Publishing events

After creating an event and their corresponding event handler, it's now time to publish those events.

When you register Eventify to DI container, by default it automatically registers InMemoryEventDispatcher to the container of given IEventPublisher abstraction. We will see how to publish event with InMemoryEventDispatcher.

Consider the following simple controller code.

using System.Threading.Tasks;
using Eventify;
using Microsoft.AspNetCore.Mvc;

namespace CustomerApp.Controllers
{
    [ApiController]
    public class CustomerController : ControllerBase
    {
        private readonly IEventPublisher _eventPublisher;

        public CustomerController(IEventPublisher eventPublisher)
        {
            _eventPublisher = eventPublisher;
        }
        
        [HttpPost]
        public IActionResult Post(Customer customer)
        {
            // Save given customer logic
            
            // publishing the CustomerRegisteredEvent with register customer.
            _eventPublisher.Publish(new CustomerRegisteredEvent(customer));

            return Json(new { Message = "Customer registered successfully." });
        }
    }
}

As you can see above IEventPublisher has one method Publish which takes the only parameter which is nothing but the event which has to be published.

Behind the scenes, the publish method will find all the EventHandlers for the given event and call their Handle method by passing current event object as an parameter which in this case is customer object.