in the installed package invokes a method in another class in the package. For example, a subscriber has installed a GeoReports package that contains CountryUtil and ContinentUtil Apex classes. The subscriber creates a new GeoReportsEx class and uses the version settings to bind it to version 2.3 of the GeoReports package. If GeoReportsEx invokes a method in ContinentUtil which internally invokes a method in CountryUtil, the request context is propagated from ContinentUtil to CountryUtil and the System.requestVersion method in CountryUtil returns version 2.3 of the GeoReports package. Apex Code Items that Are Not Versioned You can change the behavior of some Apex items across package versions. For example, you can deprecate a method so that new subscribers can no longer reference the package in a subsequent version. However, the following list of modifiers, keywords, and annotations cannot be versioned. If a package developer makes changes to one of the following modifiers, keywords, or annotations, the changes are reflected across all package versions. There are limitations on the changes that you can make to some of these items when they are used in Apex code in managed packages. Package developers can add or remove the following items: • @future • @isTest • with sharing • without sharing • transient Package developers can make limited changes to the following items: • private—can be changed to global • public—can be changed to global • protected—can be changed to global • abstract—can be changed to virtual but cannot be removed • final—can be removed but cannot be added Package developers cannot remove or change the following items: • global • virtual Package developers can add the webService keyword, but once it has been added, it cannot be removed. Note: You cannot deprecate webService methods or variables in managed package code. 234
- 237. Developing Apex in Managed Packages Testing Behavior in Package Versions Testing Behavior in Package Versions When you change the behavior in an Apex class or trigger for different package versions, it is important to test that your code runs as expected in the different package versions. You can write test methods that change the package version context to a different package version by using the system method runAs. You can only use runAs in a test method. The following sample shows a trigger with different behavior for different package versions. trigger oppValidation on Opportunity (before insert, before update) { for (Opportunity o : Trigger.new){ // Add a new validation to the package // Applies to versions of the managed package greater than 1.0 if (System.requestVersion().compareTo(new Version(1,0)) > 0) { if (o.Probability >= 50 && o.Description == null) { o.addError('All deals over 50% require a description'); } } // Validation applies to all versions of the managed package. if (o.IsWon == true && o.LeadSource == null) { o.addError('A lead source must be provided for all Closed Won deals'); } } } The following test class uses the runAs method to verify the trigger's behavior with and without a specific version: @isTest private class OppTriggerTests{ static testMethod void testOppValidation(){ // Set up 50% opportunity with no description Opportunity o = new Opportunity(); o.Name = 'Test Job'; o.Probability = 50; o.StageName = 'Prospect'; o.CloseDate = System.today(); // Test running as latest package version try{ insert o; } catch(System.DMLException e){ System.assert( e.getMessage().contains( 'All deals over 50% require a description'), e.getMessage()); } // Run test as managed package version 1.0 System.runAs(new Version(1,0)){ try{ insert o; } catch(System.DMLException e){ System.assert(false, e.getMessage()); } } // Set up a closed won opportunity with no lead source 235
- 238. Developing Apex in Managed Packages Testing Behavior in Package Versions o = new Opportunity(); o.Name = 'Test Job'; o.Probability = 50; o.StageName = 'Prospect'; o.CloseDate = System.today(); o.StageName = 'Closed Won'; // Test running as latest package version try{ insert o; } catch(System.DMLException e){ System.assert( e.getMessage().contains( 'A lead source must be provided for all Closed Won deals'), e.getMessage()); } // Run test as managed package version 1.0 System.runAs(new Version(1,0)){ try{ insert o; } catch(System.DMLException e){ System.assert( e.getMessage().contains( 'A lead source must be provided for all Closed Won deals'), e.getMessage()); } } } } 236
- 239. Chapter 10 Exposing Apex Methods as SOAP Web Services In this chapter ... You can expose your Apex methods as SOAP Web services so that external applications can access your code and your application. To expose your Apex • WebService Methods methods, use WebService Methods. Tip: • Apex SOAP Web services allow an external application to invoke Apex methods through SOAP Web services. Apex callouts enable Apex to invoke external Web or HTTP services. • Apex REST API exposes your Apex classes and methods as REST Web services. See Exposing Apex Classes as REST Web Services. 237
- 240. Exposing Apex Methods as SOAP Web Services WebService Methods WebService Methods Apex class methods can be exposed as custom SOAP Web service calls. This allows an external application to invoke an Apex Web service to perform an action in Salesforce. Use the webService keyword to define these methods. For example: global class MyWebService { webService static Id makeContact(String lastName, Account a) { Contact c = new Contact(lastName = 'Weissman', AccountId = a.Id); insert c; return c.id; } } A developer of an external application can integrate with an Apex class containing webService methods by generating a WSDL for the class. To generate a WSDL from an Apex class detail page: 1. In the application navigate to Your Name > Setup > Develop > Apex Classes. 2. Click the name of a class that contains webService methods. 3. Click Generate WSDL. Exposing Data with WebService Methods Invoking a custom webService method always uses system context. Consequently, the current user's credentials are not used, and any user who has access to these methods can use their full power, regardless of permissions, field-level security, or sharing rules. Developers who expose methods with the webService keyword should therefore take care that they are not inadvertently exposing any sensitive data. Warning: Apex class methods that are exposed through the API with the webService keyword don't enforce object permissions and field-level security by default. We recommend that you make use of the appropriate object or field describe result methods to check the current user’s access level on the objects and fields that the webService method is accessing. See Schema.DescribeSObjectResult and Schema.DescribeFieldResult. Also, sharing rules (record-level access) are enforced only when declaring a class with the with sharing keyword. This requirement applies to all Apex classes, including to classes that contain webService methods. To enforce sharing rules for webService methods, declare the class that contains these methods with the with sharing keyword. See Using the with sharing or without sharing Keywords. Considerations for Using the WebService Keyword When using the webService keyword, keep the following considerations in mind: • You cannot use the webService keyword when defining a class. However, you can use it to define top-level, outer class methods, and methods of an inner class. • You cannot use the webService keyword to define an interface, or to define an interface's methods and variables. • System-defined enums cannot be used in Web service methods. • You cannot use the webService keyword in a trigger because you cannot define a method in a trigger. • All classes that contain methods defined with the webService keyword must be declared as global. If a method or inner class is declared as global, the outer, top-level class must also be defined as global. 238
- 241. Exposing Apex Methods as SOAP Web Services Considerations for Using the WebService Keyword • Methods defined with the webService keyword are inherently global. These methods can be used by any Apex code that has access to the class. You can consider the webService keyword as a type of access modifier that enables more access than global. • You must define any method that uses the webService keyword as static. • You cannot deprecate webService methods or variables in managed package code. • Because there are no SOAP analogs for certain Apex elements, methods defined with the webService keyword cannot take the following elements as parameters. While these elements can be used within the method, they also cannot be marked as return values. ◊ Maps ◊ Sets ◊ Pattern objects ◊ Matcher objects ◊ Exception objects • You must use the webService keyword with any member variables that you want to expose as part of a Web service. You should not mark these member variables as static. • Salesforce denies access to Web service and executeanonymous requests from an AppExchange package that has Restricted access. • Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String value that is too long for the field. The following example shows a class with Web service member variables as well as a Web service method: global class SpecialAccounts { global class AccountInfo { webService String AcctName; webService Integer AcctNumber; } webService static Account createAccount(AccountInfo info) { Account acct = new Account(); acct.Name = info.AcctName; acct.AccountNumber = String.valueOf(info.AcctNumber); insert acct; return acct; } webService static Id [] createAccounts(Account parent, Account child, Account grandChild) { insert parent; child.parentId = parent.Id; insert child; grandChild.parentId = child.Id; insert grandChild; Id [] results = new Id[3]; results[0] = parent.Id; results[1] = child.Id; results[2] = grandChild.Id; return results; } testMethod static void testAccountCreate() { AccountInfo info = new AccountInfo(); info.AcctName = 'Manoj Cheenath'; 239
- 242. Exposing Apex Methods as SOAP Web Services Overloading Web Service Methods info.AcctNumber = 12345; Account acct = SpecialAccounts.createAccount(info); System.assert(acct != null); } } You can invoke this Web service using AJAX. For more information, see Apex in AJAX on page 109. Overloading Web Service Methods SOAP and WSDL do not provide good support for overloading methods. Consequently, Apex does not allow two methods marked with the webService keyword to have the same name. Web service methods that have the same name in the same class generate a compile-time error. 240
- 243. Chapter 11 Exposing Apex Classes as REST Web Services In this chapter ... You can expose your Apex classes and methods so that external applications can access your code and your application through the REST architecture. This • Introduction to Apex REST section provides an overview of how to expose your Apex classes as REST Web • Apex REST Annotations services. You'll learn about the class and method annotations and see code samples • Apex REST Methods that show you how to implement this functionality. • Exposing Data with Apex REST Web Service Methods • Apex REST Code Samples 241
- 244. Exposing Apex Classes as REST Web Services Introduction to Apex REST Introduction to Apex REST You can expose your Apex class and methods so that external applications can access your code and your application through the REST architecture. This is done by defining your Apex class with the @RestResource annotation to expose it as a REST resource. Similarly, add annotations to your methods to expose them through REST. For more information, see Apex REST Annotations on page 142 Governor Limits Calls to Apex REST classes count against the organization's API governor limits. All standard Apex governor limits apply to Apex REST classes. For example, the maximum request or response size is 3 MB. For more information, see Understanding Execution Governors and Limits. Authentication Apex REST supports these authentication mechanisms: • OAuth 2.0 • Session ID See Step Two: Set Up Authorization in the REST API Developer's Guide. Apex REST Annotations Six new annotations have been added that enable you to expose an Apex class as a RESTful Web service. • @RestResource(urlMapping='/yourUrl') • @HttpDelete • @HttpGet • @HttpPatch • @HttpPost • @HttpPut Apex REST Methods Apex REST supports two formats for representations of resources: JSON and XML. JSON representations are passed by default in the body of a request or response, and the format is indicated by the Content-Type property in the HTTP header. You can retrieve the body as a Blob from the HttpRequest object if there are no parameters to the Apex method. If parameters are defined in the Apex method, an attempt is made to deserialize the request body into those parameters. If the Apex method has a non-void return type, the resource representation is serialized into the response body. Only the following return and parameter types are allowed: • Apex primitives (excluding sObject and Blob). • sObjects • Lists or maps of Apex primitives or sObjects (only maps with String keys are supported) 242
- 245. Exposing Apex Classes as REST Web Services Apex REST Methods • User-defined types that contain member variables of the types listed above. Methods annotated with @HttpGet or @HttpDelete should have no parameters. This is because GET and DELETE requests have no request body, so there's nothing to deserialize. A single Apex class annotated with @RestResource can't have multiple methods annotated with the same HTTP request method. For example, the same class can't have two methods annotated with @HttpGet. Note: Apex REST currently doesn't support requests of Content-Type multipart/form-data. Apex REST Method Considerations Here are a few points to consider when you define Apex REST methods. • RestRequest and RestResponse objects are available by default in your Apex methods through the static RestContext object. This example shows how to access these objects through RestContext: RestRequest req = RestContext.request; RestResponse res = RestContext.response; • If the Apex method has no parameters, Apex REST copies the HTTP request body into the RestRequest.requestBody property. If the method has parameters, then Apex REST attempts to deserialize the data into those parameters and the data won't be deserialized into the RestRequest.requestBody property. • Apex REST uses similar serialization logic for the response. An Apex method with a non-void return type will have the return value serialized into RestResponse.responseBody. • Apex REST methods can be used in managed and unmanaged packages. When calling Apex REST methods that are contained in a managed package, you need to include the managed package namespace in the REST call URL. For example, if the class is contained in a managed package namespace called packageNamespace and the Apex REST methods use a URL mapping of /MyMethod/*, the URL used via REST to call these methods would be of the form https://instance.salesforce.com/services/apexrest/packageNamespace/MyMethod/. For more information about managed packages, see Developing Apex in Managed Packages. User-Defined Types You can use user-defined types for parameters in your Apex REST methods. Apex REST deserializes request data into public, private, or global class member variables of the user-defined type, unless the variable is declared as static or transient. For example, an Apex REST method that contains a user-defined type parameter might look like the following: @RestResource(urlMapping='/user_defined_type_example/*') global with sharing class MyOwnTypeRestResource { @HttpPost global static MyUserDefinedClass echoMyType(MyUserDefinedClass ic) { return ic; } global class MyUserDefinedClass { global String string1; global String string2 { get; set; } private String privateString; global transient String transientString; global static String staticString; } 243
- 246. Exposing Apex Classes as REST Web Services Apex REST Methods } Valid JSON and XML request data for this method would look like: { "ic" : { "string1" : "value for string1", "string2" : "value for string2", "privateString" : "value for privateString" } } <request> <ic> <string1>value for string1</string1> <string2>value for string2</string2> <privateString>value for privateString</privateString> </ic> </request> If a value for staticString or transientString is provided in the example request data above, an HTTP 400 status code response is generated. Note that the public, private, or global class member variables must be types allowed by Apex REST: • Apex primitives (excluding sObject and Blob). • sObjects • Lists or maps of Apex primitives or sObjects (only maps with String keys are supported) When creating user-defined types used as Apex REST method parameters, avoid introducing any class member variable definitions that result in cycles (definitions that depend on each other) at run time in your user-defined types. Here's a simple example: @RestResource(urlMapping='/CycleExample/*') global with sharing class ApexRESTCycleExample { @HttpGet global static MyUserDef1 doCycleTest() { MyUserDef1 def1 = new MyUserDef1(); MyUserDef2 def2 = new MyUserDef2(); def1.userDef2 = def2; def2.userDef1 = def1; return def1; } global class MyUserDef1 { MyUserDef2 userDef2; } global class MyUserDef2 { MyUserDef1 userDef1; } } The code in the previous example compiles, but at run time when a request is made, Apex REST detects a cycle between instances of def1 and def2, and generates an HTTP 400 status code error response. Request Data Considerations Some additional things to keep in mind for the request data for your Apex REST methods: 244
- 247. Exposing Apex Classes as REST Web Services Apex REST Methods • The name of the Apex parameters matter, although the order doesn’t. For example, valid requests in both XML and JSON look like the following: @HttpPost global static void myPostMethod(String s1, Integer i1, Boolean b1, String s2) { "s1" : "my first string", "i1" : 123, "s2" : "my second string", "b1" : false } <request> <s1>my first string</s1> <i1>123</i1> <s2>my second string</s2> <b1>false</b1> </request> • Some parameter and return types can't be used with XML as the Content-Type for the request or as the accepted format for the response, and hence, methods with these parameter or return types can't be used with XML. Maps or collections of collections, for example, List<List<String>> aren't supported. However, you can use these types with JSON. If the parameter list includes a type that's invalid for XML and XML is sent, an HTTP 415 status code is returned. If the return type is a type that's invalid for XML and XML is the requested response format, an HTTP 406 status code is returned. • For request data in either JSON or XML, valid values for Boolean parameters are: true, false (both of these are treated as case-insensitive), 1 and 0 (the numeric values, not strings of “1” or “0”). Any other values for Boolean parameters result in an error. • If the JSON or XML request data contains multiple parameters of the same name, this results in an HTTP 400 status code error response. For example, if your method specifies an input parameter named x, the following JSON request data results in an error: { "x" : "value1", "x" : "value2" } Similarly, for user-defined types, if the request data includes data for the same user-defined type member variable multiple times, this results in an error. For example, given this Apex REST method and user-defined type: @RestResource(urlMapping='/DuplicateParamsExample/*') global with sharing class ApexRESTDuplicateParamsExample { @HttpPost global static MyUserDef1 doDuplicateParamsTest(MyUserDef1 def) { return def; } global class MyUserDef1 { Integer i; } } 245
- 248. Exposing Apex Classes as REST Web Services Apex REST Methods The following JSON request data also results in an error: { "def" : { "i" : 1, "i" : 2 } } • If you need to specify a null value for one of your parameters in your request data, you can either omit the parameter entirely or specify a null value. In JSON, you can specify null as the value. In XML, you must use the http://www.w3.org/2001/XMLSchema-instance namespace with a nil value. • For XML request data, you must specify an XML namespace that references any Apex namespace your method uses. So, for example, if you define an Apex REST method such as: @RestResource(urlMapping='/namespaceExample/*') global class MyNamespaceTest { @HttpPost global static MyUDT echoTest(MyUDT def, String extraString) { return def; } global class MyUDT { Integer count; } } You can use the following XML request data: <request> <def xmlns:MyUDT="http://soap.sforce.com/schemas/class/MyNamespaceTest"> <MyUDT:count>23</MyUDT:count> </def> <extraString>test</extraString> </request> For more information on XML namespaces and Apex, see XML Namespaces. Response Status Codes The status code of a response is set automatically. This table lists some HTTP status codes and what they mean in the context of the HTTP request method. For the full list of response status codes, see RestResponse Methods. Request Method Response Status Description Code GET 200 The request was successful. PATCH 200 The request was successful and the return type is non-void. PATCH 204 The request was successful and the return type is void. DELETE, GET, PATCH, POST, 400 An unhandled user exception occurred. PUT DELETE, GET, PATCH, POST, 403 You don't have access to the specified Apex class. PUT 246
- 249. Exposing Apex Classes as REST Web Services Exposing Data with Apex REST Web Service Methods Request Method Response Status Description Code DELETE, GET, PATCH, POST, 404 The URL is unmapped in an existing @RestResource PUT annotation. DELETE, GET, PATCH, POST, 404 The URL extension is unsupported. PUT DELETE, GET, PATCH, POST, 404 The Apex class with the specified namespace couldn't be PUT found. DELETE, GET, PATCH, POST, 405 The request method doesn't have a corresponding Apex PUT method. DELETE, GET, PATCH, POST, 406 The Content-Type property in the header was set to a value PUT other than JSON or XML. DELETE, GET, PATCH, POST, 406 The header specified in the HTTP request is not supported. PUT GET, PATCH, POST, PUT 406 The XML return type specified for format is unsupported. DELETE, GET, PATCH, POST, 415 The XML parameter type is unsupported. PUT DELETE, GET, PATCH, POST, 415 The Content-Header Type specified in the HTTP request PUT header is unsupported. DELETE, GET, PATCH, POST, 500 An unhandled Apex exception occurred. PUT Exposing Data with Apex REST Web Service Methods Invoking a custom Apex REST Web service method always uses system context. Consequently, the current user's credentials are not used, and any user who has access to these methods can use their full power, regardless of permissions, field-level security, or sharing rules. Developers who expose methods using the Apex REST annotations should therefore take care that they are not inadvertently exposing any sensitive data. Warning: Apex class methods that are exposed through the Apex REST API don't enforce object permissions and field-level security by default. We recommend that you make use of the appropriate object or field describe result methods to check the current user’s access level on the objects and fields that the Apex REST API method is accessing. See Schema.DescribeSObjectResult and Schema.DescribeFieldResult. Also, sharing rules (record-level access) are enforced only when declaring a class with the with sharing keyword. This requirement applies to all Apex classes, including to classes that are exposed through Apex REST API. To enforce sharing rules for Apex REST API methods, declare the class that contains these methods with the with sharing keyword. See Using the with sharing or without sharing Keywords. 247
- 250. Exposing Apex Classes as REST Web Services Apex REST Code Samples Apex REST Code Samples These code samples show you how to expose Apex classes and methods through the REST architecture and how to call those resources from a client. • Apex REST Basic Code Sample: Provides an example of an Apex REST class with three methods that you can call to delete a record, get a record, and update a record. • Apex REST Code Sample Using RestRequest: Provides an example of an Apex REST class that adds an attachment to a record by using the RestRequest object Apex REST Basic Code Sample This sample shows you how to implement a simple REST API in Apex that handles three different HTTP request methods. For more information about authenticating with cURL, see the Quick Start section of the REST API Developer's Guide. 1. Create an Apex class in your instance, by clicking Your Name > Setup > Develop > Apex Classes > New and add this code to your new class: @RestResource(urlMapping='/Account/*') global with sharing class MyRestResource { @HttpDelete global static void doDelete() { RestRequest req = RestContext.request; RestResponse res = RestContext.response; String accountId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1); Account account = [SELECT Id FROM Account WHERE Id = :accountId]; delete account; } @HttpGet global static Account doGet() { RestRequest req = RestContext.request; RestResponse res = RestContext.response; String accountId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1); Account result = [SELECT Id, Name, Phone, Website FROM Account WHERE Id = :accountId]; return result; } @HttpPost global static String doPost(String name, String phone, String website) { Account account = new Account(); account.Name = name; account.phone = phone; account.website = website; insert account; return account.Id; } } 2. To call the doGet method from a client, open a command-line window and execute the following cURL command to retrieve an account by ID: curl -H "Authorization: Bearer sessionId" "https://instance.salesforce.com/services/apexrest/Account/accountId" 248
- 251. Exposing Apex Classes as REST Web Services Apex REST Code Sample Using RestRequest • Replace sessionId with the <sessionId> element that you noted in the login response. • Replace instance with your <serverUrl> element. • Replace accountId with the ID of an account which exists in your organization. After calling the doGet method, Salesforce returns a JSON response with data such as the following: { "attributes" : { "type" : "Account", "url" : "/services/data/v22.0/sobjects/Account/accountId" }, "Id" : "accountId", "Name" : "Acme" } Note: The cURL examples in this section don't use a namespaced Apex class so you won't see the namespace in the URL. 3. Create a file called account.txt to contain the data for the account you will create in the next step. { "name" : "Wingo Ducks", "phone" : "707-555-1234", "website" : "www.wingo.ca.us" } 4. Using a command-line window, execute the following cURL command to create a new account: curl -H "Authorization: Bearer sessionId" -H "Content-Type: application/json" -d @account.txt "https://instance.salesforce.com/services/apexrest/Account/" After calling the doPost method, Salesforce returns a response with data such as the following: "accountId" The accountId is the ID of the account you just created with the POST request. 5. Using a command-line window, execute the following cURL command to delete an account by specifying the ID: curl —X DELETE —H "Authorization: Bearer sessionId" "https://instance.salesforce.com/services/apexrest/Account/accountId" See Also: Apex REST Annotations Apex REST Code Sample Using RestRequest The following sample shows you how to add an attachment to a case by using the RestRequest object. For more information about authenticating with cURL, see the Quick Start section of the REST API Developer's Guide. In this code, the binary file data is stored in the RestRequest object, and the Apex service class accesses the binary data in the RestRequest object . 249
- 252. Exposing Apex Classes as REST Web Services Apex REST Code Sample Using RestRequest 1. Create an Apex class in your instance, by clicking Your Name > Setup > Develop > Apex Classes. Click New and add the following code to your new class: @RestResource(urlMapping='/CaseManagement/v1/*') global with sharing class CaseMgmtService { @HttpPost global static String attachPic(){ RestRequest req = RestContext.request; RestResponse res = Restcontext.response; Id caseId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1); Blob picture = req.requestBody; Attachment a = new Attachment (ParentId = caseId, Body = picture, ContentType = 'image/jpg', Name = 'VehiclePicture'); insert a; return a.Id; } } 2. Open a command-line window and execute the following cURL command to upload the attachment to a case: curl -H "Authorization: Bearer sessionId" -H "X-PrettyPrint: 1" -H "Content-Type: image/jpeg" --data-binary @file "https://instance.salesforce.com/services/apexrest/CaseManagement/v1/caseId" • Replace sessionId with the <sessionId> element that you noted in the login response. • Replace instance with your <serverUrl> element. • Replace caseId with the ID of the case you want to add the attachment to. • Replace file with the path and file name of the file you want to attach. Your command should look something like this (with the sessionId replaced with your session ID): curl -H "Authorization: Bearer sessionId" -H "X-PrettyPrint: 1" -H "Content-Type: image/jpeg" --data-binary @c:testvehiclephoto1.jpg "https://na1.salesforce.com/services/apexrest/CaseManagement/v1/500D0000003aCts" Note: The cURL examples in this section don't use a namespaced Apex class so you won't see the namespace in the URL. The Apex class returns a JSON response that contains the attachment ID such as the following: "00PD0000001y7BfMAI" 3. To verify that the attachment and the image were added to the case, navigate to Cases and select the All Open Cases view. Click on the case and then scroll down to the Attachments related list. You should see the attachment you just created. 250
- 253. Chapter 12 Invoking Callouts Using Apex In this chapter ... An Apex callout enables you to tightly integrate your Apex with an external service by making a call to an external Web service or sending a HTTP request • Adding Remote Site Settings from Apex code and then receiving the response. Apex provides integration with • SOAP Services: Defining a Class Web services that utilize SOAP and WSDL, or HTTP services (RESTful from a WSDL Document services). • Invoking HTTP Callouts Note: Before any Apex callout can call an external site, that site must • Using Certificates be registered in the Remote Site Settings page, or the callout fails. • Callout Limits and Limitations Salesforce prevents calls to unauthorized network addresses. To learn more about the two types of callouts, see: • SOAP Services: Defining a Class from a WSDL Document on page 252 • Invoking HTTP Callouts on page 262 Tip: Callouts enable Apex to invoke external web or HTTP services. Apex Web services allow an external application to invoke Apex methods through Web services. 251
- 254. Invoking Callouts Using Apex Adding Remote Site Settings Adding Remote Site Settings Before any Apex callout can call an external site, that site must be registered in the Remote Site Settings page, or the callout fails. Salesforce prevents calls to unauthorized network addresses. To add a remote site setting: 1. Click Your Name > Setup > Security Controls > Remote Site Settings. 2. Click New Remote Site. 3. Enter a descriptive term for the Remote Site Name. 4. Enter the URL for the remote site. 5. Optionally, enter a description of the site. 6. Click Save. SOAP Services: Defining a Class from a WSDL Document Classes can be automatically generated from a WSDL document that is stored on a local hard drive or network. Creating a class by consuming a WSDL document allows developers to make callouts to the external Web service in their Apex code. Note: Use Outbound Messaging to handle integration solutions when possible. Use callouts to third-party Web services only when necessary. To generate an Apex class from a WSDL: 1. In the application, click Your Name > Setup > Develop > Apex Classes. 2. Click Generate from WSDL. 3. Click Browse to navigate to a WSDL document on your local hard drive or network, or type in the full path. This WSDL document is the basis for the Apex class you are creating. Note: The WSDL document that you specify might contain a SOAP endpoint location that references an outbound port. For security reasons, Salesforce restricts the outbound ports you may specify to one of the following: • 80: This port only accepts HTTP connections. • 443: This port only accepts HTTPS connections. • 1024–66535 (inclusive): These ports accept HTTP or HTTPS connections. 4. Click Parse WSDL to verify the WSDL document contents. The application generates a default class name for each namespace in the WSDL document and reports any errors. Parsing will fail if the WSDL contains schema types or schema constructs that are not supported by Apex classes, or if the resulting classes exceed 1 million character limit on Apex classes. For example, the Salesforce SOAP API WSDL cannot be parsed. 5. Modify the class names as desired. While you can save more than one WSDL namespace into a single class by using the same class name for each namespace, Apex classes can be no more than 1 million characters total. 252
- 255. Invoking Callouts Using Apex Invoking an External Service 6. Click Generate Apex. The final page of the wizard shows which classes were successfully generated, along with any errors from other classes. The page also provides a link to view successfully generated code. The successfully-generated Apex class includes stub and type classes for calling the third-party Web service represented by the WSDL document. These classes allow you to call the external Web service from Apex. Note the following about the generated Apex: • If a WSDL document contains an Apex reserved word, the word is appended with _x when the Apex class is generated. For example, limit in a WSDL document converts to limit_x in the generated Apex class. See Reserved Keywords. For details on handling characters in element names in a WSDL that are not supported in Apex variable names, see Considerations Using WSDLs. • If an operation in the WSDL has an output message with more than one element, the generated Apex wraps the elements in an inner class. The Apex method that represents the WSDL operation returns the inner class instead of the individual elements. • Since periods (.) are not allowed in Apex class names, any periods in WSDL names used to generate Apex classes are replaced by underscores (_) in the generated Apex code. After you have generated a class from the WSDL, you can invoke the external service referenced by the WSDL. Note: Before you can use the samples in the rest of this topic, you must copy the Apex class docSampleClass from Understanding the Generated Code and add it to your organization. Invoking an External Service To invoke an external service after using its WSDL document to generate an Apex class, create an instance of the stub in your Apex code and call the methods on it. For example, to invoke the StrikeIron IP address lookup service from Apex, you could write code similar to the following: // Create the stub strikeironIplookup.DNSSoap dns = new strikeironIplookup.DNSSoap(); // Set up the license header dns.LicenseInfo = new strikeiron.LicenseInfo(); dns.LicenseInfo.RegisteredUser = new strikeiron.RegisteredUser(); dns.LicenseInfo.RegisteredUser.UserID = 'you@company.com'; dns.LicenseInfo.RegisteredUser.Password = 'your-password'; // Make the Web service call strikeironIplookup.DNSInfo info = dns.DNSLookup('www.myname.com'); HTTP Header Support You can set the HTTP headers on a Web service callout. For example, you can use this feature to set the value of a cookie in an authorization header. To set HTTP headers, add inputHttpHeaders_x and outputHttpHeaders_x to the stub. Note: In API versions 16.0 and earlier, HTTP responses for callouts are always decoded using UTF-8, regardless of the Content-Type header. In API versions 17.0 and later, HTTP responses are decoded using the encoding specified in the Content-Type header. The following samples work with the sample WSDL file in Understanding the Generated Code on page 257: 253
- 256. Invoking Callouts Using Apex Supported WSDL Features Sending HTTP Headers on a Web Service Callout docSample.DocSamplePort stub = new docSample.DocSamplePort(); stub.inputHttpHeaders_x = new Map<String, String>(); //Setting a basic authentication header stub.inputHttpHeaders_x.put('Authorization', 'Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ=='); //Setting a cookie header stub.inputHttpHeaders_x.put('Cookie', 'name=value'); //Setting a custom HTTP header stub.inputHttpHeaders_x.put('myHeader', 'myValue'); String input = 'This is the input string'; String output = stub.EchoString(input); If a value for inputHttpHeaders_x is specified, it overrides the standard headers set. Accessing HTTP Response Headers from a Web Service Callout Response docSample.DocSamplePort stub = new docSample.DocSamplePort(); stub.outputHttpHeaders_x = new Map<String, String>(); String input = 'This is the input string'; String output = stub.EchoString(input); //Getting cookie header String cookie = stub.outputHttpHeaders_x.get('Set-Cookie'); //Getting custom header String myHeader = stub.outputHttpHeaders_x.get('My-Header'); The value of outputHttpHeaders_x is null by default. You must set outputHttpHeaders_x before you have access to the content of headers in the response. Supported WSDL Features Apex supports only the document literal wrapped WSDL style and the following primitive and built-in datatypes: Schema Type Apex Type xsd:anyURI String xsd:boolean Boolean xsd:date Date xsd:dateTime Datetime xsd:double Double xsd:float Double xsd:int Integer xsd:integer Integer xsd:language String 254
- 257. Invoking Callouts Using Apex Supported WSDL Features Schema Type Apex Type xsd:long Long xsd:Name String xsd:NCName String xsd:nonNegativeInteger Integer xsd:NMTOKEN String xsd:NMTOKENS String xsd:normalizedString String xsd:NOTATION String xsd:positiveInteger Integer xsd:QName String xsd:short Integer xsd:string String xsd:time Datetime xsd:token String xsd:unsignedInt Integer xsd:unsignedLong Long xsd:unsignedShort Integer Note: The Salesforce datatype anyType is not supported in WSDLs used to generate Apex code that is saved using API version 15.0 and later. For code saved using API version 14.0 and earlier, anyType is mapped to String. Apex also supports the following schema constructs: • xsd:all, in Apex code saved using API version 15.0 and later • xsd:annotation, in Apex code saved using API version 15.0 and later • xsd:attribute, in Apex code saved using API version 15.0 and later • xsd:choice, in Apex code saved using API version 15.0 and later • xsd:element. In Apex code saved using API version 15.0 and later, the ref attribute is also supported with the following restrictions: ◊ You cannot call a ref in a different namespace. ◊ A global element cannot use ref. ◊ If an element contains ref, it cannot also contain name or type. • xsd:sequence The following data types are only supported when used as call ins, that is, when an external Web service calls an Apex Web service method. These data types are not supported as callouts, that is, when an Apex Web service method calls an external Web service. 255
- 258. Invoking Callouts Using Apex Supported WSDL Features • blob • decimal • enum Apex does not support any other WSDL constructs, types, or services, including: • RPC/encoded services • WSDL files with mulitple portTypes, multiple services, or multiple bindings • WSDL files that import external schemas. For example, the following WSDL fragment imports an external schema, which is not supported: <wsdl:types> <xsd:schema elementFormDefault="qualified" targetNamespace="http://s3.amazonaws.com/doc/2006-03-01/"> <xsd:include schemaLocation="AmazonS3.xsd"/> </xsd:schema> </wsdl:types> However, an import within the same schema is supported. In the following example, the external WSDL is pasted into the WSDL you are converting: <wsdl:types> <xsd:schema xmlns:tns="http://s3.amazonaws.com/doc/2006-03-01/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="http://s3.amazonaws.com/doc/2006-03-01/"> <xsd:element name="CreateBucket"> <xsd:complexType> <xsd:sequence> [...] </xsd:schema> </wsdl:types> • Any schema types not documented in the previous table • WSDLs that exceed the size limit, including the Salesforce WSDLs • WSDLs that don’t use the document literal wrapped style. The following WSDL snippet doesn’t use document literal wrapped style and results in an “Unable to find complexType” error when imported. <wsdl:types> <xsd:schema targetNamespace="http://test.org/AccountPollInterface/" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <xsd:element name="SFDCPollAccountsResponse" type="tns:SFDCPollResponse"/> <xsd:simpleType name="SFDCPollResponse"> <xsd:restriction base="xsd:string" /> </xsd:simpleType> </xsd:schema> </wsdl:types> This modified version wraps the simpleType element as a complexType that contains a sequence of elements. This follows the document literal style and is supported. <wsdl:types> <xsd:schema targetNamespace="http://test.org/AccountPollInterface/" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> 256
- 259. Invoking Callouts Using Apex Understanding the Generated Code <xsd:element name="SFDCPollAccountsResponse" type="tns:SFDCPollResponse" /> <xsd:complexType name="SFDCPollResponse"> <xsd:sequence> <xsd:element name="SFDCOutput" type="xsd:string" /> </xsd:sequence> </xsd:complexType> </xsd:schema> </wsdl:types> Understanding the Generated Code The following example shows how an Apex class is created from a WSDL document. The Apex class is auto-generated for you when you import the WSDL. The following code shows a sample WSDL document: <wsdl:definitions xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:s="http://www.w3.org/2001/XMLSchema" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:tns="http://doc.sample.com/docSample" targetNamespace="http://doc.sample.com/docSample" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"> <!-- Above, the schema targetNamespace maps to the Apex class name. --> <!-- Below, the type definitions for the parameters are listed. Each complexType and simpleType parameteris mapped to an Apex class inside the parent class for the WSDL. Then, each element in the complexType is mapped to a public field inside the class. --> <wsdl:types> <s:schema elementFormDefault="qualified" targetNamespace="http://doc.sample.com/docSample"> <s:element name="EchoString"> <s:complexType> <s:sequence> <s:element minOccurs="0" maxOccurs="1" name="input" type="s:string" /> </s:sequence> </s:complexType> </s:element> <s:element name="EchoStringResponse"> <s:complexType> <s:sequence> <s:element minOccurs="0" maxOccurs="1" name="EchoStringResult" type="s:string" /> </s:sequence> </s:complexType> </s:element> </s:schema> </wsdl:types> <!--The stub below defines operations. --> <wsdl:message name="EchoStringSoapIn"> <wsdl:part name="parameters" element="tns:EchoString" /> </wsdl:message> <wsdl:message name="EchoStringSoapOut"> <wsdl:part name="parameters" element="tns:EchoStringResponse" /> </wsdl:message> <wsdl:portType name="DocSamplePortType"> <wsdl:operation name="EchoString"> <wsdl:input message="tns:EchoStringSoapIn" /> 257
- 260. Invoking Callouts Using Apex Understanding the Generated Code <wsdl:output message="tns:EchoStringSoapOut" /> </wsdl:operation> </wsdl:portType> <!--The code below defines how the types map to SOAP. --> <wsdl:binding name="DocSampleBinding" type="tns:DocSamplePortType"> <wsdl:operation name="EchoString"> <soap:operation soapAction="urn:dotnet.callouttest.soap.sforce.com/EchoString" style="document" /> <wsdl:input> <soap:body use="literal" /> </wsdl:input> <wsdl:output> <soap:body use="literal" /> </wsdl:output> </wsdl:operation> </wsdl:binding> <!-- Finally, the code below defines the endpoint, which maps to the endpoint in the class --> <wsdl:service name="DocSample"> <wsdl:port name="DocSamplePort" binding="tns:DocSampleBinding"> <soap:address location="http://YourServer/YourService" /> </wsdl:port> </wsdl:service> </wsdl:definitions> From this WSDL document, the following Apex class is auto-generated. The class name docSample is the name you specify when importing the WSDL. //Generated by wsdl2apex public class docSample { public class EchoStringResponse_element { public String EchoStringResult; private String[] EchoStringResult_type_info = new String[]{ 'EchoStringResult', 'http://www.w3.org/2001/XMLSchema', 'string','0','1','false'}; private String[] apex_schema_type_info = new String[]{ 'http://doc.sample.com/docSample', 'true'}; private String[] field_order_type_info = new String[]{ 'EchoStringResult'}; } public class DocSamplePort { public String endpoint_x = 'http://YourServer/YourService'; private String[] ns_map_type_info = new String[]{ 'http://doc.sample.com/docSample', 'docSample'}; public String EchoString(String input) { docSample.EchoString_element request_x = new docSample.EchoString_element(); 258
- 261. Invoking Callouts Using Apex Testing Web Service Callouts docSample.EchoStringResponse_element response_x; request_x.input = input; Map<String, docSample.EchoStringResponse_element> response_map_x = new Map<String, docSample.EchoStringResponse_element>(); response_map_x.put('response_x', response_x); WebServiceCallout.invoke( this, request_x, response_map_x, new String[]{endpoint_x, 'urn:dotnet.callouttest.soap.sforce.com/EchoString', 'http://doc.sample.com/docSample', 'EchoString', 'http://doc.sample.com/docSample', 'EchoStringResponse', 'docSample.EchoStringResponse_element'} ); response_x = response_map_x.get('response_x'); return response_x.EchoStringResult; } } public class EchoString_element { public String input; private String[] input_type_info = new String[]{ 'input', 'http://www.w3.org/2001/XMLSchema', 'string','0','1','false'}; private String[] apex_schema_type_info = new String[]{ 'http://doc.sample.com/docSample', 'true'}; private String[] field_order_type_info = new String[]{'input'}; } } Note the following mappings from the original WSDL document: • The WSDL target namespace maps to the Apex class name. • Each complex type becomes a class. Each element in the type is a public field in the class. • The WSDL port name maps to the stub class. • Each operation in the WSDL maps to a public method. The class generated above can be used to invoke external Web services. The following code shows how to call the echoString method on the external server: docSample.DocSamplePort stub = new docSample.DocSamplePort(); String input = 'This is the input string'; String output = stub.EchoString(input); Testing Web Service Callouts Generated code is saved as an Apex class containing the methods you can invoke for calling the Web service. To deploy or package this Apex class and other accompanying code, 75% of the code must have test coverage, including the methods in the generated class. By default, test methods don’t support Web service callouts and tests that perform Web service callouts are skipped. To prevent tests from being skipped and to increase code coverage, Apex provides the built-in WebServiceMock interface and the Test.setMock method that you can use to receive fake responses in a test method. 259
- 262. Invoking Callouts Using Apex Testing Web Service Callouts Specifying a Mock Response for Testing Web Service Callouts When you create an Apex class from a WSDL, the methods in the auto-generated class call WebServiceCallout.invoke, which performs the callout to the external service. When testing these methods, you can instruct the Apex runtime to generate a fake response whenever WebServiceCallout.invoke is called. To do so, implement the WebServiceMock interface and specify a fake response that the Apex runtime should send. Here are the steps in more detail. First, implement the WebServiceMock interface and specify the fake response in the doInvoke method. global class YourWebServiceMockImpl implements WebServiceMock { global void doInvoke( Object stub, Object request, Map<String, Object> response, String endpoint, String soapAction, String requestName, String responseNS, String responseName, String responseType) { // Create response element from the autogenerated class. // Populate response element. // Add response element to the response parameter, as follows: response.put('response_x', responseElement); } } Note: • The class implementing the WebServiceMock interface can be either global or public. • You can annotate this class with @isTest since it will be used only in test context. In this way, you can exclude it from your organization’s code size limit of 3 MB. Now that you have specified the values of the fake response, instruct the Apex runtime to send this fake response by calling Test.setMock in your test method. For the first argument, pass WebServiceMock.class, and for the second argument, pass a new instance of your interface implementation of WebServiceMock, as follows: Test.setMock(WebServiceMock.class, new YourWebServiceMockImpl()); After this point, if a Web service callout is invoked in test context, the callout is not made and you receive the mock response specified in your doInvoke method implementation. Note: If the code that performs the callout is in a managed package, you must call Test.setMock from a test method in the same package with the same namespace to mock the callout. This is a full example that shows how to test a Web service callout. The implementation of the WebServiceMock interface is listed first. This example implements the doInvoke method, which returns the response you specify. In this case, the response element of the auto-generated class is created and assigned a value. Next, the response Map parameter is populated with this fake response. This example is based on the WSDL listed in Understanding the Generated Code. Import this WSDL and generate a class called docSample before you save this class. @isTest global class WebServiceMockImpl implements WebServiceMock { global void doInvoke( Object stub, Object request, Map<String, Object> response, 260
- 263. Invoking Callouts Using Apex Considerations Using WSDLs String endpoint, String soapAction, String requestName, String responseNS, String responseName, String responseType) { docSample.EchoStringResponse_element respElement = new docSample.EchoStringResponse_element(); respElement.EchoStringResult = 'Mock response'; response.put('response_x', respElement); } } This is the method that makes a Web service callout. public class WebSvcCallout { public static String callEchoString(String input) { docSample.DocSamplePort sample = new docSample.DocSamplePort(); sample.endpoint_x = 'http://api.salesforce.com/foo/bar'; // This invokes the EchoString method in the generated class String echo = sample.EchoString(input); return echo; } } This is the test class containing the test method that sets the mock callout mode. It calls the callEchoString method in the previous class and verifies that a mock response is received. @isTest private class WebSvcCalloutTest { @isTest static void testEchoString() { // This causes a fake response to be generated Test.setMock(WebServiceMock.class, new WebServiceMockImpl()); // Call the method that invokes a callout String output = WebSvcCallout.callEchoString('Hello World!'); // Verify that a fake result is returned System.assertEquals('Mock response', output); } } See Also: WebServiceMock Interface Considerations Using WSDLs Be aware of the following when generating Apex classes from a WSDL. Mapping Headers Headers defined in the WSDL document become public fields on the stub in the generated class. This is similar to how the AJAX Toolkit and .NET works. 261
- 264. Invoking Callouts Using Apex Invoking HTTP Callouts Understanding Runtime Events The following checks are performed when Apex code is making a callout to an external service. • For information on the timeout limits when making an HTTP request or a Web services call, see Callout Limits and Limitations on page 265. • Circular references in Apex classes are not allowed. • More than one loopback connection to Salesforce domains is not allowed. • To allow an endpoint to be accessed, it should be registered in Your Name > Setup > Security > Remote Site Settings. • To prevent database connections from being held up, no transactions can be open. Understanding Unsupported Characters in Variable Names A WSDL file can include an element name that is not allowed in an Apex variable name. The following rules apply when generating Apex variable names from a WSDL file: • If the first character of an element name is not alphabetic, an x character is prepended to the generated Apex variable name. • If the last character of an element name is not allowed in an Apex variable name, an x character is appended to the generated Apex variable name. • If an element name contains a character that is not allowed in an Apex variable name, the character is replaced with an underscore (_) character. • If an element name contains two characters in a row that are not allowed in an Apex variable name, the first character is replaced with an underscore (_) character and the second one is replaced with an x character. This avoids generating a variable name with two successive underscores, which is not allowed in Apex. • Suppose you have an operation that takes two parameters, a_ and a_x. The generated Apex has two variables, both named a_x. The class will not compile. You must manually edit the Apex and change one of the variable names. Debugging Classes Generated from WSDL Files Salesforce tests code with SOAP API, .NET, and Axis. If you use other tools, you might encounter issues. You can use the debugging header to return the XML in request and response SOAP messages to help you diagnose problems. For more information, see SOAP API and SOAP Headers for Apex on page 629. Invoking HTTP Callouts Apex provides several built-in classes to work with HTTP services and create HTTP requests like GET, POST, PUT, and DELETE. You can use these HTTP classes to integrate to REST-based services. They also allow you to integrate to SOAP-based web services as an alternate option to generating Apex code from a WSDL. By using the HTTP classes, instead of starting with a WSDL, you take on more responsibility for handling the construction of the SOAP message for the request and response. For more information and samples, see HTTP (RESTful) Services Classes. Also, the Force.com Toolkit for Google Data APIs makes extensive use of HTTP callouts. 262
- 265. Invoking Callouts Using Apex Using Certificates Using Certificates You can use two-way SSL authentication by sending a certificate generated in Salesforce or signed by a certificate authority (CA) with your callout. This enhances security as the target of the callout receives the certificate and can use it to authenticate the request against its keystore. To enable two-way SSL authentication for a callout: 1. Generate a certificate. 2. Integrate the certificate with your code. See Using Certificates with SOAP Services and Using Certificates with HTTP Requests. 3. If you are connecting to a third-party and you are using a self-signed certificate, share the Salesforce certificate with them so that they can add the certificate to their keystore. If you are connecting to another application used within your organization, configure your Web or application server to request a client certificate. This process depends on the type of Web or application server you use. For an example of how to set up two-way SSL with Apache Tomcat, see wiki.developerforce.com/index.php/Making_Authenticated_Web_Service_Callouts_Using_Two-Way_SSL. 4. Configure the remote site settings for the callout. Before any Apex callout can call an external site, that site must be registered in the Remote Site Settings page, or the callout fails. Generating Certificates You can use a self-signed certificate generated in Salesforce or a certificate signed by a certificate authority (CA). To generate a certificate for a callout: 1. Go to Your Name > Setup > Security Controls > Certificate and Key Management. 2. Select either Create Self-Signed Certificate or Create CA-Signed Certificate, based on what kind of certificate your external website accepts. You can't change the type of a certificate after you've created it. 3. Enter a descriptive label for the Salesforce certificate. This name is used primarily by administrators when viewing certificates. 4. Enter the Unique Name. This name is automatically populated based on the certificate label you enter. This name can contain only underscores and alphanumeric characters, and must be unique in your organization. It must begin with a letter, not include spaces, not end with an underscore, and not contain two consecutive underscores. Use the Unique Name when referring to the certificate using the Force.com Web services API or Apex. 5. Select a Key Size for your generated certificate and keys. We recommend that you use the default key size of 2048 for security reasons. Selecting 2048 generates a certificate using 2048-bit keys and is valid for two years. Selecting 1024 generates a certificate using 1024-bit keys and is valid for one year. Note: Once you save a Salesforce certificate, you can't change the key size. 6. If you're creating a CA-signed certificate, you must also enter the following information. These fields are joined together to generate a unique certificate. Field Description Common Name The fully qualified domain name of the company requesting the signed certificate. This is generally of the form: http://www.mycompany.com. 263
- 266. Invoking Callouts Using Apex Using Certificates with SOAP Services Field Description Email Address The email address associated with this certificate. Company Either the legal name of your company, or your legal name. Department The branch of your company using the certificate, such as marketing or accounting. City The city where the company resides. State The state where the company resides. Country Code A two-letter code indicating the country where the company resides. For the United States, the value is US. 7. Click Save. After you successfully save a Salesforce certificate, the certificate and corresponding keys are automatically generated. After you create a CA-signed certificate, you must upload the signed certificate before you can use it. See “Uploading Certificate Authority (CA)-Signed Certificates” in the Salesforce online help. Using Certificates with SOAP Services After you have generated a certificate in Salesforce, you can use it to support two-way authentication for a callout to a SOAP Web service. To integrate the certificate with your Apex: 1. Receive the WSDL for the Web service from the third party or generate it from the application you want to connect to. 2. Generate Apex classes from the WSDL for the Web service. See SOAP Services: Defining a Class from a WSDL Document. 3. The generated Apex classes include a stub for calling the third-party Web service represented by the WSDL document. Edit the Apex classes, and assign a value to a clientCertName_x variable on an instance of the stub class. The value must match the Unique Name of the certificate you generated using Your Name > Setup > Security Controls > Certificate and Key Management. The following example illustrates the last step of the previous procedure and works with the sample WSDL file in Understanding the Generated Code. This example assumes that you previously generated a certificate with a Unique Name of DocSampleCert. docSample.DocSamplePort stub = new docSample.DocSamplePort(); stub.clientCertName_x = 'DocSampleCert'; String input = 'This is the input string'; String output = stub.EchoString(input); There is a legacy process for using a certificate obtained from a third party for your organization. Encode your client certificate key in base64, and assign it to the clientCert_x variable on the stub. This is inherently less secure than using a Salesforce certificate because it does not follow security best practices for protecting private keys. When you use a Salesforce certificate, the private key is not shared outside Salesforce. 264
- 267. Invoking Callouts Using Apex Using Certificates with HTTP Requests Note: Do not use a client certificate generated from Your Name > Setup > Develop > API > Generate Client Certificate. You must use a certificate obtained from a third party for your organization if you use the legacy process. The following example illustrates the legacy process and works with the sample WSDL file in Understanding the Generated Code on page 257. docSample.DocSamplePort stub = new docSample.DocSamplePort(); stub.clientCert_x = 'MIIGlgIBAzCCBlAGCSqGSIb3DQEHAaCCBkEEggY9MIIGOTCCAe4GCSqGSIb3DQEHAaCCAd8EggHb'+ 'MIIB1zCCAdMGCyqGSIb3DQEMCgECoIIBgjCCAX4wKAYKKoZIhvcNAQwBAzAaBBSaUMlXnxjzpfdu'+ '6YFwZgJFMklDWFyvCnQeuZpN2E+Rb4rf9MkJ6FsmPDA9MCEwCQYFKw4DAhoFAAQU4ZKBfaXcN45w'+ '9hYm215CcA4n4d0EFJL8jr68wwKwFsVckbjyBz/zYHO6AgIEAA=='; // Password for the keystore stub.clientCertPasswd_x = 'passwd'; String input = 'This is the input string'; String output = stub.EchoString(input); Using Certificates with HTTP Requests After you have generated a certificate in Salesforce, you can use it to support two-way authentication for a callout to an HTTP request. To integrate the certificate with your Apex: 1. Generate a certificate. Note the Unique Name of the certificate. 2. In your Apex, use the setClientCertificateName method of the HttpRequest class. The value used for the argument for this method must match the Unique Name of the certificate that you generated in the previous step. The following example illustrates the last step of the previous procedure. This example assumes that you previously generated a certificate with a Unique Name of DocSampleCert. HttpRequest req = new HttpRequest(); req.setClientCertificateName('DocSampleCert'); Callout Limits and Limitations The following limits and limitations apply when Apex code makes a callout to an HTTP request or a Web services call. The Web services call can be a SOAP API call or any external Web services call. • A single Apex transaction can make a maximum of 10 callouts to an HTTP request or an API call. • The default timeout is 10 seconds. A custom timeout can be defined for each callout. The minimum is 1 millisecond and the maximum is 120 seconds seconds. See the following examples for how to set custom timeouts for Web services or HTTP callouts. • The maximum cumulative timeout for callouts by a single Apex transaction is 120 seconds. This time is additive across all callouts invoked by the Apex transaction. • You can’t make a callout when there are pending operations in the same transaction. Things that result in pending operations are DML statements, asynchronous Apex (such as future methods and batch Apex jobs), scheduled Apex, or sending email. You can make callouts before performing these types of operations. 265
- 268. Invoking Callouts Using Apex Callout Limits and Limitations Setting Callout Timeouts The following example sets a custom timeout for Web services callouts. The example works with the sample WSDL file and the generated DocSamplePort class described in Understanding the Generated Code on page 257. Set the timeout value in milliseconds by assigning a value to the special timeout_x variable on the stub. docSample.DocSamplePort stub = new docSample.DocSamplePort(); stub.timeout_x = 2000; // timeout in milliseconds The following is an example of setting a custom timeout for HTTP callouts: HttpRequest req = new HttpRequest(); req.setTimeout(2000); // timeout in milliseconds 266
- 269. Chapter 13 Reference In this chapter ... The Apex reference contains information about the Apex language. • Apex Data Manipulation Language • Data manipulation language (DML) operations—used to manipulate data (DML) Operations in the database • Apex Standard Classes and Methods • Standard classes and methods—available for primitive data types, collections, sObjects, and other parts of Apex • Apex Classes • Apex classes—prebuilt classes available for your use • Apex Interfaces • Apex interfaces—interfaces you can implement In addition, SOAP API methods and objects are available for Apex. See SOAP API and SOAP Headers for Apex on page 629 in the Appendices section. 267
- 270. Reference Apex Data Manipulation Language (DML) Operations Apex Data Manipulation Language (DML) Operations Use data manipulation language (DML) operations to insert, update, delete, and restore data in a database. You can execute DML operations using two different forms: • Apex DML statements, such as: insert SObject[] • Apex DML database methods, such as: Database.SaveResult[] result = Database.Insert(SObject[]) While most DML operations are available in either form, some exist only in one form or the other. The different DML operation forms enable different types of exception processing: • Use DML statements if you want any error that occurs during bulk DML processing to be thrown as an Apex exception that immediately interrupts control flow (by using try. . .catch blocks). This behavior is similar to the way exceptions are handled in most database procedural languages. • Use DML database methods if you want to allow partial success of a bulk DML operation—if a record fails, the remainder of the DML operation can still succeed. Your application can then inspect the rejected records and possibly retry the operation. When using this form, you can write code that never throws DML exception errors. Instead, your code can use the appropriate results array to judge success or failure. Note that DML database methods also include a syntax that supports thrown exceptions, similar to DML statements. The following Apex DML operations are available: • convertLead1 • delete • insert • merge2 • undelete • update • upsert System Context and Sharing Rules Most DML operations execute in system context, ignoring the current user's permissions, field-level security, organization-wide defaults, position in the role hierarchy, and sharing rules. However, when a DML operation is called in a class defined with the with sharing keywords, the current user's sharing rules are taken into account. For more information, see Using the with sharing or without sharing Keywords on page 134. String Field Truncation and API Version Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String value that is too long for the field. 1 convertLead is only available as a database method. 2 merge is only available as an Apex DML statement. 268
- 271. Reference ConvertLead Operation ConvertLead Operation The convertLead DML operation converts a lead into an account and contact, as well as (optionally) an opportunity. Note: convertLead is only available as a database method. Database Method Syntax • LeadConvertResult Database.convertLead(LeadConvert leadToConvert, Boolean opt_allOrNone) • LeadConvertResult[] Database.convertLead(LeadConvert[] leadsToConvert, Boolean opt_allOrNone) The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that can be used to verify which records succeeded, which failed, and why. Rules and Guidelines When converting leads, consider the following rules and guidelines: • Field mappings: The system automatically maps standard lead fields to standard account, contact, and opportunity fields. For custom lead fields, your Salesforce administrator can specify how they map to custom account, contact, and opportunity fields. For more information about field mappings, see the Salesforce online help. • Merged fields: If data is merged into existing account and contact objects, only empty fields in the target object are overwritten—existing data (including IDs) are not overwritten. The only exception is if you specify setOverwriteLeadSource on the LeadConvert object to true, in which case the LeadSource field in the target contact object is overwritten with the contents of the LeadSource field in the source LeadConvert object. • Record types: If the organization uses record types, the default record type of the new owner is assigned to records created during lead conversion. The default record type of the user converting the lead determines the lead source values available during conversion. If the desired lead source values are not available, add the values to the default record type of the user converting the lead. For more information about record types, see the Salesforce online help. • Picklist values: The system assigns the default picklist values for the account, contact, and opportunity when mapping any standard lead picklist fields that are blank. If your organization uses record types, blank values are replaced with the default picklist values of the new record owner. • Automatic feed subscriptions: When you convert a lead into a new account, contact, and opportunity, the lead owner is unsubscribed from the lead account. The lead owner, the owner of the generated records, and users that were subscribed to the lead aren’t automatically subscribed to the generated records, unless they have automatic subscriptions enabled in their Chatter feed settings. They must have automatic subscriptions enabled to see changes to the account, contact, and opportunity records in their news feed. Users must enable automatic subscriptions by selecting the Automatically follow records that I create checkbox in User Name > Setup > My Chatter Settings > My Feeds to subscribe to records they create. A user can subscribe to a record so that changes to the record are displayed in the news feed on the user's home page. This is a useful way to stay up-to-date with changes to records in Salesforce. Basic Steps for Converting Leads Converting leads involves the following basic steps: 1. Your application determines the IDs of any lead(s) to be converted. 2. Optionally, your application determines the IDs of any account(s) into which to merge the lead. Your application can use SOQL to search for accounts that match the lead name, as in the following example: SELECT Id, Name FROM Account WHERE Name='CompanyNameOfLeadBeingMerged' 269
- 272. Reference ConvertLead Operation 3. Optionally, your application determines the IDs of the contact or contacts into which to merge the lead. The application can use SOQL to search for contacts that match the lead contact name, as in the following example: SELECT Id, Name FROM Contact WHERE FirstName='FirstName' AND LastName='LastName' AND AccountId = '001...' 4. Optionally, the application determines whether opportunities should be created from the leads. 5. The application queries the LeadSource table to obtain all of the possible converted status options (SELECT ... FROM LeadStatus WHERE IsConverted='1'), and then selects a value for the converted status. 6. The application calls convertLead. 7. The application iterates through the returned result or results and examines each LeadConvertResult object to determine whether conversion succeeded for each lead. 8. Optionally, when converting leads owned by a queue, the owner must be specified. This is because accounts and contacts cannot be owned by a queue. Even if you are specifying an existing account or contact, you must still specify an owner. LeadConvert Object Methods The convertLead database method accepts up to 100 LeadConvert objects. A LeadConvert object supports the following methods: Name Arguments Return Type Description getAccountId ID Gets the ID of the account into which the lead will be merged. getContactId ID Gets the ID of the contact into which the lead will be merged. getConvertedStatus String Get the lead status value for a converted lead getLeadID ID Get the ID of the lead to convert. getOpportunityName String Get the name of the opportunity to create. getOwnerID ID Get the ID of the person to own any newly created account, contact, and opportunity. isDoNotCreateOpportunity Boolean Indicates whether an Opportunity is created during lead conversion (false, the default) or not (true). isOverWriteLeadSource Boolean Indicates whether the LeadSource field on the target Contact object is overwritten with the contents of the LeadSource field in the source Lead object (true), or not (false, the default). isSendNotificationEmail Boolean Indicates whether a notification email is sent to the owner specified by setOwnerId (true) or not (false, the default). setAccountId ID ID Void Sets the ID of the account into which the lead will be merged. This value is required only when updating an existing account, including person accounts. Otherwise, if setAccountID is specified, a new account is created. setContactId ID ID Void Sets the ID of the contact into which the lead will be merged (this contact must be associated with the account specified with setAccountId, and setAccountId must be specified). This value is required only when updating an existing contact. 270
- 273. Reference ConvertLead Operation Name Arguments Return Type Description Important: If you are converting a lead into a person account, do not specify setContactId or an error will result. Specify only setAccountId of the person account. If setContactID is specified, then the application creates a new contact that is implicitly associated with the account. The contact name and other existing data are not overwritten (unless setOverwriteLeadSource is set to true, in which case only the LeadSource field is overwritten). setConvertedStatus String Status Void Sets the lead status value for a converted lead. This field is required. setDoNotCreateOpportunity Boolean Void Specifies whether to create an opportunity during lead CreateOpportunity conversion. The default value is false: opportunities are created by default. Set this flag to true only if you do not want to create an opportunity from the lead. setLeadId ID ID Void Sets the ID of the lead to convert. This field is required. setOpportunityName String OppName Void Sets the name of the opportunity to create. If no name is specified, this value defaults to the company name of the lead. The maximum length of this field is 80 characters. If setDoNotCreateOpportunity is true, no Opportunity is created and this field must be left blank; otherwise, an error is returned. setOverwriteLeadSource Boolean Void Specifies whether to overwrite the LeadSource field on the Oewieedore vrrtLaSuc target contact object with the contents of the LeadSource field in the source lead object. The default value is false, to not overwrite the field. If you specify this as true, you must also specify setContactId for the target contact. setOwnerId ID ID Void Specifies the ID of the person to own any newly created account, contact, and opportunity. If the application does not specify this value, the owner of the new object will be the owner of the lead. This method is not applicable when merging with existing objects—if setOwnerId is specified, the ownerId field is not overwritten in an existing account or contact. setSendNotificationEmail Boolean Void Specifies whether to send a notification email to the owner SendEmail specified by setOwnerId. The default value is false, that is, to not send email. LeadConvertResult Object An array of LeadConvertResult objects is returned with the convertLead database method. Each element in the LeadConvertResult array corresponds to the SObject array passed as the SObject[] parameter in the convertLead database method, that is, the first element in the LeadConvertResult array matches the first element passed in the SObject array, the second element corresponds with the second element, and so on. If only one SObject is passed in, the LeadConvertResults array contains a single element. A LeadConvertResult object has the following methods: 271
- 274. Reference Delete Operation Name Type Description getAccountId ID The ID of the new account (if a new account was specified) or the ID of the account specified when convertLead was invoked getContactId ID The ID of the new contact (if a new contact was specified) or the ID of the contact specified when convertLead was invoked getErrors Database.Error If an error occurred, an array of one or more database error []Database.Error [] objects providing the error code and description. For more information, see Database Error Object Methods on page 396. getLeadId ID The ID of the converted lead getOpportunityId ID The ID of the new opportunity, if one was created when convertLead was invoked isSuccess Boolean A Boolean value that is set to true if the DML operation was successful for this object, false otherwise Database Method Example Lead myLead = new Lead(LastName = 'Fry', Company='Fry And Sons'); insert myLead; Database.LeadConvert lc = new database.LeadConvert(); lc.setLeadId(myLead.id); LeadStatus convertStatus = [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true LIMIT 1]; lc.setConvertedStatus(convertStatus.MasterLabel); Database.LeadConvertResult lcr = Database.convertLead(lc); System.assert(lcr.isSuccess()); Delete Operation The delete DML operation deletes one or more existing sObject records, such as individual accounts or contacts, from your organization’s data. delete is analogous to the delete() statement in the SOAP API. DML Statement Syntax delete sObject | Record.ID Database Method Syntax • DeleteResult Database.Delete((sObject recordToDelete | RecordID ID), Boolean opt_allOrNone) • DeleteResult[] Database.Delete((sObject[] recordsToDelete | RecordIDs LIST<>IDs{}), Boolean opt_allOrNone) The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that can be used to verify which records succeeded, which failed, and why. 272
- 275. Reference Delete Operation Rules and Guidelines When deleting sObject records, consider the following rules and guidelines: • To ensure referential integrity, delete supports cascading deletions. If you delete a parent object, you delete its children automatically, as long as each child record can be deleted. For example, if you delete a case record, Apex automatically deletes any CaseComment, CaseHistory, and CaseSolution records associated with that case. However, if a particular child record is not deletable or is currently being used, then the delete operation on the parent case record fails. • Certain sObjects can't be deleted. To delete an sObject record, the deletable property of the sObject must be set to true. Also, see sObjects That Do Not Support DML Operations on page 286. • You can pass a maximum of 10,000 sObject records to a single delete method. DeleteResult Object An array of Database.DeleteResult objects is returned with the delete database method. Each element in the DeleteResult array corresponds to the sObject array passed as the sObject[] parameter in the delete database method, that is, the first element in the DeleteResult array matches the first element passed in the sObject array, the second element corresponds with the second element, and so on. If only one sObject is passed in, the DeleteResults array contains a single element. A Database.DeleteResult object has the following methods: Name Type Description getErrors Database.Error If an error occurred, an array of one or more database error objects [] providing the error code and description. For more information, see Database Error Object Methods on page 396. getId ID The ID of the sObject you were trying to delete. If this field contains a value, the object was successfully deleted. If this field is empty, the operation was not successful for that object. isSuccess Boolean A Boolean value that is set to true if the DML operation was successful for this object, false otherwise DML Statement Example The following example deletes all accounts that are named 'DotCom': Account[] doomedAccts = [SELECT Id, Name FROM Account WHERE Name = 'DotCom']; try { delete doomedAccts; } catch (DmlException e) { // Process exception here } Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289. 273
- 276. Reference Insert Operation Database Method Example The following example deletes an account named 'DotCom': Account[] doomedAccts = [SELECT Id, Name FROM Account WHERE Name = 'DotCom']; Database.DeleteResult[] DR_Dels = Database.delete(doomedAccts); Insert Operation The insert DML operation adds one or more sObjects, such as individual accounts or contacts, to your organization’s data. insert is analogous to the INSERT statement in SQL. DML Statement Syntax insert sObject insert sObject[] Database Method Syntax • SaveResult Database.insert(sObject recordToInsert, Boolean opt_allOrNone | database.DMLOptions opt_DMLOptions) • SaveResult[] Database.insert(sObject[] recordsToInsert, Boolean opt_allOrNone | database.DMLOptions opt_DMLOptions) The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that can be used to verify which records succeeded, which failed, and why. For example: Database.SaveResult[] MySaveResult = Database.Insert(MyAccounts, false); The optional opt_DMLOptions parameter specifies additional data for the transaction, such as assignment rule information or rollback behavior when errors occur during record insertions. For example: //AssignmentRuleHeader //UseDefaultRule Database.DMLOptions dmo = new database.DMLOptions(); dmo.AssignmentRuleHeader.UseDefaultRule= true; Lead l = new Lead(Company='ABC', LastName='Smith'); l.setOptions(dmo); insert l; For more information, see Database DMLOptions Properties on page 393. Rules and Guidelines When inserting sObject records, consider the following rules and guidelines: • Certain sObjects cannot be created. To create an sObject record, the createable property of the sObject must be set to true. • You must supply a non-null value for all required fields. 274
- 277. Reference Insert Operation • You can pass a maximum of 10,000 sObject records to a single insert method. • The insert statement automatically sets the ID value of all new sObject records. Inserting a record that already has an ID—and therefore already exists in your organization's data—produces an error. See Lists for more information. • For some sObjects that have fields with unique constraints, inserting duplicate sObject records results in an error. For example, inserting CollaborationGroup sObjects with the same name results in an error because CollaborationGroup records must have unique names. • The insert statement can only set the foreign key ID of related sObject records. Fields on related records cannot be updated with insert. For example, if inserting a new contact, you can specify the contact's related account record by setting the value of the AccountId field. However, you cannot change the account's name without updating the account itself with a separate DML call. • The insert statement is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286. • This operation checks each batch of records for duplicate ID values. If there are duplicates, the first five are processed. For the sixth and all additional duplicate IDs, the SaveResult for those entries is marked with an error similar to the following: Maximum number of duplicate updates in one batch (5 allowed). Attempt to update Id more than once in this API call: number_of_attempts. SaveResult Object An array of SaveResult objects is returned with the insert and update database methods. Each element in the SaveResult array corresponds to the sObject array passed as the sObject[] parameter in the database method, that is, the first element in the SaveResult array matches the first element passed in the sObject array, the second element corresponds with the second element, and so on. If only one sObject is passed in, the SaveResults array contains a single element. A SaveResult object has the following methods: Name Type Description getErrors Database.Error [] If an error occurred, an array of one or more database error objects providing the error code and description. For more information, see Database Error Object Methods on page 396. getId ID The ID of the sObject you were trying to insert or update. If this field contains a value, the object was successfully inserted or updated. If this field is empty, the operation was not successful for that object. isSuccess Boolean A Boolean that is set to true if the DML operation was successful for this object, false otherwise. DML Statement Example The following example inserts an account named 'Acme': Account newAcct = new Account(name = 'Acme'); try { insert newAcct; } catch (DmlException e) { // Process exception here } 275
- 278. Reference Insert Operation Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289. Database Method Example The following example inserts an account named 'Acme': Account a = new Account(name = 'Acme'); Database.SaveResult[] lsr = Database.insert(new Account[]{a, new Account(Name = 'Acme')}, false); // Iterate through the Save Results for(Database.SaveResult sr:lsr){ if(!sr.isSuccess()) Database.Error err = sr.getErrors()[0]; } Creating Parent and Child Records in a Single Statement Using Foreign Keys You can use external ID fields as foreign keys to create parent and child records of different sObject types in a single step instead of creating the parent record first, querying its ID, and then creating the child record. To do this: • Create the child sObject and populate its required fields, and optionally other fields. • Create the parent reference sObject used only for setting the parent foreign key reference on the child sObject. This sObject has only the external ID field defined and no other fields set. • Set the foreign key field of the child sObject to the parent reference sObject you just created. • Create another parent sObject to be passed to the insert statement. This sObject must have the required fields (and optionally other fields) set in addition to the external ID field. • Call insert by passing it an array of sObjects to create. The parent sObject must precede the child sObject in the array, that is, the array index of the parent must be lower than the child’s index. The parent and child records are records related through a predefined relationship, such as a master-detail or lookup relationship. You can create related records that are up to 10 levels deep. Also, the related records created in a single call must have different sObject types. For more information, see Creating Records for Different Object Types in the SOAP API Developer's Guide. The following example shows how to create an opportunity with a parent account using the same insert statement. The example creates an Opportunity sObject and populates some of its fields, then creates two Account objects. The first account is only for the foreign key relationship, and the second is for the account creation and has the account fields set. Both accounts have the external ID field, MyExtID__c, set. Next, the sample calls Database.insert by passing it an array of sObjects. The first element in the array is the parent sObject and the second is the opportunity sObject. The Database.insert statement creates the opportunity with its parent account in a single step. Finally, the sample checks the results and writes the IDs of the created records to the debug log, or the first error if record creation fails. This sample requires an external ID text field on Account called MyExtID. public class ParentChildSample { public static void InsertParentChild() { Date dt = Date.today(); dt = dt.addDays(7); Opportunity newOpportunity = new Opportunity( Name='OpportunityWithAccountInsert', StageName='Prospecting', CloseDate=dt); // Create the parent reference. // Used only for foreign key reference // and doesn't contain any other fields. Account accountReference = new Account( MyExtID__c='SAP111111'); 276
- 279. Reference Merge Statement newOpportunity.Account = accountReference; // Create the Account object to insert. // Same as above but has Name field. // Used for the insert. Account parentAccount = new Account( Name='Hallie', MyExtID__c='SAP111111'); // Create the account and the opportunity. Database.SaveResult[] results = Database.insert(new SObject[] { parentAccount, newOpportunity }); // Check results. for (Integer i = 0; i < results.size(); i++) { if (results[i].isSuccess()) { System.debug('Successfully created ID: ' + results[i].getId()); } else { System.debug('Error: could not create sobject ' + 'for array element ' + i + '.'); System.debug(' The error reported was: ' + results[i].getErrors()[0].getMessage() + 'n'); } } } } Merge Statement The merge statement merges up to three records of the same sObject type into one of the records, deleting the others, and re-parenting any related records. Note: This DML operation does not have a matching database system method. Syntax merge sObject sObject merge sObject sObject[] merge sObject ID merge sObject ID[] The first parameter represents the master record into which the other records are to be merged. The second parameter represents the one or two other records that should be merged and then deleted. You can pass these other records into the merge statement as a single sObject record or ID, or as a list of two sObject records or IDs. Rules and Guidelines When merging sObject records, consider the following rules and guidelines: • Only leads, contacts, and accounts can be merged. See sObjects That Do Not Support DML Operations on page 286. • You can pass a master record and up to two additional sObject records to a single merge method. For more information on merging leads, contacts and accounts, see the Salesforce online help. 277
- 280. Reference Undelete Operation Example The following example merges two accounts named 'Acme Inc.' and 'Acme' into a single record: List<Account> ls = new List<Account>{new Account(name='Acme Inc.'),new Account(name='Acme')}; insert ls; Account masterAcct = [SELECT Id, Name FROM Account WHERE Name = 'Acme Inc.' LIMIT 1]; Account mergeAcct = [SELECT Id, Name FROM Account WHERE Name = 'Acme' LIMIT 1]; try { merge masterAcct mergeAcct; } catch (DmlException e) { // Process exception here } Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289. Undelete Operation The undelete DML operation restores one or more existing sObject records, such as individual accounts or contacts, from your organization’s Recycle Bin. undelete is analogous to the UNDELETE statement in SQL. DML Statement Syntax undelete sObject | Record.ID undelete sObject[] | LIST<>ID[] Database Method Syntax • UndeleteResult Database.Undelete((sObject recordToUndelete | RecordID ID), Boolean opt_allOrNone) • UndeleteResult[] Database.Undelete((sObject[] recordsToUndelete | RecordIDs LIST<>IDs{}), Boolean opt_allOrNone) The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that can be used to verify which records succeeded, which failed, and why. Rules and Guidelines When undeleting sObject records, consider the following rules and guidelines: • To ensure referential integrity, undelete restores the record associations for the following types of relationships: ◊ Parent accounts (as specified in the Parent Account field on an account) ◊ Parent cases (as specified in the Parent Case field on a case) ◊ Master solutions for translated solutions (as specified in the Master Solution field on a solution) ◊ Managers of contacts (as specified in the Reports To field on a contact) ◊ Products related to assets (as specified in the Product field on an asset) ◊ Opportunities related to quotes (as specified in the Opportunity field on a quote) ◊ All custom lookup relationships ◊ Relationship group members on accounts and relationship groups, with some exceptions ◊ Tags ◊ An article's categories, publication state, and assignments 278
- 281. Reference Undelete Operation Note: Salesforce only restores lookup relationships that have not been replaced. For example, if an asset is related to a different product prior to the original product record being undeleted, that asset-product relationship is not restored. • Certain sObjects can't be undeleted. To verify if an sObject record can be undeleted, check that the undeletable property of the sObject is set to true. • You can pass a maximum of 10,000 sObject records to a single undelete method. • You can undelete records that were deleted as the result of a merge, but the child objects will have been re-parented, which cannot be undone. • Use the ALL ROWS parameters with a SOQL query to identify deleted records, including records deleted as a result of a merge. See Querying All Records with a SOQL Statement on page 83. • Undelete is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286. UndeleteResult Object An array of Database.UndeleteResult objects is returned with the undelete database method. Each element in the UndeleteResult array corresponds to the sObject array passed as the sObject[] parameter in the undelete database method, that is, the first element in the UndeleteResult array matches the first element passed in the sObject array, the second element corresponds with the second element, and so on. If only one sObject is passed in, the UndeleteResults array contains a single element. An undeleteResult object has the following methods: Name Type Description getErrors Database.Error [] If an error occurred, an array of one or more database error objects providing the error code and description. For more information, see Database Error Object Methods on page 396. getId ID The ID of the sObject you were trying to undelete. If this field contains a value, the object was successfully undeleted. If this field is empty, the operation was not successful for that object. isSuccess Boolean A Boolean value that is set to true if the DML operation was successful for this object, false otherwise DML Statement Example The following example undeletes an account named 'Trump'. The ALL ROWS keyword queries all rows for both top level and aggregate relationships, including deleted records and archived activities. Account a = new Account(Name='AC1'); insert(a); insert(new Contact(LastName='Carter',AccountId=a.Id)); Account[] savedAccts = [SELECT Id, Name FROM Account WHERE Name = 'Trump' ALL ROWS]; try { undelete savedAccts; } catch (DmlException e) { 279
- 282. Reference Update Operation // Process exception here } Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289. Database Method Example The following example undeletes an account named 'Trump'. The ALL ROWS keyword queries all rows for both top level and aggregate relationships, including deleted records and archived activities. public class DmlTest2 { public void undeleteExample() { Account[] SavedAccts = [SELECT Id, Name FROM Account WHERE Name = 'Trump' ALL ROWS]; Database.UndeleteResult[] UDR_Dels = Database.undelete(SavedAccts); for(integer i =0; i< 10; i++) if(UDR_Dels[i].getErrors().size()>0){ // Process any errors here } } } Update Operation The update DML operation modifies one or more existing sObject records, such as individual accounts or contactsinvoice statements, in your organization’s data. update is analogous to the UPDATE statement in SQL. DML Statement Syntax update sObject update sObject[] Database Method Syntax • UpdateResult Update(sObject recordToUpdate, Boolean opt_allOrNone | database.DMLOptions opt_DMLOptions) • UpdateResult[] Update(sObject[] recordsToUpdate[], Boolean opt_allOrNone | database.DMLOptions opt_DMLOptions) The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that can be used to verify which records succeeded, which failed, and why. The optional opt_DMLOptions parameter specifies additional data for the transaction, such as assignment rule information or rollback behavior when errors occur during record insertions. For more information, see Database DMLOptions Properties on page 393. Rules and Guidelines When updating sObject records, consider the following rules and guidelines: • Certain sObjects cannot be updated. To update an sObject record, the updateable property of the sObject must be set to true. • When updating required fields you must supply a non-null value. 280
- 283. Reference Update Operation • Unlike the SOAP API, Apex allows you to change field values to null without updating the fieldsToNull array on the sObject record. The API requires an update to this array due to the inconsistent handling of null values by many SOAP providers. Because Apex runs solely on the Force.com platform, this workaround is unnecessary. • The ID of an updated sObject record cannot be modified, but related record IDs can. • This operation checks each batch of records for duplicate ID values. If there are duplicates, the first five are processed. For the sixth and all additional duplicate IDs, the SaveResult for those entries is marked with an error similar to the following: Maximum number of duplicate updates in one batch (5 allowed). Attempt to update Id more than once in this API call: number_of_attempts. • The update statement automatically modifies the values of certain fields such as LastModifiedDate, LastModifiedById, and SystemModstamp. You cannot explicitly specify these values in your Apex. • You can pass a maximum of 10,000 sObject records to a single update method. • A single update statement can only modify one type of sObject at a time. For example, if updating an account field through an existing contact that has also been modified, two update statements are required: // Use a SOQL query to access data for a contact Contact c = [SELECT Account.Name FROM Contact WHERE LastName = 'Carter' LIMIT 1]; // Now we can change fields for both the contact and its // associated account c.Account.Name = 'salesforce.com'; c.LastName = 'Roth'; // To update the database, the two types of records must be // updated separately update c; // This only changes the contact's last name update c.Account; // This updates the account name • Update is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286. SaveResult Object An array of SaveResult objects is returned with the insert and update database methods. Each element in the SaveResult array corresponds to the sObject array passed as the sObject[] parameter in the database method, that is, the first element in the SaveResult array matches the first element passed in the sObject array, the second element corresponds with the second element, and so on. If only one sObject is passed in, the SaveResults array contains a single element. A SaveResult object has the following methods: Name Type Description getErrors Database.Error [] If an error occurred, an array of one or more database error objects providing the error code and description. For more information, see Database Error Object Methods on page 396. getId ID The ID of the sObject you were trying to insert or update. If this field contains a value, the object was successfully inserted or updated. If this field is empty, the operation was not successful for that object. 281
- 284. Reference Upsert Operation Name Type Description isSuccess Boolean A Boolean that is set to true if the DML operation was successful for this object, false otherwise. DML Statement Example The following example updates the BillingCity field on a single account named 'Acme': Account a = new Account(Name='Acme2'); insert(a); Account myAcct = [SELECT Id, Name, BillingCity FROM Account WHERE Id = :a.Id]; myAcct.BillingCity = 'San Francisco'; try { update myAcct; } catch (DmlException e) { // Process exception here } Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289. Database Method Example The following example updates the BillingCity field on a single account named 'Acme': Account a = new Account(Name='Acme2'); insert(a); Account myAcct = [SELECT Id, Name, BillingCity FROM Account WHERE Id = :a.Id]; myAcct.BillingCity = 'San Francisco'; Database.SaveResult SR = database.update(myAcct); for(Database.Error err: SR.getErrors()) { // process any errors here } Upsert Operation The upsert DML operation creates new sObject records and updates existing sObject records within a single statement, using an optional custom field to determine the presence of existing objects. DML Statement Syntax upsert sObject opt_external_id upsert sObject[] opt_external_id opt_external_id is an optional variable that specifies the custom field that should be used to match records that already exist in your organization's data. This custom field must be created with the External Id attribute selected. Additionally, if the field does not have the Unique attribute selected, the context user must have the “View All” object-level permission for the target object or the “View All Data” permission so that upsert does not accidentally insert a duplicate record. 282
- 285. Reference Upsert Operation If opt_external_id is not specified, the sObject record's ID field is used by default. Note: Custom field matching is case-insensitive only if the custom field has the Unique and Treat "ABC" and "abc" as duplicate values (case insensitive) attributes selected as part of the field definition. If this is the case, “ABC123” is matched with “abc123.” For more information, see “Creating Custom Fields” in the online help. Database Method Syntax • UpsertResult Database.Upsert(sObject recordToUpsert, Schema.SObjectField External_ID_Field, Boolean opt_allOrNone) • UpsertResult[] Database.Upsert(sObject[] recordsToUpsert, Schema.SObjectField External_ID_Field, Boolean opt_allOrNone) The optional External_ID_Field parameter is an optional variable that specifies the custom field that should be used to match records that already exist in your organization's data. This custom field must be created with the External Id attribute selected. Additionally, if the field does not have the Unique attribute selected, the context user must have the “View All” object-level permission for the target object or the “View All Data” permission so that upsert does not accidentally insert a duplicate record. The External_ID_Field is of type Schema.SObjectField, that is, a field token. Find the token for the field by using the fields special method. For example, Schema.SObjectField f = Account.Fields.MyExternalId. If External_ID_Field is not specified, the sObject record's ID field is used by default. Note: Custom field matching is case-insensitive only if the custom field has the Unique and Treat "ABC" and "abc" as duplicate values (case insensitive) attributes selected as part of the field definition. If this is the case, “ABC123” is matched with “abc123.” For more information, see “Creating Custom Fields” in the online help. The optional opt_allOrNone parameter specifies whether the operation allows partial success. If you specify false for this parameter and a record fails, the remainder of the DML operation can still succeed. This method returns a result object that can be used to verify which records succeeded, which failed, and why. How Upsert Chooses to Insert or Update Upsert uses the sObject record's primary key (or the external ID, if specified) to determine whether it should create a new object record or update an existing one: • If the key is not matched, then a new object record is created. • If the key is matched once, then the existing object record is updated. • If the key is matched multiple times, then an error is generated and the object record is neither inserted or updated. Rules and Guidelines When upserting sObject records, consider the following rules and guidelines: • Certain sObjects cannot be inserted or updated. To insert an sObject record, the createable property of the sObject must be set to true. To update an sObject record, the updateable property of the sObject must be set to true. • You must supply a non-null value for all required fields on any record that will be inserted. • The ID of an sObject record cannot be modified, but related record IDs can. This action is interpreted as an update. • The upsert statement automatically modifies the values of certain fields such as LastModifiedDate, LastModifiedById, and SystemModstamp. You cannot explicitly specify these values in your Apex. • Each upsert statement consists of two operations, one for inserting records and one for updating records. Each of these operations is subject to the runtime limits for insert and update, respectively. For example, if you upsert more than 10,000 records and all of them are being updated, you receive an error. (See Understanding Execution Governors and Limits on page 225) 283
- 286. Reference Upsert Operation • The upsert statement can only set the ID of related sObject records. Fields on related records cannot be modified with upsert. For example, if updating an existing contact, you can specify the contact's related account record by setting the value of the AccountId field. However, you cannot change the account's name without updating the account itself with a separate DML statement. • Upsert is not supported with some sObjects. See sObjects That Do Not Support DML Operations on page 286. • You can use foreign keys to upsert sObject records if they have been set as reference fields. For more information, see Field Types in the Object Reference for Salesforce and Force.com. UpsertResult Object An array of Database.UpsertResult objects is returned with the upsert database method. Each element in the UpsertResult array corresponds to the sObject array passed as the sObject[] parameter in the upsert database method, that is, the first element in the UpsertResult array matches the first element passed in the sObject array, the second element corresponds with the second element, and so on. If only one sObject is passed in, the UpsertResults array contains a single element. An UpsertResult object has the following methods: Name Type Description getErrors Database.Error [] If an error occurred, an array of one or more database error objects providing the error code and description. For more information, see Database Error Object Methods on page 396. getId ID The ID of the sObject you were trying to update or insert. If this field contains a value, the object was successfully updated or inserted. If this field is empty, the operation was not successful for that object. isCreated Boolean A Boolean value that is set to true if the record was created, false if the record was updated. isSuccess Boolean A Boolean value that is set to true if the DML operation was successful for this object, false otherwise. DML Statement Examples The following example updates the city name for all existing accounts located in the city formerly known as Bombay, and also inserts a new account located in San Francisco: Account[] acctsList = [SELECT Id, Name, BillingCity FROM Account WHERE BillingCity = 'Bombay']; for (Account a : acctsList) { a.BillingCity = 'Mumbai'; } Account newAcct = new Account(Name = 'Acme', BillingCity = 'San Francisco'); acctsList.add(newAcct); try { upsert acctsList; } catch (DmlException e) { // Process exception here } 284
- 287. Reference Upsert Operation Note: For more information on processing DmlExceptions, see Bulk DML Exception Handling on page 289. Use of upsert with an external ID can reduce the number of DML statements in your code, and help you to avoid hitting governor limits (see Understanding Execution Governors and Limits). This next example uses upsert and an external ID field Line_Item_Id__c on the Asset object to maintain a one-to-one relationship between an asset and an opportunity line item. Note: Before running this sample, create a custom text field on the Asset object named Line_Item_Id__c and mark it as an external ID. For information on custom fields, see the Salesforce online help. public void upsertExample() { Opportunity opp = [SELECT Id, Name, AccountId, (SELECT Id, PricebookEntry.Product2Id, PricebookEntry.Name FROM OpportunityLineItems) FROM Opportunity WHERE HasOpportunityLineItem = true LIMIT 1]; Asset[] assets = new Asset[]{}; // Create an asset for each line item on the opportunity for (OpportunityLineItem lineItem:opp.OpportunityLineItems) { //This code populates the line item Id, AccountId, and Product2Id for each asset Asset asset = new Asset(Name = lineItem.PricebookEntry.Name, Line_Item_ID__c = lineItem.Id, AccountId = opp.AccountId, Product2Id = lineItem.PricebookEntry.Product2Id); assets.add(asset); } try { upsert assets Line_Item_ID__c; // This line upserts the assets list with // the Line_Item_Id__c field specified as the // Asset field that should be used for matching // the record that should be upserted. } catch (DmlException e) { System.debug(e.getMessage()); } } Database Method Example The following is an example that uses the Database upsert method to upsert a collection of leads that are passed in. This example allows for partial processing of records, that is, in case some records fail processing, the remaining records are still inserted or updated. It iterates through the results and adds a new task to each record that was processed successfully. The task sObjects are saved in a list, which is then bulk inserted. This example also contains a test method for testing the example. /* This class demonstrates and tests the use of the * partial processing DML operations */ public class dmlSamples { /* This method accepts a collection of lead records and creates a task for the owner(s) of any leads that were created as new, that is, not updated as a result of the upsert operation */ public static List<Database.upsertResult> upsertLeads(List<Lead> leads) { 285
- 288. Reference sObjects That Do Not Support DML Operations /* Perform the upsert. In this case the unique identifier for the insert or update decision is the Salesforce record ID. If the record ID is null the row will be inserted, otherwise an update will be attempted. */ List<Database.upsertResult> uResults = Database.upsert(leads,false); /* This is the list for new tasks that will be inserted when new leads are created. */ List<Task> tasks = new List<Task>(); for(Database.upsertResult result:uResults) { if (result.isSuccess() && result.isCreated()) tasks.add(new Task(Subject = 'Follow-up', WhoId = result.getId())); } /* If there are tasks to be inserted, insert them */ Database.insert(tasks); return uResults; } public static testMethod void testUpsertLeads() { /* We only need to test the insert side of upsert */ List<Lead> leads = new List<Lead>(); /* Create a set of leads for testing */ for(Integer i = 0;i < 100; i++) { leads.add(new Lead(LastName = 'testLead', Company = 'testCompany')); } /* Switch to the runtime limit context */ Test.startTest(); /* Exercise the method */ List<Database.upsertResult> results = DmlSamples.upsertLeads(leads); /* Switch back to the test context for limits */ Test.stopTest(); /* ID set for asserting the tasks were created as expected */ Set<Id> ids = new Set<Id>(); /* Iterate over the results, asserting success and adding the new ID to the set for use in the comprehensive assertion phase below. */ for(Database.upsertResult result:results) { System.assert(result.isSuccess()); ids.add(result.getId()); } /* Assert that exactly one task exists for each lead that was inserted. */ for(Lead l:[SELECT Id, (SELECT Subject FROM Tasks) FROM Lead WHERE Id IN :ids]) { System.assertEquals(1,l.tasks.size()); } } } sObjects That Do Not Support DML Operations DML operations are not supported with the following sObjects in Apex: • AccountTerritoryAssignmentRule 286
- 289. Reference sObjects That Cannot Be Used Together in DML Operations • AccountTerritoryAssignmentRuleItem • ApexComponent • ApexPage • BusinessHours • BusinessProcess • CategoryNode • CurrencyType • DatedConversionRate • ProcessInstance* • Profile • RecordType • SelfServiceUser • StaticResource • UserAccountTeamMember • UserTerritory • WebLink * You cannot create, update or delete ProcessInstance in the SOAP API. sObjects That Cannot Be Used Together in DML Operations Some sObjects require that you perform DML operations on only one type per transaction. For example, you cannot insert an account, then insert a user or a group member in a single transaction. The following sObjects cannot be used together in a transaction: • FieldPermissions • Group You can only insert and update a group in a transaction with other sObjects. Other DML operations are not allowed. • GroupMember You can only insert and update a group member in a transaction with other sObjects in Apex code that is saved using Salesforce.com API version 14.0 and earlier. • ObjectPermissions • PermissionSet • PermissionSetAssignment • QueueSObject • SetupEntityAccess • User You can insert a user in a transaction with other sObjects in Apex code that is saved using Salesforce.com API version 14.0 and earlier. You can insert a user in a transaction with other sObjects in Apex code that is saved using Salesforce.com API version 15.0 and later if UserRoleId is specified as null. You can update a user in a transaction with other sObjects in Apex code that is saved using Salesforce.com API version 14.0 and earlier 287
- 290. Reference sObjects That Cannot Be Used Together in DML Operations You can update a user in a transaction with other sObjects in Apex code that is saved using Salesforce.com API version 15.0 and later if the following fields are not also updated: ◊ UserRoleId ◊ IsActive ◊ ForecastEnabled ◊ IsPortalEnabled ◊ Username ◊ ProfileId • UserRole • UserTerritory • Territory • Custom settings in Apex code that is saved using Salesforce.com API version 17.0 and earlier. For these sObjects, there are no restrictions on delete DML operations. If you are using a Visualforce page with a custom controller, you can only perform DML operations on a single type of sObject within a single request or action. However, you can perform DML operations on different types of sObjects in subsequent requests, for example, you could create an account with a save button, then create a user with a submit button. You can perform DML operations on more than one type of sObject in a single class using the following process: 1. Create a method that performs a DML operation on one type of sObject. 2. Create a second method that uses the future annotation to manipulate a second sObject type. Mixed DML Operations Are Allowed in Test Methods in System.RunAs() Blocks Test methods allow for performing mixed DML operations between the sObjects listed earlier and other sObjects if the code that performs the DML operations is enclosed within System.runAs method blocks. This enables you, for example, to create a user with a role and other sObjects in the same test. The following example shows how to enclose mixed DML operations within System.runAs blocks to avoid the mixed DML error. The first block runs in the current user’s context. It creates a test user and a test account. The second block runs in the test user’s context and updates the account. Replace the user role value in the query with an existing user role in your organization before running this example. @isTest private class MixedDML { static testMethod void MixedDMLExample() { User u; Account a; User thisUser = [SELECT Id FROM User WHERE Id = :UserInfo.getUserId()]; // Insert account as current user System.runAs (thisUser) { Profile p = [SELECT Id FROM Profile WHERE Name='Standard User']; UserRole r = [SELECT Id FROM UserRole WHERE Name='SalesRep']; u = new User(alias = 'jsmtih', email='jsmith@acme.com', emailencodingkey='UTF-8', lastname='Smith', languagelocalekey='en_US', localesidkey='en_US', profileid = p.Id, userroleid = r.Id, timezonesidkey='America/Los_Angeles', username='jsmith@acme.com'); insert u; a = new Account(name='Acme'); insert a; } 288
- 291. Reference Bulk DML Exception Handling // Update account as the new user System.runAs(u) { a.website = 'www.salesforce.com'; update a; } } } Bulk DML Exception Handling Exceptions that arise from a bulk DML call (including any recursive DML operations in triggers that are fired as a direct result of the call) are handled differently depending on where the original call came from: • When errors occur because of a bulk DML call that originates directly from the Apex DML statements, or if the all_or_none parameter of a database DML method was specified as true, the runtime engine follows the “all or nothing” rule: during a single operation, all records must be updated successfully or the entire operation rolls back to the point immediately preceding the DML statement. • When errors occur because of a bulk DML call that originates from the SOAP API, the runtime engine attempts at least a partial save: 1. During the first attempt, the runtime engine processes all records. Any record that generates an error due to issues such as validation rules or unique index violations is set aside. 2. If there were errors during the first attempt, the runtime engine makes a second attempt which includes only those records that did not generate errors. All records that didn't generate an error during the first attempt are processed, and if any record generates an error (perhaps because of race conditions) it is also set aside. 3. If there were additional errors during the second attempt, the runtime engine makes a third and final attempt which includes only those records that did not generate errors during the first and second attempts. If any record generates an error, the entire operation fails with the error message, “Too many batch retries in the presence of Apex triggers and partial failures.” Note: During the second and third attempts, governor limits are reset to their original state before the first attempt. See Understanding Execution Governors and Limits on page 225. Apex Standard Classes and Methods Apex provides standard classes that contain both static and instance methods for expressions of primitive data types, as well as more complex objects. Standard static methods are similar to Java and are always of the form: Class.method(args) Standard static methods for primitive data types do not have an implicit parameter, and are invoked with no object context. For example, the following expression rounds the value of 1.75 to the nearest Integer without using any other values. Math.roundToLong(1.75); 289
- 292. Reference Apex Primitive Methods All instance methods occur on expressions of a particular data type, such as a list, set, or string. For example: String s = 'Hello, world'; Integer i = s.length(); Note: If a method is called with an object expression that evaluates to null, the Apex runtime engine throws a null pointer exception. Some classes use a namespace as a grouping mechanism for their methods. For example, the message class uses the ApexPages namespace. ApexPages.Message myMsg = new ApexPages.Message(ApexPages.FATAL, 'My Error Message'); The Apex standard classes are grouped into the following categories: • Primitives • Collections • Enums • sObjects • System • Exceptions Apex Primitive Methods Many primitive data types in Apex have methods that can be used to do additional manipulation of the data. The primitives that have methods are: • Blob • Boolean • Date • Datetime • Decimal • Double • ID • Long • String • Time Blob Methods The following is the system static method for Blob. Name Arguments Return Type Description toPdf String S Blob Creates a binary object out of the given string, encoding it as a PDF file. 290
- 293. Reference Apex Primitive Methods Name Arguments Return Type Description valueOf String S Blob Casts the specified String S to a Blob. For example: String myString = 'StringToBlob'; Blob myBlob = Blob.valueof(myString); The following are the instance methods for Blob. Name Arguments Return Type Description size Integer Returns the number of characters in the blob. For example: String myString = 'StringToBlob'; Blob myBlob = Blob.valueof(myString); Integer size = myBlob.size(); toString String Casts the blob into a String. For more information on Blobs, see Primitive Data Types on page 36. Boolean Methods The following are the static methods for Boolean. Name Arguments Return Type Description valueOf anyType x Boolean Casts x, a history tracking table field of type anyType, to a Boolean. For more information on the anyType data type, see Field Types in the Object Reference for Salesforce and Force.com. For more information on Boolean, see Primitive Data Types on page 36. Date Methods The following are the system static methods for Date. Name Arguments Return Type Description daysInMonth Integer year Integer Returns the number of days in the month for the specified year and month (1=Jan) The following Integer month example finds the number of days in the month of February in the year 1960: Integer numberDays = date.daysInMonth(1960, 2); 291
- 294. Reference Apex Primitive Methods Name Arguments Return Type Description isLeapYear Integer year Boolean Returns true if the specified year is a leap year newInstance Integer year Date Constructs a Date from Integer representations of the year, month (1=Jan), and day. The following example Integer month creates the date February 17th, 1960: Integer date Date myDate = date.newinstance(1960, 2, 17); parse String Date Date Constructs a Date from a String. The format of the String depends on the local date format. The following example works in some locales: date mydate = date.parse('12/27/2009'); today Date Returns the current date in the current user's time zone valueOf String s Date Returns a Date that contains the value of the specified String. The String should use the standard date format “yyyy-MM-dd HH:mm:ss” in the local time zone. For example: string year = '2008'; string month = '10'; string day = '5'; string hour = '12'; string minute = '20'; string second = '20'; string stringDate = year + '-' + month + '-' + day + ' ' + hour + ':' + minute + ':' + second; Date myDate = date.valueOf(stringDate); valueOf anyType x Date Casts x, a history tracking table field of type anyType, to a Date. For more information on the anyType data type, see Field Types in the Object Reference for Salesforce and Force.com. The following are the instance methods for Date. Name Arguments Return Type Description addDays Integer addlDays Date Adds the specified number of addlDays to a Date. For example: date myDate = date.newInstance(1960, 2, 17); date newDate = mydate.addDays(2); 292
- 295. Reference Apex Primitive Methods Name Arguments Return Type Description addMonths Integer addlMonths Date Adds the specified number of addlMonths to a Date addYears Integer addlYears Date Adds the specified number of addlYears to a Date day Integer Returns the day-of-month component of a Date. For example, February 5, 1999 would be day 5. dayOfYear Integer Returns the day-of-year component of a Date. For example, February 5, 1999 would be day 36. daysBetween Date compDate Integer Returns the number of days between the Date that called the method and the compDate. If the Date that calls the method occurs after the compDate, the return value is negative. For example: date startDate = date.newInstance(2008, 1, 1); date dueDate = date.newInstance(2008, 1, 30); integer numberDaysDue = startDate.daysBetween(dueDate); format String Returns the Date as a string using the locale of the context user isSameDay Date compDate Boolean Returns true if the Date that called the method is the same as the compDate. For example: date myDate = date.today(); date dueDate = date.newInstance(2008, 1, 30); boolean dueNow = myDate.isSameDay(dueDate); month Integer Returns the month component of a Date (1=Jan) monthsBetween Date compDate Integer Returns the number of months between the Date that called the method and the compDate, ignoring the difference in dates. For example, March 1 and March 30 of the same year have 0 months between them. toStartOfMonth Date Returns the first of the month for the Date that called the method. For example, July 14, 1999 returns July 1, 1999. toStartOfWeek Date Returns the start of the week for the Date that called the method, depending on the context user's locale. For example, the start of a week is Sunday in the United States locale, and Monday in European locales. For example: date myDate = date.today(); date weekStart = myDate.toStartofWeek(); 293
- 296. Reference Apex Primitive Methods Name Arguments Return Type Description year Integer Returns the year component of a Date For more information on Dates, see Primitive Data Types on page 36. Datetime Methods The following are the system static methods for Datetime. Name Arguments Return Type Description newInstance Long l Datetime Constructs a DateTime and initializes it to represent the specified number of milliseconds since January 1, 1970, 00:00:00 GMT. The returned date is in the GMT time zone. newInstance Date Date Datetime Constructs a DateTime from the specified date and time in the local time zone. The returned date is in the Time Time GMT time zone. newInstance Integer year Datetime Constructs a Datetime from Integer representations of the year, month (1=Jan), and day at midnight in the Integer month local time zone. The returned date is in the GMT time Integer day zone. For example: datetime myDate = datetime.newInstance(2008, 12, 1); newInstance Integer year Datetime Constructs a Datetime from Integer representations of the year, month (1=Jan), day, hour, minute, and Integer month second in the local time zone. The returned date is in Integer day the GMT time zone. Integer hour For example: Integer minute Datetime myDate = Integer second datetime.newInstance(2008, 12, 1, 12, 30, 2); newInstanceGmt Date date Datetime Constructs a DateTime from the specified date and time in the GMT time zone. Time time newInstanceGmt Integer year Datetime Constructs a Datetime from Integer representations of the year, month (1=Jan), and day at midnight in the Integer month GMT time zone Integer date 294
- 297. Reference Apex Primitive Methods Name Arguments Return Type Description newInstanceGmt Integer year Datetime Constructs a Datetime from Integer representations of the year, month (1=Jan), day, hour, minute, and Integer month second in the GMT time zone Integer date Integer hour Integer minute Integer second now Datetime Returns the current Datetime based on a GMT calendar. For example: datetime myDateTime = datetime.now(); The format of the returned datetime is: 'MM/DD/YYYY HH:MM PERIOD' parse String datetime Datetime Constructs a Datetime from the String datetime in the local time zone and in the format of the user locale. The returned date is in the GMT time zone. This example uses parse to create a Datetime from a date passed in as a string and that is formatted for the English (United States) locale. You may need to change the format of the date string if you have a different locale. Datetime dt = DateTime.parse( '10/14/2011 11:46 AM'); String myDtString = dt.format(); system.assertEquals( myDtString, '10/14/2011 11:46 AM'); valueOf String s Datetime Returns a Datetime that contains the value of the specified String. The String should use the standard date format “yyyy-MM-dd HH:mm:ss” in the local time zone. The returned date is in the GMT time zone. For example: string year = '2008'; string month = '10'; string day = '5'; string hour = '12'; string minute = '20'; string second = '20'; string stringDate = year + '-' + month + '-' + day + ' ' + hour + ':' + minute + ':' + second; Datetime myDate = datetime.valueOf(stringDate); 295
- 298. Reference Apex Primitive Methods Name Arguments Return Type Description valueOf anyType x Datetime Casts x, a history tracking table field of type anyType, to a Datetime. The returned date is in the GMT time zone. For more information on the anyType data type, see Field Types in the Object Reference for Salesforce and Force.com. valueOfGmt String s Datetime Returns a Datetime that contains the value of the specified String. The String should use the standard date format “yyyy-MM-dd HH:mm:ss” in the GMT time zone The following are the instance methods for Datetime. Name Arguments Return Description Type addDays Integer addlDays Datetime Adds the specified number of addlDays to a Datetime. For example: datetime myDate = datetime.newInstance (1960, 2, 17); datetime newDate = mydate.addDays(2); addHours Integer addlHours Datetime Adds the specified number of addlHours to a Datetime addMinutes Integer addlMinutes Datetime Adds the specified number of addlMinutes to a Datetime addMonths Integer addlMonths Datetime Adds the specified number of addlMonths to a Datetime addSeconds Integer addlSeconds Datetime Adds the specified number of addlSeconds to a Datetime addYears Integer addlYears Datetime Adds the specified number of addlYears to a Datetime date Date Returns the Date component of a Datetime in the local time zone of the context user. dateGMT Date Return the Date component of a Datetime in the GMT time zone day Integer Returns the day-of-month component of a Datetime in the local time zone of the context user. For example, February 5, 1999 08:30:12 would be day 5. dayGmt Integer Returns the day-of-month component of a Datetime in the GMT time zone. For example, February 5, 1999 08:30:12 would be day 5. 296
- 299. Reference Apex Primitive Methods Name Arguments Return Description Type dayOfYear Integer Returns the day-of-year component of a Datetime in the local time zone of the context user. For example, February 5, 2008 08:30:12 would be day 36. Datetime myDate = datetime.newInstance (2008, 2, 5, 8, 30, 12); system.assertEquals (myDate.dayOfYear(), 36); dayOfYearGmt Integer Returns the day-of-year component of a Datetime in the GMT time zone. For example, February 5, 1999 08:30:12 would be day 36. format String Converts the date to the local time zone and returns the converted date as a formatted string using the locale of the context user. If the time zone cannot be determined, GMT is used. format String dateFormat String Converts the date to the local time zone and returns the converted date as a string using the supplied Java simple date format. If the time zone cannot be determined, GMT is used. For example: Datetime myDT = Datetime.now(); String myDate = myDT.format('h:mm a'); For more information on the Java simple date format, see Java SimpleDateFormat. format String dateFormat String Converts the date to the specified time zone and returns the converted date as a string using the supplied Java simple date String timezone format. If the supplied time zone is not in the correct format, GMT is used. For more information on the Java simple date format, see Java SimpleDateFormat. Valid time zone values for the timezone argument are the time zones of the Java TimeZone class that correspond to the time zones returned by the TimeZone.getAvailableIDs method in Java. We recommend you use full time zone names, not the three-letter abbreviations. This example uses format to convert a GMT date to the America/New_York time zone and formats the date using the specified date format. Datetime GMTDate = Datetime.newInstanceGmt(2011,6,1,12,1,5); String strConvertedDate = 297
- 300. Reference Apex Primitive Methods Name Arguments Return Description Type GMTDate.format('MM/dd/yyyy HH:mm:ss', 'America/New_York'); // Date is converted to // the new time zone and is adjusted // for daylight saving time. System.assertEquals( '06/01/2011 08:01:05', strConvertedDate); formatGmt StringdateFormat String Returns a Datetime as a string using the supplied Java simple date format and the GMT time zone. For more information on the Java simple date format, see Java SimpleDateFormat. formatLong String Converts the date to the local time zone and returns the converted date in long date format. For example: // Passing local date based on the PST // time zone Datetime dt = DateTime.newInstance( 2012,12,28,10,0,0); // Writes 12/28/2012 10:00:00 AM PST System.debug('dt.formatLong()=' + dt.formatLong()); getTime Long Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this DateTime object hour Integer Returns the hour component of a Datetime in the local time zone of the context user hourGmt Integer Returns the hour component of a Datetime in the GMT time zone isSameDay Datetime compDt Boolean Returns true if the Datetime that called the method is the same as the compDt in the local time zone of the context user. For example: datetime myDate = datetime.now(); datetime dueDate = datetime.newInstance(2008, 1, 30); boolean dueNow = myDate.isSameDay(dueDate); millisecond Integer Return the millisecond component of a Datetime in the local time zone of the context user. millisecondGmt Integer Return the millisecond component of a Datetime in the GMT time zone. minute Integer Returns the minute component of a Datetime in the local time zone of the context user 298
- 301. Reference Apex Primitive Methods Name Arguments Return Description Type minuteGmt Integer Returns the minute component of a Datetime in the GMT time zone month Integer Returns the month component of a Datetime in the local time zone of the context user (1=Jan) monthGmt Integer Returns the month component of a Datetime in the GMT time zone (1=Jan) second Integer Returns the second component of a Datetime in the local time zone of the context user secondGmt Integer Returns the second component of a Datetime in the GMT time zone time Time Returns the time component of a Datetime in the local time zone of the context user timeGmt Time Returns the time component of a Datetime in the GMT time zone year Integer Returns the year component of a Datetime in the local time zone of the context user yearGmt Integer Returns the year component of a Datetime in the GMT time zone For more information about the Datetime, see Primitive Data Types on page 36. Decimal Methods The following are the system static methods for Decimal. Name Arguments Return Type Description valueOf Double d Decimal Returns a Decimal that contains the value of the specified Double. valueOf Long l Decimal Returns a Decimal that contains the value of the specified Long. valueOf String s Decimal Returns a Decimal that contains the value of the specified String. As in Java, the string is interpreted as representing a signed Decimal. For example: String temp = '12.4567'; Decimal myDecimal = decimal.valueOf(temp); 299
- 302. Reference Apex Primitive Methods The following are the instance methods for Decimal. Name Arguments Return Type Description abs Decimal Returns the absolute value of the Decimal. divide Decimal divisor, Decimal Divides this Decimal by divisor, and sets the scale, Integer scale that is, the number of decimal places, of the result using scale. In the following example, D has the value of 0.190: Decimal D = 19; D.Divide(100, 3); divide Decimal divisor, Decimal Divides this Decimal by divisor, sets the scale, that Integer scale, is, the number of decimal places, of the result using Object scale, and if necessary, rounds the value using roundingMode roundingMode. For more information about the valid values for roundingMode, see Rounding Mode. For example: Decimal myDecimal = 12.4567; Decimal divDec = myDecimal.divide (7, 2, System.RoundingMode.UP); system.assertEquals(divDec, 1.78); doubleValue Double Returns the Double value of this Decimal. format String Returns the String value of this Decimal using the locale of the context user. Scientific notation will be used if an exponent is needed. intValue Integer Returns the Integer value of this Decimal. longValue Long Returns the Long value of this Decimal. pow Integer exponent Decimal Returns the value of this decimal raised to the power of exponent. The value of exponent must be between 0 and 32,767. For example: Decimal myDecimal = 4.12; Decimal powDec = myDecimal.pow(2); system.assertEquals(powDec, 16.9744); If you use MyDecimal.pow(0), 1 is returned. The Math method pow does accept negative values. 300
- 303. Reference Apex Primitive Methods Name Arguments Return Type Description precision Integer Returns the total number of digits for the Decimal. For example, if the Decimal value was 123.45, precision returns 5. If the Decimal value is 123.123, precision returns 6. For example: Decimal D1 = 123.45; Integer precision1 = D1.precision(); system.assertEquals(precision1, 5); Decimal D2 = 123.123; Integer precision2 = D2.precision(); system.assertEquals(precision2, 6); round Long Returns the rounded approximation of this Decimal. The number is rounded to zero decimal places using half-even rounding mode, that is, it rounds towards the “nearest neighbor” unless both neighbors are equidistant, in which case, this mode rounds towards the even neighbor. Note that this rounding mode statistically minimizes cumulative error when applied repeatedly over a sequence of calculations. For more information about half-even rounding mode, see Rounding Mode. For example: Decimal D1 = 5.5; Long L1 = D1.round(); system.assertEquals(L1, 6); Decimal D2= 5.2; Long L2= D2.round(); system.assertEquals(L2, 5); Decimal D3= -5.7; Long L3= D3.round(); system.assertEquals(L3, -6); round System.RoundingMode Long Returns the rounded approximation of this Decimal. roundingMode The number is rounded to zero decimal places using the rounding mode specified by roundingMode. For more 301
- 304. Reference Apex Primitive Methods Name Arguments Return Type Description information about the valid values for roundingMode, see Rounding Mode. scale Integer Returns the scale of the Decimal, that is, the number of decimal places. setScale Integer scale Decimal Sets the scale of the Decimal to the given number of decimal places, using half-even rounding, if necessary. Half-even rounding mode rounds towards the “nearest neighbor” unless both neighbors are equidistant, in which case, this mode rounds towards the even neighbor. For more information about half-even rounding mode, see Rounding Mode. The value of scale must be between –33 and 33. If you do not explicitly set the scale for a Decimal, the scale is determined by the item from which the Decimal is created: • If the Decimal is created as part of a query, the scale is based on the scale of the field returned from the query. • If the Decimal is created from a String, the scale is the number of characters after the decimal point of the String. • If the Decimal is created from a non-decimal number, the scale is determined by converting the number to a String and then using the number of characters after the decimal point. setScale Integer scale, Decimal Sets the scale of the Decimal to the given number of System.RoundingMode decimal places, using the rounding mode specified by roundingMode roundingMode , if necessary. For more information about the valid values for roundingMode, see Rounding Mode. The value of scale must be between -32,768 and 32,767. If you do not explicitly set the scale for a Decimal, the scale is determined by the item from which the Decimal is created: • If the Decimal is created as part of a query, the scale is based on the scale of the field returned from the query. • If the Decimal is created from a String, the scale is the number of characters after the decimal point of the String. • If the Decimal is created from a non-decimal number, the scale is determined by converting the 302
- 305. Reference Apex Primitive Methods Name Arguments Return Type Description number to a String and then using the number of characters after the decimal point. stripTrailingZeros Decimal Returns the Decimal with any trailing zeros removed. toPlainString String Returns the String value of this Decimal, without using scientific notation. For more information on Decimal, see Primitive Data Types on page 36. Rounding Mode Rounding mode specifies the rounding behavior for numerical operations capable of discarding precision. Each rounding mode indicates how the least significant returned digit of a rounded result is to be calculated. The following are the valid values for roundingMode. Name Description CEILING Rounds towards positive infinity. That is, if the result is positive, this mode behaves the same as the UP rounding mode; if the result is negative, it behaves the same as the DOWN rounding mode. Note that this rounding mode never decreases the calculated value. For example: • Input number 5.5: CEILING round mode result: 6 • Input number 1.1: CEILING round mode result: 2 • Input number -1.1: CEILING round mode result: -1 • Input number -2.7: CEILING round mode result: -2 DOWN Rounds towards zero. This rounding mode always discards any fractions (decimal points) prior to executing. Note that this rounding mode never increases the magnitude of the calculated value. For example: • Input number 5.5: DOWN round mode result: 5 • Input number 1.1: DOWN round mode result: 1 • Input number -1.1: DOWN round mode result: -1 • Input number -2.7: DOWN round mode result: -2 FLOOR Rounds towards negative infinity. That is, if the result is positive, this mode behaves the same as theDOWN rounding mode; if negative, this mode behaves the same as the UP rounding mode. Note that this rounding mode never increases the calculated value. For example: • Input number 5.5: FLOOR round mode result: 5 • Input number 1.1: FLOOR round mode result: 1 • Input number -1.1: FLOOR round mode result: -2 • Input number -2.7: FLOOR round mode result: -3 HALF_DOWN Rounds towards the “nearest neighbor” unless both neighbors are equidistant, in which case this mode rounds down. This rounding mode behaves the same as the UP rounding mode if the discarded fraction (decimal point) is > 0.5; otherwise, it behaves the same as DOWN rounding mode. For example: 303
- 306. Reference Apex Primitive Methods Name Description • Input number 5.5: HALF_DOWN round mode result: 5 • Input number 1.1: HALF_DOWN round mode result: 1 • Input number -1.1: HALF_DOWN round mode result: -1 • Input number -2.7: HALF_DOWN round mode result: -2 HALF_EVEN Rounds towards the “nearest neighbor” unless both neighbors are equidistant, in which case, this mode rounds towards the even neighbor. This rounding mode behaves the same as the HALF_UP rounding mode if the digit to the left of the discarded fraction (decimal point) is odd. It behaves the same as the HALF_DOWN rounding method if it is even. For example: • Input number 5.5: HALF_EVEN round mode result: 6 • Input number 1.1: HALF_EVEN round mode result: 1 • Input number -1.1: HALF_EVEN round mode result: -1 • Input number -2.7: HALF_EVEN round mode result: -3 Note that this rounding mode statistically minimizes cumulative error when applied repeatedly over a sequence of calculations. HALF_UP Rounds towards the “nearest neighbor” unless both neighbors are equidistant, in which case, this mode rounds up. This rounding method behaves the same as the UP rounding method if the discarded fraction (decimal point) is >= 0.5; otherwise, this rounding method behaves the same as the DOWN rounding method. For example: • Input number 5.5: HALF_UP round mode result: 6 • Input number 1.1: HALF_UP round mode result: 1 • Input number -1.1: HALF_UP round mode result: -1 • Input number -2.7: HALF_UP round mode result: -3 UNNECESSARY Asserts that the requested operation has an exact result, which means that no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, an Exception is thrown. For example: • Input number 5.5: UNNECESSARY round mode result: Exception • Input number 1.0: UNNECESSARY round mode result: 1 UP Rounds away from zero. This rounding mode always truncates any fractions (decimal points) prior to executing. Note that this rounding mode never decreases the magnitude of the calculated value. For example: • Input number 5.5: UP round mode result: 6 • Input number 1.1: UP round mode result: 2 • Input number -1.1: UP round mode result: -2 • Input number -2.7: UP round mode result: -3 Double Methods The following are the system static methods for Double. 304
- 307. Reference Apex Primitive Methods Name Arguments Return Type Description valueOf anyType x Double Casts x, a history tracking table field of type anyType, to a Double. For more information on the anyType data type, see Field Types in the Object Reference for Salesforce and Force.com. valueOf String s Double Returns a Double that contains the value of the specified String. As in Java, the String is interpreted as representing a signed decimal. For example: Double DD1 = double.valueOf('3.14159'); The following are the instance methods for Double. Name Arguments Return Type Description format String Returns the String value for this Double using the locale of the context user intValue Integer Returns the Integer value of this Double by casting it to an Integer. For example: Double DD1 = double.valueOf('3.14159'); Integer value = DD1.intValue(); system.assertEquals(value, 3); longValue Long Returns the Long value of this Double round Long Returns the rounded value of this Double. The number is rounded to zero decimal places using half-even rounding mode, that is, it rounds towards the “nearest neighbor” unless both neighbors are equidistant, in which case, this mode rounds towards the even neighbor. Note that this rounding mode statistically minimizes cumulative error when applied repeatedly over a sequence of calculations. For more information about half-even rounding mode, see Rounding Mode. For example: Double D1 = 5.5; Long L1 = D1.round(); system.assertEquals(L1, 6); Double D2= 5.2; Long L2= D2.round(); system.assertEquals(L2, 5); Double D3= -5.7; Long L3= D3.round(); system.assertEquals(L3, -6); 305
- 308. Reference Apex Primitive Methods For more information on Double, see Primitive Data Types on page 36. ID Methods The following are the static methods for ID. Method Arguments Return Type Description valueOf String s ID Converts the specified String into an ID and returns the ID. The following are the instance methods for ID. Method Arguments Return Type Description addError String errorMsg Marks a record with a custom error message and prevents any DML operation from occurring. The errorMsg argument is the error message to mark the record with. This method is similar to the addError sObject method. addError Exception exception Marks a record with a custom error message and prevents any DML operation from occurring. The exception argument is an Exception object or a custom exception object that contains the error message to mark the record with. This method is similar to the addError sObject method. getSObjectType Schema.SObjectType Returns the token for the sObject corresponding to this ID. This method is primarily used with describe information. For more information about describes, see Understanding Apex Describe Information. For an example, see Sample: Getting an sObject Token From an ID. Sample: Getting an sObject Token From an ID This sample shows how to use the getSObjectType method to obtain an sObject token from an ID. The updateOwner method in this sample accepts a list of IDs of the sObjects to update the ownerId field of. This list contains IDs of sObjects of the same type. The second parameter is the new owner ID. Note that since it is a future method, it doesn’t accept sObject types as parameters; this is why it accepts IDs of sObjects. This method gets the sObject token from the first ID in the list, 306
- 309. Reference Apex Primitive Methods then does a describe to obtain the object name and constructs a query dynamicallly. It then queries for all sObjects and updates their owner ID fields to the new owner ID. public class MyDynamicSolution { @future public static void updateOwner(List<ID> objIds, ID newOwnerId) { // Validate input System.assert(objIds != null); System.assert(objIds.size() > 0); System.assert(newOwnerId != null); // Get the sObject token from the first ID // (the List contains IDs of sObjects of the same type). Schema.SObjectType token = objIds[0].getSObjectType(); // Using the token, do a describe // and construct a query dynamically. Schema.DescribeSObjectResult dr = token.getDescribe(); String queryString = 'SELECT ownerId FROM ' + dr.getName() + ' WHERE '; for(ID objId : objIds) { queryString += 'Id='' + objId + '' OR '; } // Remove the last ' OR' queryString = queryString.subString(0, queryString.length() - 4); sObject[] objDBList = Database.query(queryString); System.assert(objDBList.size() > 0); // Update the owner ID on the sObjects for(Integer i=0;i<objDBList.size();i++) { objDBList[i].put('ownerId', newOwnerId); } Database.SaveResult[] srList = Database.update(objDBList, false); for(Database.SaveResult sr : srList) { if (sr.isSuccess()) { System.debug('Updated owner ID successfully for ' + dr.getName() + ' ID ' + sr.getId()); } else { System.debug('Updating ' + dr.getName() + ' returned the following errors.'); for(Database.Error e : sr.getErrors()) { System.debug(e.getMessage()); } } } } } Integer Methods The following are the system static methods for Integer. Name Arguments Return Type Description valueOf anyType x Integer Casts x, a history tracking table field of type anyType, to an Integer. For more information on the anyType data type, see Field Types in the Object Reference for Salesforce and Force.com. 307
- 310. Reference Apex Primitive Methods Name Arguments Return Type Description valueOf String s Integer Returns an Integer that contains the value of the specified String. As in Java, the String is interpreted as representing a signed decimal integer. For example: Integer myInt = integer.valueOf('123'); The following are the instance methods for Integer. Name Arguments Return Type Description format String Returns the integer as a string using the locale of the context user For more information on integers, see Primitive Data Types on page 36. Long Methods The following is the system static method for Long. Name Arguments Return Type Description valueOf String s Long Returns a Long that contains the value of the specified String. As in Java, the string is interpreted as representing a signed decimal Long. For example: Long L1 = long.valueOf('123456789'); The following are the instant methods for Long. Name Arguments Return Type Description format String Returns the String format for this Long using the locale of the context user intValue Integer Returns the Integer value for this Long For more information on Long, see Primitive Data Types on page 36. String Methods The following are the system static methods for String. 308
- 311. Reference Apex Primitive Methods Name Arguments Return Type Description escapeSingleQuotes String s String Returns a String with the escape character () added before any single quotation marks in the String s. This method is useful when creating a dynamic SOQL statement, to help prevent SOQL injection. For more information on dynamic SOQL, see Dynamic SOQL. See also Splitting String Example. format String s String Treat the current string as a pattern that should be used for substitution in the same manner as apex:outputText. List<String> arguments fromCharArray List<Integer> String Returns a String from the values of the list of integers. charArray getCommonPrefix List<String> String Returns the initial sequence of characters as a String that strings is common to all the specified Strings. Example: List<String> ls = new List<String> {'SFDCApex', 'SFDCVisualforce'}; String prefix = String.getCommonPrefix( ls); System.assertEquals( 'SFDC', prefix); isBlank String s Boolean Returns true if the specified String is white space, empty (''), or null; otherwise, returns false. isEmpty String s Boolean Returns true if the specified String is empty ('') or null; otherwise, returns false. isNotBlank String s Boolean Returns true if the specified String is not whitespace, not empty (''), and not null; otherwise, returns false. isNotEmpty String s Boolean Returns true if the specified String is not empty ('') and not null; otherwise, returns false. join Object String Joins the elements of the specified iterable object, such iterableObj as a List, into a single String separated by the specified separator. String separator Example: List<Integer> li = new List<Integer> {10, 20, 30}; String s = String.join( li, '/'); System.assertEquals( '10/20/30', s); 309
- 312. Reference Apex Primitive Methods Name Arguments Return Type Description valueOf Date d String Returns a String that represents the specified Date in the standard “yyyy-MM-dd” format. For example: Date myDate = Date.Today(); String sDate = String.valueOf(myDate); valueOf Datetime dt String Returns a String that represents the specified Datetime in the standard “yyyy-MM-dd HH:mm:ss” format for the local time zone valueOf Decimal d String Returns a String that represents the specified Decimal. valueOf Double d String Returns a String that represents the specified Double. Example: Double myDouble = 12.34; String myString = String.valueOf(myDouble); System.assertEquals( '12.34', myString); valueOf Integer I String Returns a String that represents the specified Integer. valueOf Long l String Returns a String that represents the specified Long. valueOf Object x String Returns a string representation of the specified object argument. Example: List<Integer> ls = new List<Integer>(); ls.add(10); ls.add(20); String strList = String.valueOf(ls); System.assertEquals( '(10, 20)', strList); If the argument is not a String, the valueOf method converts it into a String by calling the toString method on the argument, if available, or any overridden toString method if the argument is a user-defined type. Otherwise, if no toString method is available, it returns a String representation of the argument. valueOfGmt Datetime dt String Returns a String that represents the specified Datetime in the standard “yyyy-MM-dd HH:mm:ss” format for the GMT time zone. The following are the instance methods for String. 310
- 313. Reference Apex Primitive Methods Name Arguments Return Type Description abbreviate Integer maxWidth String Returns an abbreviated version of the String, of the specified length and with ellipses appended if the current String is longer than the specified length; otherwise, returns the original String without ellipses. If maxWidth is less than four, this method throws a run-time exception. Example: String s = 'Hello Maximillian'; String s2 = s.abbreviate(8); System.assertEquals( 'Hello...', s2); System.assertEquals( 8, s2.length()); abbreviate Integer maxWidth String Returns an abbreviated version of the String, starting at the specified character offset and of the specified length. Integer offset The returned String has ellipses appended at the start and the end if characters have been removed at these locations. Note that the offset is not necessarily the leftmost character in the returned String or the first character following the ellipses, but it appears somewhere in the result. Regardless, abbreviate won’t return a String of length greater than maxWidth. If maxWidth is too small, this method throws a run-time exception. This method is based on its counterpart abbreviate method in the Apache Commons Lang StringUtils library. Example: String s = 'Hello Maximillian'; // Start at M String s2 = s.abbreviate(9,6); System.assertEquals( '...Max...', s2); System.assertEquals( 9, s2.length()); 311
- 314. Reference Apex Primitive Methods Name Arguments Return Type Description capitalize String Returns the current String with the first letter changed to title case as per the Character.toTitleCase(char) Java method. Example: String s = 'hello maximillian'; String s2 = s.capitalize(); System.assertEquals( 'Hello maximillian', s2); center Integer size String Returns a version of the current String of the specified size padded with spaces on the left and right, so that it appears in the center. If the specified size is smaller than the current String size, the entire String is returned without added spaces. Example: String s = 'hello'; String s2 = s.center(9); System.assertEquals( ' hello ', s2); center Integer size String Returns a version of the current String of the specified size padded with the specified String on the left and String padStr right, so that it appears in the center. If the specified size is smaller than the current String size, the entire String is returned without padding. Example: String s = 'hello'; String s2 = s.center(9); System.assertEquals( '--hello--', s2); compareTo String compString Integer Compares two strings lexicographically, based on the Unicode value of each character in the Strings. The result is: • A negative Integer if the String that called the method lexicographically precedes compString • A positive Integer if the String that called the method lexicographically follows compString 312
- 315. Reference Apex Primitive Methods Name Arguments Return Type Description • Zero if the Strings are equal If there is no index position at which the Strings differ, then the shorter String lexicographically precedes the longer String. For example: String myString1 = 'abcde'; String myString2 = 'abcd'; Integer result = myString1.compareTo(myString2); System.assertEquals(result, 1); Note that this method returns 0 whenever the equals method returns true. contains String compString Boolean Returns true if and only if the String that called the method contains the specified sequence of characters in the compString. For example: String myString1 = 'abcde'; String myString2 = 'abcd'; Boolean result = myString1.contains(myString2); System.assertEquals(result, true); containsAny String compString Boolean Returns true if the current String contains any of the characters in the specified String; otherwise, returns false. Example: String s = 'hello'; Boolean b1 = s.containsAny('hx'); Boolean b2 = s.containsAny('x'); System.assertEquals( true, b1); System.assertEquals( false, b2); containsIgnoreCase String compString Boolean Returns true if the current String contains the specified sequence of characters without regard to case; otherwise, returns false. Example: String s = 'hello'; Boolean b = s.containsIgnoreCase('HE'); System.assertEquals( true, b); 313
- 316. Reference Apex Primitive Methods Name Arguments Return Type Description containsNone String compString Boolean Returns true if the current String doesn’t contain the specified sequence of characters; otherwise, returns false. If compString is an empty string or the current String is empty, this method returns true. If compString is null, this method returns a run-time exception. containsOnly String compString Boolean Returns true if the current String contains characters only from the specified sequence of characters and not any other characters; otherwise, returns false. Example: String s1 = 'abba'; String s2 = 'abba xyz'; Boolean b1 = s1.containsOnly('abcd'); System.assertEquals( true, b1); Boolean b2 = s2.containsOnly('abcd'); System.assertEquals( false, b2); containsWhitespace Boolean Returns true if the current String contains any white space characters; otherwise, returns false. countMatches String compString Integer Returns the number of times the specified substring occurs in the current String. deleteWhitespace String Returns a version of the current String with all white space characters removed. difference String compString String Returns the difference between the current String and the specified String. If compString is an empty string, this method returns an empty string. If compString is null, this method throws a run-time exception. Example: String s = 'Hello Jane'; String d1 = s.difference('Hello Max'); System.assertEquals( 'Max', d1); String d2 = s.difference('Goodbye'); 314
- 317. Reference Apex Primitive Methods Name Arguments Return Type Description System.assertEquals( 'Goodbye', d2); endsWith String suffix Boolean Returns true if the String that called the method ends with the specified suffix. endsWithIgnoreCase String suffix Boolean Returns true if the current String ends with the specified suffix; otherwise, returns false. equals String compString Boolean Returns true if the compString is not null and represents the same binary sequence of characters as the String that called the method. This method is true whenever the compareTo method returns 0. For example: String myString1 = 'abcde'; String myString2 = 'abcd'; Boolean result = myString1.equals(myString2); System.assertEquals(result, false); Note that the == operator also performs String comparison, but is case-insensitive to match Apex semantics. (== is case-sensitive for ID comparison for the same reason.) equalsIgnoreCase String compString Boolean Returns true if the compString is not null and represents the same sequence of characters as the String that called the method, ignoring case. For example: String myString1 = 'abcd'; String myString2 = 'ABCD'; Boolean result = myString1.equalsIgnoreCase(myString2); System.assertEquals(result, true); escapeCsv String Returns a String for a CSV column enclosed in double quotes, if required. If the String contains a comma, newline or double quote, the returned String is enclosed in double quotes. Also, any double quote characters in the String are escaped with another double quote. If the String doesn’t contain a comma, newline or double quote, it is returned unchanged. This method is based on its counterpart escapeCsv method in the Apache Commons Lang StringEscapeUtils library. 315
- 318. Reference Apex Primitive Methods Name Arguments Return Type Description Example: String s1 = 'Max1, "Max2"'; String s2 = s1.escapeCsv(); System.assertEquals( '"Max1, ""Max2"""', s2); escapeEcmaScript String Escapes the characters in the String using EcmaScript String rules. The only difference betweenApex strings and EcmaScript strings is that in EcmaScript, a single quote and forward-slash (/) are escaped. This method is based on its counterpart escapeEcmaScript method in the Apache Commons Lang StringEscapeUtils library. Example: String s1 = '"grade": 3.9/4.0'; String s2 = s1.escapeEcmaScript(); System.debug(s2); // Output is: // "grade": 3.9/4.0 System.assertEquals( '"grade": 3.9/4.0', s2); escapeHtml3 String Escapes the characters in a String using HTML 3.0 entities. This method is based on its counterpart escapeHtml3 method in the Apache Commons Lang StringEscapeUtils library. Example: String s1 = '"<Black&White>"'; String s2 = s1.escapeHtml3(); System.debug(s2); // Output: // "<Black& // White>" 316
- 319. Reference Apex Primitive Methods Name Arguments Return Type Description escapeHtml4 String Escapes the characters in a String using HTML 4.0 entities. This method is based on its counterpart escapeHtml4 method in the Apache Commons Lang StringEscapeUtils library. Example: String s1 = '"<Black&White>"'; String s2 = s1.escapeHtml4(); System.debug(s2); // Output: // "<Black& // White>" escapeXml String Escapes the characters in a String using XML entities. Supports only the five basic XML entities (gt, lt, quot, amp, apos). Does not support DTDs or external entities. Unicode characters greater than 0x7f are not escaped. This method is based on its counterpart escapeXml method in the Apache Commons Lang StringEscapeUtils library. Example: String s1 = '"<Black&White>"'; String s2 = s1.escapeXml(); System.debug(s2); // Output: // "<Black& // White>" getLevenshtein String s Integer Returns the Levenshtein distance between the current Distance String and the specified String. The Levenshtein distance is the number of changes needed to change one String into another. Each change is a single character modification (deletion, insertion or substitution). Example: String s = 'Hello Joe'; Integer i = s.getLevenshteinDistance( 'Hello Max'); System.assertEquals( 3, i); 317
- 320. Reference Apex Primitive Methods Name Arguments Return Type Description getLevenshtein String s Integer Returns the Levenshtein distance between the current Distance String and the specified String if it is less than or equal Integer threshold than the given threshold; otherwise, returns -1. The Levenshtein distance is the number of changes needed to change one String into another. Each change is a single character modification (deletion, insertion or substitution). Example: In this example, the Levenshtein distance is 3, but the threshold argument is 2, which is less than the distance, so this method returns -1. String s = 'Hello Jane'; Integer i = s.getLevenshteinDistance( 'Hello Max', 2); System.assertEquals( -1, i); indexOf String subString Integer Returns the index of the first occurrence of the specified substring. If the substring does not occur, this method returns -1. indexOf String substring Integer Returns the zero-based index of the first occurrence of the specified substring from the point of index i. If the Integer i substring does not occur, this method returns -1. For example: String myString1 = 'abcd'; String myString2 = 'bc'; Integer result = myString1.indexOf(myString2, 0); System.assertEquals(1, result); indexOfAny String substring Integer Returns the zero-based index of the first occurrence of any character specified in the substring. If none of the characters occur, returns -1. Example: String s1 = 'abcd'; String s2 = 'xc'; Integer result = s1.indexOfAny(s2); System.assertEquals( 2, result); 318
- 321. Reference Apex Primitive Methods Name Arguments Return Type Description indexOfAnyBut String substring Integer Returns the zero-based index of the first occurrence of a character that is not in the specified substring. Otherwise, returns -1. Example: String s1 = 'abcd'; String s2 = 'xc'; Integer result = s1.indexOfAnyBut(s2); System.assertEquals( 0, result); indexOfDifference String s Integer Returns the zero-based index of the character where the current String begins to differ from the specified String. Example: String s1 = 'abcd'; String s2 = 'abxc'; Integer result = s1.indexOfDifference(s2); System.assertEquals( 2, result); indexOfIgnoreCase String substring Integer Returns the zero-based index of the first occurrence of the specified substring without regard to case. If the substring does not occur, this method returns -1. For example: String s1 = 'abcd'; String s2 = 'BC'; Integer result = s1.indexOfIgnoreCase(s2, 0); System.assertEquals(1, result); indexOfIgnoreCase String substring Integer Returns the zero-based index of the first occurrence of the specified substring from the point of index i, without Integer regard to case. If the substring does not occur, this startPosition method returns -1. isAllLowerCase Boolean Returns true if all characters in the current String are lowercase; otherwise, returns false. isAllUpperCase Boolean Returns true if all characters in the current String are uppercase; otherwise, returns false. 319
- 322. Reference Apex Primitive Methods Name Arguments Return Type Description isAlpha Boolean Returns true if all characters in the current String are Unicode letters only; otherwise, returns false. Example: // Letters only String s1 = 'abc'; // Returns true Boolean b1 = s1.isAlpha(); System.assertEquals( true, b1); // Letters and numbers String s2 = 'abc 21'; // Returns false Boolean b2 = s2.isAlpha(); System.assertEquals( false, b2); isAlphaSpace Boolean Returns true if all characters in the current String are Unicode letters or spaces only; otherwise, returns false. isAlphanumeric Boolean Returns true if all characters in the current String are Unicode letters or numbers only; otherwise, returns false. Example: // Letters only String s1 = 'abc'; // Returns true Boolean b1 = s1.isAlphanumeric(); System.assertEquals( true, b1); // Letters and numbers String