Implementing User Registration in ASP.NET Core with Identity

In this post, we will explore how to implement user registration in an ASP.NET Core application using Identity. The provided code snippet demonstrates a controller that handles user registration, including role assignment.

Code Explanation

The AuthController class is responsible for managing authentication-related actions. Here's a breakdown of the key components:

1. Dependencies: The controller depends on UserManager<ApplicationUser>, RoleManager<IdentityRole>, and a secret key from the configuration.

2. Constructor: The constructor initializes these dependencies.

3. Register Endpoint: The Register method handles user registration. It performs the following steps:

   • Checks if the username already exists.

   • Creates a new user if the username is available.

   • Assigns roles to the user based on the provided role in the registration request.

Code

namespace RedMango_API.Controllers
{
    [Route("api/auth")]
    [ApiController]
    public class AuthController : ControllerBase
    {
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly RoleManager<IdentityRole> _roleManager;
        private readonly string _secretKey;

        public AuthController(IConfiguration configuration,
            UserManager<ApplicationUser> userManager, RoleManager<IdentityRole> roleManager)
        {
            _secretKey = configuration.GetValue<string>("ApiSettings:Secret");
            _userManager = userManager;
            _roleManager = roleManager;
        }

        [HttpPost("register")]
        public async Task<IActionResult> Register([FromBody] RegisterRequestDTO model)
        {
            var userFromDb = await _userManager.FindByNameAsync(model.UserName.ToLower());

            if (userFromDb != null)
            {
                return BadRequest(new { StatusCode = HttpStatusCode.BadRequest, IsSuccess = false, ErrorMessages = new[] { "Username already exists" } });
            }

            var newUser = new ApplicationUser
            {
                UserName = model.UserName,
                Email = model.UserName,
                NormalizedEmail = model.UserName.ToUpper(),
                Name = model.Name
            };

            var result = await _userManager.CreateAsync(newUser, model.Password);
            if (result.Succeeded)
            {
                if (!await _roleManager.RoleExistsAsync(SD.Role_Admin))
                {
                    await _roleManager.CreateAsync(new IdentityRole(SD.Role_Admin));
                    await _roleManager.CreateAsync(new IdentityRole(SD.Role_Customer));
                }
                if (model.Role.ToLower() == SD.Role_Admin)
                {
                    await _userManager.AddToRoleAsync(newUser, SD.Role_Admin);
                }
                else
                {
                    await _userManager.AddToRoleAsync(newUser, SD.Role_Customer);
                }

                return Ok(new { StatusCode = HttpStatusCode.OK, IsSuccess = true });
            }

            return BadRequest(new { StatusCode = HttpStatusCode.BadRequest, IsSuccess = false, ErrorMessages = new[] { "Error while registering" } });
        }
    }
}

Hashtags

#ASPNetCore #Identity #UserRegistration #WebDevelopment #DotNet

Explanation

The AuthController class is designed to handle user registration in an ASP.NET Core application. It uses ASP.NET Core Identity to manage user information and roles. The Register method checks if a user already exists, creates a new user if not, and assigns the appropriate role based on the registration request. This setup ensures that user management is handled securely and efficiently within the application.