User Guide

Adding the finishing touches 957
• When defining the symbol, do not select the Export in First Frame option unless absolutely
necessary. Flash loads the component just before it is used in your Flash application, so if you
select this option, Flash preloads the component in the first frame of its parent. The reason you
typically do not preload the component in the first frame is for considerations on the web: the
component loads before your preloader begins, defeating the purpose of the preloader.
• Avoid multiple frame movie clips (except for the two-frame Assets layer).
• Always implement init() and size() methods and call Super.init() and Super.size()
respectively, but otherwise keep them lightweight.
• Avoid absolute references, such as _root.myVariable.
• Use createClassObject() instead of attachMovie().
• Use invalidate() and invalidateStyle() to invoke the draw() method instead of calling
draw() explicitly.