MV4 Application with EF5 model first, without ViewModels or Repositories

Question

I'm building a MVC4 app, I've used EF5 model first, and kept it pretty simple. This isn't going to a huge application, there will only ever be 4 or 5 people on it at once and all users will be authenticated before being able to access any part of the application, it's very simply a place order - dispatcher sees order - dispatcher compeletes order sort of application.

Basically my question is do I need to be worrying about repositories and ViewModels if the size and scope of my application is so small. Any view that is strongly typed to a domain entity is using all of the properties within that entity. I'm using TryOrUpdateModel in my controllers and have read some things saying this can cause a lot of problems, but not a lot of information on exactly what those problems can be. I don't want to use an incredibly complicated pattern for a very simple app.

Hopefully I've given enough detail, if anyone wants to see my code just ask, I'm really at a roadblock here though, and could really use some advice from the community. Thanks so much!

Answer 1

ViewModels: Yes

I only see bad points when passing an EF Entities directly to a view:

• You need to do manual whitelisting or blacklisting to prevent over-posting and mass assignment
• It becomes very easy to accidentally lazy load extra data from your view, resulting in select N+1 problems
• In my personal opinion, a model should closely resembly the information displayed on the view and in most cases (except for basic CRUD stuff), a view contains information from more than one Entity

Repositories: No

The Entity Framework DbContext already is an implementation of the Repository and Unit of Work patterns. If you want everything to be testable, just test against a separate database. If you want to make things loosely coupled, there are ways to do that with EF without using repositories too. To be honest, I really don't understand the popularity of custom repositories.

Answer 2

In my experience, the requirements on a software solution tend to evolve over time well beyond the initial requirement set.

By following architectural best practices now, you will be much better able to accommodate changes to the solution over its entire lifetime.

The Respository pattern and ViewModels are both powerful, and not very difficult or time consuming to implement. I would suggest using them even for small projects.

Answer 3

Yes, you still want to use a repository and view models. Both of these tools allow you to place code in one place instead of all over the place and will save you time. More than likely, it will save you copy paste errors too.

Moreover, having these tools in place will allow you to make expansions to the system easier in the future, instead of having to pour through all of the code which will have poor readability.

Separating your concerns will lead to less code overall, a more efficient system, and smaller controllers / code sections. View models and a repository are not heavily intrusive to implement. It is not like you are going to implement a controller factory or dependency injection.