Table of contents

Overview

Features

Installation

Getting Started

Sample Event and Event Handlers

publicclassProductRegisteredEvent{publicintProductId{get;}publicstringProductName{get;}publicProductRegisteredEvent(intproductId,stringproductName){ProductId=productId;ProductName=productName;}}// Sync event handlerpublicclassProductRegisteredEventHandler:IEventHandler<ProductRegisteredEvent>{publicvoidHandle(ProductRegisteredEvent@event){System.Console.WriteLine($"ProductRegisteredEventHandler handled{@event.GetType()}.");}}// Async event handlerpublicclassProductRegisteredEmailNotifier:IEventAsyncHandler<ProductRegisteredEvent>{publicTaskHandleAsync(ProductRegisteredEvent@event,CancellationTokenct=default(CancellationToken)){System.Console.WriteLine($"Sending email notification...");returnTask.CompletedTask;}}

Event Handler Registration

1. Simple Registration (No IoC container)

// This method gets called by the runtime. Use this method to add services to the container.publicvoidConfigureServices(IServiceCollectionservices){                ...// Repository.services.AddSingleton<IProductRepository,InMemoryProductRepository>();// Register event delegator.services.AddSingleton<EventDelegator>((serviceProvider)=>{// Allows registration of a multiple message handlers per message type.varregistration=newMultiMessageHandlerRegistration();registration.RegisterEventHandler<ProductRegisteredEvent>(()=>newProductRegisteredEventHandler());registration.RegisterEventHandler<ProductRegisteredEvent>(()=>newProductRegisteredEmailNotifier());returnnewEventDelegator(registration.BuildMessageHandlerResolver());});    ...}

2. Container Registration

// This method gets called by the runtime. Use this method to add services to the container.publicvoidConfigureServices(IServiceCollectionservices){                ...// Repository.services.AddSingleton<IProductRepository,InMemoryProductRepository>();// Register event handlers to the container.// The AddCqrs extension method is in Xer.Cqrs.Extensions.Microsoft.DependencyInjection package.services.AddCqrs(typeof(ProductRegisteredEventHandler).Assembly);    ...}

Delegating Events to Event Handlers

...private readonly EventDelegator_eventDelegator;publicProductsController(EventDelegator eventDelegator){_eventDelegator=eventDelegator;}[HttpGet("{productId}")]publicasyncTask<IActionResult>Notify(ProductRegisteredEventDtomodel){await_eventDelegator.SendAsync(newProductRegisteredEvent(model.ProductId,model.ProductName))    return Accepted();}...