Question

I would like to know how exactly model binding works in ASP.NET MVC3. Since I am still waiting for my Professional ASP.NET MVC3 book and I cannot find anything by googling it, you are my last hope.

I know how to perform binding with simple objects but when it comes to ViewModels, especially with nested List<T>, I am unable to perform binding.

Thanks

Francesco

UPDATE:

For clarification, I mean Model binding from View to Action Methods, thanks

Answer 1

The question is not completely clear, so I’ll address what I think you are asking for help on.

In cases where a View Model entity has a property of List<T> or some other enumerable, it is not automatically bound to the resulting model instance that is available in the action method marked as HttpPost.

You simply need to to find a place to persist the data, or, simply re-query for it in your Action method and update the posted instance.

The most reliable way I have found involves serializing the data to JSON and putting those values into hidden form fields, but when I do this, my view models no longer have the List property, but rather, the serialized properties.

This dilemma usually forces me to re-evaluate the need for the data to be available on form posts, and in most cases it is because I have tried to reuse a view model across views that have different requirements.