Code first: does fluent api influence UI?

Question

I\'m reading a book written by Julie Lerman on Code First. According to the book, annotations and fluent api give the same result. Everything depends on the style of the develop

Answer 1

If your entity model classes are doubling as your viewmodel classes, AND you are using the default out of the box DataAnnotationsValidationProvider, then you would need the dataannotations attributes on the model properties to get validation.

However, you should not double your entity classes as viewmodel classes. Take for instance, a controller that needs to have a ReturnUrl property in its model. You wouldn't want this in your entity model / database. Because of differences like this between the View model and the Entity model, the 2 should really be separate (yet cohesive) layers in your application. You can make them cohesive using a library like AutoMapper.

This is one of the reasons I prefer the fluent API. If you stick to the fluent API, then you would never put any attributes on any entity model classes or properties. When it comes time to show, insert, or update data, you put the attributes on the viewmodel classes only.

Also, the [Required] attribute on an entity type performs validation during SaveChanges, whereas a [Required] attribute on a viewmodel performs validation during model binding.