Question

I am having two issues:

1. I usually create separate view for the login to keep things simple but this time i want to have in the master page. If something goes wrong with the login process i add some error in the modelstate and keep the user to the page he currently is. What is the proper way to construct this, i mean create the current url?

2. In the register view, after submit, if that username exists, i see that model validation error in both validation summary(login form validation summary and register form validation summary).What can i do see the error message only in one particular form validation summary?

All the code is in HomeController but i will rename it to AccountController and keep here only ViewResult Index().

I gladly accept any tips of how to write it better and of course any critics.
Thanks.

    public class HomeController : Controller
    {
        private List<string> questions = new List<string>
        {
            "What is yout pet's name?",
            "What is your birth date?(mm/dd/yyyy)"
        };

        private CustomMembershipProvider mbProvider = (CustomMembershipProvider)System.Web.Security.Membership.Provider;

        public ViewResult Index()
        {
            return View();
        }

        [HttpPost]
        public ActionResult Login(LoginModel logModel, string returnUrl)
        {
            if (String.IsNullOrEmpty(logModel.LoginUsername) || String.IsNullOrEmpty(logModel.LoginPassword))
            {
                ModelState.AddModelError(string.Empty, "Please enter username and password.");
                return Current_View;
            }
            else
            {
                MembershipUser mbUser = mbProvider.GetUser(logModel.LoginUsername);
                if (mbUser == null)
                {
                    ModelState.AddModelError(string.Empty, "Invalid username.");
                    return Current_View;
                }
                else
                {
                    if (!mbUser.IsApproved)
                    {
                        ModelState.AddModelError(string.Empty, "Go to your email and confirm the registration.");
                        return Current_View;
                    }
                    if (mbUser.IsLockedOut)
                    {
                        ModelState.AddModelError(string.Empty, "Your account is locked.");
                        return Current_View;
                    }
                    bool isValid = mbProvider.ValidateUser(logModel.LoginUsername, logModel.LoginPassword);
                    if (!isValid)
                    {
                        ModelState.AddModelError(string.Empty, "Invalid credetials.");
                        return Current_View;
                    }
                    else
                    {
                        FormsAuthentication.SetAuthCookie(logModel.LoginUsername, false);
                        if (Url.IsLocalUrl(returnUrl) && returnUrl.Length > 1 && returnUrl.StartsWith("/") && !returnUrl.StartsWith("//") && !returnUrl.StartsWith("/\\"))
                        {
                            return Redirect(returnUrl);
                        }
                        else
                        {
                            return Current_View;
                        }
                    }
                }
            }            
        }

        private void SetRegisterViewData()
        {
            ViewData["Questions"] = new SelectList(questions);
        }

        public ViewResult Register()
        {
            SetRegisterViewData();
            return View();
        }

        [HttpPost]
        public ActionResult Register(RegistrationModel regInfo)
        {
            SetRegisterViewData();
            if (ModelState.IsValid)
            {
                MembershipCreateStatus status;
                MembershipUser user = mbProvider.CreateUser(regInfo.UserName, regInfo.PassWord, regInfo.Email, regInfo.SecretQuestion, regInfo.SecretAnswer, false, null, out status);
                switch (status)
                {
                    case MembershipCreateStatus.DuplicateEmail:
                        ModelState.AddModelError("Email", "That email already exists");
                        return View(regInfo);
                    case MembershipCreateStatus.DuplicateUserName:
                        ModelState.AddModelError("Username", "That username already exists");
                        return View(regInfo);
                    case MembershipCreateStatus.Success:
                        //SendConfirmationMail(regInfo.UserName);
                        return RedirectToAction("Index");
                    default:
                        ModelState.AddModelError("", "Error");
                        return View(regInfo);
                }
            }            
            return RedirectToAction("Index");
        }

        public ActionResult Logout()
        {
            FormsAuthentication.SignOut();
            return RedirectToAction("Index");
        }
    }

Answer 1

For your validation I would suggest using DataAnnotations.

In LoginModel.cs you can define your criteria and error messages.

using System.ComponentModel.DataAnnotations;

public class LoginModel{
    [Required(AllowEmptyStrings = false, ErrorMessage = @"You must supply a valid email address.")]
    [DataType(DataType.EmailAddress)]
    public String Email { get; set; }

    [Required(AllowEmptyStrings = false)]
    [DataType(DataType.EmailAddress)]
    [Compare("Email", ErrorMessage = @"Passwords do not match")]
    public String ConfirmEmail { get; set; }

    [Required(AllowEmptyStrings = false, ErrorMessage = @"Please enter a password")]
    [DataType(DataType.Password)]
    public String Password { get; set; }

    //whatever other properties you want
}

Then in your controller you can just check for:

if(ModelState.IsValid()){
    //do stuff
}

If not then return View(logModel) and the errors will be present in that object.

Appended

[HttpPost]
public ActionResult Login(LogInModel loginModel){
    if(ModelState.IsValid()){
        //do stuff if good
    }
    //not valid
    TempData["loginModel"] = loginModel;
    RedirectToAction("Index","Home");
}

In the Home ActionResult just add logic to handle the loginModel object which will have the errors in it.