ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with movie clips
Loading an external SWF file
Flash Player 9 and later, Adobe AIR 1.0 and later
In ActionScript 3.0, SWF files are loaded using the Loader class. To load an external SWF file, your ActionScript needs
to do four things:
1 Create a new URLRequest object with the url of the file.
2 Create a new Loader object.
3 Call the Loader object’s load() method, passing the URLRequest instance as a parameter.
4 Call the addChild() method on a display object container (such as the main timeline of a Flash document) to add
the Loader instance to the display list.
Ultimately, the code looks like this:
var request:URLRequest = new URLRequest("http://www.[yourdomain].com/externalSwf.swf");
var loader:Loader = new Loader()
loader.load(request);
addChild(loader);
This same code can be used to load an external image file such as a JPEG, GIF, or PNG image, by specifying the image
file’s url rather than a SWF file’s url. A SWF file, unlike an image file, may contain ActionScript. Thus, although the
process of loading a SWF file may be identical to loading an image, when loading an external SWF file both the SWF
file doing the loading and the SWF file being loaded must reside in the same security sandbox if Flash Player or AIR is
playing the SWF and you plan to use ActionScript to communicate in any way to the external SWF file. Additionally,
if the external SWF file contains classes that share the same namespace as classes in the loading SWF file, you may need
to create a new application domain for the loaded SWF file in order to avoid namespace conflicts. For more
information on security and application domain considerations, see “Working with application domains” on page 147
and “Loading content” on page 1048.
When the external SWF file is successfully loaded, it can be accessed through the Loader.content property. If the
external SWF file is published for ActionScript 3.0, this will be either a movie clip or a sprite, depending on which class
it extends.
Considerations for loading an older SWF file
Flash Player 9 and later, Adobe AIR 1.0 and later
If the external SWF file has been published with an older version of ActionScript, there are important limitations to
consider. Unlike an ActionScript 3.0 SWF file that runs in AVM2 (ActionScript Virtual Machine 2), a SWF file
published for ActionScript 1.0 or 2.0 runs in AVM1 (ActionScript Virtual Machine 1).
There are important differences when loading an ActionScript 1.0 or 2.0 SWF file into an ActionScript 3.0 SWF file
(compared to loading an ActionScript 3.0 SWF file). Flash Player provides full backward compatibility with previously
published content. Any content that runs in previous versions of Flash Player runs in Flash Player versions that
support ActionScript 3.0. However, the following limitations apply:
ActionScript 3.0 code can load a SWF file written in ActionScript 1.0 or 2.0. When an ActionScript 1.0 or 2.0 SWF
file is successfully loaded, the loaded object (the Loader.content property) is an AVM1Movie object. An
AVM1Movie instance is not the same as a MovieClip instance. It is a display object, but unlike a movie clip, it does
not include timeline-related methods or properties. The parent AVM2 SWF file cannot access the properties,
methods, or objects of the loaded AVM1Movie object.
Last updated 6/6/2012
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