/**
* Check if parent layouts may available for one child layout
* @category save_callback
*
* @param mixed $varValue
* @param \DataContainer $dc
*
* @return mixed
* @throws \Exception
*/
public function checkIfChildPossible($varValue, \DataContainer $dc)
{
if ($varValue) {
/** @noinspection PhpUndefinedMethodInspection */
$intPossibleParentLayouts = \LayoutModel::countBy(array('isChild<>1'));
if ($intPossibleParentLayouts < 1) {
throw new \Exception($GLOBALS['TL_LANG']['ERR']['noPossibleParentLayouts']);
}
}
return $varValue;
}