Allow a OneToOne relationship to be optional in Symfony2 - symfony

Question

I have a form responsible of creating and updating users. A user can (or not) have an address (OneToOne unidirectional relation from user).
When I create a user, no problem.
When I update a user, usually no problem.
Problems come up when i update a user which already has an address and try to unset all the address fields. There is then a validation error.
The wanted behavior would be to have the user->address relation set to null (and delete the previously set address on the DB).
There is a cascade_validation, the addess field in form (nested form) is set to not be required and the user entity allow the address to be null.
UPDATE
Relevant entities and forms :
User entity (Getters & Setters are classical, Symfony generated):
class User
{
[...]
/**
* #var \Address
*
* #ORM\OneToOne(targetEntity="Address", cascade="persist")
* #ORM\JoinColumn(
* name="address_id", referencedColumnName="id"
* )
*/
private $address;
[...]
}
The address entity is classical, no bidirectionnal relation to user.
User form
class UserType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
[...]
->add('address', new AddressType(), array('required' => false))
[...]
;
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Xentia\FuneoBundle\Entity\User',
'cascade_validation' => true
));
}
public function getName()
{
return 'user';
}
}
The address nested form is classical
As you can see, the is a quite classical and straightforward code. The only particular case is that address is optional. Leading to an validation error only in the case that the address was previously set (and, thus, exist in the DB and as a not null relation with the user) and the user want to unset it (all address fields are left empty).
It seems that if the related address has not an actual instance it can still be optional. But, if an instance of the address exist and is linked with the user, it can not be optional anymore.
UPDATE 2
namespace Xentia\FuneoBundle\Form\Type;
use Doctrine\Common\Util\Debug;
use Symfony\Component\Config\Definition\Exception\Exception;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
class AddressType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add("suggestLocality", null, array(
'mapped' => false,
'label' => 'Locality'
))
->add("suggestStreet", null, array(
'mapped' => false,
'label' => 'Street'
))
->add('street')
->add('locality')
->add('postalCode')
->add('country', null, array(
'label' => false,
))
->add('latitude', 'hidden')
->add('longitude', 'hidden');
$builder->addEventListener(FormEvents::PRE_SUBMIT,
function(FormEvent $event) {
$address = $event->getData();
if (!empty($address)) {
$addressLocality = $address['locality'];
if (empty($addressLocality)) {
$event->setData(null);
}
}
}
);
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Xentia\FuneoBundle\Entity\Address',
'validation_groups' => array('Default'),
));
}
public function getName()
{
return 'address';
}
}

Answer 1

Try setting orphanRemoval on your relation
/** #OneToOne(targetEntity="...", orphanRemoval=true) */
$address
EDIT
I see now, you have placed the wrong listener. First of all it should be POST_SUBMIT, PRE_SUBMIT is to process request data and modify form. On POST SUBMIT you can modify the object.