UserController.php

<?php
/**
 * This file is part of the lapera.local package.
 *
 * (c) Daniel González <daniel@desarrolla2.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace LaPera\RestBundle\Controller;

use FOS\RestBundle\Controller\FOSRestController;
use Nelmio\ApiDocBundle\Annotation\ApiDoc;
use FOS\RestBundle\Controller\Annotations\Prefix;
use FOS\RestBundle\Controller\Annotations\NamePrefix;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use LaPera\RestBundle\Form\Type\UsersType;
use LaPera\RestBundle\Form\Model\UsersModel;
use LaPera\RestBundle\Form\Handler\UsersHandler;
use LaPera\RestBundle\Model\Serializer\User;

/**
 * UsersController
 *
 * @NamePrefix("api_user_")
 */
class UserController extends FOSRestController{
  public function postUsersAction(Request $request)
    {
        $form = $this->createForm(
            new UsersType(),
            new UsersModel()
        );

    // other stuffs ..
    }
}

UserModel.php

<?php
/**
 * This file is part of the lapera.local package.
 *
 * (c) Daniel González <daniel@desarrolla2.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace LaPera\RestBundle\Form\Model;

use Symfony\Component\Validator\Constraints as Assert;
use LaPera\CoreBundle\Validator\Constraints as LaPeraAssert;

/**
 * UserModel
 */
class UserModel
{
    /**
     * @var string $username
     *
     * @Assert\NotBlank()
     * @Assert\Length( min=5 )
     * @LaPeraAssert\Username
     */
    protected $username;

    /**
     * @var string $email
     *
     * @Assert\NotBlank()
     * @Assert\Email( )
     */
    protected $email;

    /**
     * @var string $password
     *
     * @Assert\NotBlank()
     * @Assert\Length( min=5 )
     */
    protected $password;

    /**
     * @param string $email
     */
    public function setEmail($email)
    {
        $this->email = $email;
    }

    /**
     * @return string
     */
    public function getEmail()
    {
        return $this->email;
    }

    /**
     * @param string $password
     */
    public function setPassword($password)
    {
        $this->password = $password;
    }

    /**
     * @return string
     */
    public function getPassword()
    {
        return $this->password;
    }

    /**
     * @param string $username
     */
    public function setUsername($username)
    {
        $this->username = $username;
    }

    /**
     * @return string
     */
    public function getUsername()
    {
        return $this->username;
    }
}

UsersModel.php

<?php
/**
 * This file is part of the lapera.local package.
 *
 * (c) Daniel González <daniel@desarrolla2.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace LaPera\RestBundle\Form\Model;

/**
 * UsersModel
 */
class UsersModel
{
    protected $user;

    /**
     * @param mixed $user
     */
    public function setUser($user)
    {
        $this->user = $user;
    }

    /**
     * @return mixed
     */
    public function getUser()
    {
        return $this->user;
    }
}

UsersType.php

<?php
/**
 * This file is part of the lapera.local package.
 *
 * (c) Daniel González <daniel@desarrolla2.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace LaPera\RestBundle\Form\Type;

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

/**
 * UserType
 */
class UserType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array                $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add(
                'username',
                'text',
                array(
                    'required' => true,
                    'trim' => true,
                )
            )
            ->add(
                'email',
                'email',
                array(
                    'required' => true,
                    'trim' => true,
                )
            )
            ->add(
                'password',
                'password',
                array(
                    'required' => true,
                    'trim' => true,
                )
            );
    }

    /**
     * @param OptionsResolverInterface $resolver
     */
    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(
            array(
                'data_class' => 'LaPera\RestBundle\Form\Model\UserModel',
            )
        );
    }

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

UserType.php

<?php
/**
 * This file is part of the lapera.local package.
 *
 * (c) Daniel González <daniel@desarrolla2.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace LaPera\RestBundle\Form\Type;

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

/**
 * UsersType
 */
class UsersType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array                $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add(
                'user',
                new UserType(),
                array(
                    'required' => true,
                )
            );
    }

    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(
            array(
                'data_class' => 'LaPera\RestBundle\Form\Model\UsersModel',
                'csrf_protection' => false,
            )
        );
    }

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