Symfony Form - Allow removal of nested form associated entity - symfony

Question

I have a /checkout JSON API endpoint which allows an optional billingAddress parameter alongside other parameters such as email and deliveryAddress.
These addresses are stored in an Address entity related to an Order entity.
Everything works nicely if a user enters their billingAddress, but if a user removes a previously submitted billing address, I can find no way to remove the billingAddress entity. Ideally to remove the billing address I'd use the following JSON POST request.
{
"email": "nick#example.com",
"deliveryAddress": {
"line1": "1 Box Lane"
},
"billingAddress": null
}
Is this at all possible with Symfony forms?
See below for a simplified explanation of the current setup.
Entities
/**
* #ORM\Entity
*/
class Order
{
// ...
/**
* #var Address
*
* #ORM\OneToOne(targetEntity = "Address", cascade = {"persist", "remove"})
* #ORM\JoinColumn(name = "deliveryAddressId", referencedColumnName = "addressId")
*/
private $deliveryAddress;
/**
* #var Address
*
* #ORM\OneToOne(targetEntity = "Address", cascade = {"persist", "remove"}, orphanRemoval = true)
* #ORM\JoinColumn(name = "billingAddressId", referencedColumnName = "addressId", nullable = true)
*/
private $billingAddress;
public function setDeliveryAddress(Address $deliveryAddress = null)
{
$this->deliveryAddress = $deliveryAddress;
return $this;
}
public function getDeliveryAddress()
{
return $this->deliveryAddress;
}
public function setBillingAddress(Address $billingAddress = null)
{
$this->billingAddress = $billingAddress;
return $this;
}
public function getBillingAddress()
{
return $this->billingAddress;
}
// ...
}
.
/**
* #ORM\Entity
*/
class Address
{
// ...
/**
* #var string
*
* #ORM\Column(type = "string", length = 45, nullable = true)
*/
private $line1;
// ...
}
Forms
class CheckoutType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('email', EmailType::class)
->add('deliveryAddress', AddressType::class, [
'required' => true
])
->add('billingAddress', AddressType::class, [
'required' => false
]);
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => Order::class,
'csrf_protection' => false,
'allow_extra_fields' => true,
'cascade_validation' => true
]);
}
public function getBlockPrefix()
{
return '';
}
}
.
class AddressType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
// ...
->add('line1', TextType::class);
// ...
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => Address::class,
'allow_extra_fields' => true
]);
}
public function getBlockPrefix()
{
return '';
}
}

Answer 1

Form events are what you need: https://symfony.com/doc/current/form/events.html
For example if you want to remove the billingAddress field after the form submission you can do that:
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('email', EmailType::class)
->add('deliveryAddress', AddressType::class, [
'required' => true
])
->add('billingAddress', AddressType::class, [
'required' => false
]);
$builder->addEventListener(FormEvents::PRE_SUBMIT, function(FormEvent $event) {
$form = $event->getForm();
$data = $event->getData();
if (empty($data['billingAddress'])) {
$form->remove('billingAddress');
}
});
}
Read carefully the documentation to know which event will be the best for your scenario.

Answer 2

Try setting the "by_reference" option for the "billingAddress" field to false in order to make sure that the setter is called.
http://symfony.com/doc/current/reference/forms/types/form.html#by-reference

Answer 3

Big thanks to Renan and Raphael's answers as they led me to discovering the below solution which works for both a partial PATCH and full POST request.
class CheckoutType extends AbstractType
{
/** #var bool */
private $removeBilling = false;
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('email', EmailType::class)
->add('deliveryAddress', AddressType::class, [
'constraints' => [new Valid]
])
->add('billingAddress', AddressType::class, [
'required' => false,
'constraints' => [new Valid]
])
->addEventListener(FormEvents::PRE_SUBMIT, [$this, 'onPreSubmit'])
->addEventListener(FormEvents::POST_SUBMIT, [$this, 'onPostSubmit']);
}
public function onPreSubmit(FormEvent $event)
{
$data = $event->getData();
$this->removeBilling = array_key_exists('billingAddress', $data) && is_null($data['billingAddress']);
}
public function onPostSubmit(FormEvent $event)
{
if ($this->removeBilling) {
$event->getData()->setBillingAddress(null);
}
}
}