The theme manager. Type:

Provides form building and processing. Hierarchy class \Drupal\Core\Form\

protected FormBuilder::handleInputElement($form_id, &$element, FormStateInterface

The CSRF token generator to validate the form token. Type:

public FormBuilder::getCache($form_build_id, FormStateInterface $form_state)

public FormBuilder::doBuildForm($form_id, &$element, FormStateInterface

Type:

Type:

The element info manager. Type:

protected FormBuilder::buttonWasClicked($element, FormStateInterface &$