AS2 Version of MovieClip.getChildByName()?

Question

I'm trying to be responsible with my "DOM" references in this little Flash 8/AS2 project.

What has become increasingly frustrating is obtaining references to other movie clips and objects. For example, currently my code to access the submit button of a form looks something like this

var b:Button = _level0.instance4.submitBtn;

I was hoping there was an instance-retrieval method for AS2 similar to AS3's MovieClip.getChildByName() or even Javascript's document.getElementById(). Because hard-coding the names of these anonymous instances (like instance4 in the above) just feel really, really dirty.

But, I can't find anything of the sort at this AS2 Reference.

Answer 1

If the MovieClip was placed on the stage in the Flash IDE, you can give it a proper instance name in the properties panel.

If it was dynamically added, you can also give it a name, and additionally store a reference:

var my_MC=createEmptyMovieClip("instanceName", depth);

In either case, you can then adress them with _parentClip.instanceName or my_MC.

Answer 2

You could just write it yourself (code not tested but you get the idea):

MovieClip.prototype.getElementByName = function(name : String) : Object
{
    var s : String;
    var mc : Movieclip = null;

    for( s in this )
    {
     if( this[s] instanceof MovieClip )
     {
      if( s == name )
      {
       mc = this[ s ];
       break;
      }

      mc = this[s].getElementByName( name );
     }
    }

    return( mc );
}

Answer 3

There are a couple ways you can do this. The easiest way is to use Array notation. Your previous example, which looks like this:

var b:Button = _root.instance4.submitBtn;

would look like this in Array notation:

var b:Button = _root["instance4"].submitBtn;

So if you wanted to loop through 100 buttons already created and set the alpha to 0:

for( var i:Number = 0; i < 101; i++)
{
     var button:Button = _root["instance"+i].submitBtn;
     button._alpha = 0;
}

You can also use eval("instance4") to do the same thing, but I'm a little foggy on the scoping issues involved.