Doctrine Mongo document + Embed a Collection of Forms - mongodb

Question

Project with symfony 2 and mongoDB.
I'm following this tutorial: http://symfony.com/doc/current/cookbook/form/form_collections.html
But once I save the form I get this error:
Cannot create a DBRef, the document is not an object
Line of crash:
https://github.com/doctrine/mongodb-odm/blob/master/lib/Doctrine/ODM/MongoDB/DocumentManager.php#L691
Form code:
namespace Fonts\FontsBundle\Form\Type;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
class FamilyType extends AbstractType
{
public function __construct($dm)
{
$this->dm = $dm;
}
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('name', 'text', array('max_length' => 50, 'error_bubbling' => true));
$builder->add('fonts', 'collection', array(
'type' => new FontType($this->dm),
'allow_add' => true,
'by_reference' => false,
));
}
public function getName()
{
return 'Family';
}
}
Controller code:
namespace Fonts\FontsBundle\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Fonts\FontsBundle\Document\Family;
use Fonts\FontsBundle\Document\Font;
use Fonts\FontsBundle\Form\Type\FamilyType;
class FamilyBackendController extends BaseController
{
public function newAction()
{
try {
$family = new Family();
$form = $this->createForm(new FamilyType($this->getMongoService()), $family);
$request = $this->getRequest();
if ($request->getMethod() == 'POST')
{
$form->bind($request);
if ($form->isValid())
{
$this->persist($family);
$this->get('session')->setFlash('notice', 'Item successfully created.');
return ($request->request->get('save') === 'Save') ?
new RedirectResponse($this->generateUrl('backend_familys_list')) :
new RedirectResponse($this->generateUrl('backend_familys_new'));
}
}
return $this->render('FontsBundle:Backend:newFamily.html.twig', array(
'form' => $form->createView(),
));
} catch(\Exception $e) {
return new Response($e->getMessage());
}
}
}
Document:
<?php
namespace Fonts\FontsBundle\Document;
use Doctrine\ODM\MongoDB\Mapping\Annotations as MongoDB;
use Doctrine\Common\Collections\ArrayCollection;
use Symfony\Component\Validator\Constraints as Assert;
use Fonts\FontsBundle\Service\SlugService;
/**
* #MongoDB\Document(repositoryClass="Fonts\FontsBundle\Repository\FamilyRepository")
*/
class Family
{
/**
* #MongoDB\Id
*/
protected $id;
/**
* #MongoDB\String
* #MongoDB\UniqueIndex(safe=true)
* #Assert\NotBlank(message="FamilyName value should not be blank.")
* #Assert\MinLength(limit=3,message="FamilyName must have at least {{ limit }} characters.")
* #Assert\MaxLength(limit=50,message="FamilyName must have maximum {{ limit }} characters.")
*/
protected $name;
/**
* #MongoDB\ReferenceMany(targetDocument="Font", simple=true)
* #Assert\NotBlank(message="Fonts should not be blank.")
*/
protected $fonts;
/**
* #MongoDB\String
* #MongoDB\UniqueIndex(safe=true)
*/
protected $slug;
/**
* #MongoDB\Int
*/
protected $createdAt;
public function __construct()
{
$this->fonts = new \Doctrine\Common\Collections\ArrayCollection();
}
/**
* Get id
*
* #return id $id
*/
public function getId()
{
return $this->id;
}
/**
* Set name
*
* #param string $name
* #return Family
*/
public function setName($name)
{
$this->name = $name;
return $this;
}
/**
* Get name
*
* #return string $name
*/
public function getName()
{
return $this->name;
}
/**
* Add fonts
*
* #param Fonts\FontsBundle\Document\Font $fonts
*/
public function addFonts(\Fonts\FontsBundle\Document\Font $fonts)
{
$this->fonts[] = $fonts;
}
/**
* Set fonts
*
* #param Doctrine\Common\Collections\Collection $fonts
*/
public function setFonts($fonts)
{
$this->fonts = $fonts;
}
/**
* Get fonts
*
* #return Doctrine\Common\Collections\Collection $fonts
*/
public function getFonts()
{
return $this->fonts;
}
/**
* Set slug
*
* #param string $slug
* #return Family
*/
public function setSlug($slug)
{
$this->slug = $slug;
return $this;
}
/**
* Get slug
*
* #return string $slug
*/
public function getSlug()
{
return $this->slug;
}
/**
* Set createdAt
*
* #param int $createdAt
* #return Family
*/
public function setCreatedAt($createdAt)
{
$this->createdAt = $createdAt;
return $this;
}
/**
* Get createdAt
*
* #return int $createdAt
*/
public function getCreatedAt()
{
return $this->createdAt;
}
/**
* #MongoDB\PrePersist
*/
public function prePersist()
{
$this->setCreatedAt(time());
$slugService = new SlugService();
$this->setSlug($slugService->slug($this->getName()));
}
/**
* #MongoDB\PreUpdate
*/
public function preUpdate()
{
$slugService = new SlugService();
$this->setSlug($slugService->slug($this->getName()));
}
}
The form crash when I try to persist the object in the controller action_
$this->persist($family);
I tried lot of options but no one with good results. If you have some idea, please reply.