ScottGu broke the news last night that Microsoft is making a shared CDN available for the purposes of hosting the AJAX scripts. The full details of the scripts that are supported right now are available here, but basically it’s ASP.NET AJAX 4.0 Preview 5 (which just came out) and jQuery 1.3.2. If you’re using ASP.NET AJAX on the server side, you can just tell the ScriptManager to use the CDN by setting the EnableCdn property to true. I find this implementation a little misleading because it only applies to the scripts within System.Web and System.Web.Extensions. If you want support...

Good news, ASP.NET AJAX 4.0 Preview 5 is here! Better yet, Microsoft has overhauled the implementation of tracking disposable objects to include the performance enhancement that was discussed in my “ASP.NET AJAX ‘Disposable Objects’ Performance Heads Up” posts (Part I & II). So how’d they do it? They tag each disposable object with an integer value which represents the objects position in an internal array using a property named “__msdisposeindex” when it’s registered. When it’s unregistered they delete that property from the object and from the array. Small performance heads up that there is a small hidden cost of...

Ok, I had to put together a Part II to this topic because I was totally wrong in Part I about objects being able to be used as keys because… well, I’m an idiot and didn’t do all my fact checking to make sure my implementation was 100% sound. :) Thanks to Dave Reed who commented on the original post pointing out my flawed thinking. Mea culpa Basically Dave points out that JavaScript objects are really specialized hashtables called associative arrays where the keys absolute MUST be a string OR a type which can be converted to a...

Update: Make sure you read Part II as there was ultimately a fundamental flaw in this implementation which prevents it from working as I originally thought. One of the important features of the ASP.NET AJAX client side framework is the concept of disposing of components/controls so that they unregister event handlers and release DOM element references so that you don’t end up with circular references and, thus, memory leaks. The ASP.NET AJAX client framework takes the same approach as .NET does where there is a Sys.IDisposable interface which you can implement to indicate that your class requires disposal semantics. By implementing...