private function _getClassForDateTimeRelatedFields($type)
{
if (substr($type, 0, 9) == self::TIMESTAMP_FIELD || $type == self::DATETIME_FIELD) {
$field_type_class = 'datetimefield';
} elseif ($type == self::DATE_FIELD) {
$field_type_class = 'datefield';
} elseif ($type == self::TIME_FIELD) {
$field_type_class = 'timefield';
} elseif ($type == self::STRING_FIELD) {
$field_type_class = 'text';
} else {
$field_type_class = '';
}
return $field_type_class;
}