Question

I’m again struggling at validating inputs.
Let’s say I edit a customer and the field “name” is required via

[Required(ErrorMessage = Constants.ErrorMsgNameMissing)]
public string NAME { get; set; }

inside the model.

The edit method does

[HttpPost]
edit(ViewModel vm)
{
    // some code here    
    try
    {
        UpdateModel(vm);
        // some code there
    }
    catch (Exception e)
    {
        return View(vm);
    }
}

While doing UpdateModel(vm), an exception is thrown if the name is empty. Then my view shows the Html.ValidationSummary(). So far, so good.

Now, if I create a customer via

[HttpPost]
create(ViewModel vm)
{
    if (ModelState.IsValid) { ... }
}

I don’t have the method UpdateModel() since there’s nothing to update. And ModelState.IsValid seems to return true every time. Even if the ViewModel is null. So I run into trouble then.

How do I validate this? And what do I return in case of errors?

Update: I think it was too late yesterday. In fact, it DOES work. But I was hoping for an exception and forgot the else { ... }…

Answer 1

Try this:

[HttpPost, ValidateInput(true)]
create(ViewModel vm)
{
    if (ModelState.IsValid) { ... }
}