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CHAPTER 3
Using Symbols, Instances,
and Library Assets
A symbol is a graphic, button, or movie clip that you create in Macromedia Flash Basic 8 or
Macromedia Flash Professional 8.
You create the symbol only once; you can then reuse it throughout your document or in other
documents. A symbol can include artwork that you import from another application. Any
symbol that you create automatically becomes part of the library for the current document.
For more information on the library, see “Managing media assets with the library”
on page 31.
This chapter describes how to create symbols and instances in the Flash authoring
environment. You can also create buttons, movie clips, and graphics using the Button Class
and MovieClip Class (use the drawing methods of the MovieClip class to create graphics). See
Button and MovieClip in the ActionScript 2.0 Language Reference.
When you create a symbol in the authoring environment, each symbol has its own Timeline.
You can add frames, keyframes, and layers to a symbol Timeline, just as you can to the main
Timeline. For more information, see “Using the Timeline” in Getting Started with Flash. If the
symbol is a movie clip or a button, you can control the symbol with ActionScript. For more
information, see Chapter 10, “Handling Events,” in Learning ActionScript 2.0 in Flash.
An instance is a copy of a symbol located on the Stage or nested inside another symbol.
An instance can be very different from its symbol in color, size, and function. Editing the
symbol updates all of its instances, but applying effects to an instance of a symbol updates
only that instance.
Using symbols in your documents dramatically reduces file size; saving several instances of a
symbol requires less storage space than saving multiple copies of the contents of the symbol.
For example, you can reduce the file size of your documents by converting static graphics,
such as background images, into symbols and then reusing them. Using symbols can also
speed SWF file playback, because a symbol needs to be downloaded to Flash Player only once.
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