Domain event

Library to create the domain layer of your Domain-driven design (DDD) application

Installation

Pretty simple with Composer, run:

composer require gpslab/domain-event

Base usage

Create a domain event

use GpsLab\Domain\Event\Event;

final class PurchaseOrderCreatedEvent implements Event
{
    private $customer_id;

    private $create_at;

    public function __construct(CustomerId $customer_id, \DateTimeImmutable $create_at)
    {
        $this->customer_id = $customer_id;
        $this->create_at = $create_at;
    }

    public function customerId()
    {
        return $this->customer_id;
    }

    public function createAt()
    {
        return $this->create_at;
    }
}

Raise your event

use GpsLab\Domain\Event\Aggregator\AbstractAggregateEvents;

final class PurchaseOrder extends AbstractAggregateEventsRaiseInSelf
{
    private $customer_id;

    private $create_at;

    public function __construct(CustomerId $customer_id)
    {
        $this->raise(new PurchaseOrderCreatedEvent($customer_id, new \DateTimeImmutable()));
    }

    /**
     * The raise() method will automatically call this method.
     * Since it's an event you should never do some tests in this method.
     * Try to think that an Event is something that happened in the past.
     * You can not modify what happened. The only thing that you can do is create another event to compensate.
     * You do not obliged to listen this event and are not required to create this method.
     */
    protected function onPurchaseOrderCreated(PurchaseOrderCreatedEvent $event)
    {
        $this->customer_id = $event->customerId();
        $this->create_at = $event->createAt();
    }
}

Create listener

class SendEmailOnPurchaseOrderCreated
{
    private $mailer;

    public function __construct($mailer)
    {
        $this->mailer = $mailer;
    }

    public function __invoke(PurchaseOrderCreatedEvent $event)
    {
        $this->mailer->send('recipient@example.com', sprintf(
            'Purchase order created at %s for customer #%s',
            $event->createAt()->format('Y-m-d'),
            $event->customerId()
        ));
    }
}

Dispatch events

use GpsLab\Domain\Event\Bus\ListenerLocatedEventBus;
use GpsLab\Domain\Event\Listener\Locator\DirectBindingEventListenerLocator;

// first the locator
$locator = new DirectBindingEventListenerLocator();
// you can use several listeners for one event and one listener for several events
$locator->register(PurchaseOrderCreatedEvent::class, new SendEmailOnPurchaseOrderCreated(/* $mailer */));

// then the event bus
$bus = new ListenerLocatedEventBus($locator);

// do what you need to do on your Domain
$purchase_order = new PurchaseOrder(new CustomerId(1));

// this will clear the list of event in your AggregateEvents so an Event is trigger only once
$bus->pullAndPublish($purchase_order);

Documentation

• Base usage
• Raise events in self
• Listener
  • Create listener
  • Create subscriber
  • Locator
    • Direct binding locator
    • PSR-11 Container locator (PSR-11)
    • Symfony container locator (Symfony 3.3 implements a PSR-11)
• Queue
  • Queue event bus
  • Pull
    • Memory queue
    • Predis queue
  • Subscribe
    • Executing queue
    • AMQP queue
    • Predis queue
  • Serialize command
    • Simple payload serializer
    • Optimized Symfony serializer
    • Payload Symfony serializer
• Frameworks
  • Symfony bundle
• Middleware
• Payload

License

This bundle is under the MIT license. See the complete license in the file: LICENSE