/** * {@inheritdoc} */ public function settingsForm(array $form, FormStateInterface $form_state) { $element = parent::settingsForm($form, $form_state); $element['summary_rows'] = array('#type' => 'number', '#title' => t('Summary rows'), '#default_value' => $this->getSetting('summary_rows'), '#required' => TRUE, '#min' => 1); return $element; }