中文README

Netcool.EventBus

An EventBus base on netstandard2 supporting RabbitMq and Mqtt.

Most of codes retrived from dotnet-architecture/eShopOnContainers, however there are some changes:

• Replace Autofac with default asp.net core ioc container.
• Add some extension methods for adding event bus.
• Delayed to create rabbitmq channel for event publish.
• Class name changed.

Install

You can find it at nuget.org with id Netcool.EventBus.RabbitMq or Netcool.EventBus.Mqtt.

Add RabbitMq EventBus

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddEventBusRabbitMq(ops =>
    {
       ops.HostName = "localhost";
       ops.UserName = "guest";
       ops.Password = "guest";   
       ops.QueueName = "event_bus_queue";
       ops.BrokerName = "event_bus";
       ops.RetryCount = 5;
    });
}

Add Mqtt EventBus

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddEventBusMqtt(ops =>
    {
        ops.TcpIp = "localhost";
        ops.TcpPort = 1883;
        ops.ClientId = "test";
        ops.Username = "";
        ops.Password = "";
        ops.PublishRetainedMessage = true;
        ops.RetryCount = 5;
        ops.CleanSession = false;    });
}

Add Custom EventBus

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddEventBus<CustomEventBus>();
}

Publish

public class UserLoginEvent:Event
{
   public string UserName { get; set; }
}

public class ValuesController : ControllerBase
{
  private readonly IEventBus _eventBus;

  public ValuesController(IEventBus eventBus)
  {
     _eventBus = eventBus;
  }

  [HttpGet]
  public ActionResult Get()
  {
     _eventBus.Publish(new UserLoginEvent() { UserName = "Peppa" });
     return Ok();
  }
}

Subscribe

public class UserLoginEventHandler : IEventHandler<UserLoginEvent>
{
   private readonly ILogger<UserLoginEventHandler> _logger;

   public UserLoginEventHandler(ILogger<UserLoginEventHandler> logger)
   {
       _logger = logger;
   }

   public Task Handle(UserLoginEvent @event)
   {
       _logger.LogInformation($"Welcome {@event.UserName}!");
       return Task.FromResult(0);
   }
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{        
    ...
    
    app.UseEventBus(eventBus =>
    {
        eventBus.Subscribe<UserLoginEvent, UserLoginEventHandler>();
    });
}

Customize event name

There's two ways to customize event name:

EventNameAttribute

[EventName("user-login")]
public class UserLoginEvent:Event
{
   public string UserName { get; set; }
}

The event name equals to RoutingKey of Rabbitmq or Topic of Mqtt

Dynamic Event

public class UserLoginDynamicEventHandler : IDynamicEventHandler
{
    public Task Handle(dynamic eventData)
    {
        Console.WriteLine($"Welcome {eventData.UserName}!");
        return Task.FromResult(0);
    }
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{        
    ...
    
    app.UseEventBus(eventBus =>
    {
        eventBus.SubscribeDynamic<UserLoginDynamicEventHandler>("UserLoginDynamicEvent");
    });
}