At the Future of Web Applications conference earlier this month I spoke to Microsoft's corporate VP of the .NET Developer Platform, Scott Guthrie about ASP.NET MVC. Guthrie is a co-inventor of ASP.NET along with Mark Anders, now at Adobe. A few months back I wrote a piece entitled ASP.NET MVC rescues Microsoft's web platform, but I wanted to hear from Guthrie how he sees the framework evolving, and to explore whether it is time to abandon the older Web Forms approach. How does he see the future of the platform?
"The amount of buzz and religious fanaticism about [ASP.NET MVC] is amongst the highest I've been involved in, certainly since .NET 1.0 and Silverlight. Some people prefer the Web Forms model and I emphasise that Web Forms is not going away, there's all the new stuff that's coming for Web Forms 4.0.
"MVC is an alternative way to do UI and still leverage ASP.NET. For crowds like the one here at FOWA that wants total control over the markup, and who like test-driven development, it's a dream framework. Those folk tend to be more online, so they communicate better which is part of the reason you hear the buzz. I think we'll have more than a million developers using ASP.NET MVC within the first twelve months."
In your talk you mentioned the stackoverflow site which performs very well but runs on not very much in terms of hardware? Is ASP.NET MVC more efficient than Web Forms?
"ASP.NET itself has always been really fast, we've had a lot of success with large sites. One of the things people like about ASP.NET MVC is that the model fits to what they are expecting, for the large LAMP contingent which is heavily represented at this conference. And when they do the performance testing they say 'Holy cow, this thing is fast.' Stackoverflow is a great example, written I think within three weeks and scaling to that level with two machines. Performance is a feature, and one of the reasons StackOverflow works as well as it does is that it's instantaneous response time.
"Conchango just did a site, implemented in 20 weeks, a giant ecommerce project, it's 100% ASP.NET MVC. The SEO is phenomenal, the YSlow rating is phenomenal, they're just blown away. It was fun talking to them last night - the guy was jokingly saying, 'I can't believe it works so well'. It's like the best marketing literature in the world times ten. More and more when I give talks I'd say half the people are new to ASP.NET MVC, and the other half come upand say, 'by the way we've done five sites on it.' That's great to hear."
On equivalent hardware and leaving aside different coding styles, is ASP.NET MVC going to scale that bit better than Web Forms?
"No. The reality is you can build hugely scalable sites with each. Where it does help a little bit is that there is smaller page size and there's a bit more control. There's less abstractions."
And the page lifecycle is shorter?
"It is shorter. I don't think that's making any measurable perf difference. It's more that it naturally flows to what they're doing. I do think it's fast, in the same way that web forms can be fast too. But it promotes a certain way of working that, if you know what you're doing, you tend to build really fast apps."
What about the open source aspect? Are people contributing code?
"People are not contributing code directly to ASP.NET MVC, but we're shippling JQuery and we're shipping JQuery validation which are open source projects, and we are integrating them into our code. With JQuery in ASP.NET MVC version 1.0 we just shippped it, whereas in version 2.0 we have helper libraries that are making big usage of it.
"I'd say that's a first for Microsoft, we're actually taking open source software that has multiple contributors, and using it in a deep way within our own product.
"We ship the ASP.NET MVC source code under an OSI Licence. You can take the code, you can modify it, you can do builds. I know a few people that have done customer tweaks, but for the most part it's that people like being able to learn the product through the code. There's also the reassurance of knowing that if they ran into something, they could fix it."
Would you consider accepting community contributions to the code?
"We've thought about it. I think a lot of people interpret open source as 'hey, anyone can just submit stuff'. The reality is that pretty much every open source project has a closed set of contributors. They come from multiple organisations or backgrounds, but you don't check anything into the Linux kernel without Linus or Andrew signing off on the fix. That would be true of ASP.NET MVC, in that there would be a core set of contributors. At some point I think we will probably open it up to let people to contribute code, or at least patches."
What's new in the latest ASP.NET MVC 2.0 preview?
"The ability to easily do forms validation for input, server-side and especially client-side in a very declarative, easy way, is a huge productivity win.
"'Areas' provide a way to take a large project and easily structure it into multiple small projects.
"New form helpers and what we call editor and display templates for customising them is an innovative way to get strong typing, intellisense and debugging support, and a lot of flexibility in terms of UI generation.
"Asynchronous controllers allow you to call call services on the web, the Twitter, the Facebooks of the world, and much more efficiently scale your web server. The classic problem if you're calling Twitter is what's the response time of Twitter? What's the response time of Facebook? Most web servers are multi-threaded so they're processing multiple requests, but say they have 10 threads running and 15 requests come in, and each of those requests need to go and access Twitter, you're going to block 5 people while nothing is going on on the server. With the Async support we provide a way that you within your app can say, I'm going to wait for a while, yield back the thread, and when the data comes back reschedule me. It can dramatically improve the scalability of the site.
"We're doing a bunch of work around helpers for caching, paging, and a other things. In general it's a compatible release, we're trying to listen to the community, keep it a very transparent, Agile-based development process and knock off the top asks.
"We ship the source to every preview, take lots of feedback. That's the other thing people have really liked about the project, this open feedback. They don't feel like we're telling them, here's the way it is, take it or leave it. They like the fact that we've been iterating with them."
Guthrie is diplomatic about the question of Web Forms versus ASP.NET MVC, and even though I pressed him, would not quite agree that it performs much better. Clearly Web Forms is not going away. Take a look though at some of the comments from practitioners like Howard van Rooijen of EMC (formerly Conchango):
One of the great aspects of ASP.NET MVC is how lean and clean the architecture is - there is so little background noise compared to WebForms; possibly the best illustration of this is the difference between the MVC Request Pipeline vs. WebForm Page Lifecycle. The number of hoops you are forced to jump through in WebForms, compared to MVC is quite staggering.
Overall I heard nothing to change my general opinion, that if you can use ASP.NET MVC rather than Web Forms, you probably should.
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.
