Update only part of a Model, validation problem?

Question

Hi, I have a sign-up page where the user can input his FirstName, LastName, Email and Password, along with other fields.

I have bound validation attributes to this Model (called "User" and created via LINQtoSQL) and all works well.

Model code:

[MetadataType(typeof(UserValidation))]
public partial class User { }

[Bind(Exclude = "UserID")]
[PropertiesMustMatch("Password", "ConfirmPassword", ErrorMessage = "The password and confirm password don't match.")]
public class UserValidation 
{
    [Required(ErrorMessage = "First name required"), StringLength(20, MinimumLength=3, ErrorMessage = "Must be between 3 and 20 characters")]
    public string FirstName { get; set; }

    [Required(ErrorMessage = "Last name required"), StringLength(20, MinimumLength = 3, ErrorMessage = "Must be between 3 and 20 characters")]
    public string LastName { get; set; }

    [Required(ErrorMessage = "Email address required"), RegularExpression("^[a-z0-9_\\+-]+(\\.[a-z0-9_\\+-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*\\.([a-z]{2,4})$", ErrorMessage = "Must be a valid email address")]
    public string Email { get; set; }

    [Required(ErrorMessage = "Password required"), StringLength(20, MinimumLength = 6, ErrorMessage = "Password must be between 6 and 20 characters")]
    public string Password { get; set; }

    [Required(ErrorMessage = "Confirm password required"), StringLength(20, MinimumLength = 6, ErrorMessage = "Password must be between 6 and 20 characters")]
    public string ConfirmPassword { get; set; }

}

After sign-up and login, I want the user to be able to edit their FirstName, LastName and Email (lets call these "Account" fields) in one View and "Password" in another. This is where my problem lies.

When I submit a form updating the Account fields data via the same Model ("User") used in the sign-up, the IsValid method flairs up a ModelState error for the missing "Password" field.

Controller code:

    //
    // GET /Talent/Account
    public ActionResult Account()
    {
        string cookieUser = User.Identity.Name;
        User user = userRepository.GetUserByEmail(cookieUser);
        return View(user);
    }

    // POST /Talent/Account
    [HttpPost]
    public ActionResult Account(User model)
    {

        if (ModelState.IsValid)
        {
    // do something
            ModelState.AddModelError("", "All good.. "+ model.FirstName + " - " + model.LastName);
        }

        return View(model);
    }

How can I get around this?? Best practice etc...

Answer 1

In Model-View-ViewModel (MVVM) fashion, you should create two ViewModels: one for creating a new account, and the other for editing the name fields without the password required.

Apply the validation attributes to your ViewModels instead of directly to your Models.

Some sample wrapper ViewModel classes:

        [Bind(Exclude = "UserID")]    
        public class UserForAccountEdit
        {
            public User UserAccount { get; set; }

            [Required(ErrorMessage = "First name required"), StringLength(20, MinimumLength=3, ErrorMessage = "Must be between 3 and 20 characters")]  
            public string FirstName  
            {  
              get 
                   { return UserAccount.FirstName };  
              set
                   { UserAccount.FirstName = value; }
            }  

            ...
        }    



        [Bind(Exclude = "UserID")]
        [PropertiesMustMatch("Password", "ConfirmPassword", ErrorMessage = "The password and confirm password don't match.")]
        public class UserForAccountCreation
        {
            public User UserAccount { get; set; }

            [Required(ErrorMessage = "First name required"), StringLength(20, MinimumLength=3, ErrorMessage = "Must be between 3 and 20 characters")]  
            public string FirstName  
            {  
              get 
                   { return UserAccount.FirstName };  
              set
                   { UserAccount.FirstName = value; }
            }  

            ...
        }

Answer 2

I tried to implement you code like below but the 'model.LastUpdated' doesn't get recognised now??

[HttpPost] 
public ActionResult EditAccount(UserForAccountEdit model) 
{ 
    if (ModelState.IsValid) 
    { 
          model.LastUpdated = DateTime.Now;
          userRepository.Save(); 
    } 
    return View(model); 
} 

Is this rightly implemented or am I doing something wrong?