Symfony Serialize doctrine entity - symfony

Question

I have a simple entity class:
<?php
namespace AppBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Collections\ArrayCollection;
/**
* #ORM\Entity(repositoryClass="CompanyUserRepository")
* #ORM\Table(name="company_users")
*/
class CompanyUser
{
/**
* #ORM\Column(type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #ORM\Column(type="string", length=100)
*/
private $firstName;
/**
* #ORM\Column(type="string", length=100)
*/
private $lastName ;
/**
* #ORM\OneToMany(targetEntity="Score", mappedBy="user")
*/
private $scores;
/**
* Constructor
*/
public function __construct()
{
$this->scores = new ArrayCollection();
}
/**
* Get id
*
* #return integer
*/
public function getId()
{
return $this->id;
}
/**
* Set firstName
*
* #param string $firstName
*
* #return CompanyUser
*/
public function setFirstName($firstName)
{
$this->firstName = $firstName;
return $this;
}
/**
* Get firstName
*
* #return string
*/
public function getFirstName()
{
return $this->firstName;
}
/**
* Set lastName
*
* #param string $lastName
*
* #return CompanyUser
*/
public function setLastName($lastName)
{
$this->lastName = $lastName;
return $this;
}
/**
* Get lastName
*
* #return string
*/
public function getLastName()
{
return $this->lastName;
}
/**
* Add score
*
* #param \AppBundle\Entity\Score $score
*
* #return CompanyUser
*/
public function addScore(\AppBundle\Entity\Score $score)
{
$this->scores[] = $score;
return $this;
}
/**
* Remove score
*
* #param \AppBundle\Entity\Score $score
*/
public function removeScore(\AppBundle\Entity\Score $score)
{
$this->scores->removeElement($score);
}
/**
* Get scores
*
* #return \Doctrine\Common\Collections\Collection
*/
public function getScores()
{
return $this->scores;
}
}
The problem comes when I try to get all users and serialize them in json:
/**
* #Route("/api/getUsers", name="getUsers")
*/
public function getUsers(Request $request){
$users = $this->getDoctrine()
->getRepository('AppBundle:CompanyUser')
->findAll();
$serializer = $this->get('serializer');
$data = $serializer->serialize($users, 'json');
return new Response($users);
}
I get A circular reference has been detected (configured limit: 1).
When I remove the getScores getter everything works fine. I need to get only the id, firstName and lastName. Is there a way to not serialize the other objects?

Answer 1

Well, it is a common thing to handle with circular references when serializing entities with relations.
Solution no. 1: Implements serializable interface and make relations attributes are not serialize/unserialize (most cases, it is a valid solution)
Solution no. 2: The setCircularReferenceLimit() method of this normalizer sets the number of times it will serialize the same object before considering it a circular reference. Its default value is 1. So, before calling serialize() method, do this:
public function getUsers(Request $request){
$users = $this->getDoctrine()
->getRepository('AppBundle:CompanyUser')
->findAll();
$serializer = $this->get('serializer');
$serializer->setCircularReferenceLimit(2); // Change this with a proper value for your case
$data = $serializer->serialize($users, 'json');
return new Response($data);
}
**** UPDATE ****
As #Derek says in his comment, solution no. 2 can be invalid in some versions of Symfony. Then you can try to set a handler for circular references this way:
$encoder = new JsonEncoder();
$normalizer = new ObjectNormalizer();
$normalizer->setCircularReferenceHandler(function ($object) {
return $object->getName(); // Change this to a valid method of your object
});
$serializer = new Serializer(array($normalizer), array($encoder));
var_dump($serializer->serialize($org, 'json'));
This should return your entity value instead to iterate over relations.