[POC DRY] BaseEntity class to be used as base for Entities in Symfony2.

BaseEntity.php

<?php

namespace Foo\Bar\Entity;

use Doctrine\ORM\EntityManager;
use Doctrine\ORM\Mapping as ORM;

/**
 * BaseEntity
 *
 * @author Jabran Rafique <hello@jabran.me>
 * @version 1.0.0
 *
 * @ORM\MappedSuperclass
 * @ORM\HasLifecycleCallbacks
 */
class BaseEntity {

    /**
     * @ORM\Id
     * @ORM\Column(name="id", type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @ORM\Column(name="created_at", type="datetime")
     */
    private $createdAt;

    /**
     * @ORM\Column(name="updated_at", type="datetime")
     */
    private $updatedAt;

    /**
     * Helper method
     * 
     * @param Doctrine\ORM\EntityManager $em
     * @throws \RunTimeException
     * @return void
     */
    protected function save(EntityManager $em) {
        if (!$em instanceof EntityManager) {
            throw new \RunTimeException('Entity Manager is required.', 400);
        }

        $em->persist($this);
        $em->flush();
    }

    /**
     * @ORM\PrePersist
     *
     * {@inheritDoc}
     */
    public function setTimestamps() {
        $this->setCreatedAt(new \DateTime);
        $this->setUpdatedAt(new \DateTime);
    }

    /**
     * @ORM\PreUpdate
     *
     * {@inheritDoc}
     */
    public function setUpdatedAtTimestamp() {
        $this->setUpdatedAt(new \DateTime);
    }

    /**
     * @codeCoverageIgnore
     */
    public function getId() {
        return $this->id;
    }
    
    /**
     * @codeCoverageIgnore
     */
    public function setId($id) {
        $this->id = $id;
        return $this;
    }
    
    /**
     * @codeCoverageIgnore
     */
    public function getCreatedAt() {
        return $this->createdAt;
    }
    
    /**
     * @codeCoverageIgnore
     */
    public function setCreatedAt($createdAt) {
        $this->createdAt = $createdAt;
        return $this;
    }
    
    /**
     * @codeCoverageIgnore
     */
    public function getUpdatedAt() {
        return $this->updatedAt;
    }
    
    /**
     * @codeCoverageIgnore
     */
    public function setUpdatedAt($updatedAt) {
        $this->updatedAt = $updatedAt;
        return $this;
    }
}