BlogAuthenticationStateProvider.cs

using Blogifier.Shared;
using Microsoft.AspNetCore.Components.Authorization;
using System.Net.Http;
using System.Net.Http.Json;
using System.Security.Claims;
using System.Threading.Tasks;
using System;

namespace Blogifier.Admin
{
    public class BlogAuthenticationStateProvider : AuthenticationStateProvider
    {
        private readonly HttpClient _httpClient;

        public BlogAuthenticationStateProvider(HttpClient httpClient)
        {
            _httpClient = httpClient;
        }

        public override async Task<AuthenticationState> GetAuthenticationStateAsync()
        {
            Author author = await _httpClient.GetFromJsonAsync<Author>("api/author/getcurrent");
            if (author != null && author.Email != null && author.IsAdmin)
            {
                var claim = new Claim(ClaimTypes.Name, author.Email);
                var claimsIdentity = new ClaimsIdentity(new[] { claim }, "serverAuth");
                var claimsPrincipal = new ClaimsPrincipal(claimsIdentity);

                return new AuthenticationState(claimsPrincipal);
            }
            else
                return new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity()));
        }
    }
}