Symfony2 2x many-to-one in form missing form data - forms

Question

I am using a Doctrine 2x one-to-many linking table like what is recommended in the docs
My Doctrine relationships seem to be fetching data properly, as evidenced by the fact that vars.data.myCollectionName has values,
{{ ladybug_dump( bandVacancyAssociation.bandVacancy.vars.data.genres) }}
yet when I try to access the form field children in order to use the form_row twig function my data is always an empty array
{{ ladybug_dump(edit_form.bandVacancyAssociations.children[0].children)}}
Since I do have values I can reverse engineer the symfony form structure but I would rather get it working using the built-in form widgets, any assistance would be much appreciated.
Here is the relevant code
Band
/**
* #ORM\OneToMany(targetEntity="BandVacancyAssociation", mappedBy="band", cascade={"persist"})
*/
private $bandVacancyAssociations;
BandType
$builder
->add('name')
->add('description')
->add('bandVacancyAssociations','collection',
array(
'by_reference' => true,
'type' => new BandVacancyAssociationType()
)
)
BandVacancy
/**
* #ORM\OneToMany(targetEntity="BandVacancyAssociation", mappedBy="bandVacancy",fetch="EAGER")
*/
private $bandVacancyAssociations;
/**
* #ORM\ManyToMany(targetEntity="Genre", inversedBy="bandVacancies",fetch="EAGER")
* #ORM\JoinTable(name="bandvacancy_genre",
* joinColumns={#ORM\JoinColumn(name="bandvacancy_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="genre_id", referencedColumnName="id")}
* )
*/
protected $genres;
/**
* #ORM\ManyToMany(targetEntity="Instrument", inversedBy="bandVacancies",fetch="EAGER")
* #ORM\JoinTable(name="bandvacancy_instrument",
* joinColumns={#ORM\JoinColumn(name="bandvacancy_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="instrument_id", referencedColumnName="id")}
* )
*/
protected $instruments;
BandVacancyType
$builder->add('genres', 'entity', array(
'multiple' => true,
'expanded' => true,
'class' => 'ZE\BABundle\Entity\Genre',
'property' => 'name',
))
->add('instruments', 'entity', array(
'multiple' => true,
'expanded' => true,
'class' => 'ZE\BABundle\Entity\Instrument',
'property' => 'name',
));
Band Vacancy Association
/**
* #ORM\ManyToOne(targetEntity="BandVacancy", inversedBy="bandVacancyAssociations",fetch="EAGER")
*/
private $bandVacancy;
BandVacancyAssociationType
$builder
->add('bandVacancy', 'entity', array( 'class' => 'ZE\BABundle\Entity\BandVacancy'))
;

Answer 1

It turns out that the one thing I was missing was this:
/**
* #param FormBuilderInterface $builder
* #param array $options
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('bandVacancy', new BandVacancyType())
;
}
I can now loop through the values in the form.
<div class="panel">Band Vacancies
{% for bandVacancyAssociation in edit_form.bandVacancyAssociations %}
{#{{ dump(bandVacancyAssociation.vars.data.id) }}#}
<div class="panel-group" id="accordion">
<div class="panel panel-default" id="panel{{ bandVacancyAssociation.vars.data.id }}">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-target="#collapse{{ bandVacancyAssociation.vars.data.id }}"
href="#collapse{{ bandVacancyAssociation.vars.data.id }}">
{{ bandVacancyAssociation.vars.data.bandVacancy.name}}
</a>
</h4>
</div>
<div id="collapse{{ bandVacancyAssociation.vars.data.id }}" class="panel-collapse collapse in">
<div class="panel-body">
{{ form_label(bandVacancyAssociation.bandVacancy.name) }}
{{ form_widget(bandVacancyAssociation.bandVacancy.name) }}
{{ form_label(bandVacancyAssociation.bandVacancy.comment) }}
{{ form_widget(bandVacancyAssociation.bandVacancy.comment) }}
{% for genre in bandVacancyAssociation.bandVacancy.genres %}
{{ form_label(genre) }}{{ form_widget(genre) }}
{% endfor %}
{% for instrument in bandVacancyAssociation.bandVacancy.instruments %}
{{ form_label(instrument) }}{{ form_widget(instrument) }}
{% endfor %}
</div>
</div>
</div>
</div>
{% endfor %}
</div>
Thanks to whoever downvoted this question.