includes/collation/NumericUppercaseCollation.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 use MediaWiki\Language\Language;
  22 use MediaWiki\Languages\LanguageFactory;
  23
  24 /**
  25  * Collation that orders text with numbers "naturally", so that 'Foo 1' < 'Foo 2' < 'Foo 12'.
  26  *
  27  * Note that this only works in terms of sequences of digits, and the behavior for decimal fractions
  28  * or pretty-formatted numbers may be unexpected.
  29  *
  30  * Digits will be based on the wiki's content language settings. If
  31  * you change the content language of a wiki you will need to run
  32  * updateCollation.php --force. Only English (ASCII 0-9) and the
  33  * localized version will be counted. Localized digits from other languages
  34  * or weird unicode digit equivalents (e.g. ４, 𝟜, ⓸ , ⁴, etc) will not count.
  35  *
  36  * @since 1.28
  37  */
  38 class NumericUppercaseCollation extends UppercaseCollation {
  39
  40         /**
  41          * @var Language How to convert digits (usually the content language)
  42          */
  43         private $digitTransformLang;
  44
  45         /**
  46          * @param LanguageFactory $languageFactory
  47          * @param string|Language $digitTransformLang How to convert digits.
  48          *  For example, if given language "my" than ၇ is treated like 7.
  49          *  It is expected that usually this is given the content language.
  50          */
  51         public function __construct(
  52                 LanguageFactory $languageFactory,
  53                 $digitTransformLang
  54         ) {
  55                 $this->digitTransformLang = $digitTransformLang instanceof Language
  56                         ? $digitTransformLang
  57                         : $languageFactory->getLanguage( $digitTransformLang );
  58                 parent::__construct( $languageFactory );
  59         }
  60
  61         public function getSortKey( $string ) {
  62                 $sortkey = parent::getSortKey( $string );
  63                 $sortkey = $this->convertDigits( $sortkey );
  64                 // For each sequence of digits, insert the digit '0' and then the length of the sequence
  65                 // (encoded in two bytes) before it. That's all folks, it sorts correctly now! The '0' ensures
  66                 // correct position (where digits would normally sort), then the length will be compared putting
  67                 // shorter numbers before longer ones; if identical, then the characters will be compared, which
  68                 // generates the correct results for numbers of equal length.
  69                 $sortkey = preg_replace_callback( '/\d+/', static function ( $matches ) {
  70                         // Strip any leading zeros
  71                         $number = ltrim( $matches[0], '0' );
  72                         $len = strlen( $number );
  73                         // This allows sequences of up to 65536 numeric characters to be handled correctly. One byte
  74                         // would allow only for 256, which doesn't feel future-proof.
  75                         $prefix = chr( (int)floor( $len / 256 ) ) . chr( $len % 256 );
  76                         return '0' . $prefix . $number;
  77                 }, $sortkey );
  78
  79                 return $sortkey;
  80         }
  81
  82         /**
  83          * Convert localized digits to english digits.
  84          *
  85          * based on Language::parseFormattedNumber but without commas.
  86          *
  87          * @param string $string sortkey to unlocalize digits of
  88          * @return string Sortkey with all localized digits replaced with ASCII digits.
  89          */
  90         private function convertDigits( $string ) {
  91                 $table = $this->digitTransformLang->digitTransformTable();
  92                 if ( $table ) {
  93                         $table = array_filter( $table );
  94                         $flipped = array_flip( $table );
  95                         // Some languages seem to also have commas in this table.
  96                         $flipped = array_filter( $flipped, 'is_numeric' );
  97                         $string = strtr( $string, $flipped );
  98                 }
  99                 return $string;
 100         }
 101
 102         public function getFirstLetter( $string ) {
 103                 $convertedString = $this->convertDigits( $string );
 104
 105                 if ( preg_match( '/^\d/', $convertedString ) ) {
 106                         return wfMessage( 'category-header-numerals' )
 107                                 ->numParams( 0, 9 )
 108                                 ->text();
 109                 } else {
 110                         return parent::getFirstLetter( $string );
 111                 }
 112         }
 113 }