What's the best way to implement an API in ASP.NET using MVC?

Question

I've been a longtime ASP.NET developer in the web forms model, and am using a new project as an opportunity to get my feet wet with ASP.NET MVC.

The application will need an API so that a group of other apps can communicate with it. I've always built API's out just using a standard web service prior to this.

As a sidenote, I'm a little hesitant to plunge headfirst into the REST style of creating API's, for this particular instance at least. This application will likely need a concept of API versioning, and I think that the REST approach, where the API is essentially scattered across all the controllers of the site, is a little cumbersome in that regard. (But I'm not completely opposed to it if there is a good answer to the potential versioning potential requirement.)

So, what say ye, Stack Overflow denizens?

Answer 1

I would still recommend a service layer that can serve client side consumers or server side consumers. Possibly even returning data in a variety of formats, depending on the consuming caller.

Answer 2

I'd agree with Kilhoffer. Try using a "Facade" wrapper class that inherits from an "IFacade". In your Facade class put your code to consume your web service. In this way your controllers will simply make calls to the Facade. The plus side of this being that you can swap a "DummyFacade" that implements the same IFacade interface in that doesn't actually talk to the web service and just returns static content. Lets you actually do some unit testing without hitting the service. Basically the same idea as the Repository pattern.