[Flex] Misc

Some libraries will not be available under different environments (WebApp or Desktop (AIR))

use package in MXML:
<s:Application
xmlns:namespace_name="package"
e.g.: xmlns:file="flash.filesystem.*"
then in <fx:Declaration>: <file:File id="id"/>

Coding conventions:
http://sourceforge.net/adobe/flexsdk/wiki/Coding%20Conventions/
public static const AAA_BBB:String = "value"

set lib (source path): set the parent directory of lib package

show Sprite (include bitmapData )on MXML: use UIComponent:
var ui:UIComponent = new UIComponent;
ui.addChild(sprite);
group.addElement(ui);  //group: spark group