ASP.NET MVC rescues Microsoft's web platform

Too strong? Maybe, but the ASP.NET Web Forms programming model has run its course. It was hugely impressive when it originally appeared - I remember it being announced as ASP+ in 2000, and how phenomenal it seemed. You can build a web page visually, using a rich set of controls, and have ASP.NET abstract away much of the problem of managing state. It also lets you write code in any .NET language, which is just-in-time compiled at runtime for fast performance.

ASP.NET works the same as ever today; but the web has moved on. The Web Forms model makes programming the web more like programming Windows, which was cool at the time but not any longer.

Fortunately for Microsoft, it has an alternative, called ASP.NET MVC. The first full release was announced at the Mix09 conference last week, and you can download it now. I took the opportunity to ask some of the delegates what they thought of it.

The reactions I got fell into two broad categories. The first group found it difficult to puzzle out what it really was, even those who had attended sessions on the subject. The second group loved it, and never ever wanted to go near Web Forms again. In fact, such was the frustration with Web Forms among some developers, that they had developed their own alternative frameworks but were now moving to the official one.

So what's wrong with Web Forms? Complaints I heard include that it is not testable; that it is not really compatible with AJAX; that it is inflexible; that ViewState, hidden form data which preserves state across page refreshes, is a nuisance; and that it is hard to write REST-style applications or those which properly support the Back button.

Enter ASP.NET MVC, which answers all of these complaints. MVC stands for Model View Controller, though having played with it a little I find the name somewhat misleading, as well as being a mouthful (contrast the delightfully-named MonoRail, which is an interesting alternative). Why misleading? Well, it doesn't have much of a Model, as this post observes. It does have views and controllers; but I think one of the reasons developers find it hard to grok is that starting with a discussion about MVC architecture is not the best way to teach it.

I think the place to start is with URLs and routing. It also helps to know that ASP.NET MVC follows the principle of convention over configuration (though not to the same extent as Ruby on Rails). In a nutshell, ASP.NET MVC breaks the link between the URL in the browser and aspx files on the web server; instead, it processes the URL and returns what you want it to return.

A "View" in ASP.NET MVC is an .aspx page, but in the form of a lightweight template, not a Web Forms with a complex page lifecycle.

I've been playing with ASP.NET MVC recently, and it is a delight. Yes, there is more manual coding than with Web Forms, but it is worth it for the additional control you gain. Even the performance seems better, a consequence of the lightweight approach. As it happens, I'm also a believer in test-driven development. I guess I'm in the second group that I spoke to at Mix09.

Microsoft is not killing off Web Forms; rather, it is very insistent that they remain under full development. I get the impression that the company expects ASP.NET MVC to be a minority choice.

Nevertheless, if you work with ASP.NET do not hesitate to check out the new framework. Personally I think ASP.NET MVC might just rescue its web platform from a slow but inevitable decline.