Extend Doctrine2 form EntityType

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.