Accessing childs

programming flash
1

Hi,

I have a little question, How can i access childs of objects in AS 3.0.

MovieClip _shape has 4 childs block1 … block4

I used to be using this in AS 2.0, but it dosent work in AS 3.0 anymore, it says that it is undefined.


for(var i = 1; i < 5; i++){

doSomething(_shape["block"+i]);
}

Please, help me :]

thanks.

2

put each movie in an array and access it that way instead.

3

that syntax is still correct as i just used this:

mapMc[‘c’ + i]

on an AS3 project yesterday.

check to see if it’s even getting to _shape

*edit: added c0, c1, c2, etc…at author time. i think there is a getChildByName() if above doesn’t work.

4

Thank you for your replies, there is whole class:

package {
    
    import flash.display.MovieClip;
    import flash.utils.getDefinitionByName;
    
    public class Tetris_Shape extends MovieClip {
        
        private var _shape:MovieClip = new MovieClip();
        private var _xdist:int;
        private var _ydist:int;
        private var _shapeNum:uint;
        private var _posArray:Array = new Array(
                                                [[_block_size, 3*_block_size],
                                                 [_block_size,_block_size],
                                                 [_block_size, -_block_size], 
                                                 [_block_size, 3*-_block_size]],

                                                [[-_block_size, _block_size],
                                                 [_block_size, _block_size],
                                                 [_block_size, -_block_size],
                                                 [_block_size, 3*-_block_size]]

                                                 );
        private var _rotation:uint = 0;
        
        
        private var _block_size = Block.SIZE/2;
        
        public function Tetris_Shape (type:String, xdist:int, ydist:int):void {
            addChild(_shape);
            _xdist = xdist;
            _ydist = ydist;
            switch(type){
                case "I": doShape(1); break;
                case "J": doShape(2); break;
                case "L": doShape(3); break;
                case "O": doShape(4); break;
                case "S": doShape(5); break;
                case "T": doShape(6); break;
                case "Z": doShape(7); break;
            }
        }
        public function rotate ():void {
            for(var i = 1; i < 5; i++){
                trace(_shape["block"+i]);                         //undefined
                trace(_shape.block1);                             //undefined
                trace(_shape.getChildAt(i-1));                  //[object Block]
                trace(_shape.getChildByName("block"+i));   //null
            }
        }
        private function doShape (shapeNum:uint):void {
            _shapeNum = shapeNum;
            for(var i = 1; i < 5; i++){
                var block = "block"+i;
            block = new Block (shapeNum,_posArray[shapeNum-1][i-1][0],_posArray[shapeNum-1][i-1][1]);

            recalculatePositions(block, Math.atan2(_posArray[shapeNum-1][i-1][1], _posArray[shapeNum-1][i-1][0]), shapeNum, i);
            _shape.addChild(block);
            trace(block);                                   //[object Block]
            trace(_shape.getChildByName(block));           //null
            } 
        }
        
        private function recalculatePositions (block:MovieClip, newAngle:Number, shape:uint, blocknum:uint):void {
            var pyth:Number = pythagor_ab(_posArray[shape-1][blocknum-1][0], _posArray[shape-1][blocknum-1][1])
            block.x = Math.cos(block._angle + newAngle) * pyth+_xdist;
            block.y = Math.sin(block._angle + newAngle) * pyth+_ydist;
            block._angle = newAngle;
        }
        
        public static function getSymbolClone(symbolName:String, i:Number):*
        {
            return duplicate(symbolName, i);
            function duplicate (className:String, i:Number):*
                {
                    var currentClass:Class = getDefinitionByName(className+i) as Class;
                    return new currentClass();
                }
        }
        private function pythagor_ab(a:Number, b:Number):Number {
            return Math.sqrt(a*a+b*b);
        }
    }
}

and thi is in fla. file


var _currentBlock:Tetris_Shape = new Tetris_Shape("I",0,0);

addChild(_currentBlock);

_currentBlock.rotate();

I really dont know what is wrong I:-)

5

[quote=SmoothDime;2341152]that syntax is still correct as i just used this:

mapMc[‘c’ + i]

on an AS3 project yesterday.

check to see if it’s even getting to _shape

*edit: added c0, c1, c2, etc…at author time. i think there is a getChildByName() if above doesn’t work.[/quote]

The syntax is correct, but avoid doing this because when you reference a variable by using a string like this the compiler can’t check it and you’re setting yourself up for an obscure run time error.

6

Thank you guys very much.