protected static function dataTypeToIndexField($type)
    {
        $key = '';
        $currentLang = LanguageHelper::getCurrent();
        switch ($type) {
            case Property::DATA_TYPE_STRING :
                $key = 'str_value_' . $currentLang;
                break;
            case Property::DATA_TYPE_TEXT :
                $key = 'txt_value_' . $currentLang;
                break;
            case Property::DATA_TYPE_BOOLEAN :
            case Property::DATA_TYPE_INTEGER :
                $key = 'value_integer';
                break;
            case Property::DATA_TYPE_FLOAT :
                $key = 'value_float';
                break;
            case Property::DATA_TYPE_INVARIANT_STRING :
            case Property::DATA_TYPE_PACKED_JSON :
                $key = 'utr_text';
                break;
        }
        return $key;
    }