BarcodeGenerator::qr_detect_mode

private function qr_detect_mode($data) {
	$numeric = '/^[0-9]*$/';
	$alphanumeric = '/^[0-9A-Z ./:$%*+-]*$/';
	$kanji = '/^([x81-x9FxE0-xEA][x40-xFC]|[xEB][x40-xBF])*$/';
	if (preg_match($numeric, $data)) return 0;
	if (preg_match($alphanumeric, $data)) return 1;
	if (preg_match($kanji, $data)) return 3;
	return 2;
}