SimpleEventHub

A simple to use Event Hub for .NET that allows you to publish and subscribe to events of any type.

When a single instance of EventHub is distributed throughout your application using a DI container, this can enable strong decoupling between different areas of your code.

Nuget

This package can be used by installing it from Nuget

Quick Start

SimpleEventHub provides a lightweight class which allows you to subscribe to, and publish events of any type. The implementation is based off of the EventAggregator ni the Caliburn.Micro framework.

Registering

To subscribe to an event, you must "Register" an object that implements IHandle<T>, where T is the type of event you want to handle.

class SyncBaseCountingHandler : IHandle<BaseEvent>
{
    public int HandleCount { get; set; }
    public void Handle(BaseEvent eventInfo)
    {
        HandleCount++;
    }
}

To then register this handler, you should pass an instance of the handler to the Register method on an 'EventHub` instance

var hub = new EventHub();
var handler = new SyncBaseCountingHandler();

hub.Register(handler);

Publish an Event

To publish an event, pass an object of any type to the AddEvent method to the EventHub instance

var hub = new EventHub();
var handler = new SyncBaseCountingHandler();
hub.Register(handler);

hub.AddEvent(new BaseEvent());
Console.Log(handler.HandleCount); 

//Outputs: 1

Covariance

The SimpleEventHub supports covariance of event types. This means that if a handler handles a type, that the event type is derived from, the handler will still receive that event. This enables you to, for example, handle all events of any type, by implementing IHandle<object>

var hub = new EventHub();
var handler = new SyncBaseCountingHandler();
hub.Register(handler);

hub.AddEvent(new DerivedEvent());
Console.Log(handler.HandleCount); 

//Outputs: 1