Sai.MessageHub 1.0.0

Sai.MessageHub

Simple WebSocket message handler implemented as aspnetcore middleware.

Example Usage

Program.cs

using Sai.MessageHub;

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddMessageHub();
builder.Services.AddHostedService<MyWorker>(); // Example worker which sends the time to all MessageHub clients every second

var app = builder.Build();

app.UseMessageHub();

// Message handler for "counter" type. Generic type <T> relates to data type.
// Can map multiple handlers to the same type if required.
app.MapMessageHandler<int>("counter", (context, data) =>
{
	context.SendMessageToClient("counter-response", data); // echo back to sender
	context.SendMessageToAllClients("last-counter-update", DateTime.UtcNow); // send last update to all clients
});

app.Run();

MyWorker.cs

public class MyWorker : BackgroundService
{
    private readonly ILogger<MyWorker> _logger;
    private readonly IMessageHubService _messageHubService;
    public MyWorker(ILogger<MyWorker> logger, IMessageHubService messageHubService)
    {
        _logger = logger;
        _messageHubService = messageHubService;
    }

    protected override Task ExecuteAsync(CancellationToken stoppingToken)
    {
        return Task.Run(() =>
        {
            while (!stoppingToken.IsCancellationRequested)
            {
                stoppingToken.WaitHandle.WaitOne(1000);
                _messageHubService.SendMessageToAllClients("time", DateTime.UtcNow);
            }
        });
    }
}

Client.js

document.addEventListener("DOMContentLoaded", async () => {
    const messageHub = new MessageHub();

    messageHub.addMessageHandler("time", data => {
        document.querySelector(".time").innerText = data;
    });

    messageHub.addMessageHandler("counter-response", data => {
        document.querySelector(".counter-response").innerText = data;
    });

    messageHub.addMessageHandler("last-counter-update", data => {
        document.querySelector(".last-counter-update").innerText = data;
    });

    try
    {
        await messageHub.connect();
            
        let counter = 0;
        setInterval(() => {
            counter++;
            messageHub.sendMessage("counter", counter);
        }, 1000);
    }
    catch(err)
    {
        alert(err);
    }

});