add( 'attributes', CollectionType::class, [ 'entry_type' => FileInformationAttributeType::class, 'by_reference' => false, 'allow_add' => true, 'allow_delete' => true, 'prototype' => true, ] ); } public function configureOptions(OptionsResolver $resolver) { $resolver->setDefaults([ 'data_class' => FileInformation::class, ]); } }