Symfony Form Entity ManyToMany - php

Question

I have entity Skill and ManyToMany Language and I need create form and in this form add name language for skill, now I add 'multiple'=>true, in form and have many language but when $form->isValid() I have error
This value is not valid.
in form
invalidValue={array}[2]
0 = "Java"
1 = "PHP"
Why in not valid I not understand ??
rhis is my entity skill
class Skill
{
use Timestampable;
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="skill", type="string", length=255)
*/
private $skill;
/**
* #var \Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages
*
* #ORM\ManyToMany(targetEntity="CodeDirectoryProgramLanguages", inversedBy="skills")
*/
protected $language;
/**
* Constructor
*/
public function __construct()
{
$this->language = new \Doctrine\Common\Collections\ArrayCollection();
$this->platforms = new \Doctrine\Common\Collections\ArrayCollection();
$this->specialities = new \Doctrine\Common\Collections\ArrayCollection();
}
/**
* Add language
*
* #param \Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages $language
*
* #return Skill
*/
public function addLanguage(\Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages $language)
{
$this->language[] = $language;
return $this;
}
/**
* Remove language
*
* #param \Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages $language
*/
public function removeLanguage(\Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages $language)
{
$this->language->removeElement($language);
}
/**
* Get language
*
* #return \Doctrine\Common\Collections\Collection
*/
public function getLanguage()
{
return $this->language;
}
this is my form
class SkillType extends AbstractType
{
/**
* #param FormBuilderInterface $builder
* #param array $options
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('mainSkill','checkbox');
$builder->add('language','entity',
array(
'class'=>'Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages',
'multiple'=>true,
'property'=>'languages', )
);
$builder
->add('edit','submit')
;
}
/**
* #param OptionsResolverInterface $resolver
*/
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Artel\ProfileBundle\Entity\Skill',
'csrf_protection' => false
));
}
/**
* #return string
*/
public function getName()
{
return 'skill';
}
}
and my action when $form->submit($request); have this error
/**
* Edit skill.
*
* #Route("/skills/edit/{id}", name="skill_edit")
* #Method({"GET", "POST"})
* #Template()
* #ParamConverter("entity", class="MyBundle:Skill")
*/
public function editSkillsAction(Request $request, $entity)
{
$em = $this->getDoctrine()->getManager();
$form = $this->createForm(new SkillType(), $entity);
if ($request->isMethod('POST')) {
$form->bind($request);
if ($form->isValid()) {
$em->persist($entity);
$em->flush();
return $this->redirect($this->generateUrl('skills_show'));
}
}
return array(
'debug' => true,
'form' => $form->createView(),
);
}
UPDATE
I try to add in form 'expanded' => true, and everything work, doctrine create ManyToMany relation in table. Maybe is there another way ?
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('mainSkill','checkbox');
$builder->add('language','entity',
array(
'class'=>'Artel\ProfileBundle\Entity\CodeDirectoryProgramLanguages',
'property'=>'languages',
'multiple'=>true,
'expanded' => true,
)
);
$builder
->add('edit','submit')
;
}