public FormCache::deleteCache($form_build_id) Deletes

If set to TRUE the original, unprocessed form structure will be cached, which allows the entire form to be rebuilt from cache. A typical form workflow involves two page requests;

public FormStateInterface::getButtons()

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

public FormCacheInterface::getCache($form_build_id, FormStateInterface

public FormState::hasTemporaryValue($key) Determines

public FormErrorHandler::handleFormErrors(array &$form, FormStateInterface

public FormStateDecoratorBase::getRedirect()

public FormBuilder::doSubmitForm(&$form, FormStateInterface &$form_state)

public FormInterface::submitForm(array &$form, FormStateInterface $