Web Design & Development - Session 8
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This document provides an overview of object-oriented programming (OOP) concepts including classes, objects, and the $this keyword in PHP. It also discusses handling HTML forms in PHP. The key points covered are: - OOP is based on real-world objects that have states stored in variables and behaviors implemented as methods. A class defines common attributes and methods for objects. - In PHP, a class defines properties and methods, objects are instances of classes, and $this refers to the current object instance. - Form handling in PHP involves creating an HTML form, submitting user-entered data via GET or POST, and processing the submitted data with PHP scripts.
Web Design & Development - Session 8
- 1. Web Design and Development By: Shahrzad Peyman Session 8 December-2017 shahrzad.peymaan@gmail.com 1
- 2. 2 Today’s Presentation • Class • Object • $this • Form Handling
- 3. Object Oriented Programming 3 A What is Object-Oriented Programming (OOP)? Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects". So, Objects are key to understanding object-oriented technology.
- 4. What is Object? 4 ❖Many examples of real-world objects ▪ your Book, your PC, your Mobile, your Computer mouse and so on. ❖Real-world objects share two characteristics: ▪ State ▪ Behavior ❖Software Objects ▪ Modeled after real-world objects. ▪ Maintains its states in variables or attributes. ▪ Implements its behaviors with methods.
- 5. Objects 5 ▪ E.g. A Computer Mouse is a real-world Object. Its states would be its color, size and brand name and its behaviors would be left-click, right-click and middle click. ▪ Software object that modeled your real-world computer mouse. ▪ Have variables(attributes) that indicated the computer mouse’s current states: ▪ Its color is black. ▪ Its size is medium. ▪ Its brand name is Genius. ▪ Have methods that indicated the computer mouse’s current behaviors like left-click, right-click and middle click.
- 6. What is Class? 6 ▪ A class is a prototype that defines the variables and the methods common to all objects of a certain kind. ▪ A class is an entity that helps the programmer to define a new complex data type. ➢An object is an instance of a class. ➢A class defines the data and behavior of objects. ➢E.g. Apple, Orange and banana are members of the fruit class.
- 7. Class in PHP 7 ▪Basic class definitions begin with the keyword class, followed by a class name. ▪Then, followed by a pair of curly braces which enclose the definitions of the properties and methods belonging to the class.
- 8. Object in PHP 8 ▪Instance of Class
- 9. Objects and Class Sample 9
- 10. Define First Class and Object 10
- 11. $this 11 $this is mainly used to refer properties of a class. It is the way to reference an instance of a class from within itself, the same as many other object oriented languages. From the PHP docs: The pseudo-variable $this is available when a method is called from within an object context.
- 12. Form Handling 12 The main way that website users interact with PHP is through the use of HTML forms. Handling forms is a multipart process. First a form is created, into which a user can enter the required details. This data is then sent to the web server, where it is interpreted, often with some error checking. If the PHP code identifies one or more fields that require reentering, the form may be redisplayed with an error message. When the code is satisfied with the accuracy of the input, it takes some action that usually involves the database, such as entering details about a purchase.
- 13. Form Handling 13 To build a form, you must have at least the following elements: 1- An opening <form> and closing </form> tags. 2- A submission type specifying either a Get or Post method. 3- One or more input fields. 4- The destination URL to which the form data is to be submitted.
- 14. Form Handling 14
- 15. Retrieving Submitted Data 15 Only one part of the multipart form-handling process. If you enter a name and click the Submit Query button, absolutely nothing will happen other than the form being redisplayed. So now it’s time to add some PHP code to process the data submitted by the form.