Topic on Extension talk:RomanNumbers

Now updated.

RomanNumbers.php

<?php

if (!defined('MEDIAWIKI'))

        die(' This file is a MediaWiki extension, it is not a valid entry point ');

$wgExtensionCredits['parserhook'][] = array(

'name' => 'RomanNumbers',

'author' =>'Massimiliano Salvemini (corrected by Hakob Barseghyan)', 

'version' => 1.1,

'url' => '<nowiki>https://www.mediawiki.org/wiki/Extension:RomanNumbers'</nowiki>, 

'description' => 'Converts an arabic number to a roman number and vice versa'

);

class RomanNumbers {

  //Conversion: Roman Numeral to Integer

  public static function toArabic($roman)

{

    static $conv = array(

array("letter" => 'I', "number" => 1),

array("letter" => 'V', "number" => 5),

array("letter" => 'X', "number" => 10),

array("letter" => 'L', "number" => 50),

array("letter" => 'C', "number" => 100),

array("letter" => 'D', "number" => 500),

array("letter" => 'M', "number" => 1000),

array("letter" => 0,   "number" => 0)

); 

$arabic = 0;

$state  = 0;

$sidx   = 0;

$len    = strlen($roman);

while ($len > 0) {

$i = 0;

$sidx = $len -1;

while ($conv[$i]["number"] > 0) 

      {

if (strtoupper($roman[$sidx]) == $conv[$i]["letter"]) 

        {

if ($state > $conv[$i]["number"]) 

          {

$arabic -= $conv[$i]["number"];

} else 

          {

$arabic += $conv[$i]["number"];

$state   = $conv[$i]["number"];

}

}

$i++;

}

$len--;

}

return($arabic);

}

  public static function toRoman($num) 

  {

if ($num < 0 || $num > 9999) return -1;

$romanOnes = array(1=> "I",2=>"II",3=>"III",4=>"IV", 5=>"V", 6=>"VI", 7=>"VII", 8=>"VIII", 9=>"IX"   );

$romanTens = array(1=> "X", 2=>"XX", 3=>"XXX", 4=>"XL", 5=>"L", 6=>"LX", 7=>"LXX",8=>"LXXX", 9=>"XC");

$romanHund = array(1=> "C", 2=>"CC", 3=>"CCC", 4=>"CD", 5=>"D", 6=>"DC", 7=>"DCC",8=>"DCCC", 9=>"CM");

$romanThou = array(1=> "M", 2=>"MM", 3=>"MMM", 4=>"MMMM", 5=>"MMMMM", 6=>"MMMMMM",7=>"MMMMMMM", 8=>"MMMMMMMM", 9=>"MMMMMMMMM");

$ones = $num % 10;

$tens = ($num - $ones) % 100;

$hund = ($num - $tens - $ones) % 1000;

$thou = ($num - $hund - $tens - $ones) % 10000;

$tens = $tens / 10;

$hund = $hund / 100;

$thou = $thou / 1000;

$romanNum = <nowiki>''</nowiki>;

if ($thou) $romanNum .= $romanThou[$thou];

if ($hund) $romanNum .= $romanHund[$hund];

if ($tens) $romanNum .= $romanTens[$tens];

if ($ones) $romanNum .= $romanOnes[$ones];

return $romanNum;

}

}

$wgExtensionFunctions[] = 'wfRomanParse_Setup';

$wgHooks['LanguageGetMagic'][] = 'wfRomanParse_Magic'; 

function wfRomanParse_Setup() {

global $wgParser;

$wgParser->setFunctionHook( 'roman', 'wfRomanParse_Render' );

} 

function wfRomanParse_Magic( &$magicWords, $langCode ) {

$magicWords['roman'] = array( 0, 'roman' );

return true;

} 

function wfRomanParse_Render(&$parser, $param1 = <nowiki>''</nowiki>) {

        return convertRomanNumber($param1);

} 

$wgAjaxExportList[] = "convertRomanNumber";

function convertRomanNumber($num) {

if (is_numeric($num)) {

if (($num > 9999)||($num<1)) return "error";

return RomanNumbers::toRoman($num);

}

else

return RomanNumbers::toArabic($num);

}

And to make this work on MW 1.34.1, use {{#tag:roman|MCLVI}} instead of {{#roman: MCLVI}}.

I have added this as version 2.0 (2020-05-31) to the extension's page and updated the docu.