Add fullText (WHERE LIKE OR) with SonataDoctrineORMAdminBundle search to datagridFilters in SonataAdminBundle

UserAdmin.php

<?php

namespace Application\Sonata\UserBundle\Admin;

use Sonata\UserBundle\Admin\Model\UserAdmin as SonataUserAdmin;
use Sonata\AdminBundle\Datagrid\DatagridMapper;

class UserAdmin extends SonataUserAdmin
{
    protected function configureDatagridFilters(DatagridMapper $filterMapper)
    {
        $filterMapper
            ->add('full_text', 'doctrine_orm_callback', array(
                'callback' => array($this, 'getFullTextFilter'),
                'field_type' => 'text'
            ));
    }

    public function getFullTextFilter($queryBuilder, $alias, $field, $value)
    {
        if (!$value['value']) {
            return;
        }

        $queryBuilder->andWhere($queryBuilder->expr()->orX(
            $queryBuilder->expr()->like($alias.'.username', $queryBuilder->expr()->literal('%' . $value['value'] . '%')),
            $queryBuilder->expr()->like($alias.'.firstName', $queryBuilder->expr()->literal('%' . $value['value'] . '%')),
            $queryBuilder->expr()->like($alias.'.lastName', $queryBuilder->expr()->literal('%' . $value['value'] . '%')),
            $queryBuilder->expr()->like($alias.'.email', $queryBuilder->expr()->literal('%' . $value['value'] . '%'))
        ));

        return true;
    }
}