Question

I would like like to replace a spirte’s image.

But before that, i want to check if the image exist in the directory or not. Is there a way to do it?

newImage = new ImageLoader(dir + temChild.category + '/' + temChild.productUrl + '.png', {
                                                                    container : temChild,
                                                                    height : 80,
                                                                    width : 80,
                                                                    scaleMode : 'proportionalInside',
                                                                    onComplete : onColorImageLoad, 
                                                                    centerRegistration : true,
                                                                    noCache: true,
                                                                    autoDispose : true
                                                                  });

Answer 1

If you load one image with ImageLoader you can use callbacks (events).
I use ImageLoaderVars class because of aoutocomplete

var loaderVars:ImageLoaderVars = new ImageLoaderVars();
loaderVars.container=temChild;
loaderVars.height=80;
loaderVars.width=80;
loaderVars.scaleMode='proportionalInside';
loaderVars.centerRegistration=true;
loaderVars.noCache=true;
loaderVars.autoDispose=true;
loaderVars.onComplete=temChild;
loaderVars.onComplete=onColorImageLoad;

//lets watch for errors if we don't have file on the server or something else
loaderVars.onError=onErrorCallback;
loaderVars.onFail=onFailCallback;                                                        

newImage = new ImageLoader(dir+temChild.category+'/'+temChild.productUrl+'.png',
loaderVars);

private function onFailCallback(event:LoaderEvent):void
{
 //do something if you want here
}

private function onErrorCallback(event:LoaderEvent):void
{
 //do something if you want here
}

If you have many ImageLoders in one LoaderMax decide what you want from failed loaders, by default in LoaderMax skipFailed=true;. Also there are LoaderMax events: childFail, ioError, securityError.