ModelState.IsValid vs IValidateableObject in MVC3

Question

so according to Gu IValidatableObject.Validate() should get called when a controller validates it's model (i.e. before ModelState.IsValid) however simply making the model implement IValidatableObject doesn't seem to work, because Validate(..) doesn't get called.

Anyone know if there is something else I have to wire up to get this to work?

EDIT:

Here is the code as requested.

public class LoginModel : IValidatableObject
{
    [Required]
    [Description("Email Address")]
    public string Email { get; set; }

    [Required]
    [Description("Password")]
    [DataType(DataType.Password)]
    public string Password { get; set; }

    [DisplayName("Remember Me")]
    public bool RememberMe { get; set; }

    public int UserPk { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        var result = DataContext.Fetch( db => {

            var user = db.Users.FirstOrDefault(u => u.Email == Email);

            if (user == null) return new ValidationResult("That email address doesn't exist."); 
            if (user.Password != User.CreateHash(Password, user.Salt)) return new ValidationResult("The password supplied is incorrect.");

            UserPk = user.UserPk;
            return null;
        });

        return new List<ValidationResult>(){ result };
    }
}

The action. ( I don't do anything special in the Controller...)

[HttpPost]
public ActionResult Login(LoginModel model)
{
    if (ModelState.IsValid)
    {
        FormsAuthentication.SetAuthCookie(model.Email, model.RememberMe);
        return Redirect(Request.UrlReferrer.AbsolutePath);
    }

    if (ControllerContext.IsChildAction || Request.IsAjaxRequest())
        return View("LoginForm", model);

    return View(model);
}

I set a break point on the first line of LoginModel.Validate() and it doesn't seem to get hit.

Answer 1

There isn't anything more than that you just have to add it to the model you're validating. Here's an example of validation

public class User : IValidatableObject {
    public Int32 UserID { get; set; }
    public string Name { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) {
        //do your validation

        return new List<ValidationResult>();
    }
}

And your controller would use this model

public ActionResult Edit(User user) {
    if (ModelState.IsValid) {
    }
}

Hope this helps. Other requirements are .net 4 and data annotations - which you obviously need jsut for ivalidatableobject. Post any issues and we'll see if we can't resolve them - like post your model and your controller...you might be missing something.