ActionScript for Flash MX: The Definitive Guide, Second Edition

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

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Appendix C: Backward Compatibility and Player Build Updates

Controlling Movie Clips

In Chapter 13, we discussed how to control clips using Flash 5 (and later) tech-

niques. Here we consider the equivalent Flash 4 techniques.

Prior to Flash 5, we executed special Movie Clip Actions to control a movie clip. We

said, “Tell the clip named

eyes to play,” using the following:

Begin Tell Target ("eyes")

Play

End Tell Target

But as of Flash 5, movie clips can be controlled more directly, through built-in meth-

ods. For example:

eyes.play();

Similarly, to access the built-in properties of a movie clip prior to Flash 5, we used

explicit property-getting and property-setting commands, such as:

GetProperty ("ball", _width)

Set Property ("ball", X Scale) = 90

As of Flash 5, we can retrieve and set a movie clip’s properties using the dot opera-

tor, just as we access the properties of any object:

ball._width;

ball._xscale = 90;

Prior to Flash 5, to access variables inside a movie clip, we used a colon to separate

the clip name from the variable name:

Set Variable: "x" = myClip:myVariable

As of Flash 5, a variable in a movie clip is simply a property of that clip object, so we

use the dot operator to set and retrieve variable values:

x = myClip.myVariable;

Finally, prior to Flash 5, we accessed nested