Question

I’m building an ASP.NET MVC application that is client-script heavy, it will use JSON and jQuery to manipulate the DOM.

My understanding is both Web API Controller and MVC Controller can return JSON.

Given my scenario, should I use a Web API Controller or an MVC Controller?

Answer 1

Web API Controllers can be created and hosted in any ASP.NET Application, not just MVC applications. Thus, an obvious reason to create a Web API is if you do not have an MVC front-end (e.g. classic, RESTful web-services hosted by your company/organization.)

MVC Controllers typically rely on the MVC Framework, if you look at default templates and most of the work done by the community and your peers you will notice that almost all MVC Controllers are implemented with the View in mind.

Personally, I use MVC Controllers when I intend to respond with a View(), and I’ll use a Web API for anything that isn’t dependent on a particular view.

There are caveats, of course, but generally speaking if you don’t require the Model Binding behavior of MVC, your service is data-centric, and operations are Data-centric (e.g. CRUD operations) then you likely want a ‘Web API Controller’ instead of a ‘Model-View Controller’. Conversely, if your operations are View-centric (e.g. delivering a user admin page to the user), or you need MVC’s Model Binding to generate ‘ajax partials’ (very unlikely), then you will want an MVC Controller instead.

Personally, I use Web API controllers for driving JSON-based RESTful clients, I use MVC controllers for handling basic browser routing and delivery of the SPA.