How to inject UserManager & SignInManager

Question

I am trying to figure out how to inject UserManager and SignInManager. I have installed Ninject in my application and I am using it in the following manner:

Please consider this to be a brand new project. Inside Startup.cs I have the following:

public partial class Startup
{
    public void Configuration(IAppBuilder app)
    {
        ConfigureAuth(app);

        app.UseNinjectMiddleware(CreateKernel);
    }

    private static IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        kernel.Load(Assembly.GetExecutingAssembly());


        return kernel;
    }
}

now if I were to create some Dummy class and try to inject it based on its interface that works. I have tested it. What I am trying to figure out is how would I now strip out the following out of Startup.Auth.cs and inject it. Having no interfaces I can rely on, I am not sure how this is done:

app.CreatePerOwinContext(ApplicationDbContext.Create);
app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);

Just to clarify one more time, my question is: How do I instantiate ApplicationUserManager and ApplicationSignInManager and inject it in my controller parameters. Here is the controller that I am trying to inject this into:

public AccountController(ApplicationUserManager userManager, ApplicationSignInManager signInManager)
{
    UserManager = userManager;
    SignInManager = signInManager;
}

EDIT:

Here is what I tried:

private static IKernel CreateKernel()
{
    var kernel = new StandardKernel();
    kernel.Load(Assembly.GetExecutingAssembly());

    kernel.Bind<IUserStore<ApplicationUser>>().To<UserStore<ApplicationUser>>();
    kernel.Bind<UserManager<ApplicationUser>>().ToSelf();

    return kernel;
}

But with this I get null reference error

Answer 1

To give an exact answer to what my question stated, here is the code and instructions:

Step 1: Create custom User Store

public class ApplicationUserStore : UserStore<ApplicationUser>
{
    public ApplicationUserStore(ApplicationDbContext context)
        : base(context)
    {
    }
}

Step 2: Update ApplicationUserManager and move code from Create method into constructor

public class ApplicationUserManager : UserManager<ApplicationUser>
{
    public ApplicationUserManager(IUserStore<ApplicationUser> store, IdentityFactoryOptions<ApplicationUserManager> options)
        : base(store)
    {
        this.UserValidator = new UserValidator<ApplicationUser>(this)
        {
            AllowOnlyAlphanumericUserNames = false,
            RequireUniqueEmail = true
        };

        // Configure validation logic for passwords
        this.PasswordValidator = new PasswordValidator
        {
            RequiredLength = 6,
            RequireNonLetterOrDigit = true,
            RequireDigit = true,
            RequireLowercase = true,
            RequireUppercase = true,
        };

        // Configure user lockout defaults
        this.UserLockoutEnabledByDefault = true;
        this.DefaultAccountLockoutTimeSpan = TimeSpan.FromMinutes(5);
        this.MaxFailedAccessAttemptsBeforeLockout = 5;

        // Register two-factor authentication providers. This application uses Phone and Emails as a step of receiving a code for verifying the user
        // You can write your own provider and plug it in here.
        this.RegisterTwoFactorProvider("Phone Code", new PhoneNumberTokenProvider<ApplicationUser>
        {
            MessageFormat = "Your security code is {0}"
        });
        this.RegisterTwoFactorProvider("Email Code", new EmailTokenProvider<ApplicationUser>
        {
            Subject = "Security Code",
            BodyFormat = "Your security code is {0}"
        });
        this.EmailService = new EmailService();
        this.SmsService = new SmsService();
        var dataProtectionProvider = options.DataProtectionProvider;
        if (dataProtectionProvider != null)
        {
            this.UserTokenProvider =
                new DataProtectorTokenProvider<ApplicationUser>(dataProtectionProvider.Create("ASP.NET Identity"));
        }
    }
}

Step 3: Modify the Startup.Auth class and comment out the following code

//app.CreatePerOwinContext(ApplicationDbContext.Create);
//app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
//app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);

Step 4: Update Account Controller (or any other controller in question) and add the following constructor

public AccountController(ApplicationUserManager userManager, ApplicationSignInManager signInManager, IAuthenticationManager authManager)
{
    _userManager = userManager;
    _signInManager = signInManager;
    _authManager = authManager;
}

Step 5: Update Account Controller and make properties only retrivable as so:

public ApplicationSignInManager SignInManager
{
    get
    {
        return _signInManager;
    }
}

public ApplicationUserManager UserManager
{
    get
    {
        return _userManager;
    }
}

private IAuthenticationManager AuthenticationManager
{
    get
    {
        return _authManager;
    }
}

Step 6: Update Startup.cs

public partial class Startup
{
    private IAppBuilder _app;
    public void Configuration(IAppBuilder app)
    {
        ConfigureAuth(app);
        _app = app;
        app.UseNinjectMiddleware(CreateKernel);
    }

    private IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        kernel.Load(Assembly.GetExecutingAssembly());

        kernel.Bind<ApplicationDbContext>().ToSelf().InRequestScope();
        kernel.Bind<IUserStore<ApplicationUser>>().To<ApplicationUserStore>();
        kernel.Bind<ApplicationUserManager>().ToSelf();
        kernel.Bind<ApplicationSignInManager>().ToSelf();
        kernel.Bind<IAuthenticationManager>().ToMethod(x => HttpContext.Current.GetOwinContext().Authentication);
        kernel.Bind<IDataProtectionProvider>().ToMethod(x => _app.GetDataProtectionProvider());

        return kernel;
    }
}

To further expand the answer to this question, based on the comments I have received:

These managers should not be injected as classes as then you are not accomplishing DI. What should be done instead is create multiple interfaces that further separate and group methods of UserManager according to your needs. Here is an example:

public interface IUserManagerSegment
{
    Task<IdentityResult> CreateAsync(ApplicationUser user, string password);
    Task<IdentityResult> CreateAsync(ApplicationUser user);
    Task<IdentityResult> ConfirmEmailAsync(string userId, string token);
    Task<ApplicationUser> FindByNameAsync(string userName);
    Task<bool> IsEmailConfirmedAsync(string userId);
    Task<IdentityResult> ResetPasswordAsync(string userId, string token, string newPassword);
    Task<IList<string>> GetValidTwoFactorProvidersAsync(string userId);
    Task<IdentityResult> AddLoginAsync(string userId, UserLoginInfo login);
    void Dispose(bool disposing);
    void Dispose();
}

The above method has a list of few random methods I chose just to illustrate the point. With this said, we would now inject the method based on the interface such as this:

kernel.Bind<IUserManagerSegment>().To<ApplicationUserManager>();

And now our AccountController constructor would look like this:

public AccountController(IUserManagerSegment userManager, ApplicationSignInManager signInManager, IAuthenticationManager authManager)  
{
    _userManager = userManager;
    _signInManager = signInManager;
    _authManager = authManager;
}

Same thing should be done to SignInManager and AuthenticationManager.

The code above has been tested and is working. Just ensure you have referenced the following DLLs:

Ninject.dll
Ninject.Web.Common
Ninject.Web.Common.OwinHost
Ninject.Web.Mvc