protected function getCaptionControl()
{
if (($id = $this->getCaptionID()) !== '') {
if ($control = $this->getPage()->findControl($id)) {
return $control;
}
if ($control = $this->getNamingContainer()->findControl($id)) {
return $control;
}
}
throw new TInvalidDataValueException('ratinglist_invalid_caption_id', $id, $this->getID());
}