hook_form_BASE_FORM_ID_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) Provide

public ConfirmFormBase::getCancelText()

public FormBuilderInterface::retrieveForm($form_id, FormStateInterface

public FormStateInterface::hasValue($key)

public FormStateInterface::isExecuted()

public FormStateInterface::getRebuildInfo()

public FormStateDecoratorBase::isValueEmpty($key)

The element info manager. Type:

Provides a base class for forms. This class exists as a mid-point between dependency injection through ContainerInjectionInterface, and a less-structured

If TRUE, the form was submitted and has been processed and executed. This property is uncacheable. Type: