The Ring programming language version 1.5.2 book - Part 39 of 181

Ring Documentation, Release 1.5.2
Each command will define a class that belong to the MyLanguage.Natural package.
We will define two commands, Hello and Count.
So we must have two files for defining the commands in the CurrentDir()+”/../command” folder
File: hello.ring
DefineNaturalCommand.SyntaxIsKeyword([
:Package = "MyLanguage.Natural",
:Keyword = :hello,
:Function = func {
See "Hello, Sir!" + nl + nl
}
])
File: count.ring
DefineNaturalCommand.SyntaxIsKeywordNumberNumber([
:Keyword = :count,
:Function = func {
if not isattribute(self,:count_times) {
AddAttribute(self,:count_times)
Count_Times = 0
}
if Expr(1) > Expr(2) {
nStep = -1
else
nStep = 1
}
if Count_Times = 0 {
see nl+"The Numbers!" + nl
Count_Times++
else
see nl + "I will count Again!" +nl
}
for x = Expr(1) to Expr(2) step nStep {
see nl+x+nl
}
CommandReturn(fabs(Expr(1)-Expr(2))+1)
}
])
46.2 Defining Commands
To define new command we can use the DefineNaturalCommand object
This object provides the next methods :-
• SyntaxIsKeyword(aPara)
• SyntaxIsKeywordNumber(aPara)
• SyntaxIsKeywordNumberNumber(aPara)
• SyntaxIsKeywordNumbers(aPara,nCount)
• SyntaxIsKeywordString(aPara)
• SyntaxIsKeywordStringString(aPara)
46.2. Defining Commands 355

• SyntaxIsKeywordStrings(aPara,nCount)
• SyntaxIsKeywordExpression(aPara)
• SyntaxIsKeywordExpressionExpression(aPara)
• SyntaxIsKeywordExpressions(aPara,nCount)
• SyntaxIsCommand(aPara)
• SyntaxIsCommandNumber(aPara)
• SyntaxIsCommandNumberNumber(aPara)
• SyntaxIsCommandNumbers(aPara,nCount)
• SyntaxIsCommandString(aPara)
• SyntaxIsCommandStringString(aPara)
• SyntaxIsCommandStrings(aPara,nCount)
• SyntaxIsCommandExpression(aPara)
• SyntaxIsCommandExpressionExpression(aPara)
• SyntaxIsCommandExpressions(aPara,nCount)
File: mylanguage.ring
load "stdlib.ring"
load "naturallib.ring"
MyLanguage = New NaturalLanguage {
SetLanguageName(:MyLanguage)
setCommandsPath(CurrentDir()+"/../command")
SetPackageName("MyLanguage.Natural")
UseCommand(:Hello)
UseCommand(:Count)
UseCommand(:Print)
UseCommand(:IWantWindow)
UseCommand(:WindowTitleIs)
UseCommand(:IWantButton)
}
Example (1)
In the next example we will deﬁne the Print command.
We will use the SyntaxIsKeywordExpression() Method.
We pass list (as Hash) to the method. We determine the package name, the keyword and the function that will be
executed.
Inside this function we uses the Expr(nExprNumber) function to get the expression value that the user will write after
the keyword.
File: print.ring
DefineNaturalCommand.SyntaxIsKeywordExpression([
:Keyword = :print,
:Function = func {
See Expr(1)
}
])

Usage:
load "mylanguage.ring"
MyLanguage.RunString('
print "Hello, World!"
')
Output:
Hello, World!
Example (2)
File: iwantwindow.ring
DefineNaturalCommand.SyntaxIsCommand([
:Command = "i want window",
:Function = func {
See "Command: I want window" + nl
}
])
Usage:
i want window
')
Output:
Command: I want window
Example (3)
File: windowtitleis.ring
DefineNaturalCommand.SyntaxIsCommandString([
:Command = "window title is",
:Function = func {
See "Command: Window title is " + Expr(1) + nl
}
])
Usage:
I want window and the window title is "Hello World"
')
Output:
Command: I want window
Command: Window title is Hello World

46.3 Natural Library - Operators
In the next example we uses the Count command without using operators
MyLanguage.RunString("
Hello
Count 1 5
Count 5 1
")
We can add more description
MyLanguage.RunString("
Hello, Please Count from 1 to 5 then count from 5 to 1
")
Also we can use operators like “(” and ”)” around the instruction
MyLanguage {
SetOperators("()")
RunString("
Here we will play and will try something
that looks like Lisp Syntax
(count (count 1 5) (count 20 15))
Just for fun!
")
}
46.4 Defining commands using classes
This section is related to the implementation details.
When we define new command, Each command is defined by the Natural Library as a class.
We have the choice to define commands using the simple interface provided by the DefineNaturalCommand object or
by defining new class as in the next examples.
If we used DefineNaturalCommand (More Simple), The class will be defined during the runtime.
File: hello.ring
Package MyLanguage.Natural
class Hello
func AddAttributes_Hello
AddAttribute(self,:hello)
func GetHello
See "Hello, Sir!" + nl + nl
File: count.ring
46.3. Natural Library - Operators 358

Package MyLanguage.Natural
class Count
func Getcount
StartCommand()
CommandData()[:name] = :Count
CommandData()[:nExpr] = 0
CommandData()[:aExpr] = []
func BraceExprEval_Count nValue
if isCommand() and CommandData()[:name] = :Count {
if isNumber(nValue) {
CommandData()[:nExpr]++
CommandData()[:aExpr] + nValue
if CommandData()[:nExpr] = 2 {
Count_Execute()
}
}
}
func AddAttributes_Count
AddAttribute(self,:count)
func Count_Execute
if not isattribute(self,:count_times) {
AddAttribute(self,:count_times)
Count_Times = 0
}
if Expr(1) > Expr(2) {
nStep = -1
else
nStep = 1
}
if Count_Times = 0 {
see nl+"The Numbers!" + nl
Count_Times++
else
see nl + "I will count Again!" +nl
}
for x = Expr(1) to Expr(2) step nStep {
see nl+x+nl
}
CommandReturn(fabs(Expr(1)-Expr(2))+1)
46.4. Deﬁning commands using classes 359

CHAPTER
FORTYSEVEN
WEB DEVELOPMENT (CGI LIBRARY)
In this chapter we will learn about developing Web applications using a CGI Library written in the Ring language.
47.1 Conﬁgure the Apache web server
We can use Ring with any web server that support CGI. In this section we will learn about using Ring with the Apache
HTTP Server.
You can download Apache from : http://httpd.apache.org/
Or you can get it included with other projects like
XAMPP : https://www.apachefriends.org/download.html
Install then open the ﬁle:
xamppapacheconfhttpd.conf
search for
<Directory />
Then after it add
Options FollowSymLinks +ExecCGI
So we have
<Directory />
Options FollowSymLinks +ExecCGI
Search for the next line and be sure that it’s not commented
LoadModule cgi_module modules/mod_cgi.so
Search for : AddHandler cgi-script
Then add ”.ring” to the supported cgi extensions
Example
AddHandler cgi-script .cgi .ring
Example
AddHandler cgi-script .cgi .pl .asp .ring
360

Run/Start the server
Create your web applications in a directory supported by the web server.
Example:
Apache2.2htdocsmywebapplicationfolder
Example:
xampphtdocsmywebapplicationfolder
Inside the source code ﬁle (*.ring), Add this line
#!c:ringbinring.exe -cgi
Note: Change the previous line based on the path to ring.exe in your machine
47.2 Ring CGI Hello World Program
The next program is the Hello World program
See "content-type : text/html" +nl+nl+
"Hello World!" + nl
47.3 Hello World Program using the Web Library
We can use the web library to write CGI Web applications quickly
Example (1) :
Load "weblib.ring"
Import System.Web
New Page
{
Text("Hello World!")
}
Example (2) :
Load "weblib.ring"
Import System.Web
WebPage()
{
Text("Hello World!")
}
47.2. Ring CGI Hello World Program 361

Tip: the difference between ex. 1 and ex. 2 is using WebPage() function to return the page object instead of creating
the object using new statement.
47.4 Web Library Features
The next features are provided by the Web library to quickly create web applications.
• Generate HTML pages using functions
• Generate HTML pages using objects
• HTTP Get
• HTTP Post
• Files Upload
• URL Encode
• Templates
• CRUD MVC Sample
• Users Logic & Registration Sample
47.5 HTTP Get Example
The Page User Interface
Load "weblib.ring"
Import System.Web
New Page
{
Title = "Test HTTP Get"
divstart([ :style = StyleSizeFull() ] )
boxstart()
text( "Test HTTP GET" )
newline()
boxend()
divstart([ :style = Styledivcenter("600px","550px") +
StyleGradient(21) ])
divstart([:style = stylefloatleft() + stylesize("100px","100%") +
stylecolor("black") + stylegradient(58)])
formstart("ex5.ring")
tablestart([ :style = stylesize("65%","90%") +
stylemarginleft("35%") +
stylemargintop("30%") ])
rowstart([])
cellstart([])
text ( "Name : " )
cellend()
cellstart([])
cTextboxStyle = StyleMarginLeft("5%") +
StyleWidth("250px") +
StyleColor("black") +
47.4. Web Library Features 362

StyleBackColor("white")
textbox([ :name = "Name", :style = cTextboxStyle ] )
cellend()
rowend()
rowstart([])
cellstart([])
text ( "Address : " )
cellend()
cellstart([])
textbox([ :name = "Address", :style = cTextboxStyle] )
cellend()
rowend()
rowstart([])
cellstart([])
text ( "Phone : " )
cellend()
cellstart([])
textbox([ :name = "Phone", :style = cTextboxStyle ])
cellend()
rowend()
rowstart([])
cellstart([])
text ( "Age : " )
cellend()
cellstart([])
textbox([ :name = "Age", :style = cTextboxStyle ])
cellend()
rowend()
rowstart([])
cellstart([])
text ( "City: " )
cellend()
cellstart([])
listbox([ :name = "City", :items = ["Cairo","Riyadh","Jeddah"],
:style = stylemarginleft("5%") + stylewidth("400px") ] )
cellend()
rowend()
rowstart([])
cellstart([])
text ( "Country : " )
cellend()
cellstart([])
combobox([ :name = "Country",
:items = ["Egypt","Saudi Arabia","USA"],
:style = stylemarginleft("5%") +
stylewidth("400px")+
stylecolor("black")+
stylebackcolor("white")+
stylefontsize("14px") ])
cellend()
rowend()
rowstart([])
cellstart([])
text ( "Note : " )
cellend()
cellstart([])
editbox([ :name = "Notes",
:style = stylemarginleft("5%") +
47.5. HTTP Get Example 363

stylesize("400px","100px")+
stylecolor("black")+
stylebackcolor("white") ,
:value = "write comments here..." ] )
cellend()
rowend()
rowstart([])
cellstart([])
cellend()
cellstart([])
submit([ :value = "Send" , :Style = stylemarginleft("5%") ])
cellend()
rowend()
tableend()
formend()
divend()
divend()
divend()
}
Screen Shot:
47.5. HTTP Get Example 364

The Ring programming language version 1.5.2 book - Part 39 of 181

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The Ring programming language version 1.5.2 book - Part 39 of 181