includes/MagicWord.php

   1 <?
   2
   3 # This class encapsulates "magic words" such as #redirect, __NOTOC__, etc.
   4 # Usage:
   5 #     if (MagicWord::get( MAG_REDIRECT )->match( $text ) )
   6 #
   7 # Possible future improvements:
   8 #   * Simultaneous searching for a number of magic words
   9 #   * $wgMagicWords in shared memory
  10 #
  11 # Please avoid reading the data out of one of these objects and then writing
  12 # special case code. If possible, add another match()-like function here.
  13
  14 /*private*/ $wgMagicFound = false;
  15
  16 class MagicWord {
  17         /*private*/ var $mId, $mSynonyms, $mCaseSensitive, $mRegex;
  18         /*private*/ var $mRegexStart, $mBaseRegex, $mVariableRegex;
  19         /*private*/ var $mModified;
  20
  21         function MagicWord($id = 0, $syn = "", $cs = false)
  22         {
  23                 $this->mId = $id;
  24                 $this->mSynonyms = (array)$syn;
  25                 $this->mCaseSensitive = $cs;
  26                 $this->mRegex = "";
  27                 $this->mRegexStart = "";
  28                 $this->mVariableRegex = "";
  29                 $this->mModified = false;
  30         }
  31
  32         # Factory: creates an object representing an ID
  33         /*static*/ function &get( $id )
  34         {
  35                 global $wgMagicWords;
  36
  37                 if (!array_key_exists( $id, $wgMagicWords ) ) {
  38                         $mw = new MagicWord();
  39                         $mw->load( $id );
  40                         $wgMagicWords[$id] = $mw;
  41                 }
  42                 return $wgMagicWords[$id];
  43         }
  44
  45         # Initialises this object with an ID
  46         function load( $id )
  47         {
  48                 global $wgLang;
  49                 $this->mId = $id;
  50                 $wgLang->getMagic( $this );
  51         }
  52
  53         # Preliminary initialisation
  54         /* private */ function initRegex()
  55         {
  56                 $escSyn = array_map( "preg_quote", $this->mSynonyms );
  57                 $this->mBaseRegex = implode( "|", $escSyn );
  58                 $case = $this->mCaseSensitive ? "" : "i";
  59                 $this->mRegex = "/{$this->mBaseRegex}/{$case}";
  60                 $this->mRegexStart = "/^{$this->mBaseRegex}/{$case}";
  61                 $this->mVariableRegex = str_replace( "\\$1", "([A-Za-z0-9_\-]*)", $this->mRegex );
  62         }
  63
  64         # Gets a regex representing matching the word
  65         function getRegex()
  66         {
  67                 if ($this->mRegex == "" ) {
  68                         $this->initRegex();
  69                 }
  70                 return $this->mRegex;
  71         }
  72
  73         # Gets a regex matching the word, if it is at the
  74         # string start
  75         function getRegexStart()
  76         {
  77                 if ($this->mRegex == "" ) {
  78                         $this->initRegex();
  79                 }
  80                 return $this->mRegexStart;
  81         }
  82
  83         # regex without the slashes and what not
  84         function getBaseRegex()
  85         {
  86                 if ($this->mRegex == "") {
  87                         $this->initRegex();
  88                 }
  89                 return $this->mBaseRegex;
  90         }
  91
  92         # Returns true if the text contains the word
  93         function match( $text ) {
  94                 return preg_match( $this->getRegex(), $text );
  95         }
  96
  97         # Returns true if the text starts with the word
  98         function matchStart( $text )
  99         {
 100                 return preg_match( $this->getRegexStart(), $text );
 101         }
 102
 103         # Returns true if the text matches the word, and alters the
 104         # input string, removing all instances of the word
 105         function matchAndRemove( &$text )
 106         {
 107                 global $wgMagicFound;
 108                 $wgMagicFound = false;
 109                 $text = preg_replace_callback( $this->getRegex(), "pregRemoveAndRecord", $text );
 110                 return $wgMagicFound;
 111         }
 112
 113         # Replaces the word with something else
 114         function replace( $replacement, $subject )
 115         {
 116                 $res = preg_replace( $this->getRegex(), $replacement, $subject );
 117                 $this->mModified = !($res === $subject);
 118                 return $res;
 119         }
 120
 121         # Variable handling: {{SUBST:xxx}} style words
 122         # Calls back a function to determine what to replace xxx with
 123         # Input word must contain $1
 124         function substituteCallback( $text, $callback ) {
 125                 $regex = $this->getVariableRegex();
 126                 $res = preg_replace_callback( $this->getVariableRegex(), $callback, $text );
 127                 $this->mModified = !($res === $text);
 128                 return $res;
 129         }
 130
 131         # Matches the word, where $1 is a wildcard
 132         function getVariableRegex()
 133         {
 134                 if ( $this->mVariableRegex == "" ) {
 135                         $this->initRegex();
 136                 }
 137                 return $this->mVariableRegex;
 138         }
 139
 140         # Accesses the synonym list directly
 141         function getSynonym( $i ) {
 142                 return $this->mSynonyms[$i];
 143         }
 144
 145         # Returns true if the last call to replace() or substituteCallback()
 146         # returned a modified text, otherwise false.
 147         function getWasModified(){
 148                 return $this->mModified;
 149         }
 150
 151         # $magicarr is an associative array of (magic word ID => replacement)
 152         # This method uses the php feature to do several replacements at the same time,
 153         # thereby gaining some efficiency. The result is placed in the out variable
 154         # $result. The return value is true if something was replaced.
 155
 156         /* static */ function replaceMultiple( $magicarr, $subject, &$result ){
 157                 $search = array();
 158                 $replace = array();
 159                 foreach( $magicarr as $id => $replacement ){
 160                         $mw = MagicWord::get( $id );
 161                         $search[] = $mw->getRegex();
 162                         $replace[] = $replacement;
 163                 }
 164
 165                 $result = preg_replace( $search, $replace, $subject );
 166                 return !($result === $subject);
 167         }
 168 }
 169
 170 # Used in matchAndRemove()
 171 /*private*/ function pregRemoveAndRecord( $match )
 172 {
 173         global $wgMagicFound;
 174         $wgMagicFound = true;
 175         return "";
 176 }
 177
 178 ?>