includes/MagicWord.php

   1 <?php
   2 /**
   3  * File for magic words.
   4  *
   5  * See docs/magicword.txt.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  * @ingroup Parser
  24  */
  25
  26 /**
  27  * This class encapsulates "magic words" such as "#redirect", __NOTOC__, etc.
  28  *
  29  * @par Usage:
  30  * @code
  31  *     if (MagicWord::get( 'redirect' )->match( $text ) ) {
  32  *       // some code
  33  *     }
  34  * @endcode
  35  *
  36  * Possible future improvements:
  37  *   * Simultaneous searching for a number of magic words
  38  *   * MagicWord::$mObjects in shared memory
  39  *
  40  * Please avoid reading the data out of one of these objects and then writing
  41  * special case code. If possible, add another match()-like function here.
  42  *
  43  * To add magic words in an extension, use $magicWords in a file listed in
  44  * $wgExtensionMessagesFiles[].
  45  *
  46  * @par Example:
  47  * @code
  48  * $magicWords = array();
  49  *
  50  * $magicWords['en'] = array(
  51  *      'magicwordkey' => array( 0, 'case_insensitive_magic_word' ),
  52  *      'magicwordkey2' => array( 1, 'CASE_sensitive_magic_word2' ),
  53  * );
  54  * @endcode
  55  *
  56  * For magic words which are also Parser variables, add a MagicWordwgVariableIDs
  57  * hook. Use string keys.
  58  *
  59  * @ingroup Parser
  60  */
  61 class MagicWord {
  62         /**#@-*/
  63
  64         /** @var int */
  65         public $mId;
  66
  67         /** @var array */
  68         public $mSynonyms;
  69
  70         /** @var bool */
  71         public $mCaseSensitive;
  72
  73         /** @var string */
  74         private $mRegex = '';
  75
  76         /** @var string */
  77         private $mRegexStart = '';
  78
  79         /** @var string */
  80         private $mRegexStartToEnd = '';
  81
  82         /** @var string */
  83         private $mBaseRegex = '';
  84
  85         /** @var string */
  86         private $mVariableRegex = '';
  87
  88         /** @var string */
  89         private $mVariableStartToEndRegex = '';
  90
  91         /** @var bool */
  92         private $mModified = false;
  93
  94         /** @var bool */
  95         private $mFound = false;
  96
  97         static public $mVariableIDsInitialised = false;
  98         static public $mVariableIDs = array(
  99                 '!',
 100                 'currentmonth',
 101                 'currentmonth1',
 102                 'currentmonthname',
 103                 'currentmonthnamegen',
 104                 'currentmonthabbrev',
 105                 'currentday',
 106                 'currentday2',
 107                 'currentdayname',
 108                 'currentyear',
 109                 'currenttime',
 110                 'currenthour',
 111                 'localmonth',
 112                 'localmonth1',
 113                 'localmonthname',
 114                 'localmonthnamegen',
 115                 'localmonthabbrev',
 116                 'localday',
 117                 'localday2',
 118                 'localdayname',
 119                 'localyear',
 120                 'localtime',
 121                 'localhour',
 122                 'numberofarticles',
 123                 'numberoffiles',
 124                 'numberofedits',
 125                 'articlepath',
 126                 'pageid',
 127                 'sitename',
 128                 'server',
 129                 'servername',
 130                 'scriptpath',
 131                 'stylepath',
 132                 'pagename',
 133                 'pagenamee',
 134                 'fullpagename',
 135                 'fullpagenamee',
 136                 'namespace',
 137                 'namespacee',
 138                 'namespacenumber',
 139                 'currentweek',
 140                 'currentdow',
 141                 'localweek',
 142                 'localdow',
 143                 'revisionid',
 144                 'revisionday',
 145                 'revisionday2',
 146                 'revisionmonth',
 147                 'revisionmonth1',
 148                 'revisionyear',
 149                 'revisiontimestamp',
 150                 'revisionuser',
 151                 'revisionsize',
 152                 'subpagename',
 153                 'subpagenamee',
 154                 'talkspace',
 155                 'talkspacee',
 156                 'subjectspace',
 157                 'subjectspacee',
 158                 'talkpagename',
 159                 'talkpagenamee',
 160                 'subjectpagename',
 161                 'subjectpagenamee',
 162                 'numberofusers',
 163                 'numberofactiveusers',
 164                 'numberofpages',
 165                 'currentversion',
 166                 'rootpagename',
 167                 'rootpagenamee',
 168                 'basepagename',
 169                 'basepagenamee',
 170                 'currenttimestamp',
 171                 'localtimestamp',
 172                 'directionmark',
 173                 'contentlanguage',
 174                 'numberofadmins',
 175                 'cascadingsources',
 176         );
 177
 178         /* Array of caching hints for ParserCache */
 179         static public $mCacheTTLs = array(
 180                 'currentmonth' => 86400,
 181                 'currentmonth1' => 86400,
 182                 'currentmonthname' => 86400,
 183                 'currentmonthnamegen' => 86400,
 184                 'currentmonthabbrev' => 86400,
 185                 'currentday' => 3600,
 186                 'currentday2' => 3600,
 187                 'currentdayname' => 3600,
 188                 'currentyear' => 86400,
 189                 'currenttime' => 3600,
 190                 'currenthour' => 3600,
 191                 'localmonth' => 86400,
 192                 'localmonth1' => 86400,
 193                 'localmonthname' => 86400,
 194                 'localmonthnamegen' => 86400,
 195                 'localmonthabbrev' => 86400,
 196                 'localday' => 3600,
 197                 'localday2' => 3600,
 198                 'localdayname' => 3600,
 199                 'localyear' => 86400,
 200                 'localtime' => 3600,
 201                 'localhour' => 3600,
 202                 'numberofarticles' => 3600,
 203                 'numberoffiles' => 3600,
 204                 'numberofedits' => 3600,
 205                 'currentweek' => 3600,
 206                 'currentdow' => 3600,
 207                 'localweek' => 3600,
 208                 'localdow' => 3600,
 209                 'numberofusers' => 3600,
 210                 'numberofactiveusers' => 3600,
 211                 'numberofpages' => 3600,
 212                 'currentversion' => 86400,
 213                 'currenttimestamp' => 3600,
 214                 'localtimestamp' => 3600,
 215                 'pagesinnamespace' => 3600,
 216                 'numberofadmins' => 3600,
 217                 'numberingroup' => 3600,
 218         );
 219
 220         static public $mDoubleUnderscoreIDs = array(
 221                 'notoc',
 222                 'nogallery',
 223                 'forcetoc',
 224                 'toc',
 225                 'noeditsection',
 226                 'newsectionlink',
 227                 'nonewsectionlink',
 228                 'hiddencat',
 229                 'index',
 230                 'noindex',
 231                 'staticredirect',
 232                 'notitleconvert',
 233                 'nocontentconvert',
 234         );
 235
 236         static public $mSubstIDs = array(
 237                 'subst',
 238                 'safesubst',
 239         );
 240
 241         static public $mObjects = array();
 242         static public $mDoubleUnderscoreArray = null;
 243
 244         /**#@-*/
 245
 246         function __construct( $id = 0, $syn = array(), $cs = false ) {
 247                 $this->mId = $id;
 248                 $this->mSynonyms = (array)$syn;
 249                 $this->mCaseSensitive = $cs;
 250         }
 251
 252         /**
 253          * Factory: creates an object representing an ID
 254          *
 255          * @param int $id
 256          *
 257          * @return MagicWord
 258          */
 259         static function &get( $id ) {
 260                 if ( !isset( self::$mObjects[$id] ) ) {
 261                         $mw = new MagicWord();
 262                         $mw->load( $id );
 263                         self::$mObjects[$id] = $mw;
 264                 }
 265                 return self::$mObjects[$id];
 266         }
 267
 268         /**
 269          * Get an array of parser variable IDs
 270          *
 271          * @return array
 272          */
 273         static function getVariableIDs() {
 274                 if ( !self::$mVariableIDsInitialised ) {
 275                         # Get variable IDs
 276                         Hooks::run( 'MagicWordwgVariableIDs', array( &self::$mVariableIDs ) );
 277                         self::$mVariableIDsInitialised = true;
 278                 }
 279                 return self::$mVariableIDs;
 280         }
 281
 282         /**
 283          * Get an array of parser substitution modifier IDs
 284          * @return array
 285          */
 286         static function getSubstIDs() {
 287                 return self::$mSubstIDs;
 288         }
 289
 290         /**
 291          * Allow external reads of TTL array
 292          *
 293          * @param int $id
 294          * @return int
 295          */
 296         static function getCacheTTL( $id ) {
 297                 if ( array_key_exists( $id, self::$mCacheTTLs ) ) {
 298                         return self::$mCacheTTLs[$id];
 299                 } else {
 300                         return -1;
 301                 }
 302         }
 303
 304         /**
 305          * Get a MagicWordArray of double-underscore entities
 306          *
 307          * @return MagicWordArray
 308          */
 309         static function getDoubleUnderscoreArray() {
 310                 if ( is_null( self::$mDoubleUnderscoreArray ) ) {
 311                         Hooks::run( 'GetDoubleUnderscoreIDs', array( &self::$mDoubleUnderscoreIDs ) );
 312                         self::$mDoubleUnderscoreArray = new MagicWordArray( self::$mDoubleUnderscoreIDs );
 313                 }
 314                 return self::$mDoubleUnderscoreArray;
 315         }
 316
 317         /**
 318          * Clear the self::$mObjects variable
 319          * For use in parser tests
 320          */
 321         public static function clearCache() {
 322                 self::$mObjects = array();
 323         }
 324
 325         /**
 326          * Initialises this object with an ID
 327          *
 328          * @param int $id
 329          * @throws MWException
 330          */
 331         function load( $id ) {
 332                 global $wgContLang;
 333                 $this->mId = $id;
 334                 $wgContLang->getMagic( $this );
 335                 if ( !$this->mSynonyms ) {
 336                         $this->mSynonyms = array( 'brionmademeputthishere' );
 337                         throw new MWException( "Error: invalid magic word '$id'" );
 338                 }
 339         }
 340
 341         /**
 342          * Preliminary initialisation
 343          * @private
 344          */
 345         function initRegex() {
 346                 // Sort the synonyms by length, descending, so that the longest synonym
 347                 // matches in precedence to the shortest
 348                 $synonyms = $this->mSynonyms;
 349                 usort( $synonyms, array( $this, 'compareStringLength' ) );
 350
 351                 $escSyn = array();
 352                 foreach ( $synonyms as $synonym ) {
 353                         // In case a magic word contains /, like that's going to happen;)
 354                         $escSyn[] = preg_quote( $synonym, '/' );
 355                 }
 356                 $this->mBaseRegex = implode( '|', $escSyn );
 357
 358                 $case = $this->mCaseSensitive ? '' : 'iu';
 359                 $this->mRegex = "/{$this->mBaseRegex}/{$case}";
 360                 $this->mRegexStart = "/^(?:{$this->mBaseRegex})/{$case}";
 361                 $this->mRegexStartToEnd = "/^(?:{$this->mBaseRegex})$/{$case}";
 362                 $this->mVariableRegex = str_replace( "\\$1", "(.*?)", $this->mRegex );
 363                 $this->mVariableStartToEndRegex = str_replace( "\\$1", "(.*?)",
 364                         "/^(?:{$this->mBaseRegex})$/{$case}" );
 365         }
 366
 367         /**
 368          * A comparison function that returns -1, 0 or 1 depending on whether the
 369          * first string is longer, the same length or shorter than the second
 370          * string.
 371          *
 372          * @param string $s1
 373          * @param string $s2
 374          *
 375          * @return int
 376          */
 377         function compareStringLength( $s1, $s2 ) {
 378                 $l1 = strlen( $s1 );
 379                 $l2 = strlen( $s2 );
 380                 if ( $l1 < $l2 ) {
 381                         return 1;
 382                 } elseif ( $l1 > $l2 ) {
 383                         return -1;
 384                 } else {
 385                         return 0;
 386                 }
 387         }
 388
 389         /**
 390          * Gets a regex representing matching the word
 391          *
 392          * @return string
 393          */
 394         function getRegex() {
 395                 if ( $this->mRegex == '' ) {
 396                         $this->initRegex();
 397                 }
 398                 return $this->mRegex;
 399         }
 400
 401         /**
 402          * Gets the regexp case modifier to use, i.e. i or nothing, to be used if
 403          * one is using MagicWord::getBaseRegex(), otherwise it'll be included in
 404          * the complete expression
 405          *
 406          * @return string
 407          */
 408         function getRegexCase() {
 409                 if ( $this->mRegex === '' ) {
 410                         $this->initRegex();
 411                 }
 412
 413                 return $this->mCaseSensitive ? '' : 'iu';
 414         }
 415
 416         /**
 417          * Gets a regex matching the word, if it is at the string start
 418          *
 419          * @return string
 420          */
 421         function getRegexStart() {
 422                 if ( $this->mRegex == '' ) {
 423                         $this->initRegex();
 424                 }
 425                 return $this->mRegexStart;
 426         }
 427
 428         /**
 429          * Gets a regex matching the word from start to end of a string
 430          *
 431          * @return string
 432          * @since 1.23
 433          */
 434         function getRegexStartToEnd() {
 435                 if ( $this->mRegexStartToEnd == '' ) {
 436                         $this->initRegex();
 437                 }
 438                 return $this->mRegexStartToEnd;
 439         }
 440
 441         /**
 442          * regex without the slashes and what not
 443          *
 444          * @return string
 445          */
 446         function getBaseRegex() {
 447                 if ( $this->mRegex == '' ) {
 448                         $this->initRegex();
 449                 }
 450                 return $this->mBaseRegex;
 451         }
 452
 453         /**
 454          * Returns true if the text contains the word
 455          *
 456          * @param string $text
 457          *
 458          * @return bool
 459          */
 460         function match( $text ) {
 461                 return (bool)preg_match( $this->getRegex(), $text );
 462         }
 463
 464         /**
 465          * Returns true if the text starts with the word
 466          *
 467          * @param string $text
 468          *
 469          * @return bool
 470          */
 471         function matchStart( $text ) {
 472                 return (bool)preg_match( $this->getRegexStart(), $text );
 473         }
 474
 475         /**
 476          * Returns true if the text matched the word
 477          *
 478          * @param string $text
 479          *
 480          * @return bool
 481          * @since 1.23
 482          */
 483         function matchStartToEnd( $text ) {
 484                 return (bool)preg_match( $this->getRegexStartToEnd(), $text );
 485         }
 486
 487         /**
 488          * Returns NULL if there's no match, the value of $1 otherwise
 489          * The return code is the matched string, if there's no variable
 490          * part in the regex and the matched variable part ($1) if there
 491          * is one.
 492          *
 493          * @param string $text
 494          *
 495          * @return string
 496          */
 497         function matchVariableStartToEnd( $text ) {
 498                 $matches = array();
 499                 $matchcount = preg_match( $this->getVariableStartToEndRegex(), $text, $matches );
 500                 if ( $matchcount == 0 ) {
 501                         return null;
 502                 } else {
 503                         # multiple matched parts (variable match); some will be empty because of
 504                         # synonyms. The variable will be the second non-empty one so remove any
 505                         # blank elements and re-sort the indices.
 506                         # See also bug 6526
 507
 508                         $matches = array_values( array_filter( $matches ) );
 509
 510                         if ( count( $matches ) == 1 ) {
 511                                 return $matches[0];
 512                         } else {
 513                                 return $matches[1];
 514                         }
 515                 }
 516         }
 517
 518         /**
 519          * Returns true if the text matches the word, and alters the
 520          * input string, removing all instances of the word
 521          *
 522          * @param string $text
 523          *
 524          * @return bool
 525          */
 526         function matchAndRemove( &$text ) {
 527                 $this->mFound = false;
 528                 $text = preg_replace_callback(
 529                         $this->getRegex(),
 530                         array( &$this, 'pregRemoveAndRecord' ),
 531                         $text
 532                 );
 533
 534                 return $this->mFound;
 535         }
 536
 537         /**
 538          * @param string $text
 539          * @return bool
 540          */
 541         function matchStartAndRemove( &$text ) {
 542                 $this->mFound = false;
 543                 $text = preg_replace_callback(
 544                         $this->getRegexStart(),
 545                         array( &$this, 'pregRemoveAndRecord' ),
 546                         $text
 547                 );
 548
 549                 return $this->mFound;
 550         }
 551
 552         /**
 553          * Used in matchAndRemove()
 554          *
 555          * @return string
 556          */
 557         function pregRemoveAndRecord() {
 558                 $this->mFound = true;
 559                 return '';
 560         }
 561
 562         /**
 563          * Replaces the word with something else
 564          *
 565          * @param string $replacement
 566          * @param string $subject
 567          * @param int $limit
 568          *
 569          * @return string
 570          */
 571         function replace( $replacement, $subject, $limit = -1 ) {
 572                 $res = preg_replace(
 573                         $this->getRegex(),
 574                         StringUtils::escapeRegexReplacement( $replacement ),
 575                         $subject,
 576                         $limit
 577                 );
 578                 $this->mModified = $res !== $subject;
 579                 return $res;
 580         }
 581
 582         /**
 583          * Variable handling: {{SUBST:xxx}} style words
 584          * Calls back a function to determine what to replace xxx with
 585          * Input word must contain $1
 586          *
 587          * @param string $text
 588          * @param callable $callback
 589          *
 590          * @return string
 591          */
 592         function substituteCallback( $text, $callback ) {
 593                 $res = preg_replace_callback( $this->getVariableRegex(), $callback, $text );
 594                 $this->mModified = $res !== $text;
 595                 return $res;
 596         }
 597
 598         /**
 599          * Matches the word, where $1 is a wildcard
 600          *
 601          * @return string
 602          */
 603         function getVariableRegex() {
 604                 if ( $this->mVariableRegex == '' ) {
 605                         $this->initRegex();
 606                 }
 607                 return $this->mVariableRegex;
 608         }
 609
 610         /**
 611          * Matches the entire string, where $1 is a wildcard
 612          *
 613          * @return string
 614          */
 615         function getVariableStartToEndRegex() {
 616                 if ( $this->mVariableStartToEndRegex == '' ) {
 617                         $this->initRegex();
 618                 }
 619                 return $this->mVariableStartToEndRegex;
 620         }
 621
 622         /**
 623          * Accesses the synonym list directly
 624          *
 625          * @param int $i
 626          *
 627          * @return string
 628          */
 629         function getSynonym( $i ) {
 630                 return $this->mSynonyms[$i];
 631         }
 632
 633         /**
 634          * @return array
 635          */
 636         function getSynonyms() {
 637                 return $this->mSynonyms;
 638         }
 639
 640         /**
 641          * Returns true if the last call to replace() or substituteCallback()
 642          * returned a modified text, otherwise false.
 643          *
 644          * @return bool
 645          */
 646         function getWasModified() {
 647                 return $this->mModified;
 648         }
 649
 650         /**
 651          * $magicarr is an associative array of (magic word ID => replacement)
 652          * This method uses the php feature to do several replacements at the same time,
 653          * thereby gaining some efficiency. The result is placed in the out variable
 654          * $result. The return value is true if something was replaced.
 655          * @todo Should this be static? It doesn't seem to be used at all
 656          *
 657          * @param array $magicarr
 658          * @param string $subject
 659          * @param string $result
 660          *
 661          * @return bool
 662          */
 663         function replaceMultiple( $magicarr, $subject, &$result ) {
 664                 $search = array();
 665                 $replace = array();
 666                 foreach ( $magicarr as $id => $replacement ) {
 667                         $mw = MagicWord::get( $id );
 668                         $search[] = $mw->getRegex();
 669                         $replace[] = $replacement;
 670                 }
 671
 672                 $result = preg_replace( $search, $replace, $subject );
 673                 return $result !== $subject;
 674         }
 675
 676         /**
 677          * Adds all the synonyms of this MagicWord to an array, to allow quick
 678          * lookup in a list of magic words
 679          *
 680          * @param array $array
 681          * @param string $value
 682          */
 683         function addToArray( &$array, $value ) {
 684                 global $wgContLang;
 685                 foreach ( $this->mSynonyms as $syn ) {
 686                         $array[$wgContLang->lc( $syn )] = $value;
 687                 }
 688         }
 689
 690         /**
 691          * @return bool
 692          */
 693         function isCaseSensitive() {
 694                 return $this->mCaseSensitive;
 695         }
 696
 697         /**
 698          * @return int
 699          */
 700         function getId() {
 701                 return $this->mId;
 702         }
 703 }
 704
 705 /**
 706  * Class for handling an array of magic words
 707  * @ingroup Parser
 708  */
 709 class MagicWordArray {
 710         /** @var array */
 711         public $names = array();
 712
 713         /** @var array */
 714         private $hash;
 715
 716         private $baseRegex;
 717
 718         private $regex;
 719
 720         /** @todo Unused? */
 721         private $matches;
 722
 723         /**
 724          * @param array $names
 725          */
 726         function __construct( $names = array() ) {
 727                 $this->names = $names;
 728         }
 729
 730         /**
 731          * Add a magic word by name
 732          *
 733          * @param string $name
 734          */
 735         public function add( $name ) {
 736                 $this->names[] = $name;
 737                 $this->hash = $this->baseRegex = $this->regex = null;
 738         }
 739
 740         /**
 741          * Add a number of magic words by name
 742          *
 743          * @param array $names
 744          */
 745         public function addArray( $names ) {
 746                 $this->names = array_merge( $this->names, array_values( $names ) );
 747                 $this->hash = $this->baseRegex = $this->regex = null;
 748         }
 749
 750         /**
 751          * Get a 2-d hashtable for this array
 752          * @return array
 753          */
 754         function getHash() {
 755                 if ( is_null( $this->hash ) ) {
 756                         global $wgContLang;
 757                         $this->hash = array( 0 => array(), 1 => array() );
 758                         foreach ( $this->names as $name ) {
 759                                 $magic = MagicWord::get( $name );
 760                                 $case = intval( $magic->isCaseSensitive() );
 761                                 foreach ( $magic->getSynonyms() as $syn ) {
 762                                         if ( !$case ) {
 763                                                 $syn = $wgContLang->lc( $syn );
 764                                         }
 765                                         $this->hash[$case][$syn] = $name;
 766                                 }
 767                         }
 768                 }
 769                 return $this->hash;
 770         }
 771
 772         /**
 773          * Get the base regex
 774          * @return array
 775          */
 776         function getBaseRegex() {
 777                 if ( is_null( $this->baseRegex ) ) {
 778                         $this->baseRegex = array( 0 => '', 1 => '' );
 779                         foreach ( $this->names as $name ) {
 780                                 $magic = MagicWord::get( $name );
 781                                 $case = intval( $magic->isCaseSensitive() );
 782                                 foreach ( $magic->getSynonyms() as $i => $syn ) {
 783                                         // Group name must start with a non-digit in PCRE 8.34+
 784                                         $it = strtr( $i, '0123456789', 'abcdefghij' );
 785                                         $group = "(?P<{$it}_{$name}>" . preg_quote( $syn, '/' ) . ')';
 786                                         if ( $this->baseRegex[$case] === '' ) {
 787                                                 $this->baseRegex[$case] = $group;
 788                                         } else {
 789                                                 $this->baseRegex[$case] .= '|' . $group;
 790                                         }
 791                                 }
 792                         }
 793                 }
 794                 return $this->baseRegex;
 795         }
 796
 797         /**
 798          * Get an unanchored regex that does not match parameters
 799          * @return array
 800          */
 801         function getRegex() {
 802                 if ( is_null( $this->regex ) ) {
 803                         $base = $this->getBaseRegex();
 804                         $this->regex = array( '', '' );
 805                         if ( $this->baseRegex[0] !== '' ) {
 806                                 $this->regex[0] = "/{$base[0]}/iuS";
 807                         }
 808                         if ( $this->baseRegex[1] !== '' ) {
 809                                 $this->regex[1] = "/{$base[1]}/S";
 810                         }
 811                 }
 812                 return $this->regex;
 813         }
 814
 815         /**
 816          * Get a regex for matching variables with parameters
 817          *
 818          * @return string
 819          */
 820         function getVariableRegex() {
 821                 return str_replace( "\\$1", "(.*?)", $this->getRegex() );
 822         }
 823
 824         /**
 825          * Get a regex anchored to the start of the string that does not match parameters
 826          *
 827          * @return array
 828          */
 829         function getRegexStart() {
 830                 $base = $this->getBaseRegex();
 831                 $newRegex = array( '', '' );
 832                 if ( $base[0] !== '' ) {
 833                         $newRegex[0] = "/^(?:{$base[0]})/iuS";
 834                 }
 835                 if ( $base[1] !== '' ) {
 836                         $newRegex[1] = "/^(?:{$base[1]})/S";
 837                 }
 838                 return $newRegex;
 839         }
 840
 841         /**
 842          * Get an anchored regex for matching variables with parameters
 843          *
 844          * @return array
 845          */
 846         function getVariableStartToEndRegex() {
 847                 $base = $this->getBaseRegex();
 848                 $newRegex = array( '', '' );
 849                 if ( $base[0] !== '' ) {
 850                         $newRegex[0] = str_replace( "\\$1", "(.*?)", "/^(?:{$base[0]})$/iuS" );
 851                 }
 852                 if ( $base[1] !== '' ) {
 853                         $newRegex[1] = str_replace( "\\$1", "(.*?)", "/^(?:{$base[1]})$/S" );
 854                 }
 855                 return $newRegex;
 856         }
 857
 858         /**
 859          * @since 1.20
 860          * @return array
 861          */
 862         public function getNames() {
 863                 return $this->names;
 864         }
 865
 866         /**
 867          * Parse a match array from preg_match
 868          * Returns array(magic word ID, parameter value)
 869          * If there is no parameter value, that element will be false.
 870          *
 871          * @param array $m
 872          *
 873          * @throws MWException
 874          * @return array
 875          */
 876         function parseMatch( $m ) {
 877                 reset( $m );
 878                 while ( list( $key, $value ) = each( $m ) ) {
 879                         if ( $key === 0 || $value === '' ) {
 880                                 continue;
 881                         }
 882                         $parts = explode( '_', $key, 2 );
 883                         if ( count( $parts ) != 2 ) {
 884                                 // This shouldn't happen
 885                                 // continue;
 886                                 throw new MWException( __METHOD__ . ': bad parameter name' );
 887                         }
 888                         list( /* $synIndex */, $magicName ) = $parts;
 889                         $paramValue = next( $m );
 890                         return array( $magicName, $paramValue );
 891                 }
 892                 // This shouldn't happen either
 893                 throw new MWException( __METHOD__ . ': parameter not found' );
 894         }
 895
 896         /**
 897          * Match some text, with parameter capture
 898          * Returns an array with the magic word name in the first element and the
 899          * parameter in the second element.
 900          * Both elements are false if there was no match.
 901          *
 902          * @param string $text
 903          *
 904          * @return array
 905          */
 906         public function matchVariableStartToEnd( $text ) {
 907                 $regexes = $this->getVariableStartToEndRegex();
 908                 foreach ( $regexes as $regex ) {
 909                         if ( $regex !== '' ) {
 910                                 $m = array();
 911                                 if ( preg_match( $regex, $text, $m ) ) {
 912                                         return $this->parseMatch( $m );
 913                                 }
 914                         }
 915                 }
 916                 return array( false, false );
 917         }
 918
 919         /**
 920          * Match some text, without parameter capture
 921          * Returns the magic word name, or false if there was no capture
 922          *
 923          * @param string $text
 924          *
 925          * @return string|bool False on failure
 926          */
 927         public function matchStartToEnd( $text ) {
 928                 $hash = $this->getHash();
 929                 if ( isset( $hash[1][$text] ) ) {
 930                         return $hash[1][$text];
 931                 }
 932                 global $wgContLang;
 933                 $lc = $wgContLang->lc( $text );
 934                 if ( isset( $hash[0][$lc] ) ) {
 935                         return $hash[0][$lc];
 936                 }
 937                 return false;
 938         }
 939
 940         /**
 941          * Returns an associative array, ID => param value, for all items that match
 942          * Removes the matched items from the input string (passed by reference)
 943          *
 944          * @param string $text
 945          *
 946          * @return array
 947          */
 948         public function matchAndRemove( &$text ) {
 949                 $found = array();
 950                 $regexes = $this->getRegex();
 951                 foreach ( $regexes as $regex ) {
 952                         if ( $regex === '' ) {
 953                                 continue;
 954                         }
 955                         preg_match_all( $regex, $text, $matches, PREG_SET_ORDER );
 956                         foreach ( $matches as $m ) {
 957                                 list( $name, $param ) = $this->parseMatch( $m );
 958                                 $found[$name] = $param;
 959                         }
 960                         $text = preg_replace( $regex, '', $text );
 961                 }
 962                 return $found;
 963         }
 964
 965         /**
 966          * Return the ID of the magic word at the start of $text, and remove
 967          * the prefix from $text.
 968          * Return false if no match found and $text is not modified.
 969          * Does not match parameters.
 970          *
 971          * @param string $text
 972          *
 973          * @return int|bool False on failure
 974          */
 975         public function matchStartAndRemove( &$text ) {
 976                 $regexes = $this->getRegexStart();
 977                 foreach ( $regexes as $regex ) {
 978                         if ( $regex === '' ) {
 979                                 continue;
 980                         }
 981                         if ( preg_match( $regex, $text, $m ) ) {
 982                                 list( $id, ) = $this->parseMatch( $m );
 983                                 if ( strlen( $m[0] ) >= strlen( $text ) ) {
 984                                         $text = '';
 985                                 } else {
 986                                         $text = substr( $text, strlen( $m[0] ) );
 987                                 }
 988                                 return $id;
 989                         }
 990                 }
 991                 return false;
 992         }
 993 }