Best Practices when Implementing IModelBinder [closed]

Question

I'm looking for a set of best practices to use when implementing IModelBinder.

I've read three different MVC books and each one does some slightly different stuff in their implementations without any real explanation.

• The Hanselman, Haack, Guthrie, Conery book doesn't even mention IModelBinder
• Palermo recommends extending DefaultModelBinder rather than direct implementation of IModelBinder, but I don't really see how to leverage the benefits
• Sanderson mentions updating existing Model instances, as well as calling ModelState.SetModelValue() to follow convention.

I just want to make sure that my model binders are following conventions, and that I properly understand the entire ModelBindingContext.

Any tips, tricks, GOOD tutorials to recommend?

Watson

Answer 1

K Scott Allen has some tips about Model Binding: http://odetocode.com/blogs/scott/archive/2009/04/27/6-tips-for-asp-net-mvc-model-binding.aspx.

Miraculous

The article mentions Data Annotations so I wondered if I should inherit from DataAnnotationsModelBinder instead. The answer is no. MVC 2 RTM's DefaultModelBinder already contains logic from DataAnnotationsModelBinder. See #2667455 – Dialectics

Answer 2

I inherited from DefaultModelBinder, because it automatically binds basic properties in entity. I enhanced it, so it binds also navigation properties. My binder performs inherited binding first and then searches for additional, navigation property values in form. I think that Your approach should depend on what You really want to do. You can also use reflector and see what really stands behind default binder. This may convince You to inherit.

Hardej

Answer 3

Travis Illig recently wrote a really good blog article about data type validation when creating a custom model binder.

I've never seen this advice before and I thought it was really good - so I wanted to contribute this link: http://www.paraesthesia.com/archive/2012/01/31/data-type-validation-and-model-binding-in-asp-net-mvc.aspx

Watson

Answer 4

MVC Futures 2 has an extensible model binding system. You can find out more in the release documentation at http://aspnet.codeplex.com/releases/view/41742

Just download "ASP.NET MVC 2 Futures Extensible Model Binder Documentation"

Dialectics