Question

I am attempting to use the remote data annotation for the first time in MVC 3.
I am missing something simple. The setup is not firing the controller action at all and I’m not seeing the issue off hand.

I am attempting to validate username for uniqueness.

Here is the code setup.

View Code

@Html.Raw(Html.Script("jquery.validate.min.js"))
@Html.Raw(Html.Script("jquery.validate.unobtrusive.min.js"))

<tr>
            <td class="editor-label">@Html.LabelFor(model => model.UserName):</td>
            <td  class="editor-field">@Html.EditorFor(model => model.UserName)</td>
            <td>@Html.ValidationMessageFor(model => model.UserName)</td>
        </tr>

ViewModel Code

    [DisplayName("Username")]
    [StringLength(100)]
    [Remote("CheckIfUsernameExists", "UserProfile", ErrorMessage = "This username is taken. Please enter a different user name.")]
    public string UserName { get; set; }

Controller Code

[HttpGet]
        public JsonResult CheckIfUsernameExists(string userName)
        {
            return Json("false");
        }

Answer 1

Check you setting, the client validation and the unobtrusive should be enabled

<appSettings>
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>

with that the following code should work

    [Get]
    public JsonResult CheckIfUsernameExists(string userName)
    {
        return Json(false,JsonRequestBehavior.AllowGet);
    }