How to access one to one embedded form symfony2

Question

I used symfony 2 only few days. I got two entities and i want to create one form and save data from this form into database. UserDetails and Contract have relations OneToOne. I embed a form of Contract into UserDetails form (form apper on web) but when i set some data into form and click button "save" i get a error. as i notice a "try" to assign an array instead of Contract i don't know how to access this new contract entite in Controler.

example ERRORS:

ContextErrorException: Catchable Fatal Error: Argument 1 passed to Leave\DatabaseBundle\Entity\UserDetails::setContract() must be an instance of Leave\DatabaseBundle\Entity\Contract, array given, called in /var/www/nowyUrlop/vendor/symfony/symfony/src/Symfony/Component/PropertyAccess/PropertyAccessor.php on line 360 and defined in /var/www/nowyUrlop/src/Leave/DatabaseBundle/Entity/UserDetails.php line 165

at UserDetails->setContract(array('start_contr' => object(DateTime), 'end_contr' => object(DateTime), 'hours_per_week' => '6')) in /var/www/nowyUrlop/vendor/symfony/symfony/src/Symfony/Component/PropertyAccess/PropertyAccessor.php line 360

UserDetails entity:

use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Annotations\AnnotationReader;
use Leave\DatabaseBundle\Entity\User;

/**
 * @ORM\Entity
 * @ORM\Table(name="userDetails")
 */
class UserDetails {

/**
 * @ORM\Id
 * @ORM\Column(type="integer")
 * @ORM\GeneratedValue(strategy="AUTO")
 */
protected $id;

/**
 * @ORM\OneToOne(targetEntity="Contract", mappedBy="user_details", cascade={"persist"})
 */
protected $contract;

/**
 * @ORM\OneToOne(targetEntity="User", inversedBy="userDetails")
 * @ORM\JoinColumn(name="user_id", nullable = true, referencedColumnName="id")
 * */
protected $user;

Contract Entity:

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * @ORM\Entity
 * @ORM\Table(name="contract")
 */
class Contract {

/**
 * @ORM\Id
 * @ORM\Column(type="integer")
 * @ORM\GeneratedValue(strategy="AUTO")
 */
protected $id;

/**
 * @ORM\Column(type="date")
 */
protected $start_contr;

/**
 * @ORM\Column(type="date")
 */
protected $end_contr;

/**
 * @ORM\Column(type="integer")
 */
protected $type ;

/**
 * @ORM\Column(type="integer")
 */
protected $hours_per_week;

/**
 * @ORM\OneToOne(targetEntity="UserDetails", inversedBy="contract")
 * @ORM\JoinColumn(name="user_details_id", nullable = true, referencedColumnName="id")
 * */
protected $user_details;

public function setUserDetails(\Leave\DatabaseBundle\Entity\UserDetails $userDetails = null)
{
    $this->user_details = $userDetails;

    return $this;
}

/**
 * Get user_details
 *
 * @return \Leave\DatabaseBundle\Entity\UserDetails 
 */
public function getUserDetails()
{
    return $this->user_details;
}

UserDetals Form:

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Leave\DatabaseBundle\Form\Type\ContractFormType;

class UserDetailsFormType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('exp', 'text')
        ->add('total_leave', 'text')
        ->add('days_left', 'text')
        ->add('contract', new contractFormType())
        ->add('save', 'submit');
    }

    public function getName()
    {
        return 'userDetails';
    }
}

Contract Form:

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;

class ContractFormType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('start_contr', 'date', array('widget' => 'single_text'))
        ->add('end_contr', 'date', array('widget' => 'single_text'))
        ->add('hours_per_week', 'text');
}   

public function getName()
{
    return 'contractForm';
}
}

Controller:

 public function editUserAction(Request $request) {

    $user = $this->get('security.context')->getToken()->getUser();
    $userDetails = new UserDetails();
    $form = $this->createForm(new UserDetailsFormType(), $userDetails);
    $userDetails->setUser($user);

    $form->handleRequest($request);

    if ($form->isValid()) {
        $em = $this->getDoctrine()->getManager();
        $em->persist($userDetails);
        $em->flush();

        return $this->render('LeaveEmployeeBundle:Employee:editUser.html.twig', array(
                    'formEditUser' => $form->createView(),
                    'userDetails' => $userDetails,
                    'user' => $user
            ));
    }
    return $this->render('LeaveEmployeeBundle:Employee:editUser.html.twig', array(
                'formEditUser' => $form->createView()
    ));
}

Answer 1

You have to pass data_class as second parameter.

In your UserDetals Form: do the following

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Leave\DatabaseBundle\Form\Type\ContractFormType;

class UserDetailsFormType extends AbstractType
{
   public function buildForm(FormBuilderInterface $builder, array $options)
   {
       $builder->add('exp', 'text')
       ->add('total_leave', 'text')
       ->add('days_left', 'text')
       ->add('contract', new contractFormType(), array(
        'data_class' => 'Leave\DatabaseBundle\Entity\Contract')
       )
       ->add('save', 'submit');
   }

   public function getName()
   {
      return 'userDetails';
   }
}