ActionScript3 and Flex Builder 3

1. Introduction

ActionScript language allows creating animations, interactive 
and dynamic web applications. Like Javascript, ActionScript 
is a scripting language following ECMAScript specifications. 
Its related platform is Flash Player. It was first 
developed by Macromedia which became Adobe Since 2005. The 
version Actionscript 1.0 (AS 1.0) works with Flash MX; Actionscript 
2.0 (AS 2.0) works with Flash MX2004; and Actionscript 3 works 
with Flex. Actionscript needs Adobe Flash Player 
to show the file.swf generated when we compile (or run) 
Actionscript.(Flash Player and Flash Reader are totally free). 
In this tutorial, we will use Actionscript 3 working with Flex 
builder 3.

2. Installing Adobe Flex Builder 3:

Go to: www.adobe.com
   
, and download the 
60-day trial : Flex Builder 3 Professional. 
Get FB3_win.exe. 
Double_click on it and follow the instructions.

This installtion gives two programming ways:

1. In the Flex platform, build a project, set and run mxml applications.
In the directory: C:\Program Files\Adobe\Flex Builder 3, make 
FlexBuilder.exe as a shortcut in the desktop, in order to 
be called easily. 
Open Flex and start the project.


2. The other way is to write an Actionscript program, save 
at as file.as, and compile it using "mxmlc.exe".

This compiler is located in the directory:
C:\Program Files\Adobe\Flex Builder 3\sdks\3.1.0\bin

Add C:\Program Files\Adobe\Flex Builder 3\sdks\3.1.0\bin
in the path (start, setting,control pannel, system, advanced, 
environment variable)

Make a working director, say : C:\FLASH
In this working directoy, write a code, save it as file.as 
and compile as:
C:\FLASH> mxmlc file.as

If the code is correct, that is the compilation is done, 
we get:
C:\FLASH\file.swf (xxxx bytes). That is the file.wsf is 
generated and stored in the sane working directoory. This 
file.wsf can be seen in the Builder environement(just by 
double clicking on it), or opened in the browser.


In fact, the real compiler is the Java compiler that 
comes with Builder 3 software, and located in the directory:
C:\Program Files\Adobe\Flex Builder 3\jre\bin. Actionscript 
programming is an OOP(Oriented Object Programming). Its 
style is one of the Java. Sometimes, it seems that we are 
programming applets (compiled by "javac" and viewed by "appletviwer" 
or by a browser where the bycode file.class is embedded in an 
html page as <applet code=file.class></applet>). 
With Actionscript, we compile with mxmlc, and we get 
the file.wsf viwed in a browser or the Flex platform.

3. Examples

Example 1:

package {
import flash.display.Sprite;
import flash.text.TextField;

public class Regards extends Sprite {

public function Regards() {
var display_txt:TextField = new TextField();
display_txt.text = "Regards ..";
addChild(display_txt);
}
}
}


The execution gives:

C:\FLASH>mxmlc Regards.as
Loading configuration file C:\Program Files\Adobe\
Flex Builder 3\sdks\3.1.0\frameworks\flex-config.xml

C:\FLASH\Regards.swf (616 bytes)

The output is shown below, In the Mozilla Firefox 
browser and in Flash Player 9 platform:

  

Example 2: Drawing cirles

package {//package of classes
import flash.display.Sprite;
import flash.display.Shape;
import flash.display.Graphics;

public class Circles extends Sprite {

//Constructor:
public function Circles() {
colored_circle(graphics, 0x4169E1);

//New circle called child: circ
var circ:Shape = new Shape();
colored_circle(circ.graphics, 0xFFE4E1);
//Its position relatively to the first one:
circ.x = 150;
circ.y = 20;
addChild(circ);
}

//Define a fuction with two arguments of type Graphics and int:

private function colored_circle(target:Graphics, color:int):void {
target.lineStyle(1, 0x0000cd); 
//(border-width, color-width), here: blue

//Fill in the circle with the chosen color 0x0000cd
target.beginFill(color);
//Draw the related circle (x-position, y-position, radius):
target.drawCircle(200, 200, 100); 
}
}
} 

Let's compile this program:
C:\FLASH>mxmlc Circles.as
Loading configuration file C:\Program Files\Adobe\
Flex Builder 3\sdks\3.1.0\frameworks\flex-config.xml
C:\FLASH\Circles.swf (751 bytes)

The output is shown below in Flash Player 9 platform:

 

We can insert the following code:

<object
<object data ="Binaries.swf" type="application/x-shockwave-flash" width="200" height="100">
<param name="Binaries" value="Binaries.swf">  
</object>  

So the generated Circles.swf will appear within the same 
current page: