EditSkillsForm.php

<?php

namespace User\Form\Student;

use Zend\Form\Form;
use Zend\Stdlib\Hydrator\ClassMethods as ClassMethodsHydrator;

class EditSkills extends Form
{
    public function __construct()
    {
        parent::__construct('edit-skills-form');

        $this->setHydrator(new ClassMethodsHydrator(false));

        $this->add(array(
            'type'     => 'User\Form\Student',
            'name'     => 'student',
            'options'  => array(
                'use_as_base_fieldset' => true
            )
        ));

        // Add the skills
        $this->get('student')->add(array(
            'type'    => 'Zend\Form\Element\Collection',
            'name'    => 'skills',
            'options' => array(
                'count'                  => 1,
                'allow_add'              => true,
                'allow_remove'           => true,
                'should_create_template' => true,
                'target_element'         => array(
                    'type' => 'User\Form\StudentSkill'
                )
            )
        ));

        $this->add(array(
            'type'       => 'Zend\Form\Element\Submit',
            'name'       => 'submit',
            'attributes' => array(
                'value' => 'Sauvegarder',
                'class' => 'button button-blue'
            )
        ));

        $this->setValidationGroup(array(
            'student' => array(
                'skills'
            )
        ));
    }
}

StudentSkillFieldset.php

<?php

namespace User\Form;

use Common\Registry\Registry;
use DoctrineORMModule\Stdlib\Hydrator\DoctrineEntity as DoctrineHydrator;
use User\Entity\StudentSkill as StudentSkillEntity;
use Zend\Form\Fieldset;
use Zend\InputFilter\InputFilterProviderInterface;
use Zend\Stdlib\Hydrator\ClassMethods as ClassMethodsHydrator;

class StudentSkill extends Fieldset implements InputFilterProviderInterface
{
    /**
     * Constructor
     */
    public function __construct()
    {
        parent::__construct();

        $this->setHydrator(new DoctrineHydrator(Registry::get('EntityManager')))
             ->setObject(new StudentSkillEntity());

        $this->add(array(
            'name'       => 'id',
            'attributes' => array(
                'type' => 'hidden'
            )
        ));

        $this->add(array(
            'name'    => 'name',
            'attributes' => array(
                'type'      => 'text',
                'maxlength' => 32,
                'style'     => 'width: 44.8%'
            )
        ));

        $this->add(array(
            'type'    => 'Zend\Form\Element\Select',
            'name'    => 'level',
            'options' => array(
                'value_options' => array(
                    25  => 'Débutant',
                    50  => 'Intermédiaire',
                    75  => 'Confirmé',
                    100 => 'Expert'
                )
            ),
            'attributes' => array(
                'style' => 'width: 47%',
                'value' => 25,
                'class' => 'last'
            )
        ));
    }

    /**
     * @return array
     */
    public function getInputFilterSpecification()
    {
        return array(
            'id' => array(
                'required' => true,
                'allow_empty' => true
            ),

            'name' => array(
                'required'   => true,
                'filters'    => array(
                    array('name' => 'StringTrim'),
                    array('name' => 'StripTags')
                ),
                'validators' => array(
                    array(
                        'name'    => 'StringLength',
                        'options' => array('max' => 32)
                    )
                )
            ),

            'level' => array(
                'required' => true
            )
        );
    }
}