MVC Remote Validation Error kept after change

Question

I'm having trouble with my remote validation checking a second time after an invalid email has been given. I can't figure out why it's not removing the error after its no longer invalid.

Here is my Model:

[Required(ErrorMessage = "An email is required")]
[StringLength(150, MinimumLength = 4)]
[Display(Name = "Email")]
[RegularExpression("^([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$", ErrorMessage = "Invalid Email")]
[Remote("doesEmailExist", "Account", HttpMethod = "POST", ErrorMessage = "This email has already registered. Please use a different email")]
public virtual string strEmail { get; set; }

My View:

<ul>
        <li class="editor-label">@Html.LabelFor(m => m.strEmail)</li>
        <li class="editor-field">@Html.TextBoxFor(m => m.strEmail)</li>
        <li class="error">@Html.ValidationMessageFor(m => m.strEmail)</li>
</ul>

My Controller:

[HttpPost]
public JsonResult doesEmailExist(string strEmail)
    {

        var user = db.t_user.FirstOrDefault(i => i.email == strEmail);
        if (user == null)
            return Json(null);
        else
            return Json(false);

    }

Why is the remote validation not correcting itself going from an invalid entry to a valid entry?

Answer 1

Your JsonReturn need to return true (not null) if no existing email exists. Note this really should be a GET

[HttpGet]
public JsonResult doesEmailExist(string strEmail)
{
  var user = db.t_user.FirstOrDefault(i => i.email == strEmail);
  if (user == null)
    return Json(true, JsonRequestBehavior.AllowGet); // change this
  else
     return Json(false, JsonRequestBehavior.AllowGet);

}

or

 bool exists = db.t_user.Any(i => i.email == strEmail)
 return Json(!exists, JsonRequestBehavior.AllowGet);

Note also you can use [EmailAddress] in lieu of your [RegularExpression] attribute