Question

I have a controller-action with a complex object for input parameter, which is sent by a Post.
In a scenario I wouldn’t want the user submit something valid (for example he pressed a back button), but I still want to persist the state of the form, so I put it in the Session.

There is a property on the VM called Valid for marking the result of the modelstate validation for later use.

I wouldn’t want the user to somehow send this property from clientside (for example setting it to a false positive state could confuse my code if I’m not careful).

Is there an attribute, like non-serializable to be used here? (So I wouldn’t have to explicitly set it to false it in my code).

Part of my code (most of it is ripped out)

[HttpPost]
public ActionResult FormWithDelayedValidation(MyVM vm)
{
    SessionVariables.Current.OrderSecondVM = vm;

    if (ModelState.IsValid)
    {
        vm.Valid = true;
        return Redirect(somewhere);
    }

    if (vm != null) vm.Valid = false;
    return Redirect(somewhere_else);
}

Answer 1

You could use BindAttribute to control properties used when model binding.

[Bind(Exclude="Valid")]
public class MyVm
{
    public bool Valid {get; set;}
}