Accessing children on frames after gotoAndStop

Question

Hi
I have an SWF file where I want to access symbol instances on
frame 2.
I have noticed that after I call gotoAndStop(2); it takes a
little while before the symbol instances are instantiated.
I get null ref exceptions if I immediately access the
children on a frame after calling gotoAndStop, but if I wait a bit
it works, because it seems as if the children have had time to be
instantiated, see examples below.
I prefer not to rely on delaying my code, but would rather
prefer to listen for an event that could notify me when a frame is
properly "initialised", that is, when all symbol instances have
been instantiated. Is there such an event and if not, is there
another solution ?
Examples:
mc2 is a movieclip.
1) This gives null exceptions because the child of frame 2 is
null when accessed.
mc2.gotoAndStop(2);
for(var i:int = 0; i < mc2.numChildren; ++i)
var child:DisplayObject = mc2.getChildAt(i)
trace(child.name);
trace("done");
But it works if I wait a bit, because apparently I have
waited enough to allow the child to become instantiated:
mc2.gotoAndStop(2);
var intervalId:int = setInterval(callback,100);
function callback():void
clearInterval(intervalId);
for(var i:int = 0; i < mc2.numChildren; ++i)
var child:DisplayObject = mc2.getChildAt(i)
trace(child.name);
trace("callback done");
trace("done");
Is there an event that can be used instead of relying on some
delay ?
Best regards Stig Nielsson

Answer 1

My guess is that you are waiting for the timeline to advance
to frame 2, which doesn't happen instantly, it follows the frames
per second rate you establish for the file. If the frame 2 clips
don't exist in frame 1 but that's where your code (which does act
instantly) starts looking for them, then it was probably looking at
frame 1 when it ran the code.