/**
* A usort callback to sort by methods on records
*
* @param fActiveRecord $a The first record to compare
* @param fActiveRecord $b The second record to compare
* @return integer < 0 if `$a` is less than `$b`, 0 if `$a` = `$b`, > 0 if `$a` is greater than `$b`
*/
private function sortCallback($a, $b)
{
if ($this->sort_direction == 'asc') {
return fUTF8::inatcmp($a->{$this->sort_method}(), $b->{$this->sort_method}());
}
return fUTF8::inatcmp($b->{$this->sort_method}(), $a->{$this->sort_method}());
}