' . $this->t("Ajax Form contents description.") . '

', ]; $form['actions'] = [ '#type' => 'actions', ]; $form['actions']['submit'] = [ '#type' => 'submit', '#value' => $this->t('Do it'), ]; $form['actions']['preview'] = [ '#type' => 'submit', '#value' => $this->t('Preview'), // No regular submit-handler. This form only works via JavaScript. '#submit' => [], '#ajax' => [ // This means the ::preview() method on this class would be invoked in // case of a click event. However, since Drupal core's test runner only // is able to execute PHP, not JS, there is no point in actually // implementing this method, because we can never let it be called from // JS; we'd have to manually call it from PHP, at which point we would // not actually be testing it. // Therefore we consciously choose to not implement this method, because // we cannot meaningfully test it anyway. 'callback' => '::preview', 'event' => 'click', ], ]; return $form; } /** * {@inheritdoc} */ public function submitForm(array &$form, FormStateInterface $form_state) {} /** * {@inheritdoc} */ public function validateForm(array &$form, FormStateInterface $form_state) {} }