public FormBuilder::processForm($form_id, &$form, FormStateInterface &a

public &FormStateValuesTrait::getValue($key, $default

protected FormValidator::performRequiredValidation(&$elements, FormStateInterface

protected SubformState::__construct(array &$subform, array &$parent_form

public FormAjaxSubscriber::onView(GetResponse

Provides common functionality to confirmation forms. Hierarchy class \Drupal\Core\Form\

Stores information about the state of a subform. In the context of Drupal's Form API, a subform is a form definition array that will be nested

public FormStateInterface::setValidationEnforced($must_validate

public FormState::setFormState(array $form_state_additions)

public FormBase::setConfigFactory(ConfigFactoryInterface $config_factory)