Is it possible to override the required attribute on a property in a model?

Ryan Smith picture Ryan Smith · Jan 18, 2012 · Viewed 24.3k times · Source

I'm curious to find out if it is possible to override the [Required] attribute that has been set on a model. I'm sure there most be a simple solution to this problem, any takers?

Answer

moribvndvs picture moribvndvs · Jan 18, 2012

Depends on what precisely you are doing. If you are working with a subclass, using the model with the Required attribute as the base, you can do this:

Redefine the property with the new keyword, rather than override it.

public class BaseModel
{
    [Required]
    public string RequiredProperty { get; set; }
}


public class DerivativeModel : BaseModel
{
    new public string RequiredProperty { get; set; }

}

If you simply want to bind or validate a model, but skip the Required property in your controller, you can do something like:

public ActionResult SomeAction()
{
     var model = new BaseModel();

     if (TryUpdateModel(model, null, null, new[] { "RequiredProperty" })) // fourth parameter is an array of properties (by name) that are excluded
     {
          // updated and validated correctly!
          return View(model);
     }
     // failed validation
     return View(model);
}