Question

I have a class that requires another class to be specified, but I don’t want the MVC ModelState validator to check whether the secondary model is valid. Is this possible?

Here’s a brief overview:

My entities look something like this:

public class WidgetType
{
    public long Id { get; private set; }

    [Required]
    public string Name { get; set; }

    ...
}

public class Widget
{
    public long Id { get; private set; }

    [Required]
    public string Name { get; set; }

    [Required]
    public WidgetType WidgetType { get; set; }

    ...
}

I have them encapsulated in a WidgetViewModel class that I’m passing to/from the View like this:

public class WidgetViewModel
{
    public Widget Widget { get; set; }

    public ICollection<WidgetType> WidgetTypes
    {
        get
        {
            return _repository.GetWidgets();
        }
    }

    ...
}

My view looks something like this:

...
@Html.DropDownListFor( m => m.Widget.WidgetType.Id, new SelectList( new EquipmentViewModel().EquipmentTypes, "Id", "Name" ) )
...

All of this works except for validation. ModelState.IsValid is always false because "Widget.WidgetType.Name" is required. I need the user to select a WidgetType, but I don’t want ModelState to be validated deeper than “Widget.WidgetType.Id” (which should be all that Widget needs for its foreign key?).

Is there a better way to do this? I feel like there should be some way to validate without recursively inspecting deeper into the properties, but I can’t find it. What am I missing…?

Answer 1

http://blog.stevensanderson.com/2010/02/19/partial-validation-in-aspnet-mvc-2/ gives an example of partial validation