How to run a lookup query inside Doctrine2 Entity with Symfony3 - symfony

Question

I have a basic Doctrine2 entity, but one of the fields needs some formatting applied to it to turn it from a database primary key, into a user-visible "friendly ID".
I want to put the formatting logic in only one place, so that if it ever changes, it only has to be updated once.
Part of the formatting involves looking up a string from the database and using that as a prefix, as this value will be different for different installations. I am a bit stuck, because within the entity I can't (and probably shouldn't) look up the database to retrieve this prefix.
However I am not sure how else to go about this.
Here is some pseudocode illustrating what I am trying to do:
namespace AppBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use JMS\Serializer\Annotation as Serializer;
// This is also an entity, annotations/getters/setters omitted for brevity.
class Lookup {
protected $key;
protected $value;
}
class Person {
/**
* Database primary key
*
* #ORM\Id
* #ORM\GeneratedValue(strategy="IDENTITY")
*/
protected $id;
/**
* Get the person's display ID.
*
* #Serializer\VirtualProperty
* #Serializer\SerializedName("friendlyId")
*/
protected function getFriendlyId()
{
if ($this->person === null) return null;
//$prefix = 'ABC';
// The prefix should be loaded from the DB, somehow
$lookup = $this->getDoctrine()->getRepository('AppBundle:Lookup')->find('USER_PREFIX');
$prefix = $lookup->getValue();
return $prefix . $this->person->getId();
}
}

Answer 1

You could use event listeners using symfony and doctrine and listen to postLoad event by registering the service
services:
person.postload.listener:
class: AppBundle\EventListener\PersonPostLoadListener
tags:
- { name: doctrine.event_listener, event: postLoad }
Now in your listener you will have an access to entity manager
namespace AppBundle\EventListener;
use Doctrine\ORM\Event\LifecycleEventArgs;
use AppBundle\Entity\Person;
class PersonPostLoadListener
{
public function postLoad(LifecycleEventArgs $args)
{
$entity = $args->getEntity();
if (!$entity instanceof Person) {
return;
}
$entityManager = $args->getEntityManager();
$lookup =$entityManager->getRepository('AppBundle\Entity\Lookup')->findOneBy(array(
'key'=> 'USER_PREFIX'
));
$entity->setFriendlyId($entity->getId().$lookup->getValue());
//echo "<pre>";dump($entity);echo "</pre>";die('Call')
}
}
And in your person entity you need to define an un mapped property for your id and its getter and setter method like
class Person
{
private $friendlyId;
public function getFriendlyId()
{
return $this->friendlyId;
}
public function setFriendlyId($friendlyId)
{
return $this->friendlyId = $friendlyId;
}
}