fixed startup crash issues

src/DrawTogether.Actors/Local/LocalDrawingSessionActor.cs

@@ -82,10 +82,10 @@ public GetLocalActorHandle(DrawingSessionId drawingSessionId)
     private readonly IMaterializer _materializer = Context.System.Materializer();
     private IActorRef _debouncer = ActorRefs.Nobody;
 
-    public LocalDrawingSessionActor(DrawingSessionId drawingSessionId,
+    public LocalDrawingSessionActor(string drawingSessionId,
         IRequiredActor<DrawingSessionActor> drawingSessionActor)
     {
-        _drawingSessionId = drawingSessionId;
+        _drawingSessionId = new DrawingSessionId(drawingSessionId);
         _drawingSessionActor = drawingSessionActor.ActorRef;
     }
 

src/DrawTogether/Components/Layout/NavMenu.razor

@@ -26,6 +26,16 @@
 
         <AuthorizeView>
             <Authorized>
+                <div class="nav-item px-3">
+                    <button class="nav-link" @onclick="Handler">
+                        <span class="bi bi-pencil-fill-nav-menu" aria-hidden="true"></span> New Drawing
+                    </button>>
+                </div>
+                <div class="nav-item px-3">
+                    <NavLink class="nav-link" href="Account/Manage">
+                        <span class="bi bi-person-fill-nav-menu" aria-hidden="true"></span> @context.User.Identity?.Name
+                    </NavLink>
+                </div>
                 <div class="nav-item px-3">
                     <NavLink class="nav-link" href="Account/Manage">
                         <span class="bi bi-person-fill-nav-menu" aria-hidden="true"></span> @context.User.Identity?.Name
@@ -60,6 +70,8 @@
 @code {
     private string? _currentUrl;
 
+    protected string GetNewGuid() => Guid.NewGuid().ToString();
+
     protected override void OnInitialized()
     {
         _currentUrl = NavigationManager.ToBaseRelativePath(NavigationManager.Uri);
@@ -77,4 +89,10 @@
         NavigationManager.LocationChanged -= OnLocationChanged;
     }
 
+    private void Handler()
+    {
+        var newGuid = GetNewGuid();
+        NavigationManager.NavigateTo($"paint/{newGuid}");
+    }
+
 }

src/DrawTogether/Components/Pages/Home.razor

@@ -31,20 +31,21 @@ else
         <tbody>
         @foreach (var session in _drawingActivities)
         {
+            var hrefUri = $"paint/{session.Key!.SessionId}";
             <tr>
-                <td>@session.Key.SessionId</td>
+                <td>@session.Key!.SessionId</td>
                 <td>@session.Value.ActiveUsers</td>
                 <td>@session.Value.LastUpdate</td>
-                <td>Join Button</td>
+                <td><MudLink Href="@hrefUri">Join Session!</MudLink></td>
             </tr>
         }
         </tbody>
     </table>
 }
 
 @code{
-    private Dictionary<DrawingSessionId, DrawingActivityUpdate> _drawingActivities = new();
-    private CancellationTokenSource _shutdownCts = new();
+    private readonly Dictionary<DrawingSessionId, DrawingActivityUpdate> _drawingActivities = new();
+    private readonly CancellationTokenSource _shutdownCts = new();
 
     protected override async Task OnInitializedAsync()
     {

src/DrawTogether/Components/Pages/Paint.razor

@@ -60,20 +60,15 @@
 
     public DateTime LastUpdate { get; set; } = DateTime.UtcNow;
 
-    DrawingSessionId DrawingSessionId { get; set; }
+    DrawingSessionId? DrawingSessionId { get; set; }
 
     private ChannelReader<IDrawingSessionEvent>? _eventStream = null;
 
-    private IActorRef _localActorHandle;
+    private IActorRef? _localActorHandle;
     private readonly CancellationTokenSource _shutdownCts = new();
 
     private ClaimsPrincipal? _user;
-    private UserId _currentUserId;
-
-    private record StartupTasks(Task<IActorRef> LocalHandleTask, Task<DrawingSessionState> CurrentSnapshotTask, Task<LocalDrawingSessionActor.DrawingChannelResponse> EventStreamTask)
-    {
-        Task WhenAll => Task.WhenAll(LocalHandleTask, CurrentSnapshotTask, EventStreamTask);
-    }
+    private UserId? _currentUserId;
 
     protected override async Task OnInitializedAsync()
     {
@@ -162,7 +157,7 @@
     double cY = 110.0d;
     private Color _color = new("black");
     private GreaterThanZeroInteger _cursorSize = new(8);
-    
+
     private string mousePointerMessage = "foo";
     private string blazorHubDebugMessage = "bar";
 
@@ -239,7 +234,7 @@
     public async ValueTask DisposeAsync()
     {
         await _shutdownCts.CancelAsync();
-        _localActorHandle.Tell(new LocalPaintProtocol.LeavePaintSession(DrawingSessionId, _currentUserId));
+        if (DrawingSessionId != null && _currentUserId is not null) _localActorHandle.Tell(new LocalPaintProtocol.LeavePaintSession(DrawingSessionId, _currentUserId));
         _shutdownCts.Dispose();
     }