I have been looking here and there through some AS3 articles. Particularly about creating a preloader. I had quite an experience.
Normally in AS2, I have a three step process in creating flash movies.
1) Preload the main movie (using this.getBytesLoaded and this.getBytesTotal) and then us onEnterFrame to monitor its progress with some kind of progress bar
2) In main movie, preload some other external assets (using movieClipLoaderInstance_mcl.load(“some_swf.swf”, mc_instance_mc); with all the event listeners etc…)
3) Test the movie
From what I am observing, the best AS3 practice doesn’t recommend the AS2 approach. In a sense, I need to unlearn my AS2 mindset to know how things work in AS3. While scouring on the web, the most popular choice is to:
1) In the main movie, preload all other assets through using a document class (e.g. in Java standards, you can specify which of your class files to be your Main class; It’s a class that extends the MovieClip class)
2) Test the movie
There is an excellent article on the Adobe site written by Big Spaceship’s Jamie Kosoy at http://www.adobe.com/devnet/actionscript/articles/lightweight_as3.html . The thing is about this article that he includes some extra utility classes (ie. Out.as) For a first time user, it might throw him off. I was hoping of just starting preloading in a more simpler approach. Anyway, it’s a recommended read.
Other articles on AS3 Preloading:
Koen De Weggheleir’s blogs are also pertinent to this subject.