Sulu\Bundle\ContentBundle\Form\Type\BasePageDocumentType::buildForm PHP Method

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        parent::buildForm($builder, $options);
        $builder->add('extensions', TextType::class, ['property_path' => 'extensionsData']);
        $builder->add('resourceSegment', TextType::class);
        $builder->add('navigationContexts', CollectionType::class, ['type' => TextType::class, 'allow_add' => true, 'allow_delete' => true]);
        $builder->add('redirectType', IntegerType::class);
        $builder->add('redirectTarget', DocumentObjectType::class);
        $builder->add('redirectExternal', TextType::class);
        $builder->add('workflowStage', IntegerType::class);
        $builder->add('shadowLocaleEnabled', CheckboxType::class);
        $builder->add('shadowLocale', TextType::class);
        // TODO: Should be choice of available shadow locales
        $builder->setAttribute('webspace_key', $options['webspace_key']);
    }

 /**
  * {@inheritdoc}
  */
 public function buildForm(FormBuilderInterface $builder, array $options)
 {
     parent::buildForm($builder, $options);
     $builder->add('parent', DocumentObjectType::class);
     $builder->addEventListener(FormEvents::POST_SUBMIT, [$this, 'postSubmitDocumentParent']);
 }