GroupStateTable::onDelete

static function onDelete(\Bitrix\Main\Entity\Event $event)
{
	$result = new \Bitrix\Main\Entity\EventResult;
	$data = $event->getParameters();

	$listId = array();
	if(array_key_exists('ID', $data['primary']))
	{
		$listId[] = $data['primary']['ID'];
	}
	else
	{
		$filter = array();
		foreach($data['primary'] as $primKey => $primVal)
		{
			$filter[$primKey] = $primVal;
		}

		$tableDataList = static::getList(array(
			'select' => array('ID'),
			'filter' => $filter
		));
		while($tableData = $tableDataList->fetch())
		{
			$listId[] = $tableData['ID'];
		}

	}

	foreach($listId as $primaryId)
	{
		$primary = array('GROUP_STATE_ID' => $primaryId);
		GroupThreadTable::deleteList($primary);
	}

	return $result;
}