Identity 2.0 User Identity is null in MVC 5 controller initializer

Question

I have an MVC 5 project using Asp.Net Identity 2.0. I am also using a generic repository pattern. As part of the database schema I have fields for various tables which store the user id of the inserting/updating/deleting user. Therefore I would like to pass the user object, or user id at least to the generic repository to be used when modifying records.

However, as i was unable to access the identity directly in the repository class I am attempting to pass it on repository instantiation. It looks like this:

using System.Data.Entity;
using System.Threading.Tasks;
using System.Net;
using System.Web.Mvc;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;
using My.Models;

namespace My.Controllers
{
    [Authorize]
    public class FooController : MasterController
    {
        private IGenericRepositoryAsync<Topic> _repository;

        public FooController()
        {
            //Point A
            _repository = new GenericRepositoryAsync<Foo>(User.Identity);
        }


        public async Foo<ActionResult> Index()
        {
            //POINT B
            //_repository = new GenericRepositoryAsync<Foo>(User.Identity);
            return View(await _repository.GetAllAsync());
        }
    }
}

As an authorized user at "Point A" User.Identity is null, at //Point B it is not null but I don't want to have to put the repository initializer in every controller Action.

Your help and feedback is appreciated.

Answer 1

Web Api solution

You may create your on Authorize filter class and then add the userId into Request properties collection:

public class MyAuthorizeAttribute : AuthorizeAttribute 
{
    public override async Task OnAuthorizationAsync(HttpActionContext actionContext, CancellationToken cancellationToken)
    {
        if (actionContext.ActionDescriptor.GetCustomAttributes<AllowAnonymousAttribute>().Any()) return;

        base.OnAuthorization(actionContext);

        Guid userId;

        if (actionContext.RequestContext.Principal.Identity.IsAuthenticated
            && Guid.TryParse(actionContext.RequestContext.Principal.Identity.GetUserId(), out userId))
        {
            actionContext.Request.Properties.Add("userId", actionContext.RequestContext.Principal.Identity.GetUserId());
        }
    }
}

Once the class exists, you have to add this filter on Application Startup class (Global.asax web_start, Startup.cs) like this:

config.Filters.Add(new MyAuthorizeAttribute());

For Owin Startup.cs will be something like this:

public void Configuration(IAppBuilder app)
{
    ConfigureOAuth(app);

    HttpConfiguration config = new HttpConfiguration();
    WebApiConfig.Register(config);
    config.Filters.Add(new MyAuthorizeAttribute());
}

Then, in your controller you will be able to get the userId jus doing:

Guid userId = (Guid) ActionContext.Request.Properties["userId"];

MVC Solution

For MVC use directly on Controller:

using Microsoft.AspNet.Identity;

...

User.Identity.GetUserId();

Or add a filter as in Web Api solution:

public override void OnAuthorization(AuthorizationContext filterContext)
{
    ...
    Guid userId = filterContext.HttpContext.User.Identity.Name.GetUserId();
    ...
}