Dr. Dobb's | ASP.NET 3.5 Is Here

ASP.NET 3.5 Is Here

The last rev of ASP.NET brought some major changes to the platform, so what about the next rev? On the eve of the ASP.NET 3.5 release, Dino Esposito takes look at what's new and what's not.

September 05, 2007
URL:http://drdobbs.com/windows/aspnet-35-is-here/201804275

Two years ago Microsoft released a major upgrade to its ASP.NET platform and numbered the release as 2.0. It was the release of maturity expressly designed to supply many more features than the predecessor while fixing holes and gaps in the previous design. ASP.NET 2.0 had to be considered as a major release also because of its architectural repercussions and changes. The provider model, data source objects, extensibility at all levels, compilation model were just the larger of these changes. In the next few months Microsoft is expected to ship a new version of ASP.NET along with a revamped version of its flagship product for developers-Visual Studio 2008. Curiously, the version number for ASP.NET jumps to 3.5 to match the version number of the latest .NET Framework. In spite of the shift in the numbering, though, changes that developers will face with the new version of ASP.NET are not huge and could make one think of just a minor upgrade. Let's dig a little more and find out what ASP.NET 3.5 is made of.

The biggest new chunk of code in ASP.NET 3.5 is undoubtedly AJAX. ASP.NET 3.5, in fact, integrates what Microsoft already released in January 2007 as a separate, add-on platform-ASP.NET AJAX Extensions 1.0. If you intend to build your next Web applications using ASP.NET 3.5, you no longer need to install ASP.NET AJAX Extensions 1.0 on your Web server. Now it's all in one, and ASP.NET AJAX officially joined the rest of the .NET Framework. This results in one key change: from now on, specific updates to ASP.NET AJAX will be delivered via updates to .NET Framework such as service packs and hot-fixes. Does it also mean that the season of add-ons for ASP.NET is ended? Time will tell. Meanwhile, Microsoft is working on something called ASP.NET Futures. It's essentially a repository of additional controls and programming features for ASP.NET developers to integrate Silverlight in ASP.NET pages and capabilities not otherwise delivered by the core ASP.NET framework. Want one example? Programmatic support for the browser's history feature.

So, is ASP.NET 3.5 just ASP.NET 2.0 plus AJAX? Yes, it's sort of. If you look at the core set of assemblies for ASP.NET 3.5, you'll observe no significant changes to the core ones. Everything new is part of an extra assembly-system.web.extensions. In this assembly, you'll find AJAX support and a handful of new server controls. By the way, system.web.extensions is also the name of the assembly used to deliver ASP.NET AJAX Extensions 1.0. Should you uninstall ASP.NET AJAX Extensions 1.0 before installing ASP.NET 3.5 (currently in Beta 2 with final bits slated likely for the end of the year)? Not necessarily. AJAX Extensions and ASP.NET 3.5 can live side by side, and you can certainly maintain existing ASP.NET 2.0 applications with AJAX capabilities while running new 3.5 applications. However, you should be aware that a bug in the setup of Beta 2 will automatically take any existing ASP.NET 2.0 projects built with ASP.NET AJAX 1.0 and Visual Studio 2005 that you open up in Visual Studio 2008 to pick up ASP.NET 3.5. To keep old and new AJAX projects physically separated, you need to tweak the policy of the system.web.extensions assembly by running the DisableAjaxPolicy program. Note that the issue regards exclusively AJAX applications; non-AJAX Web applications built with version 2.0 and any ASP.NET 3.5 applications work side-by-side also in Beta 2.

What else is in ASP.NET 3.5? In addition to the new controls introduced by AJAX, such as UpdatePanel and ScriptManager, you find support for WCF services and a couple of view controls—the ListView and DataPager controls. The ListView control completes the series of view controls started with version 2.0 that includes TreeView, GridView, DetailsView and FormView. The ListView is a sort of smarter DataList control that supports native paging through the DataPager.

To finish off, what about LINQ?

LINQ is not part of ASP.NET 3.5 but it is indeed part of the .NET 3.5 platform and hence usable from ASP.NET. But I'll cover this in another article.