Added Authorization

Lieb/Shared/MainLayout.razor

@@ -1,4 +1,7 @@
-@inherits LayoutComponentBase
+@using System.Security.Claims
+@using Microsoft.AspNetCore.Components.Authorization
+@inject AuthenticationStateProvider AuthenticationStateProvider
+@inherits LayoutComponentBase
 
 <PageTitle>Lieb</PageTitle>
 
@@ -20,9 +23,54 @@
             </NotAuthorized>
         </AuthorizeView>
         </div>
+        <AuthorizeView>
+            <p>You can only see this if you are loged in</p>
+        </AuthorizeView>
+        <AuthorizeView Policy="Admin">
+            <p>You can only see this if you satisfy the "Admin" policy.</p>
+        </AuthorizeView>
+
 
         <article class="content px-4">
             @Body
         </article>
+        <button @onclick="GetClaimsPrincipalData">Get ClaimsPrincipal Data</button>
     </main>
 </div>
+<p>@_authMessage</p>
+
+@if (_claims.Count() > 0)
+{
+    <ul>
+        @foreach (var claim in _claims)
+        {
+            <li>@claim.Type: @claim.Value</li>
+        }
+    </ul>
+}
+
+<p>@_surnameMessage</p>
+
+@code {
+    private string _authMessage;
+    private string _surnameMessage;
+    private IEnumerable<Claim> _claims = Enumerable.Empty<Claim>();
+
+    private async Task GetClaimsPrincipalData()
+    {
+        var authState = await AuthenticationStateProvider.GetAuthenticationStateAsync();
+        var user = authState.User;
+
+        if (user.Identity.IsAuthenticated)
+        {
+            _authMessage = $"{user.Identity.Name} is authenticated.";
+            _claims = user.Claims;
+            _surnameMessage = 
+                $"Surname: {user.FindFirst(c => c.Type == ClaimTypes.Surname)?.Value}";
+        }
+        else
+        {
+            _authMessage = "The user is NOT authenticated.";
+        }
+    }
+}