DoctrineEntityListener

DoctrineEntityCompilerPass.php

<?php

namespace Acme\CommonBundle\DependencyInjection;

use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
use Symfony\Component\DependencyInjection\Reference;

class DoctrineEntityCompilerPass implements CompilerPassInterface
{
    public function process(ContainerBuilder $container)
    {
        $tagged = $container->findTaggedServiceIds('acme.listener.doctrine_entity');
        if (!$tagged) {
            return;
        }

        $definition = $container->register('acme.listener.doctrine_entity', 'Acme\DemoBundle\Listener\DoctrineEntityListener');
        $events = array();

        foreach ($tagged as $id => $tags) {
            foreach ($tags as $tag) {
                if (empty($tag['event']) || empty($tag['class'])) {
                    throw new \Exception("Services tagged acme.listener.doctrine_entity must have an event and a class argument");
                }

                $method = empty($tag['method']) ? null : $tag['method'];

                $definition->addMethodCall('register', array($tag['class'], $tag['event'], new Reference($id), $method));
                $events[$tag['event']] = 1;
            }
        }

        // TODO support more than one evm
        $evm = $container->getDefinition('doctrine.dbal.default_connection.event_manager');
        $evm->addMethodCall('addEventSubscriber', array(new Reference('acme.listener.doctrine_entity')));
    }
}

DoctrineEntityListener.php

<?php

namespace Acme\DemoBundle\Listener;

use Doctrine\ORM\Event\LifecycleEventArgs;
use Doctrine\Common\EventSubscriber;

class DoctrineEntityListener implements EventSubscriber
{   
    /**
     * $hooks[$class][$event][get_class($service)] = $method
     */
    private $hooks    = array();

    /**
     * Built once each for each entity class submitted to resolve all class inheritance
     * $cache[$class][$event][get_class($service)] = $method;
     */
    private $cache    = array();

    /**
     * Map of service_id => service to reduce size of $hooks and $cache
     */
    private $services = array();

    /**
     * Registered events
     * Used to build the service and hook only relevant events
     */
    private $events   = array();

    /**
     * Supported events by Doctrine so we detect errors early
     */
    private static $validEvents = array(
        'preRemove',
        'postRemove',
        'prePersist',
        'postPersist',
        'preUpdate',
        'postUpdate',
        'postLoad',
        );

    public function register($class, $event, $service, $method = null)
    {
        // Index with service class to ensure it is called only once
        if (!in_array($event, self::$validEvents)) {
            throw new \InvalidArgumentException("$event is not a valid Doctrine LifecycleEvent");
        }

        if (null === $method) {
            $method = $event;
        }

        $this->services[get_class($service)]              = $service;
        $this->hooks[$class][$event][get_class($service)] = $method;
        $this->events[$event] = 1;
    }

    /**
     * Called by Doctrine EVM
     */
    public function getSubscribedEvents()
    {
        return array_keys($this->events);
    }

    private function trigger($event, LifecycleEventArgs $args)
    {
        $class  = get_class($args->getEntity());

        foreach ($this->getServices($class, $event) as $service_id => $method) {
            $service = $this->services[$service_id];
            $service->$method($args);
        }
    }

    private function getServices($class, $event)
    {
        if (!isset($this->cache[$class])) {
            $this->cache[$class] = array();

            foreach ($this->hooks as $parent => $events) {
                // Test inheritance
                if (is_a($parent, $class, true)) {

                    foreach ($events as $event => $services) {
                        foreach ($services as $service => $method) {
                            $this->cache[$class][$event][$service] = $method;
                        }
                    }
                }
            }
        }

        if (isset($this->cache[$class][$event])) {
            return $this->cache[$class][$event];
        } else {
            return array();
        }
    }

    /**
     * Handles calls by Doctrine EVM
     */
    public function __call($event, $args)
    {
        if (isset($this->events[$event]) && isset($args[0]) && $args[0] instanceof LifecycleEventArgs) {
            $this->trigger($event, $args[0]);
        }
    }
}

services.yml

services:
    acme.listener.doctrine.user:
        class: Acme\DemoBundle\Listener\AclListener
        tags:
            - { name: acme.listener.doctrine_entity, class: Acme\DemoBundle\Entity\User, event: postPersist }