A Useful JavaScript Image Loader

I released a YUI implementation of image gallery script a month ago. While it was quite an enjoyable experience to explore the potential of YUI and JavaScript, I found I have created many userful code snips (for instance this Loading Panel) along the way.

Today I am going to show you another useful JavaScript code snip: Image Loader. What! You might ask. I admit that name is too generic, but it does what it does - it helps you to load images using JavaScript. Just give it an image URL, it will return a DOM image object that can be used for dynamic loading of images. This script provides a loading completion event, which is very useful for displaying preloader or extra information when the image is being loaded.

The original image loader I created relies on YUI, but I want to make it as portable as possible, so I created a standalone version.

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A Compilation of YUI Callback

I have been coding JavaScript with YUI for quite a while now. Still, I am consistently confused by various callback functions in YUI. The thing that troubled me the most was the parameters those callback functions take. The API documentation does not provide any information about this. For example, if you go to YAHOO.util.Event, under addListener method, the description for parameter fn as follow: <Function> The method the event invokes.

Yes, it's a straightforward description, but it doesn't help too much. What I really need is the signature of this callback function. For the purpose of my own use, and to benefit the community, I decided to make a compilation of callbacks in YUI.

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