Get all roles in asp.net core identity using a separate class

Question

I've been trying to get a list of all the roles out of asp.net core identity, This is how I've done t before using a controller:

public AdminController(
        UserManager<ApplicationUser> userManager,
        ILogger<AccountController> logger,
        IEmailSender emailSender,
        RoleManager<IdentityRole> roleManager,
        SignInManager<ApplicationUser> signInManager)
    {
        _userManager = userManager;
        _logger = logger;
        _emailSender = emailSender;
        _roleManager = roleManager;
        _signInManager = signInManager;
    }

private void PuplateRolesList(RegisterViewModel model)
    {
        model.Roles = _roleManager.Roles?.ToList();
    }

What I'm trying to do is have a class I can re-use that will pass back a list of all the roles and not use controller I tries this:

var roleStore = new RoleStore<AppRole, int, AppUserRole>(dbContext);
var roleMngr = new RoleManager<AppRole, int>(roleStore);

But in a class it obviously doesn't construct the role manager or dbContect, so i tried it myself but it doesn't work. Any ideas how I can have a class in my app deliver a list or roles so I don't have it all in my controller?

Thanks

Answer 1

Create a class:

public class RoleUtility 
{
    private readonly RoleManager<IdentityRole> _roleManager;

    public RoleUtility(RoleManager<IdentityRole> roleManager)
    {
        _roleManager = roleManager;
    }

    public void PopulateRolesList(RegisterViewModel model)
    {
        model.Roles = _roleManager.Roles?.ToList();
    }
}

Extract the interface:

public interface IRoleUtility
{
    void PopulateRolesList(RegisterViewModel model);
}

The RoleUtility class declaration become:

public class RoleUtility: IRoleUtility

Then, in your Startup class :

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddTransient<IRoleUtility, RoleUtility>();
}

Your controller code become:

public AdminController(
        UserManager<ApplicationUser> userManager,
        ILogger<AccountController> logger,
        IEmailSender emailSender,
        IRoleUtility roleUtility,
        SignInManager<ApplicationUser> signInManager)
    {
        _userManager = userManager;
        _logger = logger;
        _emailSender = emailSender;
        _roleUtility = roleUtility;
        _signInManager = signInManager;
    }

private void PuplateRolesList(RegisterViewModel model)
    {
        _roleUtility.PopulateRolesList(model);
    }