There are a bunch of different answers floating around here for the different RC's of ASP.NET Core on how to get the ID of the currently logged in user. I wanted to ask the definite question here. Please note that project.json now has "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0"
With RC1, you could do something like this:
using Microsoft.AspNet.Identity;
using System.Security.Claims;
User.GetUserId();
But with the newly released version 1 of EF Core, Microsoft.AspNet.Identity is not the right version.
There was suggestions to use UserManager, which seems like a lot just to get the currently logged in user:
private Task<ApplicationUser> GetCurrentUserAsync() => _userManager.GetUserAsync(HttpContext.User);
var user = await GetCurrentUserAsync();
var userId = user?.Id;
Another method that I found was:
private readonly UserManager<ApplicationUser> _userManager;
_userManager.GetUserId(User)
So with ASP.NET Core 1 RTM and EF Core 1 with the following libraries in project.json, what is the proper way to get the id of the currently logged in user?
"Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0",
"Microsoft.AspNetCore.Mvc": "1.0.0",
ASP.NET Core Identity is injected via DI in the startup.cs - as such you just have to inject UserManager via a constructor
UserManager<ApplicationUser> userManager
You can then use the following in methods
_userManager.GetUserId(User);
That's the way its used in the Sample Web Application when you create a new ASP.NET Core 1 project with Individual User Account.
If you are accessing this from withing the Controller, then using UserManager to get the user ID is pretty inefficient as you are making a round trip to the database. If you are using ClaimsIdentity, you can do something like this to get the user id:
var claimsIdentity = (ClaimsIdentity)this.User.Identity;
var claim = claimsIdentity.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier);
var userId = claim.Value;
This method just reads the user ID which is already present in the cookie, which in turn is automatically deserialized and stored in a ClaimsIdentity instance.
I use this helper class:
public static class UserHelpers
{
public static string GetUserId(this IPrincipal principal)
{
var claimsIdentity = (ClaimsIdentity)principal.Identity;
var claim = claimsIdentity.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier);
return claim.Value;
}
}
So getting a user ID becomes:
var userId = this.User.GetUserId();
If, for some reason, the required claim is not present in the Claims colleciton, you can easily add it when creating the user's ClaimsIdentity:
public class ApplicaionUser : IdentityUser
{
public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<User> manager)
{
var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
userIdentity.AddClaim(new Claim(ClaimTypes.NameIdentifier, this.UserId));
return userIdentity;
}
}