.NET Core 3 Service result to Controller to FE (data or error reason) - asp.net-core

Question

building new app on .net core 3 and Angular. Overall all works, but I want to add more intelligence to service/controller part. This is one of the api's, but this logic can be applied to others as as well.
Here's my Login Controller:
[HttpPost]
public async Task<IActionResult> Login([FromBody] UserLoginDto userLogin)
{
var token = await _userService.LoginAsync(userLogin);
if (token != null)
{
return Ok(token);
}
else
{
return BadRequest("Something went wrong");
}
}
And here's my userService:
public async Task<string> LoginAsync(UserLoginDto userLogin)
{
var user = await _userManager.FindByEmailAsync(userLogin.Email);
if (user != null)
{
var result = await _signInManager.PasswordSignInAsync(user, userLogin.Password, false, true);
if (result.Succeeded)
{
var roles = await _userManager.GetRolesAsync(user);
var tokenJson = _jwtManager.getJwtToken(user.Email, roles);
return tokenJson;
}
else
{
return null; // Return BadRequest and result reason (Failed, lockedout, etc)
}
}
else
{
return null; // User not found, return NotFound }
}
Here's my question - how should I return result from userService to Controller so, that I could respond to API call either with Ok(token) or BadRequest/NotFound with the reason.
If I keep all this LoginAsync code in controller, then it's easy, but I want to use service.
One option I was thinking was to introduce new class, something like:
public class BaseResult
{
public object Data { get; set; }
public long ResponseCode { get; set; }
public string ErrorMessage { get; set; }
}
then always return this class from service, but not fully like that idea either.
thanks!

Answer 1

Here is a working demo you could follow:
Model:
public class UserLoginDto
{
public string Email { get; set; }
public string Password { get; set; }
}
IUserService:
public interface IUserService
{
Task<IActionResult> LoginAsync(UserLoginDto userLogin);
}
UserService:
public class UserService: IUserService
{
private readonly UserManager<IdentityUser> _userManager;
private readonly SignInManager<IdentityUser> _signInManager;
private readonly IJwtManager _jwtManager;
public UserService(
UserManager<IdentityUser> userManager,
SignInManager<IdentityUser> signInManager,
IJwtManager jwtManager)
{
_userManager = userManager;
_signInManager = signInManager;
_jwtManager = jwtManager;
}
public async Task<IActionResult> LoginAsync(UserLoginDto userLogin)
{
var user = await _userManager.FindByEmailAsync(userLogin.Email);
if (user != null)
{
var result = await _signInManager.PasswordSignInAsync(user, userLogin.Password, false, true);
if (result.Succeeded)
{
var roles = await _userManager.GetRolesAsync(user);
var tokenJson = _jwtManager.getJwtToken(user.Email, roles);
return new OkObjectResult(tokenJson);
}
else
{
// Return BadRequest and result reason (Failed, lockedout, etc)
if (result.IsNotAllowed)
{
if (!await _userManager.IsEmailConfirmedAsync(user))
{
// Email isn't confirmed.
return new BadRequestObjectResult("Email isn't confirmed.");
}
if (!await _userManager.IsPhoneNumberConfirmedAsync(user))
{
// Phone Number isn't confirmed.
return new BadRequestObjectResult("Phone Number isn't confirmed.");
}
return new BadRequestObjectResult("Login IsNotAllowed");
}
else if (result.IsLockedOut)
{
// Account is locked out.
return new BadRequestObjectResult("Account is locked out.");
}
else if (result.RequiresTwoFactor)
{
// 2FA required.
return new BadRequestObjectResult("2FA required");
}
else
{
// Password is incorrect.
return new BadRequestObjectResult("Password is incorrect.");
}
}
}
else
{
return new NotFoundObjectResult("Username is incorrect"); // User not found, return NotFound }
}
}
}
Controller:
public class HomeController : Controller
{
private readonly IUserService _userService;
public HomeController(IUserService userService)
{
_userService = userService;
}
[HttpPost]
public async Task<IActionResult> Login([FromBody] UserLoginDto userLogin)
{
var result= await _userService.LoginAsync(userLogin);
return result;
}
}
Startup.cs:
Not sure what is _jwtManager.getJwtToken in your code,so I just guess it is an interface and owns a JwtManager class implemented this interface.And it contains a getJwtToken method which generated the token.
services.AddScoped<IUserService, UserService>();
services.AddScoped<IJwtManager, JwtManager>();