View model absence in registration form - asp.net-mvc

Question

I have a partial view that contains a registration form with the following fields:
E-Mail
First Name
Last Name
Password
I am posting the form using jQuery Ajax without using View Model.
Question : Is it a good approach to not use View Model in his context ?
Question : Is my approach useless in case of unit test cases?
jQuery
$.ajax({
url: "#Url.Action("Action", "Controller", new { area = "Area" })",
type: "POST",
contentType: 'application/json; charset=utf-8',
dataType: "json",
data: JSON.stringify({mail : "mails", nam : nam ......}),
traditional: true,
success: function (data) {
alert("wsaved");
}
});
[HpPost]
public Actionresult abc(string mail, string nam, sring lasnam)
{
return Json(new {succss = ru});
}

Answer 1

Is it a good approach to not use View Model in his context ?
No, it will make validation much harder. Suppose that you wanted to validate that the email is not empty and is indeed a valid email address. If you used a view model, all you had to do is decorate the Email property on your view model with the correct validation attributes. With your approach you will now have to write a couple of useless lines of code in your controller action for that.
Here's how your view model might look like:
public class RegisterUserViewModel
{
[Required]
[RegularExpression("PUT YOUR REGEX TO VALIDATE AN EMAIL HERE")]
public string Email { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
[Required]
[RegularExpression("PUT YOUR REGEX TO ENFORCE SOME PASSWORD STRENGTH")]
public string Password { get; set; }
}
and now your controller action becomes:
[HttpPost]
public ActionResult Register(RegisterViewModel model)
{
if (!ModelState.IsValid)
{
// validation failed
var errors = ModelState
.Where(x => x.Value.Errors.Count > 0)
.Select(x => new
{
Key = x.Key,
Errors = x.Value.Errors.Select(e => e.ErrorMessage)
}
);
return Json(new { success = false, errors = errors });
}
return Json(new { success = true });
}

Answer 2

IF you are using an ApiController with MVC 4, then you can use a Model to bind to, which will use (by default) Newton Json.NET.
ResponseModel
[DataContact]
public class ResponseModel
{
[DataMember]
public string Status { get; set; }
}
ActionModel
[DataContact]
public class RegisterUserViewModel
{
[Required]
[DataMember(isRequired=true)]
public string Email { get; set; }
[DataMember]
public string FirstName { get; set; }
[DataMember]
public string LastName { get; set; }
[Required]
[DataMember(isRequired="true")]
public string Password { get; set; }
}
ApiController Action
[HttpPost]
public ReponseModel Register(RegisterActionModel actionModel)
{
if (this.ModelState == valid)
{
//do stuff
return new ResponseModel()
{
Status = "OK"
};
}
else
{
return new ResponseModel()
{
Status = "Invalid Data"
}
}
}