/** * {@inheritdoc} */ public function form(array $form, FormStateInterface $form_state) { // Hide subscription widget if only one newsletter available. if (count($this->getNewsletters()) == 1) { $this->getSubscriptionWidget($form_state)->setHidden(); } $form = parent::form($form, $form_state); $form['message'] = array('#type' => 'item', '#markup' => $this->message); return $form; }