vanio/doctrine-domain-events

An extension for Doctrine2 ORM allowing usage of domain events and an ability to flush inside it's listeners.

Doctrine Domain Events

, _(*1)

Very lightweight extension for Doctrine2 ORM allowing usage of domain events together with an ability to flush inside it's listeners. This library is inspired in Beberlei's Doctrine and Domain Events article., _(*2)

Installation

Installation can be done as usually using composer. composer require vanio/doctrine-domain-events, _(*3)

You also need to register an instance of Vanio\DoctrineDomainEvents\DoctrineDomainEventDispatcher inside Doctrine's event manager., _(*4)

use Vanio\DoctrineDomainEvents\DoctrineDomainEventDispatcher;

$eventManager->addSubscriber(new DoctrineDomainEventDispatcher);

Usage

Setting up your entity

First make sure your entity implements Vanio\DoctrineDomainEvent interface and uses the Vanio\DoctrineDomainEvent\EventProviderTrait., _(*5)

use Vanio\DoctrineDomainEvent\EventProvider;
use Vanio\DoctrineDomainEvent\EventProviderTrait;

class MyEntity implements EventProvider
{
    use EventProviderTrait;
}

Raising domain events

To raise a domain event from your entity use the raise method. This method expects either an instance of Vanio\DoctrineDomainEvent\DomainEvent or just a string representing the domain event name (and optional array of properties). In case of passing a string it will be turned into an instance of the DomainEvent class. If you prefer to create your own event classes you can do so by extending the DomainEvent class, just don't forget to extend the name method. The event is dispatched at the end of transaction once your entity has been flushed and all the changes are projected into database so it is possible to both perform database queries over the changes as well as cancel the transaction. Event names will be used as method names of corresponding listeners because this implementation uses the built-in Doctrine event manager to keep it simple thus you need to make sure all your event names are globally unique., _(*6)

use Vanio\DoctrineDomainEvent\EventProvider;
use Vanio\DoctrineDomainEvent\EventProviderTrait;

class Article implements EventProvider
{
    use EventProviderTrait;

    const EVENT_ARTICLE_PUBLISHED = 'onArticlePublish';

    // ...

    public function publish()
    {
        $this->raise(self::EVENT_ARTICLE_PUBLISHED, ['property' => 'value']);
    }
}

Listening to domain events

Listening to domain events is done the same way as listening to standard Doctrine events because it uses the same event manager. You need to either prepare a listener and register it to appropriate domain event yourself or you can use a subscriber that know which events it listens to. More information about the event system can be found inside Doctrine documentation., _(*7)

Listening to domain events using a listener

class Listener
{
    public function onArticlePublish(DomainEvent $event)
    {
        // ...     
    }
}

$eventManager->addListener(Article::EVENT_ARTICLE_PUBLISHED, new Listener);

Listening to domain events using a subscriber

use Doctrine\Common\EventSubscriber;

class Subscriber implements EventSubscriber
{
    public function onArticlePublish(DomainEvent $event)
    {
        // ...     
    }

    public function getSubscribedEvents(): array
    {
        return [Article::EVENT_ARTICLE_PUBLISHED];
    }
}

$eventManager->addSubscriber(new Subscriber);