Symfony2 entities and createFormBuilder - entity-framework

Question

I need help with Symfony2 (2.8)
Created two entities Category and CategoryLang. It will be a categories.
<?php
namespace CreLabs\Bundle\SettingBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Doctrine\ORM\Mapping\Entity;
/**
* #ORM\Entity(repositoryClass="CreLabs\Bundle\SettingBundle\Entity\CategoryRepository")
* #ORM\Table(name="category")
*/
class Category
{
const STATUS_ENABLED = 1;
const STATUS_DISABLED = 0;
/**
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* #ORM\Column(type="boolean", nullable=true, options={"default": 1})
*/
protected $status;
/**
* #ORM\OneToMany(targetEntity="CategoryLang", mappedBy="category", cascade={"persist", "remove"})
*/
protected $locales;
/**
* #ORM\Column(type="datetime", nullable=false)
*/
protected $created_at;
/**
* #ORM\Column(type="datetime", nullable=true)
*/
/**
* #ORM\Column(type="datetime", nullable=true)
*/
protected $updated_at;
CategoryLang. It will be a translation of my categories.
<?php
namespace CreLabs\Bundle\SettingBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Doctrine\ORM\Mapping\Entity;
/**
* #Entity
* #ORM\Table(name="category_lang")
*/
class CategoryLang
{
/**
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* #ORM\Column(type="string", length=255)
*/
protected $name;
/**
* #ORM\Column(type="string", length=255, nullable=true)
*/
protected $description;
/**
* #ORM\ManyToOne(targetEntity="Category", inversedBy="locales", cascade={"persist", "remove"})
* #ORM\JoinColumn(name="category_id", referencedColumnName="id")
*/
protected $category;
/**
* #ORM\Column(type="string", length=2)
*/
protected $locale;
Now i trying add createFormBuilder Category Entity + CategoryLang Entities fields, but can not see normally form. Only can use array('mapped' => false and forward data from fields.
$form = $this->createFormBuilder($category);
$form = $form
->add('locale', HiddenType::class, array('mapped' => false, 'data' => $locale))
->add('name', TextType::class, array('mapped' => false, 'data' => $name))
->add('description', TextareaType::class, array('mapped' => false, 'required' => false, 'data' => $description))
->add($label, SubmitType::class, array('label' => $label));
$form = $form->getForm();
By the way have CategoryRepository with custom query
public function getCategory($category_id, $locale)
{
$repository = $this->getEntityManager()->getRepository('SettingBundle:Category');
$fields = array('p.id', 'category_info.name', 'category_info.description', 'p.status, category_info.locale');
$query = $repository->createQueryBuilder('p')
->select($fields)
->innerJoin('SettingBundle:CategoryLang', 'category_info', 'WITH', 'category_info.category = p.id')
->where('p.id = :category_id AND category_info.locale = :locale')
->setParameter('category_id', $category_id)
->setParameter('locale', $locale)
->getQuery();
$result = $query->getOneOrNullResult() != NULL ? new ArrayCollection($query->getSingleResult()) : false;
return $result;
}
Problems:
1. getCategory() -> return not object, but array or ArrayCollection. Can not be reused then need update fields in database.
/* #var $category Category */
$category = $this->getCategory($category_id, $form['locale']);
if ($category) {
// $category->setUpdatedAt(new ArrayCollection());
$locale = new CategoryLang();
$locale->setName($form['name']);
$locale->setDescription($form['description']);
$category->addLocale($locale);
$entityManager = $this->getEntityManager();
$entityManager->persist($category);
$entityManager->flush($category);
}
2. Can not get in create form builder information from child table.
Where is my problem? Can anybody help me understand my mistakes?