Question

My task is create both login and registration form on one view!

I have home view. On a home view I have two forms, login and register. They rendered by @Html.RenderPartial(partial view name, model). That forms relates to Account controller (Login and Register actions).

Let me first provide you with some code…

Models:

// Login model, that contains email and password
public class Login
{
    …
}
// Registration model that contains minimum user data, e.g. name, surname
public class Register
{
    ...
}
// Model for home view which contains models for both register and login
public class Home
{
    public Login    LoginModel    { get; set; }
    public Register RegisterModel { get; set; }
}

Views:
Index.cshtml

@model App.Models.Home.Home
<!-- Login Box -->
@{ Html.RenderPartial("_LoginArea", Model.LoginModel); }
<!-- Register Box -->
@{ Html.RenderPartial("_RegisterArea", Model.RegisterModel); }

_LoginArea.cshtml

@model App.Models.Account.Login
<div style="float: left; margin-right: 100px;">
    <h1>@Localization.Account.Login</h1>
    <!-- Login form -->
    <div id="loginBox">
    @using (Html.BeginForm("Login", "Account", FormMethod.Post)) 
    {    
        <div class="editor-label">
        @Html.LabelFor(m => m.Email):
        </div>
        <div class="editor-field">
        @Html.TextBoxFor(m => m.Email)
        @Html.ValidationMessageFor(m => m.Email)
        </div>
        <div class="editor-label">
        @Html.LabelFor(m => m.Password):
        </div>
        <div class="editor-field">
        @Html.PasswordFor(m => m.Password)
        @Html.ValidationMessageFor(m => m.Password)
        </div>
        <div class="editor-label">
        @Html.CheckBoxFor(m => m.RememberMe)
        @Html.LabelFor(m => m.RememberMe)
        </div>
        <p>
            <input type="submit" value="@Localization.Account.Login" />
        </p>    
    }
    </div>
</div>

_RegisterArea.cshtml

@model App.Models.Account.Register
<div style="vertical-align: bottom;">
    <h1>@Localization.Account.Register</h1>
    <div>
    @using (Html.BeginForm("Register", "Account"))
    {
        //same things like in login
    } 
    ...

Controllers:

HomeController

//
// GET: /Home/

public ActionResult Index(Home model)
{
    //
    // If logedin redirect to profile page
    // Else show home page view
    //

    if (Request.IsAuthenticated)
    {
        return RedirectToAction("Index", "User", new { id = HttpContext.User.Identity.Name });
    }
    else
    {
        model.LoginModel = new Login();
        model.RegisterModel = new Register();
        return View(model);
    }
}

Just show you Login action from Account controller

// 
// POST: /Account/Login

[HttpPost]
public ActionResult LogIn(Login model)
{
    if (Request.IsAuthenticated)
    {
        return RedirectToAction("Index", "User", new { id = HttpContext.User.Identity.Name });
    }
    else
    {
        if (ModelState.IsValid)
        {
            if (model.ProcessLogin())
            {
                return RedirectToAction("Index", "User", new { id = HttpContext.Session["id"] });
            }
         }
     }

     //Note: this is problem part
     // If we got this far, something failed, redisplay form
     return View("~/Views/Home/Index.cshtml", model);
}

So everything works fine, BUT! When model state is not valid I have following exception

The model item passed into the dictionary is of type 'App.Models.Account.Login', but this dictionary requires a model item of type App.Models.Home.Home'.

I can bind that partial views and account actions to Home model, but this is not what I need.
I planning to use _LoginArea.cshtml view in other views (for example in a page header of ‘User’ view, and that view has another model)
So, I need action method (e.g. Login) to retrieve Login model, not Home or whatever else. But in this case I’m unable to return model to Home view.
How can I solve this issue? What is a best proper way?
Sorry for a lot of code, just want clear things.

Answer 1

SOLVED!!! Used Html.RenderAction instead.
Here is code:

Index.cshtml

<!-- Login form -->
@{ Html.RenderAction("Login", "Account"); }

<!-- Register form -->
@{ Html.RenderAction("Register", "Account"); }

Partial views are same…

Controller’s actions:

//
// GET: /Account/Login

public ActionResult Login()
{
    Login model = new Login();

    if (TempData.ContainsKey("Login"))
    {
         ModelStateDictionary externalModelState = (ModelStateDictionary)TempData["Login"];
         foreach (KeyValuePair<string, ModelState> valuePair in externalModelState)
         {
             ModelState.Add(valuePair.Key, valuePair.Value);
         }
    }

    return View("_LoginHome", model);
}

// 
// POST: /Account/Login

[HttpPost]
public ActionResult Login(Login model)
{
    if (Request.IsAuthenticated)
    {
        return RedirectToAction("Index", "User", new { id = HttpContext.User.Identity.Name });
    }
    else
    {
        if (ModelState.IsValid)
        {
            if (model.ProcessLogin())
            {
                return RedirectToAction("Index", "User", new { id = HttpContext.Session["id"] });
            }
        }                
    }

    TempData.Remove("Login");
    TempData.Add("Login", ModelState);

    // If we got this far, something failed, redisplay form
    return RedirectToAction("Index", "Home");
}

Same things for Register actions.

As u can see I’m using TempData to store model state, and then retrieve it when action is begin render.
Other question is how we can know where we should come back if model state is invalid. My solution is to parse Request.UrlReferrer, like ataddeini said.

Big thanks to my friend Danylchuk Yaroslav for him help!