Validate login form

Question

I wan't to validate a login form. I just wan't to check if the email field and password field are filled in. If not, an error message should display. I can't get it to work.

My actionresult Login:

[HttpPost]
    public ActionResult Login(string email, string password, string returnUrl)
    {
        if (ModelState.IsValid)
        {
            try
            {
                User user = accountDal.GetAllUsers().FirstOrDefault(x => x.Email == email && x.Password == password);
                if (user != null)
                {
                    FormsAuthentication.SetAuthCookie(user.Email, false);
                    Response.Redirect(returnUrl, false);
                }
                return View();
            }
            catch
            {
                return View();
            }
        }
        return View();
    }

So as you can see, I check if the ModelState is valid.

Here is my login view:

@model ProjectInvoice.ViewModels.LoginViewModel

@{
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>

@using (Html.BeginForm())
{
    @Html.ValidationSummary(true)
        <h3>Login</h3>
        <div class="editor-label">
            @Html.LabelFor(model => model.Email)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Email)
            @Html.ValidationMessageFor(model => model.Email)
        </div>
        <div class="editor-label">
            @Html.LabelFor(model => model.Password)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Password)
            @Html.ValidationMessageFor(model => model.Password)
        </div>
        <p>
            <input type="submit" value="Create" />
        </p>
}

And my ViewModel:

public class LoginViewModel
{
    [Required]
    [Display(Name = "Email")]
    public string Email { get; set; }

    [Required]
    [Display(Name = "Password")]
    public string Password { get; set; }
}

If I use a breakpoint at the if (ModelState.IsValid) it says it is true, while this is not the case. Am I missing something, or am I doing something wrong?

yes, the login part works, but if I leave the fields empty and click the button, the page just refreshes — Reptar, Apr 07 '15 at 13:21
thats not how you want to redirect in MVC. you want to say `return Redirect(redirectUrl);` — DLeh, Apr 07 '15 at 13:22

score 3 · Answer 1 · answered Apr 07 '15 at 13:21

You need to post back your model so the properties of your model can be validated

public ActionResult Login(LoginViewModel model, string returnUrl)
{
  if (ModelState.IsValid)
  {
    ....

Note also, when you return the view, you need to return the model

return View(model);

score 1 · Accepted Answer · answered Apr 07 '15 at 13:21

1

You need to have something like following:

public ActionResult Login(LoginViewModel loginViewModel, string returnUrl)
{
    if (ModelState.IsValid)
    {
        try
        {
            User user = accountDal.GetAllUsers().FirstOrDefault(x => x.Email == loginViewModel.Email && x.Password == loginViewModel.Password);
            if (user != null)
            {
                FormsAuthentication.SetAuthCookie(user.Email, false);
                Response.Redirect(returnUrl, false);
            }
            return View();
        }
        catch
        {
            return View();
        }
    }
    return View(loginViewModel);
}

The reason why it is not working is ModelState.IsValid validates your model against the data annotation applied to the LoginViewModel class's members.

answered Apr 07 '15 at 13:21

Jenish Rabadiya

6,708
6
33
62

I see, this works fine! thank you! I must wait a few minutes before I can accept your answer – Reptar Apr 07 '15 at 13:24
is it also possible to make a custom validation message? – Reptar Apr 07 '15 at 13:32
@bbvanee Yes you can by `[Required(ErrorMessage="some meaningful message here")]` – Jenish Rabadiya Apr 07 '15 at 13:34
and if I wan't to translate this message, can I call this message in my resources, like 'Email.ErrorMessage'? – Reptar Apr 07 '15 at 13:42
@bbvanee Yes you can probably you would like to visit this SO thread http://stackoverflow.com/q/17940523/1505865 – Jenish Rabadiya Apr 07 '15 at 13:50

Ninglin · Answer 3 · 2015-04-07T13:24:03.153

0

You need to use data annotations. Like this:

public class LoginViewModel
{
    [Required]
    [Display(Name = "Email")]
    public string Email { get; set; }

    [Required]
    [Display(Name = "Password")]
    public string Password { get; set; }
}

This will invalidate you're model state. And then, in the contriller, you return it to the View using something liek this:

return View(model)

edited Apr 07 '15 at 13:24

answered Apr 07 '15 at 13:22

Ninglin

146
1
9

Yes I realized that after posting the answer. Sorry about that. But you have to return the model to the view in order for the validation message to be available. – Ninglin Apr 07 '15 at 13:49

Validate login form

3 Answers3