I tried using and I discovered that in SpaceInvader’s constructor (for eg), “this” points to a dead MovieClip that will never be put onto the stage. That means you can’t do anything really useful in your constructor.

To fix this, you can simply replace new _constructor() with _constructor.apply(mc). Also, you don’t need to copy every property if you assign to __proto__.

Here’s another version that addresses these issues:


function createExtendedMovieClip(klass:Function) {
var parent = arguments[1] || _root;
var depth = arguments[2] || parent.getNextHighestDepth();
var inst = parent._name + “_clip_” + depth;
var mc:MovieClip = parent.createEmptyMovieClip(inst, depth);
mc.constructor = klass;
mc.__proto__ = klass.prototype;
mc.constructor.call(mc);
return mc;
}