InvalidOperationException: Incorrect Content-Type: ASP.NET Core

Question

I have two forms, one for logging in and one for registering. These are both on the same view and using the same model. I'm handling the form submissions with a controller.

I'm getting the following error when visiting the login page

InvalidOperationException: Incorrect Content-Type:

Full error log: https://pastebin.com/JjfDtr6q

I've looked online and cannot find anything related directly to my problem and am not experienced enough in C#/.NET Core to understand what is causing the problem.

My View

@model PastPapers.Models.LoginModel

@{
    Layout = null;
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Login</title>
</head>

<body>
    <!-- Register form inside modal -->
    <div id="registerModal" class="">
        <div class="">
            <header class="">
                <span onclick="document.getElementById('registerModal').style.display = 'none'" class="">&times;</span>
                <h2>Register</h2>
            </header>
            <div class="">
                <form asp-controller="Login" asp-action="AttemptRegister" method="post">
                    <input asp-for="newUsername" type="text" placeholder="Username" />
                    <input asp-for="newEmail" type="email" placeholder="Email" />
                    <input asp-for="newPassword" type="password" placeholder="Password" />
                    <input type="submit" value="Register" />
                </form>
            </div>
        </div>
    </div>

    <!-- Login form -->
    <form asp-controller="Login" asp-action="AttemptLogin" method="post">
        <input asp-for="username" type="text" placeholder="Username" />
        <input asp-for="password" type="password" placeholder="Password" />
        <input type="submit" value="Login" />
    </form>

    <button onclick="document.getElementById('registerModal').style.display='block'" class="">Register</button>
</body>
</html>

My Controller

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using PastPapers.Models;

namespace PastPapers.Controllers
{
    public class LoginController : Controller
    {
        public IActionResult Index(LoginModel loginModel = null)
        {
            if (loginModel == null)
            {
                return View();
            } else
            {
                return View(loginModel);
            }            
        }

        [HttpPost]
        public IActionResult AttemptLogin(LoginModel loginModel = null)
        {
            if (loginModel != null)
            {
                loginModel.AttemptLogin();

                if (loginModel.loginSuccess)
                {
                    return RedirectToAction("Index", "Home", null);
                } else
                {
                    return RedirectToAction("Index", loginModel);
                }

            } else
            {
                return RedirectToAction("Index");
            }
        }


        [HttpPost]
        public IActionResult AttemptRegister(LoginModel loginModel = null)
        {
            if (loginModel != null)
            {
                loginModel.AttemptRegister();

                if (loginModel.registerSuccess)
                {
                    return RedirectToAction("Index");
                } else
                {
                    return RedirectToAction("Index", loginModel);
                }
            } else
            {
                return RedirectToAction("Index");
            }
        }
    }
}

My model

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;
using Newtonsoft.Json;
using PastPapers.Helpers;
using Microsoft.AspNetCore.Http;

namespace PastPapers.Models
{
    public class LoginModel : HttpContextAccessor
    {
        public string username { get; set; }
        public string password { get; set; }
        public bool loginSuccess { get; set; }
        public string loginErrorMessage { get; set; }

        public string newUsername { get; set; }
        public string newPassword { get; set; }
        public string newEmail { get; set; }
        public bool registerSuccess { get; set; }
        public string registerErrorMessage { get; set; }

        [JsonIgnore]
        public AppDb Db { get; set; }

        public LoginModel(AppDb db = null)
        {
            Db = db;
            loginSuccess = false;
            registerSuccess = false;
        }

        public LoginModel()
        {

        }

        public void AttemptRegister()
        {
            try
            {
                Db.Connection.Open();

                string sql = "INSERT INTO users (id, username, password, email) VALUES (DEFAULT, @username, @password, @email)";
                MySqlCommand cmd = new MySqlCommand(sql, Db.Connection);
                cmd.Prepare();
                cmd.Parameters.AddWithValue("@username", newUsername);
                cmd.Parameters.AddWithValue("@password", SecurePasswordHasher.Hash(newPassword));
                cmd.Parameters.AddWithValue("@email", newEmail);

                if (cmd.ExecuteNonQuery() == 0)
                {
                    System.Diagnostics.Debug.WriteLine("Account failed to create!");
                    registerSuccess = false;
                } else
                {
                    registerSuccess = true;
                }

            } catch (Exception ex)
            {
                registerErrorMessage = "Error connecting to database";
                System.Diagnostics.Debug.WriteLine(ex.Message);
            }
        }

        public void AttemptLogin()
        {
            try
            {
                Db.Connection.Open();

                string sql = "SELECT password FROM users WHERE username=@username";
                MySqlCommand cmd = new MySqlCommand(sql, Db.Connection);
                cmd.Prepare();
                cmd.Parameters.AddWithValue("@username", username);
                MySqlDataReader reader = cmd.ExecuteReader();

                if (reader.Read())
                {
                    string dbPassword = reader.GetString(0);

                    if (SecurePasswordHasher.Verify(password, dbPassword))
                    {
                        loginSuccess = true;
                        HttpContext.Session.SetString("username", username);

                    } else
                    {
                        loginSuccess = false;
                        loginErrorMessage = "Incorrect password";
                    }
                } else
                {
                    loginErrorMessage = "Unknown username";
                }

            } catch (Exception ex)
            {
                loginErrorMessage = "Error connecting to database";
                System.Diagnostics.Debug.WriteLine(ex.Message);
            }

        }
    }
}

Why is your LoginModel inheriting from HttpContextAccessor? I see where you use it, but it’s almost certainly going to be the cause of your issues. — Kirk Larkin
– Kirk Larkin, Commented Feb 7, 2018 at 19:53
So that I can access the HTTP variable to set username etc. What is the correct way of accessing the session variables in a model? — Theo Crowley
– Theo Crowley, Commented Feb 7, 2018 at 19:55

Balah · Accepted Answer · 2018-02-07 21:22:27Z

5

I'd forego the whole inheritance of HttpContextAccessor (or rather IHttpContextAccessor) as you will be losing out on the functionality provided by the concrete HttpContextAccessor. Instead, inject HttpContextAccessor into the controller, and then use the result of the manipulation on the Login model to then set the session values. Like this:

In your Startup.ConfigureServices add this line:

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

This enables the HttpContext to be injected into controller.

Then in your controller, add a constructor that accepts IHttpContextAccessor:

public LoginController(IHttpContextAccessor contextAccessor)
{
    // save to a field, like _httpContext = contextAccessor.HttpContext;
}

Then pass that HttpContext into LoginModel.AttemptLogin as a parameter. That way you still get to fulfill your requirement to access the HTTP variable, and the code is more maintainable and predictable.

There is one caveat - there is a small performance hit by adding the HttpContextAccessor to the services. But overall its better.

answered Feb 7, 2018 at 21:22

Balah

2,5402 gold badges19 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

anisite Over a year ago

According to MS documentation, NEVER save HttpContext into a field, ONLY accessor itself. learn.microsoft.com/en-us/aspnet/core/performance/…

Theo Crowley · Accepted Answer · 2018-02-07 20:06:06Z

Replaced inheritance of HttpContextAccessor with IHttpContextAccessor and added a public HttpContext attribute. New model below.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;
using Newtonsoft.Json;
using PastPapers.Helpers;
using Microsoft.AspNetCore.Http;

namespace PastPapers.Models
{
    public class LoginModel : IHttpContextAccessor
    {
        public string username { get; set; }
        public string password { get; set; }
        public bool loginSuccess { get; set; }
        public string loginErrorMessage { get; set; }

        public string newUsername { get; set; }
        public string newPassword { get; set; }
        public string newEmail { get; set; }
        public bool registerSuccess { get; set; }
        public string registerErrorMessage { get; set; }

        [JsonIgnore]
        public AppDb Db { get; set; }
        public HttpContext HttpContext { get; set; }

        public LoginModel(AppDb db = null)
        {
            Db = db;
            loginSuccess = false;
            registerSuccess = false;
        }

        public LoginModel()
        {

        }

        public void AttemptRegister()
        {
            try
            {
                Db.Connection.Open();

                string sql = "INSERT INTO users (id, username, password, email) VALUES (DEFAULT, @username, @password, @email)";
                MySqlCommand cmd = new MySqlCommand(sql, Db.Connection);
                cmd.Prepare();
                cmd.Parameters.AddWithValue("@username", newUsername);
                cmd.Parameters.AddWithValue("@password", SecurePasswordHasher.Hash(newPassword));
                cmd.Parameters.AddWithValue("@email", newEmail);

                if (cmd.ExecuteNonQuery() == 0)
                {
                    System.Diagnostics.Debug.WriteLine("Account failed to create!");
                    registerSuccess = false;
                } else
                {
                    registerSuccess = true;
                }

            } catch (Exception ex)
            {
                registerErrorMessage = "Error connecting to database";
                System.Diagnostics.Debug.WriteLine(ex.Message);
            }
        }

        public void AttemptLogin()
        {
            try
            {
                Db.Connection.Open();

                string sql = "SELECT password FROM users WHERE username=@username";
                MySqlCommand cmd = new MySqlCommand(sql, Db.Connection);
                cmd.Prepare();
                cmd.Parameters.AddWithValue("@username", username);
                MySqlDataReader reader = cmd.ExecuteReader();

                if (reader.Read())
                {
                    string dbPassword = reader.GetString(0);

                    if (SecurePasswordHasher.Verify(password, dbPassword))
                    {
                        loginSuccess = true;
                        HttpContext.Session.SetString("username", username);

                    } else
                    {
                        loginSuccess = false;
                        loginErrorMessage = "Incorrect password";
                    }
                } else
                {
                    loginErrorMessage = "Unknown username";
                }

            } catch (Exception ex)
            {
                loginErrorMessage = "Error connecting to database";
                System.Diagnostics.Debug.WriteLine(ex.Message);
            }

        }
    }
}

Collectives™ on Stack Overflow

InvalidOperationException: Incorrect Content-Type: ASP.NET Core

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related