inanzzz | PrePersist and postPersist event subscriber on an entity

The prePersist takes place just before persisting an object into the database and the postPersist takes place right after persist. Example below inserts a new record into UserLog entity with event subscriber when creating a new record in User entity within controller.

UserController.php

public function createAction()
{
    $user = new User();
    $user->setUsername('username');
    $user->setPassword('password');
    $this->entityManager->persist($user);
    $this->entityManager->flush();
}

Subscriber.yml

services:
    application_backend.event_subscriber.user_entity:
        class: Application\BackendBundle\EventSubscriber\UserEntitySubscriber
        tags:
                - { name: doctrine.event_subscriber }

UserEntitySubscriber.php

namespace Application\BackendBundle\EventSubscriber;

use Doctrine\Common\EventSubscriber;
use Doctrine\ORM\Event\LifecycleEventArgs;
use Application\BackendBundle\Entity\User;
use Application\BackendBundle\Entity\UserLog;

class UserEntitySubscriber implements EventSubscriber
{
    public function getSubscribedEvents()
    {
        return array('prePersist', 'postPersist');
    }

    public function prePersist(LifecycleEventArgs $args)
    {
        $this->index($args, 'prePersist');
    }

    public function postPersist(LifecycleEventArgs $args)
    {
        $this->index($args, 'postPersist');
    }

    public function index(LifecycleEventArgs $args, $event)
    {
        $entity = $args->getEntity();

        if ($entity instanceof User) {
            $log = new UserLog();
            $log->setUserId($entity->getId());
            $log->setMessage($event . ' at ' . date('d/m/Y H:i:s'));

            $em = $args->getEntityManager();
            $em->persist($log);
            $em->flush();
        }
    }
}

Result

mysql> SELECT * FROM user;
+----+----------+------------+
| id | username | password   |
+----+----------+------------+
|  1 | MEBKZT   | 1436015275 |
+----+----------+------------+
1 row in set (0.00 sec)

mysql> SELECT * FROM user_log;
+----+---------+------------------------------------+
| id | user_id | message                            |
+----+---------+------------------------------------+
|  1 |    NULL | prePersist at 29/06/2015 20:06:56  |
|  2 |       1 | postPersist at 29/06/2015 20:06:56 |
+----+---------+------------------------------------+
2 rows in set (0.00 sec)