as3 - How to add a movieclip into the parent's parent? - actionscript-3

Question

I have a gun child inside of a movieclip called "player" and "player" is inside another movieclip called "level one".
So inside the gun class, the code spawns a bullet. Which has to spawn in the parent's parent. So the bullet can shoot into the level.
private function fire(m: MouseEvent)
{
//when bullet fired
var b = new Bullet;
MovieClip(MovieClip(parent).parent).addChild(b);
}
However, the bullet never appears in the parent's parent. What could be the issue here?
UPDATED CODE:
In gun class:
function fire(e:MouseEvent):void
{
dispatchEvent(new Event('fire!', true));
}
In player class:
protected function fire(e: Event)
{
var b: Bullet = new Bullet();
// bullet must be in same position and angle as player.gun
b.rotation = player.gun.rotation;
b.x = player.gun.x; + player.gun.width * Math.cos(player.gun.rotation / 180 * Math.PI);
b.y = player.gun.y + player.gun.width * Math.sin(player.gun.rotation / 180 * Math.PI);
addChild(b);
}

Answer 1

You missed to strong typing the variable and add parentheses
Try
var b:Bullet = new Bullet();
Why don't you keep a reference to the parent.parent?
var b:Bullet = new Bullet(parent)
...
public function Bullet(spawnTarget:MovieClip)
{
_spawnTarget = spawnTarget;
}
private function fire(m: MouseEvent)
{
//when bullet fired
var b = new Bullet;
_spawnTarget.addChild(b);
}

Answer 2

Using parent.parent is risky because you'd always need to make sure that the gun class is instantiated in a child of the game class. Also, you can't create guns in any other position in the hierarchy which can be a problem if your game grows bigger.
You can solve this with listeners (as the comments state, and this is an example of passing a game reference. Each instance receives a reference to game, so each instance can call public function on game:
Game.as
myPlayer = new Player(this);
public function addBulletToWorld(){
}
Player.as
public function Player(game){
myGun = new Gun(game);
}
Gun.as
public function Gun(game){
game.addBulletToWorld();
}

Answer 3

If you absolutely insist on using the parent.parent thing, just set a break point at that line and see what parent.parent actually is, then adjust as needed to match your actual structure. But aside from the fact that this is just bad practice, it's going to limit you to where you can't use this Class anywhere but at that one depth.
I'd recommend just generating a custom event when you want to fire the bullet, and letting the grandparent handle it.
In Gun:
function fire(e:MoudeEvent):void {
dispatchEvent(new Event('fire!', true));//setting it true lets it bubble up to the parent
}
In Game
protected var bullets:Vector. = new Vector();
public function Game() {
addEventListener('fire!', fire);
}
//note I worked with Flex too long to use private methods very often
protected function fire(e:Event) {
var bullet:Bullet = new Bullet();
bullet.x = MoveClip(e.target).x);
bullet.y = MoveClip(e.target).y);
addChild(bullet);
bullets.push(bullet);//I assume you're going to want to move this or something, so we need to store it to manage it
}