The form error handler. Type:

public FormStateInterface::isValueEmpty($key)

Wraps AJAX form submissions that are triggered via an exception. Hierarchy class

Custom exception to break out of AJAX form processing. Hierarchy class \Drupal\Core\Form\

public FormSubmitter::redirectForm(FormStateInterface $form_state)

public FormSubmitter::doSubmitForm(&$form, FormStateInterface &

Request key for AJAX forms that submit to the form's original route. This constant is distinct from a "drupal_ajax" value for

public ConfirmFormBase::getConfirmText()

hook_ajax_render_alter(array &$data) Alter the Ajax command data that is sent to the client.

The form definition. Type: