private function locateParam($params, $param)
{
$value = null;
$keys = explode('.', $param);
for ($i = 0, $mx = count($keys); $i < $mx; $i++) {
$key = $keys[$i];
if (isset($params[$key])) {
$value = $params[$key];
if ($i + 1 < $mx && is_array($value)) {
return $this->locateParam($value, implode('.', array_slice($keys, $i)));
}
}
}
return $value;
}