Now with multi connections

src/backend/server/src/Todo.Api/Hubs/TodoHub.cs

@@ -1,107 +1,173 @@
+using System.Collections.Concurrent;
+using System.Security.Claims;
 using System.Text.Json;
 using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.SignalR;
 using Todo.Api.Hubs.Models;
 using Todo.Core.Interfaces.Persistence;
 
-namespace Todo.Api.Hubs
+namespace Todo.Api.Hubs;
+
+[Authorize]
+public class TodoHub : Hub
 {
-    [Authorize]
+    private readonly ITodoRepository _todoRepository;
-    public class TodoHub : Hub
+
+    private static readonly ConcurrentDictionary<string, List<string>> ConnectedUsers = new();
+
+    public override Task OnConnectedAsync()
     {
-        private readonly ITodoRepository _todoRepository;
+        var userId = Context.User.FindFirstValue("sub");
 
-        public TodoHub(ITodoRepository todoRepository)
+        // Try to get a List of existing user connections from the cache
+        ConnectedUsers.TryGetValue(userId, out var existingUserConnectionIds);
+
+        // happens on the very first connection from the user
+        existingUserConnectionIds ??= new List<string>();
+
+        // First add to a List of existing user connections (i.e. multiple web browser tabs)
+        existingUserConnectionIds.Add(Context.ConnectionId);
+
+
+        // Add to the global dictionary of connected users
+        ConnectedUsers.TryAdd(userId, existingUserConnectionIds);
+
+        return base.OnConnectedAsync();
+    }
+
+    public override Task OnDisconnectedAsync(Exception? exception)
+    {
+        var userId = Context.User.FindFirstValue("sub");
+
+        ConnectedUsers.TryGetValue(userId, out var existingUserConnectionIds);
+
+        // remove the connection id from the List 
+        existingUserConnectionIds?.Remove(Context.ConnectionId);
+
+        // If there are no connection ids in the List, delete the user from the global cache (ConnectedUsers).
+        if (existingUserConnectionIds?.Count == 0)
         {
-            _todoRepository = todoRepository;
+            // if there are no connections for the user,
+            // just delete the userName key from the ConnectedUsers concurent dictionary
+            ConnectedUsers.TryRemove(userId, out _);
         }
 
-        public async Task CreateTodo(string todoTitle, string projectName)
+        return base.OnDisconnectedAsync(exception);
-        {
+    }
-            if (todoTitle is null)
-                throw new ArgumentException("title cannot be null");
-            var _ = await _todoRepository.CreateTodoAsync(todoTitle, projectName);
 
-            var todos = await _todoRepository.GetNotDoneTodos();
-            var serializedTodos =
-                JsonSerializer.Serialize(todos
-                    .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Project = t.Project })
-                    .ToList());
 
-            await Clients.Caller.SendAsync("getInboxTodos", serializedTodos);
+    public TodoHub(ITodoRepository todoRepository)
-        }
+    {
+        _todoRepository = todoRepository;
+    }
 
-        public async Task UpdateTodo(string todoId, bool todoStatus)
+    public async Task CreateTodo(string todoTitle, string projectName)
-        {
+    {
-            await _todoRepository.UpdateTodoStatus(todoId, todoStatus);
+        if (todoTitle is null)
+            throw new ArgumentException("title cannot be null");
+        var _ = await _todoRepository.CreateTodoAsync(todoTitle, projectName);
 
-            var todos = await _todoRepository.GetNotDoneTodos();
+        var todos = await _todoRepository.GetNotDoneTodos();
-            var serializedTodos =
+        var serializedTodos =
-                JsonSerializer.Serialize(todos
+            JsonSerializer.Serialize(todos
-                    .Select(t => new TodoResponse
+                .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Project = t.Project })
-                        { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
-                    .ToList());
-
-            await Clients.Caller.SendAsync("getInboxTodos", serializedTodos);
-        }
-
-        public async Task GetTodos()
-        {
-            var todos = await _todoRepository.GetTodosAsync();
-            var serializedTodos = JsonSerializer.Serialize(todos
-                .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
                 .ToList());
 
-            await Clients.Caller.SendAsync("todos", serializedTodos);
+        await RunOnUserConnections(async (connections) =>
-        }
+            await Clients.Clients(connections).SendAsync("getInboxTodos", serializedTodos));
+    }
 
-        public async Task GetInboxTodos()
+
-        {
+    public async Task UpdateTodo(string todoId, bool todoStatus)
-            var todos = await _todoRepository.GetNotDoneTodos();
+    {
-            var serializedTodos = JsonSerializer.Serialize(todos
+        await _todoRepository.UpdateTodoStatus(todoId, todoStatus);
-                .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
+
+        var todos = await _todoRepository.GetNotDoneTodos();
+        var serializedTodos =
+            JsonSerializer.Serialize(todos
+                .Select(t => new TodoResponse
+                    { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
                 .ToList());
 
-            await Clients.Caller.SendAsync("getInboxTodos", serializedTodos);
+        await RunOnUserConnections(async (connections) =>
-        }
+            await Clients.Clients(connections).SendAsync("getInboxTodos", serializedTodos));
+    }
 
-        public async Task GetTodo(string todoId)
+    public async Task GetTodos()
+    {
+        var todos = await _todoRepository.GetTodosAsync();
+        var serializedTodos = JsonSerializer.Serialize(todos
+            .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
+            .ToList());
+
+        await RunOnUserConnections(async (connections) =>
+            await Clients.Clients(connections).SendAsync("todos", serializedTodos));
+    }
+
+    public async Task GetInboxTodos()
+    {
+        var todos = await _todoRepository.GetNotDoneTodos();
+        var serializedTodos = JsonSerializer.Serialize(todos
+            .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
+            .ToList());
+
+        await RunOnUserConnections(async (connections) =>
+            await Clients.Clients(connections).SendAsync("getInboxTodos", serializedTodos));
+    }
+
+    public async Task GetTodo(string todoId)
+    {
+        var todo = await _todoRepository.GetTodoByIdAsync(todoId);
+        var serializedTodo = JsonSerializer.Serialize(new TodoResponse()
         {
-            var todo = await _todoRepository.GetTodoByIdAsync(todoId);
+            Id = todo.Id,
-            var serializedTodo = JsonSerializer.Serialize(new TodoResponse()
+            Project = todo.Project,
-            {
+            Status = todo.Status,
-                Id = todo.Id,
+            Title = todo.Title,
-                Project = todo.Project,
+        });
-                Status = todo.Status,
-                Title = todo.Title,
-            });
 
-            await Clients.Caller.SendAsync("getTodo", serializedTodo);
+        await RunOnUserConnections(async (connections) =>
-        }
+            await Clients.Clients(connections).SendAsync("getTodo", serializedTodo));
+    }
 
-        public async Task ReplaceTodo(string updateTodoRequest)
+    public async Task ReplaceTodo(string updateTodoRequest)
+    {
+        var updateTodo = JsonSerializer.Deserialize<UpdateTodoRequest>(updateTodoRequest);
+        if (updateTodo is null)
+            throw new InvalidOperationException("Could not parse invalid updateTodo");
+
+        var updatedTodo = await _todoRepository.UpdateTodoAsync(new Core.Entities.Todo()
         {
-            var updateTodo = JsonSerializer.Deserialize<UpdateTodoRequest>(updateTodoRequest);
+            Id = updateTodo.Id,
-            if (updateTodo is null)
+            Project = updateTodo.Project,
-                throw new InvalidOperationException("Could not parse invalid updateTodo");
+            Status = updateTodo.Status,
+            Title = updateTodo.Title
+        });
 
-            var updatedTodo = await _todoRepository.UpdateTodoAsync(new Core.Entities.Todo()
+        var serializedTodo = JsonSerializer.Serialize(new TodoResponse()
-            {
+        {
-                Id = updateTodo.Id,
+            Id = updatedTodo.Id,
-                Project = updateTodo.Project,
+            Project = updatedTodo.Project,
-                Status = updateTodo.Status,
+            Status = updatedTodo.Status,
-                Title = updateTodo.Title
+            Title = updatedTodo.Title,
-            });
+        });
 
-            var serializedTodo = JsonSerializer.Serialize(new TodoResponse()
+        await RunOnUserConnections(async (connections) =>
-            {
+            await Clients.Clients(connections).SendAsync("getTodo", serializedTodo));
-                Id = updatedTodo.Id,
+    }
-                Project = updatedTodo.Project,
-                Status = updatedTodo.Status,
-                Title = updatedTodo.Title,
-            });
 
-            await Clients.Caller.SendAsync("getTodo", serializedTodo);
+    private Task RunOnUserConnections(Func<IEnumerable<string>, Task> action)
-        }
+    {
+        var userId = Context.User.FindFirstValue("sub");
+        if (userId is null)
+            throw new InvalidOperationException("User id was invalid. Something has gone terribly wrong");
+
+        ConnectedUsers.TryGetValue(userId, out var connections);
+
+        if (connections is not null)
+            action(connections);
+
+        return Task.CompletedTask;
     }
 }

src/backend/server/src/Todo.Api/Startup.cs

@@ -27,6 +27,7 @@ namespace Todo.Api
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddControllers();
+            services.AddHttpContextAccessor();
             services.AddCors(options =>
             {
                 options.AddDefaultPolicy(builder =>

src/backend/server/src/Todo.Api/Todo.Api.csproj

@@ -3,6 +3,7 @@
     <PropertyGroup>
         <TargetFramework>net6.0</TargetFramework>
         <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
+        <Nullable>enable</Nullable>
     </PropertyGroup>
 
     <ItemGroup>

src/client/src/presentation/contexts/SocketContext.tsx

@@ -40,7 +40,9 @@ export const SocketProvider: FC = (props) => {
       process.env.NEXT_PUBLIC_SERVER_URL || "http://localhost:5000";
 
     const connection = new HubConnectionBuilder()
-      .withUrl(`${serverUrl}/hubs/todo`)
+      .withUrl(`${serverUrl}/hubs/todo`, {
+          withCredentials: true
+      })
       .withAutomaticReconnect()
       .configureLogging(LogLevel.Information)
       .build();