Accessing AuthenticationStateProvider from DbContext or Startup.cs

Is it possible to access Blazor’s AuthenticationStateProvider from a DbContext or in Startup.Configure()?

I receive this error:

GetAuthenticationStateAsync was called before SetAuthenticationState.

@Blackleones, did you ever get this line to work in your DbContext? ref https://github.com/dotnet/aspnetcore/issues/17442#issuecomment-600222301

var userId = await _currentUserService.GetUserId();

[Bobetti]

I don’t know where to write, but I have a similar problem in Blazor Server application, so I will describe my situation.

In short -> I need to get logged in user Id from dbcontext, why ->

Inside dbcontext class I have the following method:

public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = new CancellationToken())
       {            

           foreach (var entry in ChangeTracker.Entries<AuditableEntity>())
           {
               switch (entry.State)
               {
                   case EntityState.Added:
                       entry.Entity.CreatedBy = _loggedUserService.UserId;
                       entry.Entity.Created = _dateTime.Now;
                       break;
                   case EntityState.Modified:
                       entry.Entity.LastModifiedBy = _loggedUserService.UserId;
                       entry.Entity.LastModified = _dateTime.Now;
                       break;
               }
           }
           var res = await base.SaveChangesAsync(cancellationToken);            

           return res;
       }

loggedUserService previously worked fine and looks like this ->

public class LoggedInUserService : ILoggedInUserService
   {
       public LoggedInUserService(IHttpContextAccessor httpContextAccessor)
       {
           var id = httpContextAccessor.HttpContext?.User?.FindFirstValue(ClaimTypes.NameIdentifier);
    if (!string.IsNullOrEmpty(id))
           {
               UserId = Guid.Parse(id);
           }
       }

       public Guid? UserId { get; }
   }

Now, in .Net 6 - httpContextAccessor is not working anymore.

Rewriting the loggedUserService to start using AuthenticationStateProvider doesn’t bring results because I get the exception in this case: GetAuthenticationStateAsync was called before SetAuthenticationState.

So, what should I do? Any help?

[mrlife]

The issue is kind of in the other direction. With the Audit.NET audit framework package, there is a configuration that’s set up once in Startup.cs. There’s code in that configuration that runs on the server after EF Core’s SaveChanges completes that needs to access the user in order to log who made the change. Currently, the only option is to use HttpContextAccessor, which is not recommended because it is not guaranteed to work in Blazor apps.

@mrlife Does your configured Audit.NET code always run in the context of a request? If it does, then I think using IHttpContextAccessor should be fine for this scenario. The recommendation in the Blazor docs is really about code running in the context of Blazor components. Blazor components are for client UI and are intended to be hosting model agnostic (Server/WebAssembly/Hybrid), so you shouldn’t assume they run in the context of a request. But given that this is for auditing DB access, it doesn’t sound like the Blazor restriction applies to your scenario.

Hi @danroth27,

SaveChanges is called from a .razor page, so I’m not sure if that is in the context of the one http request Blazor uses or not. The configured Audit.NET code exists at the application level on the server.

I tell that code to find the user id with the following in Program.cs (app doesn’t use Startup.cs):

app.Services.GetService<IHttpContextAccessor>()?.HttpContext?.User?.FindFirstValue("UserId");