Remote ViewModel validation of nested objects not working

Question

I have a class user which looks like this:

public class User
{
    public int UserId { get; set; }

    [Required(ErrorMessage = \"A username is required.\")         


        

Answer 1

The issue with the validation of the PasswordConfigurmation property against the User.Password property is caused by a bug in in the 'jquery.validate.unobtrusive.js' file.

Originally, the jquery 'equalTo' function is:

adapters.add("equalto", ["other"], function (options) {
var prefix = getModelPrefix(options.element.name),
other = options.params.other,
fullOtherName = appendModelPrefix(other, prefix),
element = $(options.form).find(":input[name=" + fullOtherName + "]")[0];

setValidationValues(options, "equalTo", element);
});

You just need to modify this line:

element = $(options.form).find(":input[name=" + fullOtherName + "]")[0];

to:

element = $(options.form).find(":input[name='" + fullOtherName + "']")[0];

Note the addition on the single quotes around the 'fullOtherName' selector. Once you've made this change, the client side validation works as expected.

Answer 2

Inheritance seems like a standard way of adding functionality in this case. How about having your RegistrationViewModel derive from the UserViewModel:

public class RegistrationViewModel : UserViewModel
{
    [DisplayName("Password confirmation")]
    [Required]
    [Compare("Password", ErrorMessage = "The password do not match")]
    public string PasswordConfirmation { get; set; }
}

and:

public ActionResult UsernameExists(string Username)
{
   ...
}

Answer 3

For the remote validation part nothing jumps out at me. It might be helpful to open up firebug and see what the request that is being fired looks like. You should see something roughly like this if everything is properly wired up...

http://localhost:14547/[Controller]/[ActionName]?[ParamName]=[paramValue]

From the request you provided, you can either use a prefix like you ended up doing or you can make your action take a user named UserToRegister and then within the action access the UserName property. This is the recommended way of dealing with remote validation of objects and might be a little easier to think about than using a Bind attribute.

For the compare validation, it appears that on the client side validation is succeeding but on the server side validation fails because the validation context does not contain a property named User.Password, only a property named User.