public function __construct(QForm $objForm, $strGroupingId) {
if (strlen($strGroupingId) == 0)
$this->strGroupingId = $objForm->GenerateControlId();
else {
// Verify ControlId is only AlphaNumeric Characters
$strMatches = array();
$strPattern = '/[A-Za-z0-9]*/';
preg_match($strPattern, $strGroupingId, $strMatches);
if (count($strMatches) && ($strMatches[0] == $strGroupingId))
$this->strGroupingId = $strGroupingId;
else
throw new QCallerException('GroupingIDs must be only alphanumeric chacters: ' . $strGroupingId);
}
try {
$objForm->AddGrouping($this);
} catch (QCallerException $objExc) {
$objExc->IncrementOffset();
throw $objExc;
}
}