-

src/Apollinare.API/Hubs/CollaborationHub.cs

@@ -309,6 +309,30 @@ public class CollaborationHub : Hub
         Console.WriteLine($"[Collaboration] DataSaved sent to others in room {roomKey}");
     }
 
+    /// <summary>
+    /// Sincronizza l'intero template con tutti gli altri collaboratori nella room
+    /// Usato per sync efficienti - invia il template completo invece di richiedere reload dal server
+    /// Supporta compressione opzionale per template grandi
+    /// </summary>
+    public async Task BroadcastTemplateSync(string roomKey, string templateJson, int version, bool compressed = false)
+    {
+        var senderId = Context.ConnectionId;
+        Console.WriteLine($"[Collaboration] BroadcastTemplateSync from {senderId} for room {roomKey}, version {version}, size: {templateJson.Length} bytes, compressed: {compressed}");
+
+        UpdateUserActivity(senderId);
+
+        await Clients.OthersInGroup(roomKey).SendAsync("TemplateSync", new TemplateSyncMessage
+        {
+            TemplateJson = templateJson,
+            SenderConnectionId = senderId,
+            Version = version,
+            Compressed = compressed,
+            Timestamp = DateTime.UtcNow
+        });
+
+        Console.WriteLine($"[Collaboration] TemplateSync broadcast complete for room {roomKey}");
+    }
+
     #endregion
 
     #region Lifecycle
@@ -517,6 +541,19 @@ public class DataSavedMessage
     public DateTime Timestamp { get; set; }
 }
 
+/// <summary>
+/// Message for efficient template sync - sends full template JSON (compressed optional)
+/// Used for initial sync and full resync requests
+/// </summary>
+public class TemplateSyncMessage
+{
+    public string TemplateJson { get; set; } = string.Empty;
+    public string SenderConnectionId { get; set; } = string.Empty;
+    public int Version { get; set; } // Incrementing version number for conflict detection
+    public bool Compressed { get; set; } // Whether TemplateJson is base64-encoded gzip
+    public DateTime Timestamp { get; set; }
+}
+
 public class UserLeftMessage
 {
     public string ConnectionId { get; set; } = string.Empty;

src/Apollinare.API/Hubs/DataHub.cs

@@ -12,19 +12,50 @@ public class DataHub : Hub
     /// </summary>
     public async Task NotifyDataChanged(string entityType, string action, object? data = null)
     {
-        await Clients.Others.SendAsync("DataChanged", entityType, action, data);
+        try
+        {
+            await Clients.Others.SendAsync("DataChanged", entityType, action, data);
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[DataHub] Error in NotifyDataChanged: {ex.Message}");
+        }
     }
 
     public override async Task OnConnectedAsync()
     {
-        await base.OnConnectedAsync();
-        Console.WriteLine($"Client connected: {Context.ConnectionId}");
+        try
+        {
+            Console.WriteLine($"[DataHub] Client connecting: {Context.ConnectionId}");
+            await base.OnConnectedAsync();
+            Console.WriteLine($"[DataHub] Client connected: {Context.ConnectionId}");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[DataHub] Error in OnConnectedAsync: {ex.Message}");
+            throw;
+        }
     }
 
     public override async Task OnDisconnectedAsync(Exception? exception)
     {
-        await base.OnDisconnectedAsync(exception);
-        Console.WriteLine($"Client disconnected: {Context.ConnectionId}");
+        try
+        {
+            if (exception != null)
+            {
+                Console.WriteLine($"[DataHub] Client disconnected with error: {Context.ConnectionId} - {exception.Message}");
+            }
+            else
+            {
+                Console.WriteLine($"[DataHub] Client disconnected: {Context.ConnectionId}");
+            }
+            await base.OnDisconnectedAsync(exception);
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"[DataHub] Error in OnDisconnectedAsync: {ex.Message}");
+            throw;
+        }
     }
 }
 

src/Apollinare.API/Program.cs

@@ -19,20 +19,23 @@ builder.Services.AddScoped<DemoDataService>();
 builder.Services.AddScoped<ReportGeneratorService>();
 builder.Services.AddSingleton<DataNotificationService>();
 
-// SignalR
-builder.Services.AddSignalR()
+// SignalR - with increased message size for template sync (default is 32KB)
+builder.Services.AddSignalR(options =>
+    {
+        options.MaximumReceiveMessageSize = 1024 * 1024; // 1MB max message size
+    })
     .AddJsonProtocol(options =>
     {
         options.PayloadSerializerOptions.ReferenceHandler = ReferenceHandler.IgnoreCycles;
         options.PayloadSerializerOptions.DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull;
     });
 
-// CORS - Allow credentials for SignalR
+// CORS - Allow credentials for SignalR (accepts any origin for external access)
 builder.Services.AddCors(options =>
 {
     options.AddPolicy("AllowFrontend", policy =>
     {
-        policy.SetIsOriginAllowed(origin => new Uri(origin).Host == "localhost")
+        policy.SetIsOriginAllowed(_ => true) // Permette qualsiasi origine
               .AllowAnyHeader()
               .AllowAnyMethod()
               .AllowCredentials();