HubLifecycle stuffs

Related to hub Lifecycle

In SignalR, the hub lifecycle refers to the various stages a hub goes through from creation to disposal. Here is an overview of the hub lifecycle in SignalR:

1. Hub Creation: When a client connects to the SignalR server, an instance of the hub class is created. This instance is used to handle all interactions with the client.

2. OnConnectedAsync: This method is called when a new connection is established with the hub. You can override this method to perform actions when a client connects, such as sending a welcome message or initializing resources.

3. Hub Methods: These are the methods defined in the hub class that clients can call. Each time a client calls a hub method, a new instance of the hub is created to handle the call. After the method execution, the instance is disposed of.

4. OnDisconnectedAsync: This method is called when a connection with the hub is terminated. You can override this method to perform cleanup actions, such as releasing resources or notifying other clients about the disconnection.

5. Hub Disposal: After the OnDisconnectedAsync method is called, the hub instance is disposed of. This is the final stage in the hub lifecycle.

Here is a simple example of a SignalR hub in C#:

using Microsoft.AspNetCore.SignalR;
using System.Threading.Tasks;

public class ChatHub : Hub
{
    public override async Task OnConnectedAsync()
    {
        await Clients.Caller.SendAsync("ReceiveMessage", "Welcome to the chat!");
        await base.OnConnectedAsync();
    }

    public async Task SendMessage(string user, string message)
    {
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }

    public override async Task OnDisconnectedAsync(Exception exception)
    {
        await base.OnDisconnectedAsync(exception);
    }
}

In this example:

• OnConnectedAsync is overridden to send a welcome message to the client when they connect.
• SendMessage is a hub method that clients can call to send messages to all connected clients.
• OnDisconnectedAsync is overridden to handle any cleanup when a client disconnects.
• Other Methods