if ($triggered) {
// Output the element's value from $form_state.
- drupal_set_message(t('@label value: @value', ['@label' => $element['#title'], '@value' => $form_state->getValue('name')]));
+ \Drupal::messenger()->addStatus(t('@label value: @value', ['@label' => $element['#title'], '@value' => $form_state->getValue('name')]));
// Trigger a form validation error to see our changes.
$form_state->setErrorByName('');