getting Deep into Flex - actionscript-3

Question

The better you understand what you are doing, the better you will do it.
I want to get Deep into Flex . I did some simple Event-Handling and
The better you understand what you are doing, the better you will do it.
But i have i big question:
What does the Compiler do ?!
What happens with the MXML file ?
lets say we have a simple code ( code from blogflexexamples):
<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/12/27/changing-the-flex-colorpicker-controls-swatch-panel-background-color/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="top"
backgroundColor="white">
<mx:Style>
.myColorPicker {
swatchPanelStyleName: myCustomSwatchPanelStyleName;
}
.myCustomSwatchPanelStyleName {
backgroundColor: haloBlue;
}
</mx:Style>
<mx:Script>
<![CDATA[
import mx.events.ColorPickerEvent;
private function backgroundColor_change(evt:ColorPickerEvent):void {
var cssObj:CSSStyleDeclaration = StyleManager.getStyleDeclaration(".myCustomSwatchPanelStyleName");
cssObj.setStyle("backgroundColor", evt.color);
colorPicker.open();
}
]]>
</mx:Script>
<mx:ApplicationControlBar dock="true">
<mx:Form styleName="plain">
<mx:FormItem label="backgroundColor:">
<mx:ColorPicker change="backgroundColor_change(event);" />
</mx:FormItem>
</mx:Form>
</mx:ApplicationControlBar>
<mx:ColorPicker id="colorPicker"
styleName="myColorPicker"
editable="false" />
</mx:Application>
does this generate an Actionscript file ?
and if it does : Can i see the the .as file ( like preprocessor in C++ )?

Answer 1

Yes. MXML is translated into an ActionScript class. You can see the generated as code by adding -keep-generated-actionscript switch to the Additional compiler arguments in Project properties->Flex compiler.

Answer 2

Another good reference is the recently-released book Developing Flex 4 Components by Mike Jones. It mentions the compilation of MXML to Actionscript on page 4 and provides a solid grounding in how Flex components work.

Answer 3

For reference, here are some good places to digg deep into the Flex Compiler:
Diving in the Data Binding Waters (with Presentation Slides) - Shows how [Bindable] is converted into actionscript
Flex SDK Compiler Source Code
Flex 3 Compiler Design
Flex Mojos (with Source SVN) - Awesome code customizing how the compiler processes things.
Clement Wong's Blog - He was the previous leading Flex Compiler Engineer, points to some good resources.
Customizing Metadata Processing with Flex 4 Custom Compiler Extensions - New resources for the Compiler