ASP.NET MVC - Respository/Service/Controller

Question

Should a Controller ever need to call a Repository directly, or should it always run though the service layer? Or are there other options?

Answer 1

If you have a service layer and your're using it in a way that abstracts the business logic away from the repository (as you should with a service layer) then no, your controllers should only be making calls to the service methods. The service layer will then be the coupling to the repo.

Further to Mayo's answer: the model are the data classes that will be passed throughout the application (repo, service and UI/controllers) so the UI/web layer should 'operate' on them just like the other layers will.

I think if you implement a service layer in the context of Fowler's definition and the modern aspnet mvc adaptions, then you should have your controller actions designed as very small and lightweight methods, calling the 'meaty' business logic from your service layer.

EDIT: I guess i wasn't clear: I'm not saying having a service layer is the only option, just trying to answer part of the question pertaining to the case where you do use a service layer. Agreed, a service layer is not always necessary, especially for smaller projects.

Answer 2

You don't always need a service layer - in simple situations it is just over engineering the solution. It's fine for controller to call repository. But, if you see your controllers bloating with logic, or you are repeating yourself in controller actions, then look at putting a service between the controller and repository, and move some of the logic from the controller to ther service layer.