Succinct and light-weight API: REST+JSON in .NET

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Problem :

Summary: I need to know if there is an existing light-weight implementation of REST+JSON in .NET world which does not use WCF. If not, I am looking for some folks who would be interested to start a joint venture for an Open Source project.

I do not know about you but I was a big fan of WCF when it came out and I praised its design for its modularity and extensibility. However, as I used it more and more often, fundamental issues started to come into light to the point that I now feel it has to be scrapped and redesigned. That seems to be a big statement but I believe these are major issues:

  1. First of all, WCF internally uses SOAP for message which means if the transport message is not SOAP, we incur the cost of transforming to and back from SOAP for every call. This is expensive and time consuming.
  2. Transforming the outgoing message requires “plugging in” a message inspector and “stealing” the message. As the name implies, this is an inspector (must be used for inspection and logging) so using that for changing the message is frankly a hack.
  3. It was design according to WSDL and the world has changed so much since 2001. Implementing REST also requires stealing the message. WCF was designed according to WSDL and not REST.
  4. Channel stack is unnecessarily heavy.
  5. The main stack is protocol agnostic. This is not a advantage, it is a fundamental flaw. As you know, access to a lot of protocol level information was added later because was impossible to implement some important user scenarios. For example, client’s IP address in TCP was not accessible and added later (now accessible using perationContext.Current.IncomingMessageProperties[RemoteEndpointMessageProperty.Name])
  6. Interoperability with other platforms can be an issue.

Now it seems that a lot of designs are moving towards simplicity of JSON and REST. I just love their simplicity and I can see my washing machine consuming JSON in 5-10 years and hosting a REST service! I believe their implementation in .NET was a hack and we seriously need a very light weight and simple framework (because these are simple and light weight) to host REST+JSON services inside and outside IIS. I hope such a framework exist but if not, I am really eager to get something going with a number of like-minded folks.

So what do you think? Does such a framework exist? If not, is anyone interested?

Solution :

MVC that spits out JSON instead of HTML seems like a possibility. You have the freedom to either use the JsonDataContractSerializer or JSON.Net to serialize your datacontracts.

Take a look at OpenRasta. It looks like it addresses many of your concerns.

If you really don’t want to use IIS, you can implement your own HTTP listener process. This let’s you write your own standalone application to respond to HTTP requests (which may be run as a service if you so desire) without any of the overhead of IIS, WCF or any other container process framework. Your process would live on top of the HTTP.sys functionality exposed by Windows, and exposed by the .Net framework through the HttpListener class.

Take a look at http://msdn.microsoft.com/en-us/library/system.net.httplistener.aspx

Note that you will need to write your own infrastructure for matching incoming requests and dispatching them to corresponding handlers (the equivalent of ASP.Net MVC’s UrlRoutingModule/RouteTable.Routes/MvcRouteHandler), and you will need to flow the HttpListenerContext everywhere in order to examine the incoming request and complete it. But this gives you the ultimate in flexibility in what you can do.

And it certainly performs – I have benchmarked a basic HttpListener implementation on a standard desktop-class machine at over 3000 requests served/second, so the framework itself will not hold you back.

There is MicroRest, an open source project I started a while. Here’s the blurb I wrote:

MicroRest is a tiny REST framework – 5 classes, around 500 lines of code. All output is JSON. It allows you to add REST capabilities to your ASP.NET applications without needing to go through the huge ugly mess of WCF rest (which doesn’t provide ‘clean’ URLs in 3.5). It also allows you to use POCOs (and complex objects in some cases) inside your REST methods, where WCF restricts you to using ints and strings

Contributions are very welcome – it does rely on System.Web.Routing right now, so needs Cassini/IISExpress as an embedded web server. I’m looking at writing a custom route parser so it can move to Kayak as some point.

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