Actionscript 2 Proper way to define function on MovieClip

Question

I'm trying to write a function on a MovieClip, and call it from the root clip. What works fine in ActionScript 3 doesn't seem to be working properly in ActionScript 2.

Frame 1 of the _root MovieClip:

var newMovieClip:MovieClip = _root.attachMovie('Notification', id, 0);
newMovieClip.SetNotificationText("Test text");

Frame 1 of the Notification MovieClip:

function SetNotificationText(inputText : String){
    notificationText.text = inputText;
}

The result is that the MovieClip is created but the text is not changed.

Am I doing this wrong?

Marty · Accepted Answer · 2013-05-20T07:40:31.443

To add functions to a MovieClip in AS2, you need to use one of these methods:

Add the method to the prototype of MovieClip:

MovieClip.prototype.SetNotificationText = function(inputText:String):Void
{
    if(this["notificationText"] !== undefined)
    {
        // If we're going to use the prototype, at least do some checks
        // to make sure the caller MovieClip has the text field we expect.
        this.notificationText.text = inputText;
    }
}

newMovieClip.SetNotificationText("Test text");

Make the MovieClip and argument of the function:

function SetNotificationText(mc:MovieClip, inputText:String):Void
{
    mc.notificationText.text = inputText;
}

SetNotificationText(newMovieClip, "Test text");

Add the method directly to the newly created MovieClip:

var newMovieClip:MovieClip = _root.attachMovie('Notification', id, 0);

newMovieClip.SetNotificationText(inputText:String):Void
{
    notificationText.text = inputText;
}

newMovieClip.SetNotificationText("Test text");

Option 2 is best overall - it's the cleanest and avoids overhead of creating a new function for every new MovieClip. It also avoids messing around with the prototype, which at best should be used to add generic methods, like a removeItem() method on Array.

Actionscript 2 Proper way to define function on MovieClip

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