Drupal 8에서 #element_validate 및 #value_callback 사용 방법
공식 Form API Documentation을 따르지만 Drupal 8에서는이 코드가 작동하지 않습니다. public function buildForm(array $form, FormStateInterface $form_state) { $form['upload'] = array( '#title' => t('Upload Images'), '#type' => 'managed_file', '#upload_location' => 'public://image_example_images/', '#element_validate' => array('file_generic_settings_max_filesize'), ); return $form; } private function file_generic_settings_max_filesize($element, &$form_state) { form_error($element, 'This is an error.'); } $ form_state-> …