WCF Web Api vs WebHttpBinding

Question

I'm new to WCF RESTFull services developpment and I'm looking for some usefull information and your experience feedback about using webHttpBinding compared to the new WCF Web API http://wcf.codeplex.com/.

What I'm looking for is to know about the shortcomings of webHttpBinding and therefore why to use the new Web api and especially what problems the new API resolves. If you could point me to some blog posts comparing both of them or just talking about the problems when using webHttpBinding I would appreciate. Thank you in advance.

Haerle

Answer 1

Main shortcomings I would say is that the webhttpbinding makes it difficult to handle HTTP specific concerns. It works great if all you are doing is passing an object over HTTP that is serialized into XML or JSON and which may be transported over different formats.

HTTP is much more than a simple transport protocol for XML and JSON, it is an application layer protocol with rich semantics. Web API is specifically targetting folks that want to build systems over HTTP that fully levergage HTTP's richness.

1. Web API embraces that HTTP Resources can have a multitude of representations based on the needs of different clients. One end of the spectrum could be a dumb browser that just talks to a service using a Form url encoded post and a GET, while the other end could be a more rich client that uses Atom/OData or a hypermedia based media type.

2. Web API embraces that there are other HTTP specific concerns like conneg, etags, etc which allow better leveraging intermediary web servers.

3. Web API is designed with more testability in mind, thus you can address working with HTTP messages or other concerns in a more testable manner.

4. Web API has a more simplified configuration story.

You can read more about the rationale here: http://blogs.msdn.com/b/endpoint/archive/2010/11/01/wcf-web-apis-http-your-way.aspx

Imbibe

From a Microsoft Program Manager, it really sounds like "If you're doing HTTP, you can forget about WCF" to me. Is this what you're saying? What's the future of WCF in the HTTP area? – Inwrought

WCF Web API is WCF :-) What we are saying is that WCF Web API is much better suited for working with HTTP / building RESTful services than WCF 4.0 / webhttbinding. – Imbibe

Answer 2

The most significant difference for me is the change in programming model. You no longer write 'services' which expose 'operations' bound to HTTP idioms (GET, POST etc.). With Web APIs you create 'resources' (POCOs) with which your clients can interact.

Web APIs seem to be better at handling various custom media types (like PNG images for example).

Last but not least, Web APIs are far better suited for automated testing. For instance, you no longer have to use static context classes to access HTTP concepts such as response codes. You use POCO request and response classes which can be easily instantiated in automated tests using old-style new() operator.

I agree with Ladislav that Web APIs are just a preview now and building application on top of it can be both risky and forbidden by the means of license agreement (but I haven't checked that).

Have you considered @serialseb's OpenRasta? It is stable and offers very nice programming model for building RESTful services.

Surplus

Answer 3

The Web API is something like possible future of REST development in WCF. It is just preview which can significantly change before final release (probably in next version of .NET framework). So if you want to build production REST service you should use webHttpBinding.

Available information about Web Api can be found for example on .NET Connected Framework team's blog and on the site you mentioned. It is simplification and extension of current REST API.

Anchusin

Web API will ship out of band on .NET 4.0 similar to MVC. You can find it at wcf.codeplex.com. – Imbibe

Answer 4

Web API provides a REST-friendly HTTP based API. Web API uses the patterns of MVC and is going to be very familiar to ASP.NET MVC developers. Web API can leverage the capabilities of HTTP as an application layer protocol, returning resources in multiple representations (XML, JSON, HTML etc.) according the the client's request headers.

On the other hand WCF webHttpBinding uses the patterns of WCF, and is going to appeal more to the WCF developer - ServiceContracts, OperationContracts, comprehensive (or overweight, depending how you look at it, config file), ability to self-host outside of IIS.

One of the things I like about Web API is the ability to use dynamic types to escape the constraints of the type system. I also like the default exception behavior in Web API - contrast WCF webHttpBinding where, by default, exceptions bubble up as HTTP 500 + an HTML payload (yuk!).

Its nice to have the choice between two excellent technologies here. I wouldn't describe Web API as 'newer' or 'better' that WCF, as this implies its a replacement technology and that WCF webHttpBinding is legacy, which I don't believe is true.

I chose to use WCF webHttpBinding recently to expose a JSON API for an existing WCF SOAP service. I believe it was a good choice because it fitted that style of that existing solution and minimized the amount of change required.

Totipalmate