Greensocks Imageloader how to check if a image exist before loading the image

[bluebill1049]

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

});

[Carl]

The only way to know if an asset is there is to attempt to load it.

You can listen for a number of load-related errors using an ImageLoader.

 

Consider the following example which attempts to load an image that doesn't exist:

 

import com.greensock.loading.*;
import com.greensock.events.LoaderEvent;

var img:ImageLoader = new ImageLoader("image.jpg", {
onFail:onFail,
onerror:onerror,
onIOError: onIOError});

function onFail(e:LoaderEvent){
trace("onFail");
}

function onerror(e:LoaderEvent){
trace("onerror");
}

function onIOError(e:LoaderEvent){
trace("onIOError");
}

img.load();

 

Will output the following info:

 

 

onIOError
----
Error on ImageLoader 'loader0' (image.jpg): Error #2035: URL Not Found. URL: file:////Volumes/Macintosh%20HD/Users/cschooff/Downloads/bezierDemo/image.jpg
----
onerror
onFail

 

All three errors fire in this scenario. An onIOError should be all you need though.

 

Other than that, I don't know what to suggest to detect the presence of an image.

 

Keep in mind that ImageLoader's support an alternateURL which will automatically load a "fallback" image in case of failuer:

 

 

alternateURL : String - If you define an alternateURL, the loader will initially try to load from its original url and if it fails, it will automatically (and permanently) change the loader's url to the alternateURL and try again. Think of it as a fallback or backup url. It is perfectly acceptable to use the same alternateURL for multiple loaders (maybe a default image for various ImageLoaders for example).

 

http://api.greensock...mageLoader.html