Child form type

TagType.php

<?php

namespace ForaSoft\ImproveClassBundle\Form\Type;

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

class TagType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('tag');
    }

    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            'data_class'=>'ForaSoft\ImproveClassBundle\Entity\Tag',
        ));
    }

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

}