.NET Framework SignalR Clients.Caller Not working as expected - asp.net

Question

I am currently using SignalR in my .NET framework project to send updates to the client for a long running process. There can be many processes running simultaneously and the client will subscribe to any one of the process using an unique ID. I am using Groups to identify the clients who are subscribed to a particular process. If a client subscribes to a process in middle, I must send all the previous messages to that client. The code goes something like this
public class ProgressHub : Hub
{
public async Task SubscribeToProgress(string id)
{
foreach (var message in GetPreviousMessages(id)) // Getting all the previous messages
{
await Clients.Caller.SendMessage(message); // Sending Messages to the current caller alone
}
await Groups.Add(Context.ConnectionId, id); // Added the current client to a group to be used further
}
}
The client listens to Send Message
The above code snippet is not working (No messages in the network tab).
I tried many things
await Clients.Client(Context.ConnectionId).SendMessage(message);
await Clients.All.SendMessage(message); // Just to check if it works
all the above without await, but nothing seems to work.
After fiddling around a bit, I was able to come up with this
public class ProgressHub : Hub
{
public async Task SubscribeToProgress(string id)
{
await Groups.Add(Context.ConnectionId, id); // Adding client to the group first
foreach (var message in GetPreviousMessages(id))
{
await Clients.Group(id).SendMessage(message); // Sending messages to the group all together
}
}
}
But this has an undesirable side effect of sending the older messages to client who are already connected. Sure, I can exclude the other connectionIDs and send out the message, but this seems like an hack. Logically speaking, the first snippet should have worked just fine.

Answer 1

are you add configuration in Program.cs ?
using SignalRChat.Hubs;
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRazorPages();
builder.Services.AddSignalR();
var app = builder.Build();
if (!app.Environment.IsDevelopment())
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapRazorPages();
app.MapHub<ChatHub>("/chatHub");
app.Run();
and you can read this reference :
Microsoft