Nette\Forms\Rules::check PHP Метод

    public function check()
    {
        if ($this->required !== NULL) {
            return;
        }
        foreach ($this->rules as $rule) {
            if ($rule->control === $this->control && ($rule->validator === Form::FILLED || $rule->validator === Form::BLANK)) {
                // ignore
            } elseif ($rule->branch) {
                if ($rule->branch->check() === TRUE) {
                    return TRUE;
                }
            } else {
                trigger_error("Missing setRequired(TRUE | FALSE) on field '{$rule->control->getName()}' in form '{$rule->control->getForm()->getName()}'.", E_USER_WARNING);
                return TRUE;
            }
        }
    }