How to bind a model property with DefaultModelBinder - ASP.NET MVC2

Question

I have the following scenario.

I have the Edit/Employee view populated with a model from an Entity Framework entity (Employee)
I post from Edit/Employee to the Save/Employee controller action. The Save/Employee action expect another type (EmployeeSave) which has Employee as property

This is the Edit/Employee method

    public ActionResult Edit(EmployeesEdit command)
    {
        var employee = command.Execute();
        if (employee != null)
        {
            return View(employee);
        }
        return View("Index");
    }

This is the Save/Employee method

  public ActionResult Save(EmployeesSave command)
    {
        var result = command.Execute();
        if (result)
        {
            return View(command.Employee);
        }
        return View("Error");
    }

This is the EmployeeSave class

public class EmployeesSave
{
    public bool Execute()
    {
        // ... save the employee   
        return true;

    }
    //I want this prop populated by my model binder
    public Employee Employee { get; set; }  
}

The MVC DefaultModelBinder is able to resolve both Employee and EmployeeSave classes.

What is creating the command object to pass into the action method in your example? — Bless Yahu, Mar 27 '12 at 16:29

score 1 · Accepted Answer · answered Aug 11 '11 at 12:09

1

You might need to use BindAttribute here. If your view contains the properties of the EmployeeSaveViewModel and Employee named like this (I made up property names)

<input type="text" name="EmployeeSaveViewModel.Property1" />
<input type="text" name="EmployeeSaveViewModel.Employee.Name" />
<input type="text" name="EmployeeSaveViewModel.Employee.SomeProperty" />

Then, your action could look like this:

[HttpPost]
public ActionResult Save([Bind(Prefix="EmployeeSaveViewModel")] 
                         EmployeeSaveViewModel vm)
{
    if(ModelState.IsValid)
    {
        // do something fancy
    }

    // go back to Edit to correct errors
    return View("Edit", vm);
}

answered Aug 11 '11 at 12:09

David Fox

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That could be a good approach if I have the EmployeesSave as model. But as you can see in the Edit action I just added the model is the Employee. This is what I have in my view: `` – ab_732 Aug 11 '11 at 14:41
I believe that this would be the best approach. Doesn't make any sense to write a custom model binder for every command/action in your application, even if inheriting from the DefaultModelBinder. Injecting the command as viewmodel is more error proof and time saver. – ab_732 Aug 15 '11 at 14:39

score 0 · Answer 2 · answered Aug 11 '11 at 11:42

You could resolve it by passing the edited data back to Edit action that handles HttpPost. Inside create EmployeeSave object and assign its Employee property the value of Employee returned to yout Edit action. Call Save action by passing EmployeeSave object.

[HttpGet]
public ActionResult Edit()
{
    return View();
}

[HttpPost]
public ActionResult Edit(Employee employee)
{
    EmployeeSave employeeSave = new EmployeeSave { Employee = employee };

    return View("Save", employeeSave);
}

Another method would be to use EmployeeSave instead of Employee as your model.

Using EmployeeSave instead Employee would fix the issue. But I would like to keep separated the command from view. So let the view work only with the model. Maybe is it required a Custom Binder? — ab_732, Aug 11 '11 at 14:44

How to bind a model property with DefaultModelBinder - ASP.NET MVC2

2 Answers2