Club Drupal

• *
• IDNA Convert (idna_convert.class.php) *
• *
• http://idnaconv.phlymail.de mailto:phlymail@phlylabs.de * *******************************************************************************
• (c) 2004-2007 phlyLabs, Berlin *
• This file is encoded in UTF-8 * *******************************************************************************

Introduction

The class idna_convert allows to convert internationalized domain names
(see RFC 3490, 3491, 3492 and 3454 for detials) as they can be used with various
registries worldwide to be translated between their original (localized) form
and their encoded form as it will be used in the DNS (Domain Name System).

The class provides two public methods, encode() and decode(), which do exactly
what you would expect them to do. You are allowed to use complete domain names,
simple strings and complete email addresses as well. That means, that you might
use any of the following notations:

• xn--nrgler-wxa
• xn--brse-5qa.xn--knrz-1ra.info

Errors, incorrectly encoded or invalid strings will lead to either a FALSE
response (when in strict mode) or to only partially converted strings.
You can query the occured error by calling the method get_last_error().

Unicode strings are expected to be either UTF-8 strings, UCS-4 strings or UCS-4
arrays. The default format is UTF-8. For setting different encodings, you can
call the method setParams() - please see the inline documentation for details.
ACE strings (the Punycode form) are always 7bit ASCII strings.

ATTENTION: We no longer supply the PHP5 version of the class. It is not
necessary for achieving a successfull conversion, since the supplied PHP code is
compatible with both PHP4 and PHP5. We expect to see no compatibility issues
with the upcoming PHP6, too.

Files

idna_convert.class.php - The actual class
idna_convert.create.npdata.php - Useful for (re)creating the NPData file
npdata.ser - Serialized data for NamePrep
example.php - An example web page for converting
ReadMe.txt - This file
LICENCE - The LGPL licence file

The class is contained in idna_convert.class.php.
MAKE SURE to copy the npdata.ser file into the same folder as the class file
itself!

Examples

1. Say we wish to encode the domain name nörgler.com:

// Include the class
include_once('idna_convert.class.php');
// Instantiate it *
$IDN = new idna_convert();
// The input string, if input is not UTF-8 or UCS-4, it must be converted before
$input = utf8_encode('nörgler.com');
// Encode it to its punycode presentation
$output = $IDN->encode($input);
// Output, what we got now
echo $output; // This will read: xn--nrgler-wxa.com

1. We received an email from a punycoded domain and are willing to learn, how the domain name reads originally

// Include the class
include_once('idna_convert.class.php');
// Instantiate it (depending on the version you are using) with
$IDN = new idna_convert();
// The input string
$input = 'andre@xn--brse-5qa.xn--knrz-1ra.info';
// Encode it to its punycode presentation
$output = $IDN->decode($input);
// Output, what we got now, if output should be in a format different to UTF-8
// or UCS-4, you will have to convert it before outputting it
echo utf8_decode($output); // This will read: andre@börse.knörz.info

1. The input is read from a UCS-4 coded file and encoded line by line. By appending the optional second parameter we tell enode() about the input format to be used

// Include the class
include_once('idna_convert.class.php');
// Instantiate it
$IDN = new dinca_convert();
// Iterate through the input file line by line
foreach (file('ucs4-domains.txt') as $line) {
echo $IDN->encode(trim($line), 'ucs4_string');
echo "\n";
}

NPData

Should you need to recreate the npdata.ser file, which holds all necessary translation
tables in a serialized format, you can run the file idna_convert.create.npdata.php, which
creates the file for you and stores it in the same folder, where it is placed.
Should you need to do changes to the tables you can do so, but beware of the consequences.

Contact us

In case of errors, bugs, questions, wishes, please don't hesitate to contact us
under the email address above.

The team of phlyLabs
http://phlylabs.de
mailto:phlymail@phlylabs.de