UserWithRoleSelectorType.php

<?php
namespace Acme\UserBundle\Form\Type;

use JMS\DiExtraBundle\Annotation\FormType;

use Symfony\Component\OptionsResolver\Options;

use Symfony\Component\OptionsResolver\OptionsResolverInterface;

use Doctrine\ORM\EntityRepository;

use Symfony\Component\Form\AbstractType;

/**
 * @FormType()
 */
class UserWithRoleSelectorType extends AbstractType
{
    public function getParent()
    {
        return "entity";
    }
    
    public function getName()
    {
        return "acme_user_with_role_selector";
    }
    
    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setRequired(array('role'));
        $resolver->setDefaults(array('class' => 'Acme\UserBundle\Entity\User',
                                     'property' => 'username',
                                     'query_builder' => function(Options $options, $value) {
                                         $serRole = serialize($options['role']);
                                         return function(EntityRepository $er) use($serRole) {
                                             $searchStr = "%{$serRole}%";
                                             return $er->createQueryBuilder('u')->leftJoin('u.userClass', 'uc')
                                                                                ->leftJoin('uc.groups', 'g')
                                                                                ->where('g.roles LIKE :searchStr')
                                                                                ->setParameter('searchStr', $searchStr)
                                                                                ->orderBy('u.username', 'ASC');
                                         };
                                     }));
    }
}