The config factory. Subclasses should use the self::config() method, which may be overridden to address specific needs when loading config,

public static OptGroup::flattenOptions(array $array) Allows

The class resolver. Type:

public FormState::getRedirect() Gets the

public FormStateInterface::isSubmitted()

public static FormState::hasAnyErrors() Determines

protected FormAjaxSubscriber::getFormAjaxException(\Exception

Defines element value callables which are safe to run even when the form state has an invalid CSRF token. Excluded from this list on purpose:

public FormState::has($property) Determines

The HTTP form method to use for finding the input for this form. May be 'POST' or 'GET'. Defaults to 'POST'. Note that 'GET' method forms do