Extend Doctrine2 form EntityType - php

Question

I'm looking for a way to extend Symfony 2 EntityType
Symfony\Bridge\Doctrine\Form\Type\EntityType
as in a new type extending this one, not creating a FormTypeExtension - and I can't figure it out. Does anyone know any proper way to do that?
I've tried simply extending it that way:
class NestedEntityType extends EntityType {
public function getName() {
return $this->getBlockPrefix();
}
public function getBlockPrefix() {
return 'nested_entity';
}
}
and then in sonata admin class I have:
protected function configureFormFields(FormMapper $formMapper)
{
$formMapper->add('types', NestedEntityType::class, [
'label' => false,
'multiple' => true,
'expanded' => true,
'by_reference' => false
]);
}
but unfortunately it causes Fatal Error:
Catchable Fatal Error: Argument 1 passed to
Symfony\Bridge\Doctrine\Form\Type\DoctrineType::__construct() must
implement interface Doctrine\Common\Persistence\ManagerRegistry, none
given, called in
I need to keep the whole functionality of EntityType, with one exception - the way it's presented. That's why I need to extend this type (I use it in other fields, so I can't just modify the template for it!).
I'm using Symfony 2.8 (just for the record).

Answer 1

You should not extend it directly but use parent option
/**
* {#inheritdoc}
*/
public function getParent()
{
return EntityType::class;
}
So something like
class NestedEntityType extends AbstractType
{
public function getName()
{
return $this->getBlockPrefix();
}
public function getBlockPrefix()
{
return 'nested_entity';
}
/**
* {#inheritdoc}
*/
public function getParent()
{
return EntityType::class;
}
}
That way if FormType you're extending from has something in injected (or setted) into constructor, you don't need to care as symfony will do it for you.

Answer 2

So, if you need a create a reusable solution, for different Entities, you don't need a configureOptions in this case.
You need to create an elementType in you code like
$this->createForm(NestedEntityType::class, null, ['class' => YourEntity::class]);
And in this case, you will need to pass as an option a name of class Entity which is nested.

Answer 3

If you would go to EntityType, you'll see it's extending DoctrineType and needs dependencies in constructor -
public function __construct(ManagerRegistry $registry, PropertyAccessorInterface $propertyAccessor = null)
{
$this->registry = $registry;
$this->propertyAccessor = $propertyAccessor ?: PropertyAccess::createPropertyAccessor();
}
So, your class NestedEntityType uses the same constructor and needs the same dependencies.
Actually, what you need is
class NestedEntityType extends AbstractType {
public function getParent() {
return EntityType::class;
}
public function getName() {
return $this->getBlockPrefix();
}
public function getBlockPrefix() {
return 'nested_entity';
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'class' => YourEntity::class
]);
}
}
UPD: Of course you need configure options, according to EntityType doc. See method I've added to code.