AS3-从Document类外部访问库项目

Question

How do you access Library items from classes other than the document class?

For example, if I create a movie clip in Flash and Export it for Actionscript with the name Foo, I can do this in the document class:

var f = new Foo();
this.addChild(f);

And it appears on the stage, as it should. But I need to be able to create other instances of this object from other classes. If I use the same code above in SomeOtherClass.as, I get nothing on the stage, obviously because this class doesn't know about the Foo object in the library.

I know I probably need to use appplicationDomain.getDefinition somehow. This doesn't work:

var a = new ApplicationDomain(ApplicationDomain.currentDomain);
var foo: Class = a.getDefinition ( "com.me.CustomClass" ) ;
var f = new foo( ) ;
addChild ( f ) ;

TypeError: Error #1007: Instantiation attempted on a non-constructor.

Answer 1

Looks like an application domain problem. The loaded swf cannot access classes defined in the loader.

You should give the loaded swf access to the loader swf library. Try using LoaderContext .

Off the top of my head:

var loader:Loader = new Loader();
var ctx:LoaderContext = new LoaderContext(false,ApplicationDomain.current);
loader.load(yourRequest,ctx);

Answer 2

I don't ever remember this being a problem. I think (it's been a while!) that you need to write a code class derived from MovieClip or similar and associate with the library item somewhere in its properties. Of course once this is done, you can treat the library classes the same as any other class.

EDIT:

try this:

var foo:Class=loaderInstance.contentLoaderInfo.applicationDomain.getDefinition("MyClass");
var x:*=new foo();

Upon closer reading of your problem, I realize that this is code at the loader side, not the loadee side. Definitely barking up the right tree though.

Answer 3

Try something more like this:

var foo:Class = ApplicationDomain.currentDomain.getDefinition("SymbolName") as Class;

I believe the symbol name should not have a package name at the beginning, for a library symbol.

Answer 4

I find these answers somewhat over-cooked, because all I've ever done to use a Library Item from any class is to import it like any standard import. Surely that's why we select Export for Actionscript.

For example:

package 
{
   import foo;                     // Library MovieClip
   import flash.display.MovieClip; // Must import MovieClip to Extend it.
   .......

   public class something extends MovieClip
   {
     private var _foo:foo;   // Create a local reference of the imported Library Item.
     ......

    public function something():void
    {
     _foo = new foo(); // Create a new instance of the imported Library Item.
     .........
    }
   }
  }  

I find this works each and every time, can't say whether or not it's the right way. but it works for me.