injection_in_doctrine_entities.md

Injection of DomainEventDispatcher in Doctrine entities

This feature allows you to merge your doctrine entities with DDD model.

To achieve this goal it provides you a set of classes to extends doctrine behavior on entity instantiation.

How it works

Doctrine uses an Instantiator class to instantiate entities. (this is some kind of factory)

As this Instantiator is hardly instantiated by Doctrine, we need to extend the ORM core. Which mean this feature may be in conflict with some other packages that may extend doctrine behavior (I don't know any).

Usage without integration

<?php
use Biig\Component\Domain\Event\DomainEventDispatcher;

$dispatcher = new DomainEventDispatcher();
$configuration = new \Doctrine\ORM\Configuration();
$entityManager = new \Doctrine\ORM\EntityManager($connection, $configuration);
$entityManager->getEventManager()->addEventSubscriber(new PostLoadDispatcherInjectionListener($dispatcher));

Symfony integration

⚠ You need to know it

When you use this feature, you need to keep in mind that instantiate entities by hand makes no sense. Be sure to use at least the default instantiator. Accessible with the service biig_domain.instantiator.default if you use Symfony bundle.

In debug mode, if you don't use the instantiator to create your entities, then you'll receive a FlushedEntityDoesntContainsDispatcherException. It probably means that you're using the new keyword to create an entity, and then persisting it to the database. This exception should tell you which entity is causing the error to help your debugging. To fix it, just follow the usages defined above.