Filtering association field

gistfile1.php

<?php

namespace BVD\PetroleumBundle\Util;

use Lexik\Bundle\FormFilterBundle\Filter\Extension\Type\TextFilterType;
use Lexik\Bundle\FormFilterBundle\Filter\Extension\Type\FilterTypeInterface;
use Lexik\Bundle\FormFilterBundle\Filter\Extension\Type\AbstractFilterType;
use Doctrine\ORM\QueryBuilder;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
use Symfony\Component\Form\FormInterface;

use Lexik\Bundle\FormFilterBundle\Filter\Expr;

class EntityNameFilterType extends AbstractFilterType implements FilterTypeInterface {
    /**
     * {@inheritdoc}
     */
    public function getName()
    {
        return 'filter_entity_name';
    }
    
    /**
     * {@inheritdoc}
     */
    public function getParent()
    {
        return 'text';
    }
    
    /**
     * {@inheritdoc}
     */
    public function getTransformerId()
    {
        return 'lexik_form_filter.transformer.default';
    }
    
    /**
     * {@inheritdoc}
     */
    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        parent::setDefaultOptions($resolver);
    
        $resolver->setDefaults(array(
                        'association_field' => "",
        ));
    }
    
    /**
     * {@inheritdoc}
     */
    public function applyFilter(QueryBuilder $queryBuilder, Expr $expr, $field, array $values, FormInterface $form = null)
    {
        $field = $form->getConfig()->getOptions()['association_field'];
        
        if (!empty($values['value'])) {
            $queryBuilder->andWhere($expr->stringLike($field, $values['value'], TextFilterType::PATTERN_CONTAINS));
        }
    }
}