Here’s and example of our Library & LibraryManager classes that we use in some of our Flex and AS 3.0 projects to manage our external assets stored in SWF’s.

The classes enabled you to create multiple libraries of embedded (retaining and giving access to code) or loaded SWF’s.

You can create instance of Library wherever you want, but you can also create them through the LibraryManager giving you a single class to gain access to all your Library instances.

Here’s a quick example creating 2 Library instances using the LibraryManager. Each Library contains 2 SWF’s, each containing a BitmapData and MovieClip which are created using the Library. One Library instance embeds the SWF’s the other loads them. Not shown in the example, but you can also have a mix of loaded and embedded SWF’s in the same Library, and they contain fonts as well as custom classes.

LibraryExample
LibraryExample source (NOTE: The source has already been edited but not updated here. I suggest you pull down the latest version from our google code repository)

You can obviously get it one our Google Code repository.

Want to start writing AS 3.0 or use Flex 2.0, but need to use them alongside older elements created in AS 2.0 and published for Flash Player 8 or lower? You could use LocalConnection or ExternalInterface, both having their own limitations, or you could take a look at FlashInterface.

FlashInterface allows direct communication between AVMs with a common API for both AS 2.0 and AS 3.0. It also supports controlling Flash Player 7 and lower SFW’s through a Flash 8 wrapper.

Features
Bi-direction communication between AVMs, Synchronous calls, Returns values from within same call, Common API, Call Local Properties, Call Local Methods, Anonymous Calls, Global Access to SWF elements, Optional Event Listener Model, No limitation on data size.

Download, documentation, tutorials and examples.