Question

I have two projects, A and B, that reference a library, MyExternalLibrary. A and B are .swfs (two different AS3 projects) and MyExternalLibrary is a .swc. When my application is run, A loads B.

There is a Class, MyLoader, in MyExternalLibrary that B uses extensively. MyExternalLibrary.MyLoader loads .swfs that are present on our server (we don’t embed them because they are loaded dynamically per user-request).

Note that our server contains A, B and all of the .swfs we are going to download.

Now, A must also load some of the .swfs on our server. Consequentially, A must also use MyLoader in MyExternalLibrary. So, In A, I add a reference to MyLoader, so that its binary is included during compilation. I only add a reference to MyLoader — I don’t actually instantiate or modify it. That is, somewhere in A‘s code (before B is loaded), I have:

MyLoader;

I (obviously) import the Class as well. This ensures that MyLoader‘s binary will be included in A‘s .swf.

Just referencing MyExternalLibary.MyLoader in A breaks B‘s functionality with MyLoader — all of the .swfs that B loads will not cast to its associated Class, despite being a MovieClip and having all of the proper fields. Furthermore, in the debugger, the loaded MovieClips show that they are of the correct Class. For example, if I load a .swf, it will be a MovieClip; moreover, the debugger states it is of type B.mySwfs.MyClass, but I cannot cast it to B.mySwfs.MyClass. I believe the culprit is ApplicationDomain.

Note that commenting out that line of code makes everything in B cast properly.

If anyone has any idea about what’s going on, I’d love some advice. I think that this issue deals with ApplicationDomain since A owns MyExternalLibrary.MyLoader, and I’m trying to cast a MovieClip loaded by A into a Class that is in B. When I comment out all references to MyExternalLibrary.MyLoader in A, B now owns MyExternalLibrary.MyLoader, so it is able to cast to classes in B. That is my hunch!

Thanks,

Answer 1

The solution was to ensure that B‘s ApplicationDomain is the same as A‘s ApplicationDomain. This is done by parameterizing an instance of LoaderContext in either Loader.load or Loader.loadBytes.

For example, A loads B with the following line of code:

m_loader.load(new URLRequest("B.swf"), new LoaderContext(false, ApplicationDomain.currentDomain));

This adds all of B‘s Class definitions to A. So, when A loads a .swf, and that MovieClip is casted to a Class in B, everything will work because A and B are in the same ApplicationDomain. So, an Object loaded by A can be casted to a Class that is in B.

If anyone else encounters this problem, I highly suggest taking a look at GreenSock’s SWFLoader: http://www.greensock.com/as/docs/tween/com/greensock/loading/SWFLoader.html