Cross domain problems in Flash - actionscript-3

Question

I have two swf files hosted on different domains aaa.com/a.swf and bbb.com/b.swf. a.swf is loading b.swf and trying to cast it to some interface. When both of these swf files are under the same domain everything works fine. But when they are under different domains I'm getting null after casting b.swf to the implemented interface IComponent. Both of these swfs are compiled with use-network=true and with the same IComponent.as.
public class Wrapper extends Sprite
{
public function Wrapper()
{
super();
var request:URLRequest = new URLRequest("http://aaa.com/Component.swf");
var loaderContext:LoaderContext = new LoaderContext();
loaderContext.applicationDomain = ApplicationDomain.currentDomain;
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.COMPLETE,onLoadingComplete);
loader.load(request,loaderContext);
addChild(loader);
}
private function onLoadingComplete(event:Event):void
{
var target:LoaderInfo = event.target as LoaderInfo;
var component:IComponent = target.content as IComponent;
component.init({"s":1});
component.run();
}
}
public class Component extends Sprite implements IComponent
{
public function Component()
{
super();
Security.allowInsecureDomain("*");
}
public function init(params:Object):void
{
//some actions
}
public function run():void
{
//some actions
}
}

Answer 1

Try this:
//Assuming you've set a crossdomain policy file
var loaderContext:LoaderContext =
new LoaderContext( true , ApplicationDomain.currentDomain )
It seems that the reason why it's not working has to do with the fact that either IComponent is not recognized or that there's a definition conflict. I would have thought that with ApplicationDomain set to currentDomain, a definition conflict should have been avoided... but it may be worth trying to leave each SWF within their own domain.
//Assuming you've set a crossdomain policy file
var loaderContext:LoaderContext =
new LoaderContext( true );
You could also check if IComponent "exists" before loading the other SWF. This could help in diagnosing what's going on...
var ClassName:Object = getDefinitionByName('IComponent');
trace( ClassName );

Answer 2

Maybe you have to set cross-domain security policy by crossdomain.xml file
http://www.adobe.com/devnet/flashplayer/articles/fplayer9_security.html
For example:
<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy
SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
<allow-access-from domain="*.example.com" />
</cross-domain-policy>

Answer 3

Thanks all for answers, I've found a working solution today.
Instead of casting loaded content to IComponent I'm casting it to object
var component:Object = (event.target as LoaderInfo).content as Object;
component["init"](null);
component["run"]();
I's confimed from testing that even when we are using shared class with static fields and methods it doesn't work. Both of wrapper and component are instantiating their own instances of shared class. It's really strange.
If you have the same problems please ensure that your wrapper/component classes have Security.allowDomain calls

Answer 4

This is a bug in the player:
http://bugs.adobe.com/jira/browse/ASC-3529
It happens when you try to "share" an interface between swfs that were loaded from different domains. This should work provided that you put both swfs under the same app domain (as you have).
Using an Object works, but kind of defeats the purpose of using an interface in the first place.
Here's a workaround that basically loads the swf as a binary and then uses Loader::loadBytes to actually load the swf into memory:
http://blog.aleksandarandreev.com/?p=42

Answer 5

my idea about syntax errors was pointless, here's an edit:
this code:
private function ololo():void{
var request:URLRequest = new URLRequest("http://domain/file.swf");
var loaderContext:LoaderContext = new LoaderContext();
loaderContext.applicationDomain = ApplicationDomain.currentDomain;
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.COMPLETE,onLoadingComplete);
loader.load(request,loaderContext);
}
private function onLoadingComplete(e:Event):void {
var target:LoaderInfo = e.target as LoaderInfo;
addChild(target.content as Sprite);
}
works well even if files are on completely different domains.
does it work if you treat your IComponent as Sprite?