public static function sortChildren(&$children)
{
$childRows = explode('<', $children);
array_shift($childRows);
// remove the first (empty) row
$sort = array();
$prevKey = 0;
$pos = 0;
$key = 0;
foreach ($childRows as $childRow) {
$pos++;
$date = ESINHandler::getChildDate($childRow, 'birthdate');
if (!$date) {
$date = ESINHandler::getChildDate($childRow, 'chrdate');
}
if ($date) {
$k = StructuredData::getDateKey($date, true);
if ($k) {
$key = $k;
$prevKey = $key;
}
}
if (!$key) {
$key = $prevKey;
}
// if no date, assume same as previous
$sort[$key * 50 + $pos] = $childRow;
}
if (count($sort)) {
ksort($sort, SORT_NUMERIC);
$children = '<' . join('<', $sort);
}
}