AS3 - Loading multiple videos into the same container - addChild removeChild - actionscript-3

Question

This is a function that loads a specific video into a MovieClip container at 0.0 using a video class.
public var mainVideo:SimpleVideo;
public function loadVideo(videoString:String) :void{
mainVideo = new
SimpleVideo("videos/"+videoString+".flv","",true,video_container.positionMc);
video_container.addEventListener(MouseEvent.MOUSE_DOWN,controlVideoPlayer);
addChild(mainVideo);
trace('adding new video to container');
}
I'd like to preferably check, each time a video is loaded, to see if there already is another video loaded. And if there is, then remove it, and add the new video.
I've tried using removeChild() in a variety of ways, but it doesn't seem to work correctly.
Would I use removeChild(mainVideo)? video_container.removeChild(mainVideo)?
And how would I be able to check if there was already an existing mainVideo?
Any help would be greatly appreciated!
-Update-
If I try and use removeChild(mainVideo) I get this error:
TypeError: Error #2007: Parameter child must be non-null. at
flash.display::DisplayObjectContainer/removeChild() at
Main/removeVideo() at MethodInfo-127()

Answer 1

If you add the video into a container movieclip rather than onto stage, and that container only has just one instance of SimpleVideo in its display list at a time, you could do:
if( myVideoContainer.numChildren > 0 )
{
myVideoContainer.removeChild( myVideoContainer.getChildAt( 0 ) );
}
A bigger issue though is how the SimpleVideo class you are using cleans itself up. Most video classes have a cleanup or kill function that removes the listeners and cleans up the netStream. I would think you'd need to call something like that as well as removing the video instance from the container.

Answer 2

I hope this respone may help you
--> Would I use removeChild(mainVideo) ? video_container.removeChild(mainVideo) ?
you should use removeChild function but you need to know who is the parent of mainVideo and call this function of his parent, in your case, I think, video_container is not the parent because is a variable near mainVideo and you add mainVideo to the instance of the class which has loadVideo function
sometimes you can use mainVideo.parent.removeChild(mainVideo), not the best approach but it works, it's better to know who is the parent and call function removeChild() explicitly on that "parent"
--> would I be able to check if there was already an existing mainVideo?
well, you can do a simple if(mainVideo != null) { .. } because in function loadVideo you create new instances each time, that means if you called at least one time this function then if condition should be true that means you have already an existing mainVideo
--> TypeError: Error #2007: Parameter child must be non-null.
that means your mainVideo is not instantiated, because I guess you have not called loadVideo() yet, that's why #putvande asked you to provide more code, we need to see where and when you call removeChild()