/**
* Method to get the next ordering value for a group of rows defined by an SQL WHERE clause.
* This is useful for placing a new item last in a group of items in the table.
*
* @param string $where WHERE clause to use for selecting the MAX(ordering) for the table.
*
* @return mixed Boolean false an failure or the next ordering value as an integer.
*/
public function getNextOrder($where = '')
{
// If there is no ordering field set an error and return false.
$ordering = $this->getColumnAlias('ordering');
if (!in_array($ordering, $this->getKnownFields())) {
throw new UnexpectedValueException(sprintf('%s does not support ordering.', get_class($this)));
}
// Get the largest ordering value for a given where clause.
$query = $this->_db->getQuery(true);
$query->select('MAX(' . $this->_db->qn($ordering) . ')');
$query->from($this->_tbl);
if ($where) {
$query->where($where);
}
$this->_db->setQuery($query);
$max = (int) $this->_db->loadResult();
// Return the largest ordering value + 1.
return $max + 1;
}