How to load external assets from an AS3 file using the Flex SDK

Resource.as:

package
{
   import flash.display.Sprite;

   // This _must_ inherit from Sprite, or the resources can't be attached to
   // the main movie.
   public class Resources extends Sprite
   {
      // List your resources here, as public variables
      [Embed(source="mysource.swf",symbol="AnySymbol")]
      public var SomeSymbol:Class;
   }
}

compile:

mxmlc Resources.as -output resources.swf -sp . -no-network=false

"...load it into your app using a standard flash.display.Loader, without specifying an applicationDomain. Once loaded, get at the assets like this:"

var ResourceClass:Class = loader.contentLoaderInfo.applicationDomain.getDefinition("Resources") as Class;
var resources:Object = new ResourceClass();
var symClass:Class = resources['SomeSymbol'] as Class;
var symbol:MovieClip = new symClass() as MovieClip;

http://wildwinter.blogspot.com/