Tweet.cs

using BlazorClient;
using Microsoft.AspNetCore.SignalR;

namespace UndoExample;

public record Tweet(Guid TweetId, string Message) : ICommand;
public record Tweeted(Guid TweetId, string Message) : IEvent;

public class TweetHandler : IHandleMessages<Tweet>
{
    private readonly ILogger<TweetHandler> _logger;

    public TweetHandler(ILogger<TweetHandler> logger)
    {
        _logger = logger;
    }
    
    public async Task Handle(Tweet message, IMessageHandlerContext context)
    {
        _logger.LogInformation($"Tweeted: {message.Message}");
        
        // Do something here like persisting the tweet to the DB.

        await context.Publish(new Tweeted(message.TweetId, message.Message));

    }
}

public class TweetedSignalRHandler : IHandleMessages<Tweeted>
{
    private readonly IHubContext<TweetHub> _hubContext;

    public TweetedSignalRHandler(IHubContext<TweetHub> hubContext)
    {
        _hubContext = hubContext;
    }
    
    public async Task Handle(Tweeted message, IMessageHandlerContext context)
    {
        await _hubContext.Clients.All.SendAsync("tweeted", message.TweetId, message.Message, context.CancellationToken);
    }
}