Updating a Model in asp.net mvc

Question

Our project manager has asked us to refactor an app that was using the Repository Pattern (it was done using Nerddinner as example) to now use a service Layer. My problem now is that Im not sure how to Update a Model cause the UpdateModel method is supposed to be used in the controller... whats a recomended approach to updating a model using repository pattern along with a service layer?? please help

Answer 1

I would suggest you 'hide' your current Repository Pattern inside your service layer. Data access code should not be visible to the clients of the service.

You can implement a collection of DTOs that will be returned from service layer or accepted as parameters. Those objects can be just POCOs to hold the data in a database-agnostic way.

DTOs are usually accompanied by Adapters for translation to/from your data access classes (that represent tables). This approach allows you to change database schema without changing service layer interface.

You can treat those DTOs as models in MVC, if your project is simple and data for your views matches the service layer DTOs. You can also define your models in MVC project and let controller or another set of adapters translate models into DTOs.

My preferred design includes model that are declared in MVC (Models folder) that work with strongly-typed views. UpdateModel method then works with those classes. Next controller or ModelAdapter creates an instances of Service Layer DTOs and passes them to services. DTO adapters inside services are then responsible to populate data access classes from repository pattern.