Question

Here’s my problem:

We have an intranet asp.net mvc 3 application with a controlled set of users. We have a Person class, that contains a large amount of information, that is initially loaded and stored in the session. The data/editing for this object spans across many screens. Basically, each screen is a subset of the Person’s data.

I’m trying to take advantage of the built in model binding in asp.net mvc. Should I create a data class that binds the form data from each screen and then updates my session object using a service object?

Example below: DxFormData contains a subset of the person data and will only be used as a parameter on this method.

 public ActionResult Dx(DxFormData data)
 {
    // Update current session Person object with data passed in if modelstate is valid
    var viewModel = this.GetDxViewModel();        
    return View(viewModel);
 }

public class DxForm Data
{
    public string AdmitDx { get; set; }
    public string PrinDx { get; set; }
}

I’m looking for thoughts on this approach and if there’s a better solution available to me. The problem that I see, is that the person class contains all the data and I’m creating another class with a subset of that data. Obviously, duplicating the properties.

Side note: I did write a custom model binder that returned the session person for binding. However, I am continually getting errors when it attempts to bind.

Answer 1

I don’t see problem with this approach. If you try to use the Parent class as the action parameter then in each form submit action then you will get validation errors because the model is not completely filled, so you should use view models in this case and unfortunately you can’t avoid duplicating properties.