Show Custom Message for remote validation success response - validation

Question

I am using remote validation to check the availability of username during registration for my asp.net mvc 3 applicaion (C#).
I am using MVC remote Attribute validation as:
[Remote("IsUserNameAvailable", "User")]
public string UserName { get; set; }
I need to show the message on two conditions:
Show error message "Username not available" - Failure Condition
Show Success message "Username available" - Success Condition
I am able to show the Failure Condition's message without any issue like:
return Json("Username not available", JsonRequestBehavior.AllowGet);
But for Success Condition, I need to send true in response(not with the custom message) as:
return Json(true, JsonRequestBehavior.AllowGet);
How can i show custom message for Success Condition of Remote validation?

Answer 1

see this link...
here
One way to achieve that is to add a custom HTTP response header from the validation action:
public ActionResult IsUserNameAvailable(string username)
{
if (IsValid(username))
{
// add the id that you want to communicate to the client
// in case of validation success as a custom HTTP header
Response.AddHeader("X-ID", "123");
return Json(true, JsonRequestBehavior.AllowGet);
}
return Json("The username is invalid", JsonRequestBehavior.AllowGet);
}
Now on the client we obviously have a standard form and an input field for the username:
#model MyViewModel
#using (Html.BeginForm())
{
#Html.EditorFor(x => x.UserName)
#Html.ValidationMessageFor(x => x.UserName)
<button type="submit">OK</button>
}
and now the last piece of the puzzle is to attach a complete handler to the remote rule on the username field:
$(function () {
$('#UserName').rules().remote.complete = function (xhr) {
if (xhr.status == 200 && xhr.responseText === 'true') {
// validation succeeded => we fetch the id that
// was sent from the server
var id = xhr.getResponseHeader('X-ID');
// and of course we do something useful with this id
alert(id);
}
};
});

Answer 2

Are you able to return an object (which will be serialised to Json)?
Such as:
var answer = new { success = true, message = "Username available" };
return Json(answer, JsonRequestBehavior.AllowGet);
Then you can parse this in the view.
Also, if you do it this way, but the username is NOT available, you could add a few suggested usernames too.
e.g.
// pretend they chose "dave"
List<string> alternativeNames = new List<string>() { "dave1", "dave2" };
var answer = new { success = false, message = "Username not available", alternatives = alternativeNames };
return Json(answer, JsonRequestBehavior.AllowGet);