Question

Orm/Yaml

Subject:
    type: entity
    repositoryClass: My\SampleBundle\Repository\SubjectRepository
    id:
        id:
            type: integer
            generator: { strategy: AUTO }
    fields:
        body:
            type: text
    oneToMany:
        choices:
            targetEntity: Choice
            mappedBy: subject
            cascade: ["persist", "remove"]
Choice:
    type: entity
    repositoryClass: My\SampleBundle\Repository\ChoiceRepository
    id:
        id:
            type: integer
            generator: { strategy: AUTO }
    fields:
        choice:
            type: text
    manyToOne:
        subject:
            targetEntity: Subject
            inversedBy: choices
            joinColumn:
                name: subject_id
                referencedColumnName: id

View

<form action="{{ path('path_create or path_edit', {'id': id}) }}" method="post" {{ form_enctype(form) }}>

    // ...

    <ul id="choice-list" data-prototype="{{ form_widget(form.choices.vars.prototype.choice) | e }}">
        {% for choice in form.choices %}
            <li>
                <div class="errors">
                    {{ form_errors(choice.choice) }}
                </div>
                {{ form_widget(choice.choice) }}
            </li>
        {% endfor %}
    </ul>

    <!-- ## The field can be added by JavaScript. -->
    <span class="add-another-choice">Add another choice</span>
    {{ form_rest(form) }}
    <input type="submit" class="_button" />
</form>

Form/Type

class SubjectType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('body', 'textarea');
        $builder->add('choices', 'collection', array(
            'type' => new ChoiceType(),
            'options' => array(
                'required'  => false
            ),
            'allow_add' => true,
            'by_reference' => false,
            'allow_delete' => true,
            'prototype' => true
        ));
    }

    // ...
}

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

    // ...
}

Validation

Subject:
    properties:
        body:
            - NotBlank: ~
            - MinLength: 8
        choices:
            - Valid: ~
Choice:
    properties:
        choice:
            - NotBlank: ~

Controller

public function createAction(Request $request, $id)
{
    $em = $this->get('doctrine')->getEntityManager();

    $subject = new Subject();
    $subject->getChoices()->add(new Choice());

    $form = $this->createForm(new SubjectType(), $subject);

    if ($request->getMethod() == 'POST') {
        $form->bindRequest($request);           //<= error on this point. Why?
                                                // if there is the empty field.
        if ($form->isValid()) {
            return // ...
        }
    }

    return $this->render('MySampleBundle:Subject:create.html.twig', array(
        'form' => $form->createView(),
    ));
}

---

I try collection form of symfony2.
But, when the field is increased by Javascript, it will fail, if there is the empty field.
When the field is increased, it is before execution of validation and becomes an error. (Catchable Fatal Error:))

How can I manage to achieve that?

---

EDIT:

If the value is set up, two or more registration will be successful.
If there is an item to which the value is not set, two or more registration will go wrong.
bindRequest function failed.
If only the part of an empty value adds an entity, it will be successful.
However, it seems that it is not right way.

Answer 1

Remove required=false from choice form field or add nullable=true to schema choice field