includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.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  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  */
  33 class Title {
  34         /** @var MapCacheLRU */
  35         static private $titleCache = null;
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         /** @var string Text form (spaces not underscores) of the main part */
  58         public $mTextform = '';
  59
  60         /** @var string URL-encoded form of the main part */
  61         public $mUrlform = '';
  62
  63         /** @var string Main part with underscores */
  64         public $mDbkeyform = '';
  65
  66         /** @var string Database key with the initial letter in the case specified by the user */
  67         protected $mUserCaseDBKey;
  68
  69         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  70         public $mNamespace = NS_MAIN;
  71
  72         /** @var string Interwiki prefix */
  73         public $mInterwiki = '';
  74
  75         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  76         private $mLocalInterwiki = false;
  77
  78         /** @var string Title fragment (i.e. the bit after the #) */
  79         public $mFragment = '';
  80
  81         /** @var int Article ID, fetched from the link cache on demand */
  82         public $mArticleID = -1;
  83
  84         /** @var bool|int ID of most recent revision */
  85         protected $mLatestID = false;
  86
  87         /**
  88          * @var bool|string ID of the page's content model, i.e. one of the
  89          *   CONTENT_MODEL_XXX constants
  90          */
  91         public $mContentModel = false;
  92
  93         /** @var int Estimated number of revisions; null of not loaded */
  94         private $mEstimateRevisions;
  95
  96         /** @var array Array of groups allowed to edit this article */
  97         public $mRestrictions = array();
  98
  99         /** @var bool */
 100         protected $mOldRestrictions = false;
 101
 102         /** @var bool Cascade restrictions on this page to included templates and images? */
 103         public $mCascadeRestriction;
 104
 105         /** Caching the results of getCascadeProtectionSources */
 106         public $mCascadingRestrictions;
 107
 108         /** @var array When do the restrictions on this page expire? */
 109         protected $mRestrictionsExpiry = array();
 110
 111         /** @var bool Are cascading restrictions in effect on this page? */
 112         protected $mHasCascadingRestrictions;
 113
 114         /** @var array Where are the cascading restrictions coming from on this page? */
 115         public $mCascadeSources;
 116
 117         /** @var bool Boolean for initialisation on demand */
 118         public $mRestrictionsLoaded = false;
 119
 120         /** @var string Text form including namespace/interwiki, initialised on demand */
 121         protected $mPrefixedText = null;
 122
 123         /** @var mixed Cached value for getTitleProtection (create protection) */
 124         public $mTitleProtection;
 125
 126         /**
 127          * @var int Namespace index when there is no namespace. Don't change the
 128          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 129          *   Zero except in {{transclusion}} tags.
 130          */
 131         public $mDefaultNamespace = NS_MAIN;
 132
 133         /**
 134          * @var bool Is $wgUser watching this page? null if unfilled, accessed
 135          * through userIsWatching()
 136          */
 137         protected $mWatched = null;
 138
 139         /** @var int The page length, 0 for special pages */
 140         protected $mLength = -1;
 141
 142         /** @var null Is the article at this title a redirect? */
 143         public $mRedirect = null;
 144
 145         /** @var array Associative array of user ID -> timestamp/false */
 146         private $mNotificationTimestamp = array();
 147
 148         /** @var bool Whether a page has any subpages */
 149         private $mHasSubpages;
 150
 151         /** @var bool The (string) language code of the page's language and content code. */
 152         private $mPageLanguage = false;
 153
 154         /** @var string The page language code from the database */
 155         private $mDbPageLanguage = null;
 156
 157         /** @var TitleValue A corresponding TitleValue object */
 158         private $mTitleValue = null;
 159
 160         /** @var bool Would deleting this page be a big deletion? */
 161         private $mIsBigDeletion = null;
 162         // @}
 163
 164         /**
 165          * B/C kludge: provide a TitleParser for use by Title.
 166          * Ideally, Title would have no methods that need this.
 167          * Avoid usage of this singleton by using TitleValue
 168          * and the associated services when possible.
 169          *
 170          * @return TitleParser
 171          */
 172         private static function getTitleParser() {
 173                 global $wgContLang, $wgLocalInterwikis;
 174
 175                 static $titleCodec = null;
 176                 static $titleCodecFingerprint = null;
 177
 178                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 179                 // make sure we are using the right one. To detect changes over the course
 180                 // of a request, we remember a fingerprint of the config used to create the
 181                 // codec singleton, and re-create it if the fingerprint doesn't match.
 182                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 183
 184                 if ( $fingerprint !== $titleCodecFingerprint ) {
 185                         $titleCodec = null;
 186                 }
 187
 188                 if ( !$titleCodec ) {
 189                         $titleCodec = new MediaWikiTitleCodec(
 190                                 $wgContLang,
 191                                 GenderCache::singleton(),
 192                                 $wgLocalInterwikis
 193                         );
 194                         $titleCodecFingerprint = $fingerprint;
 195                 }
 196
 197                 return $titleCodec;
 198         }
 199
 200         /**
 201          * B/C kludge: provide a TitleParser for use by Title.
 202          * Ideally, Title would have no methods that need this.
 203          * Avoid usage of this singleton by using TitleValue
 204          * and the associated services when possible.
 205          *
 206          * @return TitleFormatter
 207          */
 208         private static function getTitleFormatter() {
 209                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 210                 //      which implements TitleFormatter.
 211                 return self::getTitleParser();
 212         }
 213
 214         function __construct() {
 215         }
 216
 217         /**
 218          * Create a new Title from a prefixed DB key
 219          *
 220          * @param string $key The database key, which has underscores
 221          *      instead of spaces, possibly including namespace and
 222          *      interwiki prefixes
 223          * @return Title|null Title, or null on an error
 224          */
 225         public static function newFromDBkey( $key ) {
 226                 $t = new Title();
 227                 $t->mDbkeyform = $key;
 228                 if ( $t->secureAndSplit() ) {
 229                         return $t;
 230                 } else {
 231                         return null;
 232                 }
 233         }
 234
 235         /**
 236          * Create a new Title from a TitleValue
 237          *
 238          * @param TitleValue $titleValue Assumed to be safe.
 239          *
 240          * @return Title
 241          */
 242         public static function newFromTitleValue( TitleValue $titleValue ) {
 243                 return self::makeTitle(
 244                         $titleValue->getNamespace(),
 245                         $titleValue->getText(),
 246                         $titleValue->getFragment() );
 247         }
 248
 249         /**
 250          * Create a new Title from text, such as what one would find in a link. De-
 251          * codes any HTML entities in the text.
 252          *
 253          * @param string $text The link text; spaces, prefixes, and an
 254          *   initial ':' indicating the main namespace are accepted.
 255          * @param int $defaultNamespace The namespace to use if none is specified
 256          *   by a prefix.  If you want to force a specific namespace even if
 257          *   $text might begin with a namespace prefix, use makeTitle() or
 258          *   makeTitleSafe().
 259          * @throws MWException
 260          * @return Title|null Title or null on an error.
 261          */
 262         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 263                 if ( is_object( $text ) ) {
 264                         throw new MWException( 'Title::newFromText given an object' );
 265                 }
 266
 267                 $cache = self::getTitleCache();
 268
 269                 /**
 270                  * Wiki pages often contain multiple links to the same page.
 271                  * Title normalization and parsing can become expensive on
 272                  * pages with many links, so we can save a little time by
 273                  * caching them.
 274                  *
 275                  * In theory these are value objects and won't get changed...
 276                  */
 277                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 278                         return $cache->get( $text );
 279                 }
 280
 281                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 282                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 283
 284                 $t = new Title();
 285                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 286                 $t->mDefaultNamespace = intval( $defaultNamespace );
 287
 288                 if ( $t->secureAndSplit() ) {
 289                         if ( $defaultNamespace == NS_MAIN ) {
 290                                 $cache->set( $text, $t );
 291                         }
 292                         return $t;
 293                 } else {
 294                         return null;
 295                 }
 296         }
 297
 298         /**
 299          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 300          *
 301          * Example of wrong and broken code:
 302          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 303          *
 304          * Example of right code:
 305          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 306          *
 307          * Create a new Title from URL-encoded text. Ensures that
 308          * the given title's length does not exceed the maximum.
 309          *
 310          * @param string $url The title, as might be taken from a URL
 311          * @return Title|null The new object, or null on an error
 312          */
 313         public static function newFromURL( $url ) {
 314                 $t = new Title();
 315
 316                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 317                 # but some URLs used it as a space replacement and they still come
 318                 # from some external search tools.
 319                 if ( strpos( self::legalChars(), '+' ) === false ) {
 320                         $url = str_replace( '+', ' ', $url );
 321                 }
 322
 323                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 324                 if ( $t->secureAndSplit() ) {
 325                         return $t;
 326                 } else {
 327                         return null;
 328                 }
 329         }
 330
 331         /**
 332          * @return MapCacheLRU
 333          */
 334         private static function getTitleCache() {
 335                 if ( self::$titleCache == null ) {
 336                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 337                 }
 338                 return self::$titleCache;
 339         }
 340
 341         /**
 342          * Returns a list of fields that are to be selected for initializing Title
 343          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 344          * whether to include page_content_model.
 345          *
 346          * @return array
 347          */
 348         protected static function getSelectFields() {
 349                 global $wgContentHandlerUseDB;
 350
 351                 $fields = array(
 352                         'page_namespace', 'page_title', 'page_id',
 353                         'page_len', 'page_is_redirect', 'page_latest',
 354                 );
 355
 356                 if ( $wgContentHandlerUseDB ) {
 357                         $fields[] = 'page_content_model';
 358                 }
 359
 360                 return $fields;
 361         }
 362
 363         /**
 364          * Create a new Title from an article ID
 365          *
 366          * @param int $id The page_id corresponding to the Title to create
 367          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 368          * @return Title|null The new object, or null on an error
 369          */
 370         public static function newFromID( $id, $flags = 0 ) {
 371                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 372                 $row = $db->selectRow(
 373                         'page',
 374                         self::getSelectFields(),
 375                         array( 'page_id' => $id ),
 376                         __METHOD__
 377                 );
 378                 if ( $row !== false ) {
 379                         $title = Title::newFromRow( $row );
 380                 } else {
 381                         $title = null;
 382                 }
 383                 return $title;
 384         }
 385
 386         /**
 387          * Make an array of titles from an array of IDs
 388          *
 389          * @param int[] $ids Array of IDs
 390          * @return Title[] Array of Titles
 391          */
 392         public static function newFromIDs( $ids ) {
 393                 if ( !count( $ids ) ) {
 394                         return array();
 395                 }
 396                 $dbr = wfGetDB( DB_SLAVE );
 397
 398                 $res = $dbr->select(
 399                         'page',
 400                         self::getSelectFields(),
 401                         array( 'page_id' => $ids ),
 402                         __METHOD__
 403                 );
 404
 405                 $titles = array();
 406                 foreach ( $res as $row ) {
 407                         $titles[] = Title::newFromRow( $row );
 408                 }
 409                 return $titles;
 410         }
 411
 412         /**
 413          * Make a Title object from a DB row
 414          *
 415          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 416          * @return Title Corresponding Title
 417          */
 418         public static function newFromRow( $row ) {
 419                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 420                 $t->loadFromRow( $row );
 421                 return $t;
 422         }
 423
 424         /**
 425          * Load Title object fields from a DB row.
 426          * If false is given, the title will be treated as non-existing.
 427          *
 428          * @param stdClass|bool $row Database row
 429          */
 430         public function loadFromRow( $row ) {
 431                 if ( $row ) { // page found
 432                         if ( isset( $row->page_id ) ) {
 433                                 $this->mArticleID = (int)$row->page_id;
 434                         }
 435                         if ( isset( $row->page_len ) ) {
 436                                 $this->mLength = (int)$row->page_len;
 437                         }
 438                         if ( isset( $row->page_is_redirect ) ) {
 439                                 $this->mRedirect = (bool)$row->page_is_redirect;
 440                         }
 441                         if ( isset( $row->page_latest ) ) {
 442                                 $this->mLatestID = (int)$row->page_latest;
 443                         }
 444                         if ( isset( $row->page_content_model ) ) {
 445                                 $this->mContentModel = strval( $row->page_content_model );
 446                         } else {
 447                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 448                         }
 449                         if ( isset( $row->page_lang ) ) {
 450                                 $this->mDbPageLanguage = (string)$row->page_lang;
 451                         }
 452                 } else { // page not found
 453                         $this->mArticleID = 0;
 454                         $this->mLength = 0;
 455                         $this->mRedirect = false;
 456                         $this->mLatestID = 0;
 457                         $this->mContentModel = false; # initialized lazily in getContentModel()
 458                 }
 459         }
 460
 461         /**
 462          * Create a new Title from a namespace index and a DB key.
 463          * It's assumed that $ns and $title are *valid*, for instance when
 464          * they came directly from the database or a special page name.
 465          * For convenience, spaces are converted to underscores so that
 466          * eg user_text fields can be used directly.
 467          *
 468          * @param int $ns The namespace of the article
 469          * @param string $title The unprefixed database key form
 470          * @param string $fragment The link fragment (after the "#")
 471          * @param string $interwiki The interwiki prefix
 472          * @return Title The new object
 473          */
 474         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 475                 $t = new Title();
 476                 $t->mInterwiki = $interwiki;
 477                 $t->mFragment = $fragment;
 478                 $t->mNamespace = $ns = intval( $ns );
 479                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 480                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 481                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 482                 $t->mTextform = str_replace( '_', ' ', $title );
 483                 $t->mContentModel = false; # initialized lazily in getContentModel()
 484                 return $t;
 485         }
 486
 487         /**
 488          * Create a new Title from a namespace index and a DB key.
 489          * The parameters will be checked for validity, which is a bit slower
 490          * than makeTitle() but safer for user-provided data.
 491          *
 492          * @param int $ns The namespace of the article
 493          * @param string $title Database key form
 494          * @param string $fragment The link fragment (after the "#")
 495          * @param string $interwiki Interwiki prefix
 496          * @return Title The new object, or null on an error
 497          */
 498         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 499                 if ( !MWNamespace::exists( $ns ) ) {
 500                         return null;
 501                 }
 502
 503                 $t = new Title();
 504                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 505                 if ( $t->secureAndSplit() ) {
 506                         return $t;
 507                 } else {
 508                         return null;
 509                 }
 510         }
 511
 512         /**
 513          * Create a new Title for the Main Page
 514          *
 515          * @return Title The new object
 516          */
 517         public static function newMainPage() {
 518                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 519                 // Don't give fatal errors if the message is broken
 520                 if ( !$title ) {
 521                         $title = Title::newFromText( 'Main Page' );
 522                 }
 523                 return $title;
 524         }
 525
 526         /**
 527          * Extract a redirect destination from a string and return the
 528          * Title, or null if the text doesn't contain a valid redirect
 529          * This will only return the very next target, useful for
 530          * the redirect table and other checks that don't need full recursion
 531          *
 532          * @param string $text Text with possible redirect
 533          * @return Title The corresponding Title
 534          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 535          */
 536         public static function newFromRedirect( $text ) {
 537                 ContentHandler::deprecated( __METHOD__, '1.21' );
 538
 539                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 540                 return $content->getRedirectTarget();
 541         }
 542
 543         /**
 544          * Extract a redirect destination from a string and return the
 545          * Title, or null if the text doesn't contain a valid redirect
 546          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 547          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 548          *
 549          * @param string $text Text with possible redirect
 550          * @return Title
 551          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 552          */
 553         public static function newFromRedirectRecurse( $text ) {
 554                 ContentHandler::deprecated( __METHOD__, '1.21' );
 555
 556                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 557                 return $content->getUltimateRedirectTarget();
 558         }
 559
 560         /**
 561          * Extract a redirect destination from a string and return an
 562          * array of Titles, or null if the text doesn't contain a valid redirect
 563          * The last element in the array is the final destination after all redirects
 564          * have been resolved (up to $wgMaxRedirects times)
 565          *
 566          * @param string $text Text with possible redirect
 567          * @return Title[] Array of Titles, with the destination last
 568          * @deprecated since 1.21, use Content::getRedirectChain instead.
 569          */
 570         public static function newFromRedirectArray( $text ) {
 571                 ContentHandler::deprecated( __METHOD__, '1.21' );
 572
 573                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 574                 return $content->getRedirectChain();
 575         }
 576
 577         /**
 578          * Get the prefixed DB key associated with an ID
 579          *
 580          * @param int $id The page_id of the article
 581          * @return Title|null An object representing the article, or null if no such article was found
 582          */
 583         public static function nameOf( $id ) {
 584                 $dbr = wfGetDB( DB_SLAVE );
 585
 586                 $s = $dbr->selectRow(
 587                         'page',
 588                         array( 'page_namespace', 'page_title' ),
 589                         array( 'page_id' => $id ),
 590                         __METHOD__
 591                 );
 592                 if ( $s === false ) {
 593                         return null;
 594                 }
 595
 596                 $n = self::makeName( $s->page_namespace, $s->page_title );
 597                 return $n;
 598         }
 599
 600         /**
 601          * Get a regex character class describing the legal characters in a link
 602          *
 603          * @return string The list of characters, not delimited
 604          */
 605         public static function legalChars() {
 606                 global $wgLegalTitleChars;
 607                 return $wgLegalTitleChars;
 608         }
 609
 610         /**
 611          * Returns a simple regex that will match on characters and sequences invalid in titles.
 612          * Note that this doesn't pick up many things that could be wrong with titles, but that
 613          * replacing this regex with something valid will make many titles valid.
 614          *
 615          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 616          *
 617          * @return string Regex string
 618          */
 619         static function getTitleInvalidRegex() {
 620                 wfDeprecated( __METHOD__, '1.25' );
 621                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 622         }
 623
 624         /**
 625          * Utility method for converting a character sequence from bytes to Unicode.
 626          *
 627          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 628          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 629          *
 630          * @param string $byteClass
 631          * @return string
 632          */
 633         public static function convertByteClassToUnicodeClass( $byteClass ) {
 634                 $length = strlen( $byteClass );
 635                 // Input token queue
 636                 $x0 = $x1 = $x2 = '';
 637                 // Decoded queue
 638                 $d0 = $d1 = $d2 = '';
 639                 // Decoded integer codepoints
 640                 $ord0 = $ord1 = $ord2 = 0;
 641                 // Re-encoded queue
 642                 $r0 = $r1 = $r2 = '';
 643                 // Output
 644                 $out = '';
 645                 // Flags
 646                 $allowUnicode = false;
 647                 for ( $pos = 0; $pos < $length; $pos++ ) {
 648                         // Shift the queues down
 649                         $x2 = $x1;
 650                         $x1 = $x0;
 651                         $d2 = $d1;
 652                         $d1 = $d0;
 653                         $ord2 = $ord1;
 654                         $ord1 = $ord0;
 655                         $r2 = $r1;
 656                         $r1 = $r0;
 657                         // Load the current input token and decoded values
 658                         $inChar = $byteClass[$pos];
 659                         if ( $inChar == '\\' ) {
 660                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 661                                         $x0 = $inChar . $m[0];
 662                                         $d0 = chr( hexdec( $m[1] ) );
 663                                         $pos += strlen( $m[0] );
 664                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 665                                         $x0 = $inChar . $m[0];
 666                                         $d0 = chr( octdec( $m[0] ) );
 667                                         $pos += strlen( $m[0] );
 668                                 } elseif ( $pos + 1 >= $length ) {
 669                                         $x0 = $d0 = '\\';
 670                                 } else {
 671                                         $d0 = $byteClass[$pos + 1];
 672                                         $x0 = $inChar . $d0;
 673                                         $pos += 1;
 674                                 }
 675                         } else {
 676                                 $x0 = $d0 = $inChar;
 677                         }
 678                         $ord0 = ord( $d0 );
 679                         // Load the current re-encoded value
 680                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 681                                 $r0 = sprintf( '\x%02x', $ord0 );
 682                         } elseif ( $ord0 >= 0x80 ) {
 683                                 // Allow unicode if a single high-bit character appears
 684                                 $r0 = sprintf( '\x%02x', $ord0 );
 685                                 $allowUnicode = true;
 686                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 687                                 $r0 = '\\' . $d0;
 688                         } else {
 689                                 $r0 = $d0;
 690                         }
 691                         // Do the output
 692                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 693                                 // Range
 694                                 if ( $ord2 > $ord0 ) {
 695                                         // Empty range
 696                                 } elseif ( $ord0 >= 0x80 ) {
 697                                         // Unicode range
 698                                         $allowUnicode = true;
 699                                         if ( $ord2 < 0x80 ) {
 700                                                 // Keep the non-unicode section of the range
 701                                                 $out .= "$r2-\\x7F";
 702                                         }
 703                                 } else {
 704                                         // Normal range
 705                                         $out .= "$r2-$r0";
 706                                 }
 707                                 // Reset state to the initial value
 708                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 709                         } elseif ( $ord2 < 0x80 ) {
 710                                 // ASCII character
 711                                 $out .= $r2;
 712                         }
 713                 }
 714                 if ( $ord1 < 0x80 ) {
 715                         $out .= $r1;
 716                 }
 717                 if ( $ord0 < 0x80 ) {
 718                         $out .= $r0;
 719                 }
 720                 if ( $allowUnicode ) {
 721                         $out .= '\u0080-\uFFFF';
 722                 }
 723                 return $out;
 724         }
 725
 726         /**
 727          * Make a prefixed DB key from a DB key and a namespace index
 728          *
 729          * @param int $ns Numerical representation of the namespace
 730          * @param string $title The DB key form the title
 731          * @param string $fragment The link fragment (after the "#")
 732          * @param string $interwiki The interwiki prefix
 733          * @param bool $canoncialNamespace If true, use the canonical name for
 734          *   $ns instead of the localized version.
 735          * @return string The prefixed form of the title
 736          */
 737         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 738                 $canoncialNamespace = false
 739         ) {
 740                 global $wgContLang;
 741
 742                 if ( $canoncialNamespace ) {
 743                         $namespace = MWNamespace::getCanonicalName( $ns );
 744                 } else {
 745                         $namespace = $wgContLang->getNsText( $ns );
 746                 }
 747                 $name = $namespace == '' ? $title : "$namespace:$title";
 748                 if ( strval( $interwiki ) != '' ) {
 749                         $name = "$interwiki:$name";
 750                 }
 751                 if ( strval( $fragment ) != '' ) {
 752                         $name .= '#' . $fragment;
 753                 }
 754                 return $name;
 755         }
 756
 757         /**
 758          * Escape a text fragment, say from a link, for a URL
 759          *
 760          * @param string $fragment Containing a URL or link fragment (after the "#")
 761          * @return string Escaped string
 762          */
 763         static function escapeFragmentForURL( $fragment ) {
 764                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 765                 # fragments appear not to work in IE (at least up to 7) or in at least
 766                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 767                 # to care if they aren't encoded.
 768                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 769         }
 770
 771         /**
 772          * Callback for usort() to do title sorts by (namespace, title)
 773          *
 774          * @param Title $a
 775          * @param Title $b
 776          *
 777          * @return int Result of string comparison, or namespace comparison
 778          */
 779         public static function compare( $a, $b ) {
 780                 if ( $a->getNamespace() == $b->getNamespace() ) {
 781                         return strcmp( $a->getText(), $b->getText() );
 782                 } else {
 783                         return $a->getNamespace() - $b->getNamespace();
 784                 }
 785         }
 786
 787         /**
 788          * Determine whether the object refers to a page within
 789          * this project (either this wiki or a wiki with a local
 790          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 791          *
 792          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 793          */
 794         public function isLocal() {
 795                 if ( $this->isExternal() ) {
 796                         $iw = Interwiki::fetch( $this->mInterwiki );
 797                         if ( $iw ) {
 798                                 return $iw->isLocal();
 799                         }
 800                 }
 801                 return true;
 802         }
 803
 804         /**
 805          * Is this Title interwiki?
 806          *
 807          * @return bool
 808          */
 809         public function isExternal() {
 810                 return $this->mInterwiki !== '';
 811         }
 812
 813         /**
 814          * Get the interwiki prefix
 815          *
 816          * Use Title::isExternal to check if a interwiki is set
 817          *
 818          * @return string Interwiki prefix
 819          */
 820         public function getInterwiki() {
 821                 return $this->mInterwiki;
 822         }
 823
 824         /**
 825          * Was this a local interwiki link?
 826          *
 827          * @return bool
 828          */
 829         public function wasLocalInterwiki() {
 830                 return $this->mLocalInterwiki;
 831         }
 832
 833         /**
 834          * Determine whether the object refers to a page within
 835          * this project and is transcludable.
 836          *
 837          * @return bool True if this is transcludable
 838          */
 839         public function isTrans() {
 840                 if ( !$this->isExternal() ) {
 841                         return false;
 842                 }
 843
 844                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 845         }
 846
 847         /**
 848          * Returns the DB name of the distant wiki which owns the object.
 849          *
 850          * @return string The DB name
 851          */
 852         public function getTransWikiID() {
 853                 if ( !$this->isExternal() ) {
 854                         return false;
 855                 }
 856
 857                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 858         }
 859
 860         /**
 861          * Get a TitleValue object representing this Title.
 862          *
 863          * @note Not all valid Titles have a corresponding valid TitleValue
 864          * (e.g. TitleValues cannot represent page-local links that have a
 865          * fragment but no title text).
 866          *
 867          * @return TitleValue|null
 868          */
 869         public function getTitleValue() {
 870                 if ( $this->mTitleValue === null ) {
 871                         try {
 872                                 $this->mTitleValue = new TitleValue(
 873                                         $this->getNamespace(),
 874                                         $this->getDBkey(),
 875                                         $this->getFragment() );
 876                         } catch ( InvalidArgumentException $ex ) {
 877                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 878                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 879                         }
 880                 }
 881
 882                 return $this->mTitleValue;
 883         }
 884
 885         /**
 886          * Get the text form (spaces not underscores) of the main part
 887          *
 888          * @return string Main part of the title
 889          */
 890         public function getText() {
 891                 return $this->mTextform;
 892         }
 893
 894         /**
 895          * Get the URL-encoded form of the main part
 896          *
 897          * @return string Main part of the title, URL-encoded
 898          */
 899         public function getPartialURL() {
 900                 return $this->mUrlform;
 901         }
 902
 903         /**
 904          * Get the main part with underscores
 905          *
 906          * @return string Main part of the title, with underscores
 907          */
 908         public function getDBkey() {
 909                 return $this->mDbkeyform;
 910         }
 911
 912         /**
 913          * Get the DB key with the initial letter case as specified by the user
 914          *
 915          * @return string DB key
 916          */
 917         function getUserCaseDBKey() {
 918                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 919                         return $this->mUserCaseDBKey;
 920                 } else {
 921                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 922                         return $this->mDbkeyform;
 923                 }
 924         }
 925
 926         /**
 927          * Get the namespace index, i.e. one of the NS_xxxx constants.
 928          *
 929          * @return int Namespace index
 930          */
 931         public function getNamespace() {
 932                 return $this->mNamespace;
 933         }
 934
 935         /**
 936          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 937          *
 938          * @throws MWException
 939          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 940          * @return string Content model id
 941          */
 942         public function getContentModel( $flags = 0 ) {
 943                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 944                         $linkCache = LinkCache::singleton();
 945                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 946                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 947                 }
 948
 949                 if ( !$this->mContentModel ) {
 950                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 951                 }
 952
 953                 if ( !$this->mContentModel ) {
 954                         throw new MWException( 'Failed to determine content model!' );
 955                 }
 956
 957                 return $this->mContentModel;
 958         }
 959
 960         /**
 961          * Convenience method for checking a title's content model name
 962          *
 963          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 964          * @return bool True if $this->getContentModel() == $id
 965          */
 966         public function hasContentModel( $id ) {
 967                 return $this->getContentModel() == $id;
 968         }
 969
 970         /**
 971          * Get the namespace text
 972          *
 973          * @return string Namespace text
 974          */
 975         public function getNsText() {
 976                 if ( $this->isExternal() ) {
 977                         // This probably shouldn't even happen. ohh man, oh yuck.
 978                         // But for interwiki transclusion it sometimes does.
 979                         // Shit. Shit shit shit.
 980                         //
 981                         // Use the canonical namespaces if possible to try to
 982                         // resolve a foreign namespace.
 983                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 984                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 985                         }
 986                 }
 987
 988                 try {
 989                         $formatter = self::getTitleFormatter();
 990                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 991                 } catch ( InvalidArgumentException $ex ) {
 992                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 993                         return false;
 994                 }
 995         }
 996
 997         /**
 998          * Get the namespace text of the subject (rather than talk) page
 999          *
1000          * @return string Namespace text
1001          */
1002         public function getSubjectNsText() {
1003                 global $wgContLang;
1004                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1005         }
1006
1007         /**
1008          * Get the namespace text of the talk page
1009          *
1010          * @return string Namespace text
1011          */
1012         public function getTalkNsText() {
1013                 global $wgContLang;
1014                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1015         }
1016
1017         /**
1018          * Could this title have a corresponding talk page?
1019          *
1020          * @return bool
1021          */
1022         public function canTalk() {
1023                 return MWNamespace::canTalk( $this->mNamespace );
1024         }
1025
1026         /**
1027          * Is this in a namespace that allows actual pages?
1028          *
1029          * @return bool
1030          */
1031         public function canExist() {
1032                 return $this->mNamespace >= NS_MAIN;
1033         }
1034
1035         /**
1036          * Can this title be added to a user's watchlist?
1037          *
1038          * @return bool
1039          */
1040         public function isWatchable() {
1041                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1042         }
1043
1044         /**
1045          * Returns true if this is a special page.
1046          *
1047          * @return bool
1048          */
1049         public function isSpecialPage() {
1050                 return $this->getNamespace() == NS_SPECIAL;
1051         }
1052
1053         /**
1054          * Returns true if this title resolves to the named special page
1055          *
1056          * @param string $name The special page name
1057          * @return bool
1058          */
1059         public function isSpecial( $name ) {
1060                 if ( $this->isSpecialPage() ) {
1061                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1062                         if ( $name == $thisName ) {
1063                                 return true;
1064                         }
1065                 }
1066                 return false;
1067         }
1068
1069         /**
1070          * If the Title refers to a special page alias which is not the local default, resolve
1071          * the alias, and localise the name as necessary.  Otherwise, return $this
1072          *
1073          * @return Title
1074          */
1075         public function fixSpecialName() {
1076                 if ( $this->isSpecialPage() ) {
1077                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1078                         if ( $canonicalName ) {
1079                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1080                                 if ( $localName != $this->mDbkeyform ) {
1081                                         return Title::makeTitle( NS_SPECIAL, $localName );
1082                                 }
1083                         }
1084                 }
1085                 return $this;
1086         }
1087
1088         /**
1089          * Returns true if the title is inside the specified namespace.
1090          *
1091          * Please make use of this instead of comparing to getNamespace()
1092          * This function is much more resistant to changes we may make
1093          * to namespaces than code that makes direct comparisons.
1094          * @param int $ns The namespace
1095          * @return bool
1096          * @since 1.19
1097          */
1098         public function inNamespace( $ns ) {
1099                 return MWNamespace::equals( $this->getNamespace(), $ns );
1100         }
1101
1102         /**
1103          * Returns true if the title is inside one of the specified namespaces.
1104          *
1105          * @param int $namespaces,... The namespaces to check for
1106          * @return bool
1107          * @since 1.19
1108          */
1109         public function inNamespaces( /* ... */ ) {
1110                 $namespaces = func_get_args();
1111                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1112                         $namespaces = $namespaces[0];
1113                 }
1114
1115                 foreach ( $namespaces as $ns ) {
1116                         if ( $this->inNamespace( $ns ) ) {
1117                                 return true;
1118                         }
1119                 }
1120
1121                 return false;
1122         }
1123
1124         /**
1125          * Returns true if the title has the same subject namespace as the
1126          * namespace specified.
1127          * For example this method will take NS_USER and return true if namespace
1128          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1129          * as their subject namespace.
1130          *
1131          * This is MUCH simpler than individually testing for equivalence
1132          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1133          * @since 1.19
1134          * @param int $ns
1135          * @return bool
1136          */
1137         public function hasSubjectNamespace( $ns ) {
1138                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1139         }
1140
1141         /**
1142          * Is this Title in a namespace which contains content?
1143          * In other words, is this a content page, for the purposes of calculating
1144          * statistics, etc?
1145          *
1146          * @return bool
1147          */
1148         public function isContentPage() {
1149                 return MWNamespace::isContent( $this->getNamespace() );
1150         }
1151
1152         /**
1153          * Would anybody with sufficient privileges be able to move this page?
1154          * Some pages just aren't movable.
1155          *
1156          * @return bool
1157          */
1158         public function isMovable() {
1159                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1160                         // Interwiki title or immovable namespace. Hooks don't get to override here
1161                         return false;
1162                 }
1163
1164                 $result = true;
1165                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1166                 return $result;
1167         }
1168
1169         /**
1170          * Is this the mainpage?
1171          * @note Title::newFromText seems to be sufficiently optimized by the title
1172          * cache that we don't need to over-optimize by doing direct comparisons and
1173          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1174          * ends up reporting something differently than $title->isMainPage();
1175          *
1176          * @since 1.18
1177          * @return bool
1178          */
1179         public function isMainPage() {
1180                 return $this->equals( Title::newMainPage() );
1181         }
1182
1183         /**
1184          * Is this a subpage?
1185          *
1186          * @return bool
1187          */
1188         public function isSubpage() {
1189                 return MWNamespace::hasSubpages( $this->mNamespace )
1190                         ? strpos( $this->getText(), '/' ) !== false
1191                         : false;
1192         }
1193
1194         /**
1195          * Is this a conversion table for the LanguageConverter?
1196          *
1197          * @return bool
1198          */
1199         public function isConversionTable() {
1200                 // @todo ConversionTable should become a separate content model.
1201
1202                 return $this->getNamespace() == NS_MEDIAWIKI &&
1203                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1204         }
1205
1206         /**
1207          * Does that page contain wikitext, or it is JS, CSS or whatever?
1208          *
1209          * @return bool
1210          */
1211         public function isWikitextPage() {
1212                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1213         }
1214
1215         /**
1216          * Could this page contain custom CSS or JavaScript for the global UI.
1217          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1218          * or CONTENT_MODEL_JAVASCRIPT.
1219          *
1220          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1221          * for that!
1222          *
1223          * Note that this method should not return true for pages that contain and
1224          * show "inactive" CSS or JS.
1225          *
1226          * @return bool
1227          */
1228         public function isCssOrJsPage() {
1229                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1230                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1231                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1232
1233                 # @note This hook is also called in ContentHandler::getDefaultModel.
1234                 #   It's called here again to make sure hook functions can force this
1235                 #   method to return true even outside the MediaWiki namespace.
1236
1237                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1238
1239                 return $isCssOrJsPage;
1240         }
1241
1242         /**
1243          * Is this a .css or .js subpage of a user page?
1244          * @return bool
1245          */
1246         public function isCssJsSubpage() {
1247                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1248                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1249                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1250         }
1251
1252         /**
1253          * Trim down a .css or .js subpage title to get the corresponding skin name
1254          *
1255          * @return string Containing skin name from .css or .js subpage title
1256          */
1257         public function getSkinFromCssJsSubpage() {
1258                 $subpage = explode( '/', $this->mTextform );
1259                 $subpage = $subpage[count( $subpage ) - 1];
1260                 $lastdot = strrpos( $subpage, '.' );
1261                 if ( $lastdot === false ) {
1262                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1263                 }
1264                 return substr( $subpage, 0, $lastdot );
1265         }
1266
1267         /**
1268          * Is this a .css subpage of a user page?
1269          *
1270          * @return bool
1271          */
1272         public function isCssSubpage() {
1273                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1274                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1275         }
1276
1277         /**
1278          * Is this a .js subpage of a user page?
1279          *
1280          * @return bool
1281          */
1282         public function isJsSubpage() {
1283                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1284                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1285         }
1286
1287         /**
1288          * Is this a talk page of some sort?
1289          *
1290          * @return bool
1291          */
1292         public function isTalkPage() {
1293                 return MWNamespace::isTalk( $this->getNamespace() );
1294         }
1295
1296         /**
1297          * Get a Title object associated with the talk page of this article
1298          *
1299          * @return Title The object for the talk page
1300          */
1301         public function getTalkPage() {
1302                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1303         }
1304
1305         /**
1306          * Get a title object associated with the subject page of this
1307          * talk page
1308          *
1309          * @return Title The object for the subject page
1310          */
1311         public function getSubjectPage() {
1312                 // Is this the same title?
1313                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1314                 if ( $this->getNamespace() == $subjectNS ) {
1315                         return $this;
1316                 }
1317                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1318         }
1319
1320         /**
1321          * Get the other title for this page, if this is a subject page
1322          * get the talk page, if it is a subject page get the talk page
1323          *
1324          * @since 1.25
1325          * @throws MWException
1326          * @return Title
1327          */
1328         public function getOtherPage() {
1329                 if ( $this->isSpecialPage() ) {
1330                         throw new MWException( 'Special pages cannot have other pages' );
1331                 }
1332                 if ( $this->isTalkPage() ) {
1333                         return $this->getSubjectPage();
1334                 } else {
1335                         return $this->getTalkPage();
1336                 }
1337         }
1338
1339         /**
1340          * Get the default namespace index, for when there is no namespace
1341          *
1342          * @return int Default namespace index
1343          */
1344         public function getDefaultNamespace() {
1345                 return $this->mDefaultNamespace;
1346         }
1347
1348         /**
1349          * Get the Title fragment (i.e.\ the bit after the #) in text form
1350          *
1351          * Use Title::hasFragment to check for a fragment
1352          *
1353          * @return string Title fragment
1354          */
1355         public function getFragment() {
1356                 return $this->mFragment;
1357         }
1358
1359         /**
1360          * Check if a Title fragment is set
1361          *
1362          * @return bool
1363          * @since 1.23
1364          */
1365         public function hasFragment() {
1366                 return $this->mFragment !== '';
1367         }
1368
1369         /**
1370          * Get the fragment in URL form, including the "#" character if there is one
1371          * @return string Fragment in URL form
1372          */
1373         public function getFragmentForURL() {
1374                 if ( !$this->hasFragment() ) {
1375                         return '';
1376                 } else {
1377                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1378                 }
1379         }
1380
1381         /**
1382          * Set the fragment for this title. Removes the first character from the
1383          * specified fragment before setting, so it assumes you're passing it with
1384          * an initial "#".
1385          *
1386          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1387          * Still in active use privately.
1388          *
1389          * @param string $fragment Text
1390          */
1391         public function setFragment( $fragment ) {
1392                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1393         }
1394
1395         /**
1396          * Prefix some arbitrary text with the namespace or interwiki prefix
1397          * of this object
1398          *
1399          * @param string $name The text
1400          * @return string The prefixed text
1401          */
1402         private function prefix( $name ) {
1403                 $p = '';
1404                 if ( $this->isExternal() ) {
1405                         $p = $this->mInterwiki . ':';
1406                 }
1407
1408                 if ( 0 != $this->mNamespace ) {
1409                         $p .= $this->getNsText() . ':';
1410                 }
1411                 return $p . $name;
1412         }
1413
1414         /**
1415          * Get the prefixed database key form
1416          *
1417          * @return string The prefixed title, with underscores and
1418          *  any interwiki and namespace prefixes
1419          */
1420         public function getPrefixedDBkey() {
1421                 $s = $this->prefix( $this->mDbkeyform );
1422                 $s = str_replace( ' ', '_', $s );
1423                 return $s;
1424         }
1425
1426         /**
1427          * Get the prefixed title with spaces.
1428          * This is the form usually used for display
1429          *
1430          * @return string The prefixed title, with spaces
1431          */
1432         public function getPrefixedText() {
1433                 if ( $this->mPrefixedText === null ) {
1434                         $s = $this->prefix( $this->mTextform );
1435                         $s = str_replace( '_', ' ', $s );
1436                         $this->mPrefixedText = $s;
1437                 }
1438                 return $this->mPrefixedText;
1439         }
1440
1441         /**
1442          * Return a string representation of this title
1443          *
1444          * @return string Representation of this title
1445          */
1446         public function __toString() {
1447                 return $this->getPrefixedText();
1448         }
1449
1450         /**
1451          * Get the prefixed title with spaces, plus any fragment
1452          * (part beginning with '#')
1453          *
1454          * @return string The prefixed title, with spaces and the fragment, including '#'
1455          */
1456         public function getFullText() {
1457                 $text = $this->getPrefixedText();
1458                 if ( $this->hasFragment() ) {
1459                         $text .= '#' . $this->getFragment();
1460                 }
1461                 return $text;
1462         }
1463
1464         /**
1465          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1466          *
1467          * @par Example:
1468          * @code
1469          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1470          * # returns: 'Foo'
1471          * @endcode
1472          *
1473          * @return string Root name
1474          * @since 1.20
1475          */
1476         public function getRootText() {
1477                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1478                         return $this->getText();
1479                 }
1480
1481                 return strtok( $this->getText(), '/' );
1482         }
1483
1484         /**
1485          * Get the root page name title, i.e. the leftmost part before any slashes
1486          *
1487          * @par Example:
1488          * @code
1489          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1490          * # returns: Title{User:Foo}
1491          * @endcode
1492          *
1493          * @return Title Root title
1494          * @since 1.20
1495          */
1496         public function getRootTitle() {
1497                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1498         }
1499
1500         /**
1501          * Get the base page name without a namespace, i.e. the part before the subpage name
1502          *
1503          * @par Example:
1504          * @code
1505          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1506          * # returns: 'Foo/Bar'
1507          * @endcode
1508          *
1509          * @return string Base name
1510          */
1511         public function getBaseText() {
1512                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1513                         return $this->getText();
1514                 }
1515
1516                 $parts = explode( '/', $this->getText() );
1517                 # Don't discard the real title if there's no subpage involved
1518                 if ( count( $parts ) > 1 ) {
1519                         unset( $parts[count( $parts ) - 1] );
1520                 }
1521                 return implode( '/', $parts );
1522         }
1523
1524         /**
1525          * Get the base page name title, i.e. the part before the subpage name
1526          *
1527          * @par Example:
1528          * @code
1529          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1530          * # returns: Title{User:Foo/Bar}
1531          * @endcode
1532          *
1533          * @return Title Base title
1534          * @since 1.20
1535          */
1536         public function getBaseTitle() {
1537                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1538         }
1539
1540         /**
1541          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1542          *
1543          * @par Example:
1544          * @code
1545          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1546          * # returns: "Baz"
1547          * @endcode
1548          *
1549          * @return string Subpage name
1550          */
1551         public function getSubpageText() {
1552                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1553                         return $this->mTextform;
1554                 }
1555                 $parts = explode( '/', $this->mTextform );
1556                 return $parts[count( $parts ) - 1];
1557         }
1558
1559         /**
1560          * Get the title for a subpage of the current page
1561          *
1562          * @par Example:
1563          * @code
1564          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1565          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1566          * @endcode
1567          *
1568          * @param string $text The subpage name to add to the title
1569          * @return Title Subpage title
1570          * @since 1.20
1571          */
1572         public function getSubpage( $text ) {
1573                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1574         }
1575
1576         /**
1577          * Get a URL-encoded form of the subpage text
1578          *
1579          * @return string URL-encoded subpage name
1580          */
1581         public function getSubpageUrlForm() {
1582                 $text = $this->getSubpageText();
1583                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1584                 return $text;
1585         }
1586
1587         /**
1588          * Get a URL-encoded title (not an actual URL) including interwiki
1589          *
1590          * @return string The URL-encoded form
1591          */
1592         public function getPrefixedURL() {
1593                 $s = $this->prefix( $this->mDbkeyform );
1594                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1595                 return $s;
1596         }
1597
1598         /**
1599          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1600          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1601          * second argument named variant. This was deprecated in favor
1602          * of passing an array of option with a "variant" key
1603          * Once $query2 is removed for good, this helper can be dropped
1604          * and the wfArrayToCgi moved to getLocalURL();
1605          *
1606          * @since 1.19 (r105919)
1607          * @param array|string $query
1608          * @param bool $query2
1609          * @return string
1610          */
1611         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1612                 if ( $query2 !== false ) {
1613                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1614                                 "method called with a second parameter is deprecated. Add your " .
1615                                 "parameter to an array passed as the first parameter.", "1.19" );
1616                 }
1617                 if ( is_array( $query ) ) {
1618                         $query = wfArrayToCgi( $query );
1619                 }
1620                 if ( $query2 ) {
1621                         if ( is_string( $query2 ) ) {
1622                                 // $query2 is a string, we will consider this to be
1623                                 // a deprecated $variant argument and add it to the query
1624                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1625                         } else {
1626                                 $query2 = wfArrayToCgi( $query2 );
1627                         }
1628                         // If we have $query content add a & to it first
1629                         if ( $query ) {
1630                                 $query .= '&';
1631                         }
1632                         // Now append the queries together
1633                         $query .= $query2;
1634                 }
1635                 return $query;
1636         }
1637
1638         /**
1639          * Get a real URL referring to this title, with interwiki link and
1640          * fragment
1641          *
1642          * @see self::getLocalURL for the arguments.
1643          * @see wfExpandUrl
1644          * @param array|string $query
1645          * @param bool $query2
1646          * @param string $proto Protocol type to use in URL
1647          * @return string The URL
1648          */
1649         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1650                 $query = self::fixUrlQueryArgs( $query, $query2 );
1651
1652                 # Hand off all the decisions on urls to getLocalURL
1653                 $url = $this->getLocalURL( $query );
1654
1655                 # Expand the url to make it a full url. Note that getLocalURL has the
1656                 # potential to output full urls for a variety of reasons, so we use
1657                 # wfExpandUrl instead of simply prepending $wgServer
1658                 $url = wfExpandUrl( $url, $proto );
1659
1660                 # Finally, add the fragment.
1661                 $url .= $this->getFragmentForURL();
1662
1663                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1664                 return $url;
1665         }
1666
1667         /**
1668          * Get a URL with no fragment or server name (relative URL) from a Title object.
1669          * If this page is generated with action=render, however,
1670          * $wgServer is prepended to make an absolute URL.
1671          *
1672          * @see self::getFullURL to always get an absolute URL.
1673          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1674          *  valid to link, locally, to the current Title.
1675          * @see self::newFromText to produce a Title object.
1676          *
1677          * @param string|array $query An optional query string,
1678          *   not used for interwiki links. Can be specified as an associative array as well,
1679          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1680          *   Some query patterns will trigger various shorturl path replacements.
1681          * @param array $query2 An optional secondary query array. This one MUST
1682          *   be an array. If a string is passed it will be interpreted as a deprecated
1683          *   variant argument and urlencoded into a variant= argument.
1684          *   This second query argument will be added to the $query
1685          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1686          *   pair in the first parameter array instead.
1687          *
1688          * @return string String of the URL.
1689          */
1690         public function getLocalURL( $query = '', $query2 = false ) {
1691                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1692
1693                 $query = self::fixUrlQueryArgs( $query, $query2 );
1694
1695                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1696                 if ( $interwiki ) {
1697                         $namespace = $this->getNsText();
1698                         if ( $namespace != '' ) {
1699                                 # Can this actually happen? Interwikis shouldn't be parsed.
1700                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1701                                 $namespace .= ':';
1702                         }
1703                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1704                         $url = wfAppendQuery( $url, $query );
1705                 } else {
1706                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1707                         if ( $query == '' ) {
1708                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1709                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1710                         } else {
1711                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1712                                 $url = false;
1713                                 $matches = array();
1714
1715                                 if ( !empty( $wgActionPaths )
1716                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1717                                 ) {
1718                                         $action = urldecode( $matches[2] );
1719                                         if ( isset( $wgActionPaths[$action] ) ) {
1720                                                 $query = $matches[1];
1721                                                 if ( isset( $matches[4] ) ) {
1722                                                         $query .= $matches[4];
1723                                                 }
1724                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1725                                                 if ( $query != '' ) {
1726                                                         $url = wfAppendQuery( $url, $query );
1727                                                 }
1728                                         }
1729                                 }
1730
1731                                 if ( $url === false
1732                                         && $wgVariantArticlePath
1733                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1734                                         && $this->getPageLanguage()->hasVariants()
1735                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1736                                 ) {
1737                                         $variant = urldecode( $matches[1] );
1738                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1739                                                 // Only do the variant replacement if the given variant is a valid
1740                                                 // variant for the page's language.
1741                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1742                                                 $url = str_replace( '$1', $dbkey, $url );
1743                                         }
1744                                 }
1745
1746                                 if ( $url === false ) {
1747                                         if ( $query == '-' ) {
1748                                                 $query = '';
1749                                         }
1750                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1751                                 }
1752                         }
1753
1754                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1755
1756                         // @todo FIXME: This causes breakage in various places when we
1757                         // actually expected a local URL and end up with dupe prefixes.
1758                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1759                                 $url = $wgServer . $url;
1760                         }
1761                 }
1762                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1763                 return $url;
1764         }
1765
1766         /**
1767          * Get a URL that's the simplest URL that will be valid to link, locally,
1768          * to the current Title.  It includes the fragment, but does not include
1769          * the server unless action=render is used (or the link is external).  If
1770          * there's a fragment but the prefixed text is empty, we just return a link
1771          * to the fragment.
1772          *
1773          * The result obviously should not be URL-escaped, but does need to be
1774          * HTML-escaped if it's being output in HTML.
1775          *
1776          * @param array $query
1777          * @param bool $query2
1778          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1779          * @see self::getLocalURL for the arguments.
1780          * @return string The URL
1781          */
1782         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1783                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1784                         $ret = $this->getFullURL( $query, $query2, $proto );
1785                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1786                         $ret = $this->getFragmentForURL();
1787                 } else {
1788                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1789                 }
1790                 return $ret;
1791         }
1792
1793         /**
1794          * Get the URL form for an internal link.
1795          * - Used in various Squid-related code, in case we have a different
1796          * internal hostname for the server from the exposed one.
1797          *
1798          * This uses $wgInternalServer to qualify the path, or $wgServer
1799          * if $wgInternalServer is not set. If the server variable used is
1800          * protocol-relative, the URL will be expanded to http://
1801          *
1802          * @see self::getLocalURL for the arguments.
1803          * @return string The URL
1804          */
1805         public function getInternalURL( $query = '', $query2 = false ) {
1806                 global $wgInternalServer, $wgServer;
1807                 $query = self::fixUrlQueryArgs( $query, $query2 );
1808                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1809                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1810                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1811                 return $url;
1812         }
1813
1814         /**
1815          * Get the URL for a canonical link, for use in things like IRC and
1816          * e-mail notifications. Uses $wgCanonicalServer and the
1817          * GetCanonicalURL hook.
1818          *
1819          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1820          *
1821          * @see self::getLocalURL for the arguments.
1822          * @return string The URL
1823          * @since 1.18
1824          */
1825         public function getCanonicalURL( $query = '', $query2 = false ) {
1826                 $query = self::fixUrlQueryArgs( $query, $query2 );
1827                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1828                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1829                 return $url;
1830         }
1831
1832         /**
1833          * Get the edit URL for this Title
1834          *
1835          * @return string The URL, or a null string if this is an interwiki link
1836          */
1837         public function getEditURL() {
1838                 if ( $this->isExternal() ) {
1839                         return '';
1840                 }
1841                 $s = $this->getLocalURL( 'action=edit' );
1842
1843                 return $s;
1844         }
1845
1846         /**
1847          * Is $wgUser watching this page?
1848          *
1849          * @deprecated since 1.20; use User::isWatched() instead.
1850          * @return bool
1851          */
1852         public function userIsWatching() {
1853                 global $wgUser;
1854
1855                 if ( is_null( $this->mWatched ) ) {
1856                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1857                                 $this->mWatched = false;
1858                         } else {
1859                                 $this->mWatched = $wgUser->isWatched( $this );
1860                         }
1861                 }
1862                 return $this->mWatched;
1863         }
1864
1865         /**
1866          * Can $user perform $action on this page?
1867          * This skips potentially expensive cascading permission checks
1868          * as well as avoids expensive error formatting
1869          *
1870          * Suitable for use for nonessential UI controls in common cases, but
1871          * _not_ for functional access control.
1872          *
1873          * May provide false positives, but should never provide a false negative.
1874          *
1875          * @param string $action Action that permission needs to be checked for
1876          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1877          * @return bool
1878          */
1879         public function quickUserCan( $action, $user = null ) {
1880                 return $this->userCan( $action, $user, false );
1881         }
1882
1883         /**
1884          * Can $user perform $action on this page?
1885          *
1886          * @param string $action Action that permission needs to be checked for
1887          * @param User $user User to check (since 1.19); $wgUser will be used if not
1888          *   provided.
1889          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1890          * @return bool
1891          */
1892         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1893                 if ( !$user instanceof User ) {
1894                         global $wgUser;
1895                         $user = $wgUser;
1896                 }
1897
1898                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1899         }
1900
1901         /**
1902          * Can $user perform $action on this page?
1903          *
1904          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1905          *
1906          * @param string $action Action that permission needs to be checked for
1907          * @param User $user User to check
1908          * @param string $rigor One of (quick,full,secure)
1909          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1910          *   - full   : does cheap and expensive checks possibly from a slave
1911          *   - secure : does cheap and expensive checks, using the master as needed
1912          * @param bool $short Set this to true to stop after the first permission error.
1913          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1914          *   whose corresponding errors may be ignored.
1915          * @return array Array of arguments to wfMessage to explain permissions problems.
1916          */
1917         public function getUserPermissionsErrors(
1918                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1919         ) {
1920                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1921
1922                 // Remove the errors being ignored.
1923                 foreach ( $errors as $index => $error ) {
1924                         $error_key = is_array( $error ) ? $error[0] : $error;
1925
1926                         if ( in_array( $error_key, $ignoreErrors ) ) {
1927                                 unset( $errors[$index] );
1928                         }
1929                 }
1930
1931                 return $errors;
1932         }
1933
1934         /**
1935          * Permissions checks that fail most often, and which are easiest to test.
1936          *
1937          * @param string $action The action to check
1938          * @param User $user User to check
1939          * @param array $errors List of current errors
1940          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1941          * @param bool $short Short circuit on first error
1942          *
1943          * @return array List of errors
1944          */
1945         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1946                 if ( !Hooks::run( 'TitleQuickPermissions',
1947                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1948                 ) {
1949                         return $errors;
1950                 }
1951
1952                 if ( $action == 'create' ) {
1953                         if (
1954                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1955                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1956                         ) {
1957                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1958                         }
1959                 } elseif ( $action == 'move' ) {
1960                         if ( !$user->isAllowed( 'move-rootuserpages' )
1961                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1962                                 // Show user page-specific message only if the user can move other pages
1963                                 $errors[] = array( 'cant-move-user-page' );
1964                         }
1965
1966                         // Check if user is allowed to move files if it's a file
1967                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1968                                 $errors[] = array( 'movenotallowedfile' );
1969                         }
1970
1971                         // Check if user is allowed to move category pages if it's a category page
1972                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1973                                 $errors[] = array( 'cant-move-category-page' );
1974                         }
1975
1976                         if ( !$user->isAllowed( 'move' ) ) {
1977                                 // User can't move anything
1978                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1979                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1980                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1981                                         // custom message if logged-in users without any special rights can move
1982                                         $errors[] = array( 'movenologintext' );
1983                                 } else {
1984                                         $errors[] = array( 'movenotallowed' );
1985                                 }
1986                         }
1987                 } elseif ( $action == 'move-target' ) {
1988                         if ( !$user->isAllowed( 'move' ) ) {
1989                                 // User can't move anything
1990                                 $errors[] = array( 'movenotallowed' );
1991                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1992                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1993                                 // Show user page-specific message only if the user can move other pages
1994                                 $errors[] = array( 'cant-move-to-user-page' );
1995                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1996                                         && $this->mNamespace == NS_CATEGORY ) {
1997                                 // Show category page-specific message only if the user can move other pages
1998                                 $errors[] = array( 'cant-move-to-category-page' );
1999                         }
2000                 } elseif ( !$user->isAllowed( $action ) ) {
2001                         $errors[] = $this->missingPermissionError( $action, $short );
2002                 }
2003
2004                 return $errors;
2005         }
2006
2007         /**
2008          * Add the resulting error code to the errors array
2009          *
2010          * @param array $errors List of current errors
2011          * @param array $result Result of errors
2012          *
2013          * @return array List of errors
2014          */
2015         private function resultToError( $errors, $result ) {
2016                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2017                         // A single array representing an error
2018                         $errors[] = $result;
2019                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2020                         // A nested array representing multiple errors
2021                         $errors = array_merge( $errors, $result );
2022                 } elseif ( $result !== '' && is_string( $result ) ) {
2023                         // A string representing a message-id
2024                         $errors[] = array( $result );
2025                 } elseif ( $result === false ) {
2026                         // a generic "We don't want them to do that"
2027                         $errors[] = array( 'badaccess-group0' );
2028                 }
2029                 return $errors;
2030         }
2031
2032         /**
2033          * Check various permission hooks
2034          *
2035          * @param string $action The action to check
2036          * @param User $user User to check
2037          * @param array $errors List of current errors
2038          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2039          * @param bool $short Short circuit on first error
2040          *
2041          * @return array List of errors
2042          */
2043         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2044                 // Use getUserPermissionsErrors instead
2045                 $result = '';
2046                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2047                         return $result ? array() : array( array( 'badaccess-group0' ) );
2048                 }
2049                 // Check getUserPermissionsErrors hook
2050                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2051                         $errors = $this->resultToError( $errors, $result );
2052                 }
2053                 // Check getUserPermissionsErrorsExpensive hook
2054                 if (
2055                         $rigor !== 'quick'
2056                         && !( $short && count( $errors ) > 0 )
2057                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2058                 ) {
2059                         $errors = $this->resultToError( $errors, $result );
2060                 }
2061
2062                 return $errors;
2063         }
2064
2065         /**
2066          * Check permissions on special pages & namespaces
2067          *
2068          * @param string $action The action to check
2069          * @param User $user User to check
2070          * @param array $errors List of current errors
2071          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2072          * @param bool $short Short circuit on first error
2073          *
2074          * @return array List of errors
2075          */
2076         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2077                 # Only 'createaccount' can be performed on special pages,
2078                 # which don't actually exist in the DB.
2079                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2080                         $errors[] = array( 'ns-specialprotected' );
2081                 }
2082
2083                 # Check $wgNamespaceProtection for restricted namespaces
2084                 if ( $this->isNamespaceProtected( $user ) ) {
2085                         $ns = $this->mNamespace == NS_MAIN ?
2086                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2087                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2088                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2089                 }
2090
2091                 return $errors;
2092         }
2093
2094         /**
2095          * Check CSS/JS sub-page permissions
2096          *
2097          * @param string $action The action to check
2098          * @param User $user User to check
2099          * @param array $errors List of current errors
2100          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2101          * @param bool $short Short circuit on first error
2102          *
2103          * @return array List of errors
2104          */
2105         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2106                 # Protect css/js subpages of user pages
2107                 # XXX: this might be better using restrictions
2108                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2109                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2110                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2111                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2112                                         $errors[] = array( 'mycustomcssprotected', $action );
2113                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2114                                         $errors[] = array( 'mycustomjsprotected', $action );
2115                                 }
2116                         } else {
2117                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2118                                         $errors[] = array( 'customcssprotected', $action );
2119                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2120                                         $errors[] = array( 'customjsprotected', $action );
2121                                 }
2122                         }
2123                 }
2124
2125                 return $errors;
2126         }
2127
2128         /**
2129          * Check against page_restrictions table requirements on this
2130          * page. The user must possess all required rights for this
2131          * action.
2132          *
2133          * @param string $action The action to check
2134          * @param User $user User to check
2135          * @param array $errors List of current errors
2136          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2137          * @param bool $short Short circuit on first error
2138          *
2139          * @return array List of errors
2140          */
2141         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2142                 foreach ( $this->getRestrictions( $action ) as $right ) {
2143                         // Backwards compatibility, rewrite sysop -> editprotected
2144                         if ( $right == 'sysop' ) {
2145                                 $right = 'editprotected';
2146                         }
2147                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2148                         if ( $right == 'autoconfirmed' ) {
2149                                 $right = 'editsemiprotected';
2150                         }
2151                         if ( $right == '' ) {
2152                                 continue;
2153                         }
2154                         if ( !$user->isAllowed( $right ) ) {
2155                                 $errors[] = array( 'protectedpagetext', $right, $action );
2156                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2157                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2158                         }
2159                 }
2160
2161                 return $errors;
2162         }
2163
2164         /**
2165          * Check restrictions on cascading pages.
2166          *
2167          * @param string $action The action to check
2168          * @param User $user User to check
2169          * @param array $errors List of current errors
2170          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2171          * @param bool $short Short circuit on first error
2172          *
2173          * @return array List of errors
2174          */
2175         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2176                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2177                         # We /could/ use the protection level on the source page, but it's
2178                         # fairly ugly as we have to establish a precedence hierarchy for pages
2179                         # included by multiple cascade-protected pages. So just restrict
2180                         # it to people with 'protect' permission, as they could remove the
2181                         # protection anyway.
2182                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2183                         # Cascading protection depends on more than this page...
2184                         # Several cascading protected pages may include this page...
2185                         # Check each cascading level
2186                         # This is only for protection restrictions, not for all actions
2187                         if ( isset( $restrictions[$action] ) ) {
2188                                 foreach ( $restrictions[$action] as $right ) {
2189                                         // Backwards compatibility, rewrite sysop -> editprotected
2190                                         if ( $right == 'sysop' ) {
2191                                                 $right = 'editprotected';
2192                                         }
2193                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2194                                         if ( $right == 'autoconfirmed' ) {
2195                                                 $right = 'editsemiprotected';
2196                                         }
2197                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2198                                                 $pages = '';
2199                                                 foreach ( $cascadingSources as $page ) {
2200                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2201                                                 }
2202                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2203                                         }
2204                                 }
2205                         }
2206                 }
2207
2208                 return $errors;
2209         }
2210
2211         /**
2212          * Check action permissions not already checked in checkQuickPermissions
2213          *
2214          * @param string $action The action to check
2215          * @param User $user User to check
2216          * @param array $errors List of current errors
2217          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2218          * @param bool $short Short circuit on first error
2219          *
2220          * @return array List of errors
2221          */
2222         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2223                 global $wgDeleteRevisionsLimit, $wgLang;
2224
2225                 if ( $action == 'protect' ) {
2226                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2227                                 // If they can't edit, they shouldn't protect.
2228                                 $errors[] = array( 'protect-cantedit' );
2229                         }
2230                 } elseif ( $action == 'create' ) {
2231                         $title_protection = $this->getTitleProtection();
2232                         if ( $title_protection ) {
2233                                 if ( $title_protection['permission'] == ''
2234                                         || !$user->isAllowed( $title_protection['permission'] )
2235                                 ) {
2236                                         $errors[] = array(
2237                                                 'titleprotected',
2238                                                 User::whoIs( $title_protection['user'] ),
2239                                                 $title_protection['reason']
2240                                         );
2241                                 }
2242                         }
2243                 } elseif ( $action == 'move' ) {
2244                         // Check for immobile pages
2245                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2246                                 // Specific message for this case
2247                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2248                         } elseif ( !$this->isMovable() ) {
2249                                 // Less specific message for rarer cases
2250                                 $errors[] = array( 'immobile-source-page' );
2251                         }
2252                 } elseif ( $action == 'move-target' ) {
2253                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2254                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2255                         } elseif ( !$this->isMovable() ) {
2256                                 $errors[] = array( 'immobile-target-page' );
2257                         }
2258                 } elseif ( $action == 'delete' ) {
2259                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2260                         if ( !$tempErrors ) {
2261                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2262                                         $user, $tempErrors, $rigor, true );
2263                         }
2264                         if ( $tempErrors ) {
2265                                 // If protection keeps them from editing, they shouldn't be able to delete.
2266                                 $errors[] = array( 'deleteprotected' );
2267                         }
2268                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2269                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2270                         ) {
2271                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2272                         }
2273                 }
2274                 return $errors;
2275         }
2276
2277         /**
2278          * Check that the user isn't blocked from editing.
2279          *
2280          * @param string $action The action to check
2281          * @param User $user User to check
2282          * @param array $errors List of current errors
2283          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2284          * @param bool $short Short circuit on first error
2285          *
2286          * @return array List of errors
2287          */
2288         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2289                 // Account creation blocks handled at userlogin.
2290                 // Unblocking handled in SpecialUnblock
2291                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2292                         return $errors;
2293                 }
2294
2295                 global $wgEmailConfirmToEdit;
2296
2297                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2298                         $errors[] = array( 'confirmedittext' );
2299                 }
2300
2301                 $useSlave = ( $rigor !== 'secure' );
2302                 if ( ( $action == 'edit' || $action == 'create' )
2303                         && !$user->isBlockedFrom( $this, $useSlave )
2304                 ) {
2305                         // Don't block the user from editing their own talk page unless they've been
2306                         // explicitly blocked from that too.
2307                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2308                         // @todo FIXME: Pass the relevant context into this function.
2309                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2310                 }
2311
2312                 return $errors;
2313         }
2314
2315         /**
2316          * Check that the user is allowed to read this page.
2317          *
2318          * @param string $action The action to check
2319          * @param User $user User to check
2320          * @param array $errors List of current errors
2321          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2322          * @param bool $short Short circuit on first error
2323          *
2324          * @return array List of errors
2325          */
2326         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2327                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2328
2329                 $whitelisted = false;
2330                 if ( User::isEveryoneAllowed( 'read' ) ) {
2331                         # Shortcut for public wikis, allows skipping quite a bit of code
2332                         $whitelisted = true;
2333                 } elseif ( $user->isAllowed( 'read' ) ) {
2334                         # If the user is allowed to read pages, he is allowed to read all pages
2335                         $whitelisted = true;
2336                 } elseif ( $this->isSpecial( 'Userlogin' )
2337                         || $this->isSpecial( 'ChangePassword' )
2338                         || $this->isSpecial( 'PasswordReset' )
2339                 ) {
2340                         # Always grant access to the login page.
2341                         # Even anons need to be able to log in.
2342                         $whitelisted = true;
2343                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2344                         # Time to check the whitelist
2345                         # Only do these checks is there's something to check against
2346                         $name = $this->getPrefixedText();
2347                         $dbName = $this->getPrefixedDBkey();
2348
2349                         // Check for explicit whitelisting with and without underscores
2350                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2351                                 $whitelisted = true;
2352                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2353                                 # Old settings might have the title prefixed with
2354                                 # a colon for main-namespace pages
2355                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2356                                         $whitelisted = true;
2357                                 }
2358                         } elseif ( $this->isSpecialPage() ) {
2359                                 # If it's a special page, ditch the subpage bit and check again
2360                                 $name = $this->getDBkey();
2361                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2362                                 if ( $name ) {
2363                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2364                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2365                                                 $whitelisted = true;
2366                                         }
2367                                 }
2368                         }
2369                 }
2370
2371                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2372                         $name = $this->getPrefixedText();
2373                         // Check for regex whitelisting
2374                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2375                                 if ( preg_match( $listItem, $name ) ) {
2376                                         $whitelisted = true;
2377                                         break;
2378                                 }
2379                         }
2380                 }
2381
2382                 if ( !$whitelisted ) {
2383                         # If the title is not whitelisted, give extensions a chance to do so...
2384                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2385                         if ( !$whitelisted ) {
2386                                 $errors[] = $this->missingPermissionError( $action, $short );
2387                         }
2388                 }
2389
2390                 return $errors;
2391         }
2392
2393         /**
2394          * Get a description array when the user doesn't have the right to perform
2395          * $action (i.e. when User::isAllowed() returns false)
2396          *
2397          * @param string $action The action to check
2398          * @param bool $short Short circuit on first error
2399          * @return array List of errors
2400          */
2401         private function missingPermissionError( $action, $short ) {
2402                 // We avoid expensive display logic for quickUserCan's and such
2403                 if ( $short ) {
2404                         return array( 'badaccess-group0' );
2405                 }
2406
2407                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2408                         User::getGroupsWithPermission( $action ) );
2409
2410                 if ( count( $groups ) ) {
2411                         global $wgLang;
2412                         return array(
2413                                 'badaccess-groups',
2414                                 $wgLang->commaList( $groups ),
2415                                 count( $groups )
2416                         );
2417                 } else {
2418                         return array( 'badaccess-group0' );
2419                 }
2420         }
2421
2422         /**
2423          * Can $user perform $action on this page? This is an internal function,
2424          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2425          * checks on wfReadOnly() and blocks)
2426          *
2427          * @param string $action Action that permission needs to be checked for
2428          * @param User $user User to check
2429          * @param string $rigor One of (quick,full,secure)
2430          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2431          *   - full   : does cheap and expensive checks possibly from a slave
2432          *   - secure : does cheap and expensive checks, using the master as needed
2433          * @param bool $short Set this to true to stop after the first permission error.
2434          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2435          */
2436         protected function getUserPermissionsErrorsInternal(
2437                 $action, $user, $rigor = 'secure', $short = false
2438         ) {
2439                 if ( $rigor === true ) {
2440                         $rigor = 'secure'; // b/c
2441                 } elseif ( $rigor === false ) {
2442                         $rigor = 'quick'; // b/c
2443                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2444                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2445                 }
2446
2447                 # Read has special handling
2448                 if ( $action == 'read' ) {
2449                         $checks = array(
2450                                 'checkPermissionHooks',
2451                                 'checkReadPermissions',
2452                         );
2453                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2454                 # here as it will lead to duplicate error messages. This is okay to do
2455                 # since anywhere that checks for create will also check for edit, and
2456                 # those checks are called for edit.
2457                 } elseif ( $action == 'create' ) {
2458                         $checks = array(
2459                                 'checkQuickPermissions',
2460                                 'checkPermissionHooks',
2461                                 'checkPageRestrictions',
2462                                 'checkCascadingSourcesRestrictions',
2463                                 'checkActionPermissions',
2464                                 'checkUserBlock'
2465                         );
2466                 } else {
2467                         $checks = array(
2468                                 'checkQuickPermissions',
2469                                 'checkPermissionHooks',
2470                                 'checkSpecialsAndNSPermissions',
2471                                 'checkCSSandJSPermissions',
2472                                 'checkPageRestrictions',
2473                                 'checkCascadingSourcesRestrictions',
2474                                 'checkActionPermissions',
2475                                 'checkUserBlock'
2476                         );
2477                 }
2478
2479                 $errors = array();
2480                 while ( count( $checks ) > 0 &&
2481                                 !( $short && count( $errors ) > 0 ) ) {
2482                         $method = array_shift( $checks );
2483                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2484                 }
2485
2486                 return $errors;
2487         }
2488
2489         /**
2490          * Get a filtered list of all restriction types supported by this wiki.
2491          * @param bool $exists True to get all restriction types that apply to
2492          * titles that do exist, False for all restriction types that apply to
2493          * titles that do not exist
2494          * @return array
2495          */
2496         public static function getFilteredRestrictionTypes( $exists = true ) {
2497                 global $wgRestrictionTypes;
2498                 $types = $wgRestrictionTypes;
2499                 if ( $exists ) {
2500                         # Remove the create restriction for existing titles
2501                         $types = array_diff( $types, array( 'create' ) );
2502                 } else {
2503                         # Only the create and upload restrictions apply to non-existing titles
2504                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2505                 }
2506                 return $types;
2507         }
2508
2509         /**
2510          * Returns restriction types for the current Title
2511          *
2512          * @return array Applicable restriction types
2513          */
2514         public function getRestrictionTypes() {
2515                 if ( $this->isSpecialPage() ) {
2516                         return array();
2517                 }
2518
2519                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2520
2521                 if ( $this->getNamespace() != NS_FILE ) {
2522                         # Remove the upload restriction for non-file titles
2523                         $types = array_diff( $types, array( 'upload' ) );
2524                 }
2525
2526                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2527
2528                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2529                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2530
2531                 return $types;
2532         }
2533
2534         /**
2535          * Is this title subject to title protection?
2536          * Title protection is the one applied against creation of such title.
2537          *
2538          * @return array|bool An associative array representing any existent title
2539          *   protection, or false if there's none.
2540          */
2541         public function getTitleProtection() {
2542                 // Can't protect pages in special namespaces
2543                 if ( $this->getNamespace() < 0 ) {
2544                         return false;
2545                 }
2546
2547                 // Can't protect pages that exist.
2548                 if ( $this->exists() ) {
2549                         return false;
2550                 }
2551
2552                 if ( $this->mTitleProtection === null ) {
2553                         $dbr = wfGetDB( DB_SLAVE );
2554                         $res = $dbr->select(
2555                                 'protected_titles',
2556                                 array(
2557                                         'user' => 'pt_user',
2558                                         'reason' => 'pt_reason',
2559                                         'expiry' => 'pt_expiry',
2560                                         'permission' => 'pt_create_perm'
2561                                 ),
2562                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2563                                 __METHOD__
2564                         );
2565
2566                         // fetchRow returns false if there are no rows.
2567                         $row = $dbr->fetchRow( $res );
2568                         if ( $row ) {
2569                                 if ( $row['permission'] == 'sysop' ) {
2570                                         $row['permission'] = 'editprotected'; // B/C
2571                                 }
2572                                 if ( $row['permission'] == 'autoconfirmed' ) {
2573                                         $row['permission'] = 'editsemiprotected'; // B/C
2574                                 }
2575                         }
2576                         $this->mTitleProtection = $row;
2577                 }
2578                 return $this->mTitleProtection;
2579         }
2580
2581         /**
2582          * Remove any title protection due to page existing
2583          */
2584         public function deleteTitleProtection() {
2585                 $dbw = wfGetDB( DB_MASTER );
2586
2587                 $dbw->delete(
2588                         'protected_titles',
2589                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2590                         __METHOD__
2591                 );
2592                 $this->mTitleProtection = false;
2593         }
2594
2595         /**
2596          * Is this page "semi-protected" - the *only* protection levels are listed
2597          * in $wgSemiprotectedRestrictionLevels?
2598          *
2599          * @param string $action Action to check (default: edit)
2600          * @return bool
2601          */
2602         public function isSemiProtected( $action = 'edit' ) {
2603                 global $wgSemiprotectedRestrictionLevels;
2604
2605                 $restrictions = $this->getRestrictions( $action );
2606                 $semi = $wgSemiprotectedRestrictionLevels;
2607                 if ( !$restrictions || !$semi ) {
2608                         // Not protected, or all protection is full protection
2609                         return false;
2610                 }
2611
2612                 // Remap autoconfirmed to editsemiprotected for BC
2613                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2614                         $semi[$key] = 'editsemiprotected';
2615                 }
2616                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2617                         $restrictions[$key] = 'editsemiprotected';
2618                 }
2619
2620                 return !array_diff( $restrictions, $semi );
2621         }
2622
2623         /**
2624          * Does the title correspond to a protected article?
2625          *
2626          * @param string $action The action the page is protected from,
2627          * by default checks all actions.
2628          * @return bool
2629          */
2630         public function isProtected( $action = '' ) {
2631                 global $wgRestrictionLevels;
2632
2633                 $restrictionTypes = $this->getRestrictionTypes();
2634
2635                 # Special pages have inherent protection
2636                 if ( $this->isSpecialPage() ) {
2637                         return true;
2638                 }
2639
2640                 # Check regular protection levels
2641                 foreach ( $restrictionTypes as $type ) {
2642                         if ( $action == $type || $action == '' ) {
2643                                 $r = $this->getRestrictions( $type );
2644                                 foreach ( $wgRestrictionLevels as $level ) {
2645                                         if ( in_array( $level, $r ) && $level != '' ) {
2646                                                 return true;
2647                                         }
2648                                 }
2649                         }
2650                 }
2651
2652                 return false;
2653         }
2654
2655         /**
2656          * Determines if $user is unable to edit this page because it has been protected
2657          * by $wgNamespaceProtection.
2658          *
2659          * @param User $user User object to check permissions
2660          * @return bool
2661          */
2662         public function isNamespaceProtected( User $user ) {
2663                 global $wgNamespaceProtection;
2664
2665                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2666                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2667                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2668                                         return true;
2669                                 }
2670                         }
2671                 }
2672                 return false;
2673         }
2674
2675         /**
2676          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2677          *
2678          * @return bool If the page is subject to cascading restrictions.
2679          */
2680         public function isCascadeProtected() {
2681                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2682                 return ( $sources > 0 );
2683         }
2684
2685         /**
2686          * Determines whether cascading protection sources have already been loaded from
2687          * the database.
2688          *
2689          * @param bool $getPages True to check if the pages are loaded, or false to check
2690          * if the status is loaded.
2691          * @return bool Whether or not the specified information has been loaded
2692          * @since 1.23
2693          */
2694         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2695                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2696         }
2697
2698         /**
2699          * Cascading protection: Get the source of any cascading restrictions on this page.
2700          *
2701          * @param bool $getPages Whether or not to retrieve the actual pages
2702          *        that the restrictions have come from and the actual restrictions
2703          *        themselves.
2704          * @return array Two elements: First is an array of Title objects of the
2705          *        pages from which cascading restrictions have come, false for
2706          *        none, or true if such restrictions exist but $getPages was not
2707          *        set. Second is an array like that returned by
2708          *        Title::getAllRestrictions(), or an empty array if $getPages is
2709          *        false.
2710          */
2711         public function getCascadeProtectionSources( $getPages = true ) {
2712                 global $wgContLang;
2713                 $pagerestrictions = array();
2714
2715                 if ( $this->mCascadeSources !== null && $getPages ) {
2716                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2717                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2718                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2719                 }
2720
2721                 $dbr = wfGetDB( DB_SLAVE );
2722
2723                 if ( $this->getNamespace() == NS_FILE ) {
2724                         $tables = array( 'imagelinks', 'page_restrictions' );
2725                         $where_clauses = array(
2726                                 'il_to' => $this->getDBkey(),
2727                                 'il_from=pr_page',
2728                                 'pr_cascade' => 1
2729                         );
2730                 } else {
2731                         $tables = array( 'templatelinks', 'page_restrictions' );
2732                         $where_clauses = array(
2733                                 'tl_namespace' => $this->getNamespace(),
2734                                 'tl_title' => $this->getDBkey(),
2735                                 'tl_from=pr_page',
2736                                 'pr_cascade' => 1
2737                         );
2738                 }
2739
2740                 if ( $getPages ) {
2741                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2742                                 'pr_expiry', 'pr_type', 'pr_level' );
2743                         $where_clauses[] = 'page_id=pr_page';
2744                         $tables[] = 'page';
2745                 } else {
2746                         $cols = array( 'pr_expiry' );
2747                 }
2748
2749                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2750
2751                 $sources = $getPages ? array() : false;
2752                 $now = wfTimestampNow();
2753
2754                 foreach ( $res as $row ) {
2755                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2756                         if ( $expiry > $now ) {
2757                                 if ( $getPages ) {
2758                                         $page_id = $row->pr_page;
2759                                         $page_ns = $row->page_namespace;
2760                                         $page_title = $row->page_title;
2761                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2762                                         # Add groups needed for each restriction type if its not already there
2763                                         # Make sure this restriction type still exists
2764
2765                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2766                                                 $pagerestrictions[$row->pr_type] = array();
2767                                         }
2768
2769                                         if (
2770                                                 isset( $pagerestrictions[$row->pr_type] )
2771                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2772                                         ) {
2773                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2774                                         }
2775                                 } else {
2776                                         $sources = true;
2777                                 }
2778                         }
2779                 }
2780
2781                 if ( $getPages ) {
2782                         $this->mCascadeSources = $sources;
2783                         $this->mCascadingRestrictions = $pagerestrictions;
2784                 } else {
2785                         $this->mHasCascadingRestrictions = $sources;
2786                 }
2787
2788                 return array( $sources, $pagerestrictions );
2789         }
2790
2791         /**
2792          * Accessor for mRestrictionsLoaded
2793          *
2794          * @return bool Whether or not the page's restrictions have already been
2795          * loaded from the database
2796          * @since 1.23
2797          */
2798         public function areRestrictionsLoaded() {
2799                 return $this->mRestrictionsLoaded;
2800         }
2801
2802         /**
2803          * Accessor/initialisation for mRestrictions
2804          *
2805          * @param string $action Action that permission needs to be checked for
2806          * @return array Restriction levels needed to take the action. All levels are
2807          *     required. Note that restriction levels are normally user rights, but 'sysop'
2808          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2809          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2810          */
2811         public function getRestrictions( $action ) {
2812                 if ( !$this->mRestrictionsLoaded ) {
2813                         $this->loadRestrictions();
2814                 }
2815                 return isset( $this->mRestrictions[$action] )
2816                                 ? $this->mRestrictions[$action]
2817                                 : array();
2818         }
2819
2820         /**
2821          * Accessor/initialisation for mRestrictions
2822          *
2823          * @return array Keys are actions, values are arrays as returned by
2824          *     Title::getRestrictions()
2825          * @since 1.23
2826          */
2827         public function getAllRestrictions() {
2828                 if ( !$this->mRestrictionsLoaded ) {
2829                         $this->loadRestrictions();
2830                 }
2831                 return $this->mRestrictions;
2832         }
2833
2834         /**
2835          * Get the expiry time for the restriction against a given action
2836          *
2837          * @param string $action
2838          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2839          *     or not protected at all, or false if the action is not recognised.
2840          */
2841         public function getRestrictionExpiry( $action ) {
2842                 if ( !$this->mRestrictionsLoaded ) {
2843                         $this->loadRestrictions();
2844                 }
2845                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2846         }
2847
2848         /**
2849          * Returns cascading restrictions for the current article
2850          *
2851          * @return bool
2852          */
2853         function areRestrictionsCascading() {
2854                 if ( !$this->mRestrictionsLoaded ) {
2855                         $this->loadRestrictions();
2856                 }
2857
2858                 return $this->mCascadeRestriction;
2859         }
2860
2861         /**
2862          * Loads a string into mRestrictions array
2863          *
2864          * @param ResultWrapper $res Resource restrictions as an SQL result.
2865          * @param string $oldFashionedRestrictions Comma-separated list of page
2866          *        restrictions from page table (pre 1.10)
2867          */
2868         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2869                 $rows = array();
2870
2871                 foreach ( $res as $row ) {
2872                         $rows[] = $row;
2873                 }
2874
2875                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2876         }
2877
2878         /**
2879          * Compiles list of active page restrictions from both page table (pre 1.10)
2880          * and page_restrictions table for this existing page.
2881          * Public for usage by LiquidThreads.
2882          *
2883          * @param array $rows Array of db result objects
2884          * @param string $oldFashionedRestrictions Comma-separated list of page
2885          *   restrictions from page table (pre 1.10)
2886          */
2887         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2888                 global $wgContLang;
2889                 $dbr = wfGetDB( DB_SLAVE );
2890
2891                 $restrictionTypes = $this->getRestrictionTypes();
2892
2893                 foreach ( $restrictionTypes as $type ) {
2894                         $this->mRestrictions[$type] = array();
2895                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2896                 }
2897
2898                 $this->mCascadeRestriction = false;
2899
2900                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2901
2902                 if ( $oldFashionedRestrictions === null ) {
2903                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2904                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2905                 }
2906
2907                 if ( $oldFashionedRestrictions != '' ) {
2908
2909                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2910                                 $temp = explode( '=', trim( $restrict ) );
2911                                 if ( count( $temp ) == 1 ) {
2912                                         // old old format should be treated as edit/move restriction
2913                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2914                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2915                                 } else {
2916                                         $restriction = trim( $temp[1] );
2917                                         if ( $restriction != '' ) { //some old entries are empty
2918                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2919                                         }
2920                                 }
2921                         }
2922
2923                         $this->mOldRestrictions = true;
2924
2925                 }
2926
2927                 if ( count( $rows ) ) {
2928                         # Current system - load second to make them override.
2929                         $now = wfTimestampNow();
2930
2931                         # Cycle through all the restrictions.
2932                         foreach ( $rows as $row ) {
2933
2934                                 // Don't take care of restrictions types that aren't allowed
2935                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2936                                         continue;
2937                                 }
2938
2939                                 // This code should be refactored, now that it's being used more generally,
2940                                 // But I don't really see any harm in leaving it in Block for now -werdna
2941                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2942
2943                                 // Only apply the restrictions if they haven't expired!
2944                                 if ( !$expiry || $expiry > $now ) {
2945                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2946                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2947
2948                                         $this->mCascadeRestriction |= $row->pr_cascade;
2949                                 }
2950                         }
2951                 }
2952
2953                 $this->mRestrictionsLoaded = true;
2954         }
2955
2956         /**
2957          * Load restrictions from the page_restrictions table
2958          *
2959          * @param string $oldFashionedRestrictions Comma-separated list of page
2960          *   restrictions from page table (pre 1.10)
2961          */
2962         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2963                 global $wgContLang;
2964                 if ( !$this->mRestrictionsLoaded ) {
2965                         if ( $this->exists() ) {
2966                                 $dbr = wfGetDB( DB_SLAVE );
2967
2968                                 $res = $dbr->select(
2969                                         'page_restrictions',
2970                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2971                                         array( 'pr_page' => $this->getArticleID() ),
2972                                         __METHOD__
2973                                 );
2974
2975                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2976                         } else {
2977                                 $title_protection = $this->getTitleProtection();
2978
2979                                 if ( $title_protection ) {
2980                                         $now = wfTimestampNow();
2981                                         $expiry = $wgContLang->formatExpiry( $title_protection['expiry'], TS_MW );
2982
2983                                         if ( !$expiry || $expiry > $now ) {
2984                                                 // Apply the restrictions
2985                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2986                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
2987                                         } else { // Get rid of the old restrictions
2988                                                 $this->mTitleProtection = false;
2989                                         }
2990                                 } else {
2991                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2992                                 }
2993                                 $this->mRestrictionsLoaded = true;
2994                         }
2995                 }
2996         }
2997
2998         /**
2999          * Flush the protection cache in this object and force reload from the database.
3000          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3001          */
3002         public function flushRestrictions() {
3003                 $this->mRestrictionsLoaded = false;
3004                 $this->mTitleProtection = null;
3005         }
3006
3007         /**
3008          * Purge expired restrictions from the page_restrictions table
3009          */
3010         static function purgeExpiredRestrictions() {
3011                 if ( wfReadOnly() ) {
3012                         return;
3013                 }
3014
3015                 $method = __METHOD__;
3016                 $dbw = wfGetDB( DB_MASTER );
3017                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3018                         $dbw->delete(
3019                                 'page_restrictions',
3020                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3021                                 $method
3022                         );
3023                         $dbw->delete(
3024                                 'protected_titles',
3025                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3026                                 $method
3027                         );
3028                 } );
3029         }
3030
3031         /**
3032          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3033          *
3034          * @return bool
3035          */
3036         public function hasSubpages() {
3037                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3038                         # Duh
3039                         return false;
3040                 }
3041
3042                 # We dynamically add a member variable for the purpose of this method
3043                 # alone to cache the result.  There's no point in having it hanging
3044                 # around uninitialized in every Title object; therefore we only add it
3045                 # if needed and don't declare it statically.
3046                 if ( $this->mHasSubpages === null ) {
3047                         $this->mHasSubpages = false;
3048                         $subpages = $this->getSubpages( 1 );
3049                         if ( $subpages instanceof TitleArray ) {
3050                                 $this->mHasSubpages = (bool)$subpages->count();
3051                         }
3052                 }
3053
3054                 return $this->mHasSubpages;
3055         }
3056
3057         /**
3058          * Get all subpages of this page.
3059          *
3060          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3061          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3062          *  doesn't allow subpages
3063          */
3064         public function getSubpages( $limit = -1 ) {
3065                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3066                         return array();
3067                 }
3068
3069                 $dbr = wfGetDB( DB_SLAVE );
3070                 $conds['page_namespace'] = $this->getNamespace();
3071                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3072                 $options = array();
3073                 if ( $limit > -1 ) {
3074                         $options['LIMIT'] = $limit;
3075                 }
3076                 $this->mSubpages = TitleArray::newFromResult(
3077                         $dbr->select( 'page',
3078                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3079                                 $conds,
3080                                 __METHOD__,
3081                                 $options
3082                         )
3083                 );
3084                 return $this->mSubpages;
3085         }
3086
3087         /**
3088          * Is there a version of this page in the deletion archive?
3089          *
3090          * @return int The number of archived revisions
3091          */
3092         public function isDeleted() {
3093                 if ( $this->getNamespace() < 0 ) {
3094                         $n = 0;
3095                 } else {
3096                         $dbr = wfGetDB( DB_SLAVE );
3097
3098                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3099                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3100                                 __METHOD__
3101                         );
3102                         if ( $this->getNamespace() == NS_FILE ) {
3103                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3104                                         array( 'fa_name' => $this->getDBkey() ),
3105                                         __METHOD__
3106                                 );
3107                         }
3108                 }
3109                 return (int)$n;
3110         }
3111
3112         /**
3113          * Is there a version of this page in the deletion archive?
3114          *
3115          * @return bool
3116          */
3117         public function isDeletedQuick() {
3118                 if ( $this->getNamespace() < 0 ) {
3119                         return false;
3120                 }
3121                 $dbr = wfGetDB( DB_SLAVE );
3122                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3123                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3124                         __METHOD__
3125                 );
3126                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3127                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3128                                 array( 'fa_name' => $this->getDBkey() ),
3129                                 __METHOD__
3130                         );
3131                 }
3132                 return $deleted;
3133         }
3134
3135         /**
3136          * Get the article ID for this Title from the link cache,
3137          * adding it if necessary
3138          *
3139          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3140          *  for update
3141          * @return int The ID
3142          */
3143         public function getArticleID( $flags = 0 ) {
3144                 if ( $this->getNamespace() < 0 ) {
3145                         $this->mArticleID = 0;
3146                         return $this->mArticleID;
3147                 }
3148                 $linkCache = LinkCache::singleton();
3149                 if ( $flags & self::GAID_FOR_UPDATE ) {
3150                         $oldUpdate = $linkCache->forUpdate( true );
3151                         $linkCache->clearLink( $this );
3152                         $this->mArticleID = $linkCache->addLinkObj( $this );
3153                         $linkCache->forUpdate( $oldUpdate );
3154                 } else {
3155                         if ( -1 == $this->mArticleID ) {
3156                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3157                         }
3158                 }
3159                 return $this->mArticleID;
3160         }
3161
3162         /**
3163          * Is this an article that is a redirect page?
3164          * Uses link cache, adding it if necessary
3165          *
3166          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3167          * @return bool
3168          */
3169         public function isRedirect( $flags = 0 ) {
3170                 if ( !is_null( $this->mRedirect ) ) {
3171                         return $this->mRedirect;
3172                 }
3173                 if ( !$this->getArticleID( $flags ) ) {
3174                         $this->mRedirect = false;
3175                         return $this->mRedirect;
3176                 }
3177
3178                 $linkCache = LinkCache::singleton();
3179                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3180                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3181                 if ( $cached === null ) {
3182                         # Trust LinkCache's state over our own
3183                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3184                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3185                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3186                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3187                         # LinkCache to refresh its data from the master.
3188                         $this->mRedirect = false;
3189                         return $this->mRedirect;
3190                 }
3191
3192                 $this->mRedirect = (bool)$cached;
3193
3194                 return $this->mRedirect;
3195         }
3196
3197         /**
3198          * What is the length of this page?
3199          * Uses link cache, adding it if necessary
3200          *
3201          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3202          * @return int
3203          */
3204         public function getLength( $flags = 0 ) {
3205                 if ( $this->mLength != -1 ) {
3206                         return $this->mLength;
3207                 }
3208                 if ( !$this->getArticleID( $flags ) ) {
3209                         $this->mLength = 0;
3210                         return $this->mLength;
3211                 }
3212                 $linkCache = LinkCache::singleton();
3213                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3214                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3215                 if ( $cached === null ) {
3216                         # Trust LinkCache's state over our own, as for isRedirect()
3217                         $this->mLength = 0;
3218                         return $this->mLength;
3219                 }
3220
3221                 $this->mLength = intval( $cached );
3222
3223                 return $this->mLength;
3224         }
3225
3226         /**
3227          * What is the page_latest field for this page?
3228          *
3229          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3230          * @return int Int or 0 if the page doesn't exist
3231          */
3232         public function getLatestRevID( $flags = 0 ) {
3233                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3234                         return intval( $this->mLatestID );
3235                 }
3236                 if ( !$this->getArticleID( $flags ) ) {
3237                         $this->mLatestID = 0;
3238                         return $this->mLatestID;
3239                 }
3240                 $linkCache = LinkCache::singleton();
3241                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3242                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3243                 if ( $cached === null ) {
3244                         # Trust LinkCache's state over our own, as for isRedirect()
3245                         $this->mLatestID = 0;
3246                         return $this->mLatestID;
3247                 }
3248
3249                 $this->mLatestID = intval( $cached );
3250
3251                 return $this->mLatestID;
3252         }
3253
3254         /**
3255          * This clears some fields in this object, and clears any associated
3256          * keys in the "bad links" section of the link cache.
3257          *
3258          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3259          * loading of the new page_id. It's also called from
3260          * WikiPage::doDeleteArticleReal()
3261          *
3262          * @param int $newid The new Article ID
3263          */
3264         public function resetArticleID( $newid ) {
3265                 $linkCache = LinkCache::singleton();
3266                 $linkCache->clearLink( $this );
3267
3268                 if ( $newid === false ) {
3269                         $this->mArticleID = -1;
3270                 } else {
3271                         $this->mArticleID = intval( $newid );
3272                 }
3273                 $this->mRestrictionsLoaded = false;
3274                 $this->mRestrictions = array();
3275                 $this->mRedirect = null;
3276                 $this->mLength = -1;
3277                 $this->mLatestID = false;
3278                 $this->mContentModel = false;
3279                 $this->mEstimateRevisions = null;
3280                 $this->mPageLanguage = false;
3281                 $this->mDbPageLanguage = null;
3282                 $this->mIsBigDeletion = null;
3283         }
3284
3285         /**
3286          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3287          *
3288          * @param string $text Containing title to capitalize
3289          * @param int $ns Namespace index, defaults to NS_MAIN
3290          * @return string Containing capitalized title
3291          */
3292         public static function capitalize( $text, $ns = NS_MAIN ) {
3293                 global $wgContLang;
3294
3295                 if ( MWNamespace::isCapitalized( $ns ) ) {
3296                         return $wgContLang->ucfirst( $text );
3297                 } else {
3298                         return $text;
3299                 }
3300         }
3301
3302         /**
3303          * Secure and split - main initialisation function for this object
3304          *
3305          * Assumes that mDbkeyform has been set, and is urldecoded
3306          * and uses underscores, but not otherwise munged.  This function
3307          * removes illegal characters, splits off the interwiki and
3308          * namespace prefixes, sets the other forms, and canonicalizes
3309          * everything.
3310          *
3311          * @return bool True on success
3312          */
3313         private function secureAndSplit() {
3314                 # Initialisation
3315                 $this->mInterwiki = '';
3316                 $this->mFragment = '';
3317                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3318
3319                 $dbkey = $this->mDbkeyform;
3320
3321                 try {
3322                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3323                         //        the parsing code with Title, while avoiding massive refactoring.
3324                         // @todo: get rid of secureAndSplit, refactor parsing code.
3325                         $titleParser = self::getTitleParser();
3326                         $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3327                 } catch ( MalformedTitleException $ex ) {
3328                         return false;
3329                 }
3330
3331                 # Fill fields
3332                 $this->setFragment( '#' . $parts['fragment'] );
3333                 $this->mInterwiki = $parts['interwiki'];
3334                 $this->mLocalInterwiki = $parts['local_interwiki'];
3335                 $this->mNamespace = $parts['namespace'];
3336                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3337
3338                 $this->mDbkeyform = $parts['dbkey'];
3339                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3340                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3341
3342                 # We already know that some pages won't be in the database!
3343                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3344                         $this->mArticleID = 0;
3345                 }
3346
3347                 return true;
3348         }
3349
3350         /**
3351          * Get an array of Title objects linking to this Title
3352          * Also stores the IDs in the link cache.
3353          *
3354          * WARNING: do not use this function on arbitrary user-supplied titles!
3355          * On heavily-used templates it will max out the memory.
3356          *
3357          * @param array $options May be FOR UPDATE
3358          * @param string $table Table name
3359          * @param string $prefix Fields prefix
3360          * @return Title[] Array of Title objects linking here
3361          */
3362         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3363                 if ( count( $options ) > 0 ) {
3364                         $db = wfGetDB( DB_MASTER );
3365                 } else {
3366                         $db = wfGetDB( DB_SLAVE );
3367                 }
3368
3369                 $res = $db->select(
3370                         array( 'page', $table ),
3371                         self::getSelectFields(),
3372                         array(
3373                                 "{$prefix}_from=page_id",
3374                                 "{$prefix}_namespace" => $this->getNamespace(),
3375                                 "{$prefix}_title" => $this->getDBkey() ),
3376                         __METHOD__,
3377                         $options
3378                 );
3379
3380                 $retVal = array();
3381                 if ( $res->numRows() ) {
3382                         $linkCache = LinkCache::singleton();
3383                         foreach ( $res as $row ) {
3384                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3385                                 if ( $titleObj ) {
3386                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3387                                         $retVal[] = $titleObj;
3388                                 }
3389                         }
3390                 }
3391                 return $retVal;
3392         }
3393
3394         /**
3395          * Get an array of Title objects using this Title as a template
3396          * Also stores the IDs in the link cache.
3397          *
3398          * WARNING: do not use this function on arbitrary user-supplied titles!
3399          * On heavily-used templates it will max out the memory.
3400          *
3401          * @param array $options May be FOR UPDATE
3402          * @return Title[] Array of Title the Title objects linking here
3403          */
3404         public function getTemplateLinksTo( $options = array() ) {
3405                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3406         }
3407
3408         /**
3409          * Get an array of Title objects linked from this Title
3410          * Also stores the IDs in the link cache.
3411          *
3412          * WARNING: do not use this function on arbitrary user-supplied titles!
3413          * On heavily-used templates it will max out the memory.
3414          *
3415          * @param array $options May be FOR UPDATE
3416          * @param string $table Table name
3417          * @param string $prefix Fields prefix
3418          * @return array Array of Title objects linking here
3419          */
3420         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3421                 global $wgContentHandlerUseDB;
3422
3423                 $id = $this->getArticleID();
3424
3425                 # If the page doesn't exist; there can't be any link from this page
3426                 if ( !$id ) {
3427                         return array();
3428                 }
3429
3430                 if ( count( $options ) > 0 ) {
3431                         $db = wfGetDB( DB_MASTER );
3432                 } else {
3433                         $db = wfGetDB( DB_SLAVE );
3434                 }
3435
3436                 $namespaceFiled = "{$prefix}_namespace";
3437                 $titleField = "{$prefix}_title";
3438
3439                 $fields = array(
3440                         $namespaceFiled,
3441                         $titleField,
3442                         'page_id',
3443                         'page_len',
3444                         'page_is_redirect',
3445                         'page_latest'
3446                 );
3447
3448                 if ( $wgContentHandlerUseDB ) {
3449                         $fields[] = 'page_content_model';
3450                 }
3451
3452                 $res = $db->select(
3453                         array( $table, 'page' ),
3454                         $fields,
3455                         array( "{$prefix}_from" => $id ),
3456                         __METHOD__,
3457                         $options,
3458                         array( 'page' => array(
3459                                 'LEFT JOIN',
3460                                 array( "page_namespace=$namespaceFiled", "page_title=$titleField" )
3461                         ) )
3462                 );
3463
3464                 $retVal = array();
3465                 if ( $res->numRows() ) {
3466                         $linkCache = LinkCache::singleton();
3467                         foreach ( $res as $row ) {
3468                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3469                                 if ( $titleObj ) {
3470                                         if ( $row->page_id ) {
3471                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3472                                         } else {
3473                                                 $linkCache->addBadLinkObj( $titleObj );
3474                                         }
3475                                         $retVal[] = $titleObj;
3476                                 }
3477                         }
3478                 }
3479                 return $retVal;
3480         }
3481
3482         /**
3483          * Get an array of Title objects used on this Title as a template
3484          * Also stores the IDs in the link cache.
3485          *
3486          * WARNING: do not use this function on arbitrary user-supplied titles!
3487          * On heavily-used templates it will max out the memory.
3488          *
3489          * @param array $options May be FOR UPDATE
3490          * @return Title[] Array of Title the Title objects used here
3491          */
3492         public function getTemplateLinksFrom( $options = array() ) {
3493                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3494         }
3495
3496         /**
3497          * Get an array of Title objects referring to non-existent articles linked
3498          * from this page.
3499          *
3500          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3501          *   should use redirect table in this case).
3502          * @return Title[] Array of Title the Title objects
3503          */
3504         public function getBrokenLinksFrom() {
3505                 if ( $this->getArticleID() == 0 ) {
3506                         # All links from article ID 0 are false positives
3507                         return array();
3508                 }
3509
3510                 $dbr = wfGetDB( DB_SLAVE );
3511                 $res = $dbr->select(
3512                         array( 'page', 'pagelinks' ),
3513                         array( 'pl_namespace', 'pl_title' ),
3514                         array(
3515                                 'pl_from' => $this->getArticleID(),
3516                                 'page_namespace IS NULL'
3517                         ),
3518                         __METHOD__, array(),
3519                         array(
3520                                 'page' => array(
3521                                         'LEFT JOIN',
3522                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3523                                 )
3524                         )
3525                 );
3526
3527                 $retVal = array();
3528                 foreach ( $res as $row ) {
3529                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3530                 }
3531                 return $retVal;
3532         }
3533
3534         /**
3535          * Get a list of URLs to purge from the Squid cache when this
3536          * page changes
3537          *
3538          * @return string[] Array of String the URLs
3539          */
3540         public function getSquidURLs() {
3541                 $urls = array(
3542                         $this->getInternalURL(),
3543                         $this->getInternalURL( 'action=history' )
3544                 );
3545
3546                 $pageLang = $this->getPageLanguage();
3547                 if ( $pageLang->hasVariants() ) {
3548                         $variants = $pageLang->getVariants();
3549                         foreach ( $variants as $vCode ) {
3550                                 $urls[] = $this->getInternalURL( '', $vCode );
3551                         }
3552                 }
3553
3554                 // If we are looking at a css/js user subpage, purge the action=raw.
3555                 if ( $this->isJsSubpage() ) {
3556                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3557                 } elseif ( $this->isCssSubpage() ) {
3558                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3559                 }
3560
3561                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3562                 return $urls;
3563         }
3564
3565         /**
3566          * Purge all applicable Squid URLs
3567          */
3568         public function purgeSquid() {
3569                 global $wgUseSquid;
3570                 if ( $wgUseSquid ) {
3571                         $urls = $this->getSquidURLs();
3572                         $u = new SquidUpdate( $urls );
3573                         $u->doUpdate();
3574                 }
3575         }
3576
3577         /**
3578          * Move this page without authentication
3579          *
3580          * @deprecated since 1.25 use MovePage class instead
3581          * @param Title $nt The new page Title
3582          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3583          */
3584         public function moveNoAuth( &$nt ) {
3585                 wfDeprecated( __METHOD__, '1.25' );
3586                 return $this->moveTo( $nt, false );
3587         }
3588
3589         /**
3590          * Check whether a given move operation would be valid.
3591          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3592          *
3593          * @deprecated since 1.25, use MovePage's methods instead
3594          * @param Title $nt The new title
3595          * @param bool $auth Whether to check user permissions (uses $wgUser)
3596          * @param string $reason Is the log summary of the move, used for spam checking
3597          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3598          */
3599         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3600                 global $wgUser;
3601
3602                 if ( !( $nt instanceof Title ) ) {
3603                         // Normally we'd add this to $errors, but we'll get
3604                         // lots of syntax errors if $nt is not an object
3605                         return array( array( 'badtitletext' ) );
3606                 }
3607
3608                 $mp = new MovePage( $this, $nt );
3609                 $errors = $mp->isValidMove()->getErrorsArray();
3610                 if ( $auth ) {
3611                         $errors = wfMergeErrorArrays(
3612                                 $errors,
3613                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3614                         );
3615                 }
3616
3617                 return $errors ? : true;
3618         }
3619
3620         /**
3621          * Check if the requested move target is a valid file move target
3622          * @todo move this to MovePage
3623          * @param Title $nt Target title
3624          * @return array List of errors
3625          */
3626         protected function validateFileMoveOperation( $nt ) {
3627                 global $wgUser;
3628
3629                 $errors = array();
3630
3631                 $destFile = wfLocalFile( $nt );
3632                 $destFile->load( File::READ_LATEST );
3633                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3634                         && !$destFile->exists() && wfFindFile( $nt )
3635                 ) {
3636                         $errors[] = array( 'file-exists-sharedrepo' );
3637                 }
3638
3639                 return $errors;
3640         }
3641
3642         /**
3643          * Move a title to a new location
3644          *
3645          * @deprecated since 1.25, use the MovePage class instead
3646          * @param Title $nt The new title
3647          * @param bool $auth Indicates whether $wgUser's permissions
3648          *  should be checked
3649          * @param string $reason The reason for the move
3650          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3651          *  Ignored if the user doesn't have the suppressredirect right.
3652          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3653          */
3654         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3655                 global $wgUser;
3656                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3657                 if ( is_array( $err ) ) {
3658                         // Auto-block user's IP if the account was "hard" blocked
3659                         $wgUser->spreadAnyEditBlock();
3660                         return $err;
3661                 }
3662                 // Check suppressredirect permission
3663                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3664                         $createRedirect = true;
3665                 }
3666
3667                 $mp = new MovePage( $this, $nt );
3668                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3669                 if ( $status->isOK() ) {
3670                         return true;
3671                 } else {
3672                         return $status->getErrorsArray();
3673                 }
3674         }
3675
3676         /**
3677          * Move this page's subpages to be subpages of $nt
3678          *
3679          * @param Title $nt Move target
3680          * @param bool $auth Whether $wgUser's permissions should be checked
3681          * @param string $reason The reason for the move
3682          * @param bool $createRedirect Whether to create redirects from the old subpages to
3683          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3684          * @return array Array with old page titles as keys, and strings (new page titles) or
3685          *     arrays (errors) as values, or an error array with numeric indices if no pages
3686          *     were moved
3687          */
3688         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3689                 global $wgMaximumMovedPages;
3690                 // Check permissions
3691                 if ( !$this->userCan( 'move-subpages' ) ) {
3692                         return array( 'cant-move-subpages' );
3693                 }
3694                 // Do the source and target namespaces support subpages?
3695                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3696                         return array( 'namespace-nosubpages',
3697                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3698                 }
3699                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3700                         return array( 'namespace-nosubpages',
3701                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3702                 }
3703
3704                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3705                 $retval = array();
3706                 $count = 0;
3707                 foreach ( $subpages as $oldSubpage ) {
3708                         $count++;
3709                         if ( $count > $wgMaximumMovedPages ) {
3710                                 $retval[$oldSubpage->getPrefixedText()] =
3711                                                 array( 'movepage-max-pages',
3712                                                         $wgMaximumMovedPages );
3713                                 break;
3714                         }
3715
3716                         // We don't know whether this function was called before
3717                         // or after moving the root page, so check both
3718                         // $this and $nt
3719                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3720                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3721                         ) {
3722                                 // When moving a page to a subpage of itself,
3723                                 // don't move it twice
3724                                 continue;
3725                         }
3726                         $newPageName = preg_replace(
3727                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3728                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3729                                         $oldSubpage->getDBkey() );
3730                         if ( $oldSubpage->isTalkPage() ) {
3731                                 $newNs = $nt->getTalkPage()->getNamespace();
3732                         } else {
3733                                 $newNs = $nt->getSubjectPage()->getNamespace();
3734                         }
3735                         # Bug 14385: we need makeTitleSafe because the new page names may
3736                         # be longer than 255 characters.
3737                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3738
3739                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3740                         if ( $success === true ) {
3741                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3742                         } else {
3743                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3744                         }
3745                 }
3746                 return $retval;
3747         }
3748
3749         /**
3750          * Checks if this page is just a one-rev redirect.
3751          * Adds lock, so don't use just for light purposes.
3752          *
3753          * @return bool
3754          */
3755         public function isSingleRevRedirect() {
3756                 global $wgContentHandlerUseDB;
3757
3758                 $dbw = wfGetDB( DB_MASTER );
3759
3760                 # Is it a redirect?
3761                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3762                 if ( $wgContentHandlerUseDB ) {
3763                         $fields[] = 'page_content_model';
3764                 }
3765
3766                 $row = $dbw->selectRow( 'page',
3767                         $fields,
3768                         $this->pageCond(),
3769                         __METHOD__,
3770                         array( 'FOR UPDATE' )
3771                 );
3772                 # Cache some fields we may want
3773                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3774                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3775                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3776                 $this->mContentModel = $row && isset( $row->page_content_model )
3777                         ? strval( $row->page_content_model )
3778                         : false;
3779
3780                 if ( !$this->mRedirect ) {
3781                         return false;
3782                 }
3783                 # Does the article have a history?
3784                 $row = $dbw->selectField( array( 'page', 'revision' ),
3785                         'rev_id',
3786                         array( 'page_namespace' => $this->getNamespace(),
3787                                 'page_title' => $this->getDBkey(),
3788                                 'page_id=rev_page',
3789                                 'page_latest != rev_id'
3790                         ),
3791                         __METHOD__,
3792                         array( 'FOR UPDATE' )
3793                 );
3794                 # Return true if there was no history
3795                 return ( $row === false );
3796         }
3797
3798         /**
3799          * Checks if $this can be moved to a given Title
3800          * - Selects for update, so don't call it unless you mean business
3801          *
3802          * @deprecated since 1.25, use MovePage's methods instead
3803          * @param Title $nt The new title to check
3804          * @return bool
3805          */
3806         public function isValidMoveTarget( $nt ) {
3807                 # Is it an existing file?
3808                 if ( $nt->getNamespace() == NS_FILE ) {
3809                         $file = wfLocalFile( $nt );
3810                         $file->load( File::READ_LATEST );
3811                         if ( $file->exists() ) {
3812                                 wfDebug( __METHOD__ . ": file exists\n" );
3813                                 return false;
3814                         }
3815                 }
3816                 # Is it a redirect with no history?
3817                 if ( !$nt->isSingleRevRedirect() ) {
3818                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3819                         return false;
3820                 }
3821                 # Get the article text
3822                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3823                 if ( !is_object( $rev ) ) {
3824                         return false;
3825                 }
3826                 $content = $rev->getContent();
3827                 # Does the redirect point to the source?
3828                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3829                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3830
3831                 if ( $redirTitle ) {
3832                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3833                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3834                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3835                                 return false;
3836                         } else {
3837                                 return true;
3838                         }
3839                 } else {
3840                         # Fail safe (not a redirect after all. strange.)
3841                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3842                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3843                         return false;
3844                 }
3845         }
3846
3847         /**
3848          * Get categories to which this Title belongs and return an array of
3849          * categories' names.
3850          *
3851          * @return array Array of parents in the form:
3852          *        $parent => $currentarticle
3853          */
3854         public function getParentCategories() {
3855                 global $wgContLang;
3856
3857                 $data = array();
3858
3859                 $titleKey = $this->getArticleID();
3860
3861                 if ( $titleKey === 0 ) {
3862                         return $data;
3863                 }
3864
3865                 $dbr = wfGetDB( DB_SLAVE );
3866
3867                 $res = $dbr->select(
3868                         'categorylinks',
3869                         'cl_to',
3870                         array( 'cl_from' => $titleKey ),
3871                         __METHOD__
3872                 );
3873
3874                 if ( $res->numRows() > 0 ) {
3875                         foreach ( $res as $row ) {
3876                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3877                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3878                         }
3879                 }
3880                 return $data;
3881         }
3882
3883         /**
3884          * Get a tree of parent categories
3885          *
3886          * @param array $children Array with the children in the keys, to check for circular refs
3887          * @return array Tree of parent categories
3888          */
3889         public function getParentCategoryTree( $children = array() ) {
3890                 $stack = array();
3891                 $parents = $this->getParentCategories();
3892
3893                 if ( $parents ) {
3894                         foreach ( $parents as $parent => $current ) {
3895                                 if ( array_key_exists( $parent, $children ) ) {
3896                                         # Circular reference
3897                                         $stack[$parent] = array();
3898                                 } else {
3899                                         $nt = Title::newFromText( $parent );
3900                                         if ( $nt ) {
3901                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3902                                         }
3903                                 }
3904                         }
3905                 }
3906
3907                 return $stack;
3908         }
3909
3910         /**
3911          * Get an associative array for selecting this title from
3912          * the "page" table
3913          *
3914          * @return array Array suitable for the $where parameter of DB::select()
3915          */
3916         public function pageCond() {
3917                 if ( $this->mArticleID > 0 ) {
3918                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3919                         return array( 'page_id' => $this->mArticleID );
3920                 } else {
3921                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3922                 }
3923         }
3924
3925         /**
3926          * Get the revision ID of the previous revision
3927          *
3928          * @param int $revId Revision ID. Get the revision that was before this one.
3929          * @param int $flags Title::GAID_FOR_UPDATE
3930          * @return int|bool Old revision ID, or false if none exists
3931          */
3932         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3933                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3934                 $revId = $db->selectField( 'revision', 'rev_id',
3935                         array(
3936                                 'rev_page' => $this->getArticleID( $flags ),
3937                                 'rev_id < ' . intval( $revId )
3938                         ),
3939                         __METHOD__,
3940                         array( 'ORDER BY' => 'rev_id DESC' )
3941                 );
3942
3943                 if ( $revId === false ) {
3944                         return false;
3945                 } else {
3946                         return intval( $revId );
3947                 }
3948         }
3949
3950         /**
3951          * Get the revision ID of the next revision
3952          *
3953          * @param int $revId Revision ID. Get the revision that was after this one.
3954          * @param int $flags Title::GAID_FOR_UPDATE
3955          * @return int|bool Next revision ID, or false if none exists
3956          */
3957         public function getNextRevisionID( $revId, $flags = 0 ) {
3958                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3959                 $revId = $db->selectField( 'revision', 'rev_id',
3960                         array(
3961                                 'rev_page' => $this->getArticleID( $flags ),
3962                                 'rev_id > ' . intval( $revId )
3963                         ),
3964                         __METHOD__,
3965                         array( 'ORDER BY' => 'rev_id' )
3966                 );
3967
3968                 if ( $revId === false ) {
3969                         return false;
3970                 } else {
3971                         return intval( $revId );
3972                 }
3973         }
3974
3975         /**
3976          * Get the first revision of the page
3977          *
3978          * @param int $flags Title::GAID_FOR_UPDATE
3979          * @return Revision|null If page doesn't exist
3980          */
3981         public function getFirstRevision( $flags = 0 ) {
3982                 $pageId = $this->getArticleID( $flags );
3983                 if ( $pageId ) {
3984                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3985                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3986                                 array( 'rev_page' => $pageId ),
3987                                 __METHOD__,
3988                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3989                         );
3990                         if ( $row ) {
3991                                 return new Revision( $row );
3992                         }
3993                 }
3994                 return null;
3995         }
3996
3997         /**
3998          * Get the oldest revision timestamp of this page
3999          *
4000          * @param int $flags Title::GAID_FOR_UPDATE
4001          * @return string MW timestamp
4002          */
4003         public function getEarliestRevTime( $flags = 0 ) {
4004                 $rev = $this->getFirstRevision( $flags );
4005                 return $rev ? $rev->getTimestamp() : null;
4006         }
4007
4008         /**
4009          * Check if this is a new page
4010          *
4011          * @return bool
4012          */
4013         public function isNewPage() {
4014                 $dbr = wfGetDB( DB_SLAVE );
4015                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4016         }
4017
4018         /**
4019          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4020          *
4021          * @return bool
4022          */
4023         public function isBigDeletion() {
4024                 global $wgDeleteRevisionsLimit;
4025
4026                 if ( !$wgDeleteRevisionsLimit ) {
4027                         return false;
4028                 }
4029
4030                 if ( $this->mIsBigDeletion === null ) {
4031                         $dbr = wfGetDB( DB_SLAVE );
4032
4033                         $revCount = $dbr->selectRowCount(
4034                                 'revision',
4035                                 '1',
4036                                 array( 'rev_page' => $this->getArticleID() ),
4037                                 __METHOD__,
4038                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4039                         );
4040
4041                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4042                 }
4043
4044                 return $this->mIsBigDeletion;
4045         }
4046
4047         /**
4048          * Get the approximate revision count of this page.
4049          *
4050          * @return int
4051          */
4052         public function estimateRevisionCount() {
4053                 if ( !$this->exists() ) {
4054                         return 0;
4055                 }
4056
4057                 if ( $this->mEstimateRevisions === null ) {
4058                         $dbr = wfGetDB( DB_SLAVE );
4059                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4060                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4061                 }
4062
4063                 return $this->mEstimateRevisions;
4064         }
4065
4066         /**
4067          * Get the number of revisions between the given revision.
4068          * Used for diffs and other things that really need it.
4069          *
4070          * @param int|Revision $old Old revision or rev ID (first before range)
4071          * @param int|Revision $new New revision or rev ID (first after range)
4072          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4073          * @return int Number of revisions between these revisions.
4074          */
4075         public function countRevisionsBetween( $old, $new, $max = null ) {
4076                 if ( !( $old instanceof Revision ) ) {
4077                         $old = Revision::newFromTitle( $this, (int)$old );
4078                 }
4079                 if ( !( $new instanceof Revision ) ) {
4080                         $new = Revision::newFromTitle( $this, (int)$new );
4081                 }
4082                 if ( !$old || !$new ) {
4083                         return 0; // nothing to compare
4084                 }
4085                 $dbr = wfGetDB( DB_SLAVE );
4086                 $conds = array(
4087                         'rev_page' => $this->getArticleID(),
4088                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4089                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4090                 );
4091                 if ( $max !== null ) {
4092                         return $dbr->selectRowCount( 'revision', '1',
4093                                 $conds,
4094                                 __METHOD__,
4095                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4096                         );
4097                 } else {
4098                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4099                 }
4100         }
4101
4102         /**
4103          * Get the authors between the given revisions or revision IDs.
4104          * Used for diffs and other things that really need it.
4105          *
4106          * @since 1.23
4107          *
4108          * @param int|Revision $old Old revision or rev ID (first before range by default)
4109          * @param int|Revision $new New revision or rev ID (first after range by default)
4110          * @param int $limit Maximum number of authors
4111          * @param string|array $options (Optional): Single option, or an array of options:
4112          *     'include_old' Include $old in the range; $new is excluded.
4113          *     'include_new' Include $new in the range; $old is excluded.
4114          *     'include_both' Include both $old and $new in the range.
4115          *     Unknown option values are ignored.
4116          * @return array|null Names of revision authors in the range; null if not both revisions exist
4117          */
4118         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4119                 if ( !( $old instanceof Revision ) ) {
4120                         $old = Revision::newFromTitle( $this, (int)$old );
4121                 }
4122                 if ( !( $new instanceof Revision ) ) {
4123                         $new = Revision::newFromTitle( $this, (int)$new );
4124                 }
4125                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4126                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4127                 // in the sanity check below?
4128                 if ( !$old || !$new ) {
4129                         return null; // nothing to compare
4130                 }
4131                 $authors = array();
4132                 $old_cmp = '>';
4133                 $new_cmp = '<';
4134                 $options = (array)$options;
4135                 if ( in_array( 'include_old', $options ) ) {
4136                         $old_cmp = '>=';
4137                 }
4138                 if ( in_array( 'include_new', $options ) ) {
4139                         $new_cmp = '<=';
4140                 }
4141                 if ( in_array( 'include_both', $options ) ) {
4142                         $old_cmp = '>=';
4143                         $new_cmp = '<=';
4144                 }
4145                 // No DB query needed if $old and $new are the same or successive revisions:
4146                 if ( $old->getId() === $new->getId() ) {
4147                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4148                                 array() :
4149                                 array( $old->getUserText( Revision::RAW ) );
4150                 } elseif ( $old->getId() === $new->getParentId() ) {
4151                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4152                                 $authors[] = $old->getUserText( Revision::RAW );
4153                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4154                                         $authors[] = $new->getUserText( Revision::RAW );
4155                                 }
4156                         } elseif ( $old_cmp === '>=' ) {
4157                                 $authors[] = $old->getUserText( Revision::RAW );
4158                         } elseif ( $new_cmp === '<=' ) {
4159                                 $authors[] = $new->getUserText( Revision::RAW );
4160                         }
4161                         return $authors;
4162                 }
4163                 $dbr = wfGetDB( DB_SLAVE );
4164                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4165                         array(
4166                                 'rev_page' => $this->getArticleID(),
4167                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4168                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4169                         ), __METHOD__,
4170                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4171                 );
4172                 foreach ( $res as $row ) {
4173                         $authors[] = $row->rev_user_text;
4174                 }
4175                 return $authors;
4176         }
4177
4178         /**
4179          * Get the number of authors between the given revisions or revision IDs.
4180          * Used for diffs and other things that really need it.
4181          *
4182          * @param int|Revision $old Old revision or rev ID (first before range by default)
4183          * @param int|Revision $new New revision or rev ID (first after range by default)
4184          * @param int $limit Maximum number of authors
4185          * @param string|array $options (Optional): Single option, or an array of options:
4186          *     'include_old' Include $old in the range; $new is excluded.
4187          *     'include_new' Include $new in the range; $old is excluded.
4188          *     'include_both' Include both $old and $new in the range.
4189          *     Unknown option values are ignored.
4190          * @return int Number of revision authors in the range; zero if not both revisions exist
4191          */
4192         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4193                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4194                 return $authors ? count( $authors ) : 0;
4195         }
4196
4197         /**
4198          * Compare with another title.
4199          *
4200          * @param Title $title
4201          * @return bool
4202          */
4203         public function equals( Title $title ) {
4204                 // Note: === is necessary for proper matching of number-like titles.
4205                 return $this->getInterwiki() === $title->getInterwiki()
4206                         && $this->getNamespace() == $title->getNamespace()
4207                         && $this->getDBkey() === $title->getDBkey();
4208         }
4209
4210         /**
4211          * Check if this title is a subpage of another title
4212          *
4213          * @param Title $title
4214          * @return bool
4215          */
4216         public function isSubpageOf( Title $title ) {
4217                 return $this->getInterwiki() === $title->getInterwiki()
4218                         && $this->getNamespace() == $title->getNamespace()
4219                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4220         }
4221
4222         /**
4223          * Check if page exists.  For historical reasons, this function simply
4224          * checks for the existence of the title in the page table, and will
4225          * thus return false for interwiki links, special pages and the like.
4226          * If you want to know if a title can be meaningfully viewed, you should
4227          * probably call the isKnown() method instead.
4228          *
4229          * @return bool
4230          */
4231         public function exists() {
4232                 $exists = $this->getArticleID() != 0;
4233                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4234                 return $exists;
4235         }
4236
4237         /**
4238          * Should links to this title be shown as potentially viewable (i.e. as
4239          * "bluelinks"), even if there's no record by this title in the page
4240          * table?
4241          *
4242          * This function is semi-deprecated for public use, as well as somewhat
4243          * misleadingly named.  You probably just want to call isKnown(), which
4244          * calls this function internally.
4245          *
4246          * (ISSUE: Most of these checks are cheap, but the file existence check
4247          * can potentially be quite expensive.  Including it here fixes a lot of
4248          * existing code, but we might want to add an optional parameter to skip
4249          * it and any other expensive checks.)
4250          *
4251          * @return bool
4252          */
4253         public function isAlwaysKnown() {
4254                 $isKnown = null;
4255
4256                 /**
4257                  * Allows overriding default behavior for determining if a page exists.
4258                  * If $isKnown is kept as null, regular checks happen. If it's
4259                  * a boolean, this value is returned by the isKnown method.
4260                  *
4261                  * @since 1.20
4262                  *
4263                  * @param Title $title
4264                  * @param bool|null $isKnown
4265                  */
4266                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4267
4268                 if ( !is_null( $isKnown ) ) {
4269                         return $isKnown;
4270                 }
4271
4272                 if ( $this->isExternal() ) {
4273                         return true;  // any interwiki link might be viewable, for all we know
4274                 }
4275
4276                 switch ( $this->mNamespace ) {
4277                         case NS_MEDIA:
4278                         case NS_FILE:
4279                                 // file exists, possibly in a foreign repo
4280                                 return (bool)wfFindFile( $this );
4281                         case NS_SPECIAL:
4282                                 // valid special page
4283                                 return SpecialPageFactory::exists( $this->getDBkey() );
4284                         case NS_MAIN:
4285                                 // selflink, possibly with fragment
4286                                 return $this->mDbkeyform == '';
4287                         case NS_MEDIAWIKI:
4288                                 // known system message
4289                                 return $this->hasSourceText() !== false;
4290                         default:
4291                                 return false;
4292                 }
4293         }
4294
4295         /**
4296          * Does this title refer to a page that can (or might) be meaningfully
4297          * viewed?  In particular, this function may be used to determine if
4298          * links to the title should be rendered as "bluelinks" (as opposed to
4299          * "redlinks" to non-existent pages).
4300          * Adding something else to this function will cause inconsistency
4301          * since LinkHolderArray calls isAlwaysKnown() and does its own
4302          * page existence check.
4303          *
4304          * @return bool
4305          */
4306         public function isKnown() {
4307                 return $this->isAlwaysKnown() || $this->exists();
4308         }
4309
4310         /**
4311          * Does this page have source text?
4312          *
4313          * @return bool
4314          */
4315         public function hasSourceText() {
4316                 if ( $this->exists() ) {
4317                         return true;
4318                 }
4319
4320                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4321                         // If the page doesn't exist but is a known system message, default
4322                         // message content will be displayed, same for language subpages-
4323                         // Use always content language to avoid loading hundreds of languages
4324                         // to get the link color.
4325                         global $wgContLang;
4326                         list( $name, ) = MessageCache::singleton()->figureMessage(
4327                                 $wgContLang->lcfirst( $this->getText() )
4328                         );
4329                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4330                         return $message->exists();
4331                 }
4332
4333                 return false;
4334         }
4335
4336         /**
4337          * Get the default message text or false if the message doesn't exist
4338          *
4339          * @return string|bool
4340          */
4341         public function getDefaultMessageText() {
4342                 global $wgContLang;
4343
4344                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4345                         return false;
4346                 }
4347
4348                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4349                         $wgContLang->lcfirst( $this->getText() )
4350                 );
4351                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4352
4353                 if ( $message->exists() ) {
4354                         return $message->plain();
4355                 } else {
4356                         return false;
4357                 }
4358         }
4359
4360         /**
4361          * Updates page_touched for this page; called from LinksUpdate.php
4362          *
4363          * @return bool True if the update succeeded
4364          */
4365         public function invalidateCache() {
4366                 if ( wfReadOnly() ) {
4367                         return false;
4368                 }
4369
4370                 if ( $this->mArticleID === 0 ) {
4371                         return true; // avoid gap locking if we know it's not there
4372                 }
4373
4374                 $method = __METHOD__;
4375                 $dbw = wfGetDB( DB_MASTER );
4376                 $conds = $this->pageCond();
4377                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method ) {
4378                         $dbw->update(
4379                                 'page',
4380                                 array( 'page_touched' => $dbw->timestamp() ),
4381                                 $conds,
4382                                 $method
4383                         );
4384                 } );
4385
4386                 return true;
4387         }
4388
4389         /**
4390          * Update page_touched timestamps and send squid purge messages for
4391          * pages linking to this title. May be sent to the job queue depending
4392          * on the number of links. Typically called on create and delete.
4393          */
4394         public function touchLinks() {
4395                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4396                 $u->doUpdate();
4397
4398                 if ( $this->getNamespace() == NS_CATEGORY ) {
4399                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4400                         $u->doUpdate();
4401                 }
4402         }
4403
4404         /**
4405          * Get the last touched timestamp
4406          *
4407          * @param DatabaseBase $db Optional db
4408          * @return string Last-touched timestamp
4409          */
4410         public function getTouched( $db = null ) {
4411                 if ( $db === null ) {
4412                         $db = wfGetDB( DB_SLAVE );
4413                 }
4414                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4415                 return $touched;
4416         }
4417
4418         /**
4419          * Get the timestamp when this page was updated since the user last saw it.
4420          *
4421          * @param User $user
4422          * @return string|null
4423          */
4424         public function getNotificationTimestamp( $user = null ) {
4425                 global $wgUser, $wgShowUpdatedMarker;
4426                 // Assume current user if none given
4427                 if ( !$user ) {
4428                         $user = $wgUser;
4429                 }
4430                 // Check cache first
4431                 $uid = $user->getId();
4432                 // avoid isset here, as it'll return false for null entries
4433                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4434                         return $this->mNotificationTimestamp[$uid];
4435                 }
4436                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4437                         $this->mNotificationTimestamp[$uid] = false;
4438                         return $this->mNotificationTimestamp[$uid];
4439                 }
4440                 // Don't cache too much!
4441                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4442                         $this->mNotificationTimestamp = array();
4443                 }
4444                 $dbr = wfGetDB( DB_SLAVE );
4445                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4446                         'wl_notificationtimestamp',
4447                         array(
4448                                 'wl_user' => $user->getId(),
4449                                 'wl_namespace' => $this->getNamespace(),
4450                                 'wl_title' => $this->getDBkey(),
4451                         ),
4452                         __METHOD__
4453                 );
4454                 return $this->mNotificationTimestamp[$uid];
4455         }
4456
4457         /**
4458          * Generate strings used for xml 'id' names in monobook tabs
4459          *
4460          * @param string $prepend Defaults to 'nstab-'
4461          * @return string XML 'id' name
4462          */
4463         public function getNamespaceKey( $prepend = 'nstab-' ) {
4464                 global $wgContLang;
4465                 // Gets the subject namespace if this title
4466                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4467                 // Checks if canonical namespace name exists for namespace
4468                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4469                         // Uses canonical namespace name
4470                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4471                 } else {
4472                         // Uses text of namespace
4473                         $namespaceKey = $this->getSubjectNsText();
4474                 }
4475                 // Makes namespace key lowercase
4476                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4477                 // Uses main
4478                 if ( $namespaceKey == '' ) {
4479                         $namespaceKey = 'main';
4480                 }
4481                 // Changes file to image for backwards compatibility
4482                 if ( $namespaceKey == 'file' ) {
4483                         $namespaceKey = 'image';
4484                 }
4485                 return $prepend . $namespaceKey;
4486         }
4487
4488         /**
4489          * Get all extant redirects to this Title
4490          *
4491          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4492          * @return Title[] Array of Title redirects to this title
4493          */
4494         public function getRedirectsHere( $ns = null ) {
4495                 $redirs = array();
4496
4497                 $dbr = wfGetDB( DB_SLAVE );
4498                 $where = array(
4499                         'rd_namespace' => $this->getNamespace(),
4500                         'rd_title' => $this->getDBkey(),
4501                         'rd_from = page_id'
4502                 );
4503                 if ( $this->isExternal() ) {
4504                         $where['rd_interwiki'] = $this->getInterwiki();
4505                 } else {
4506                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4507                 }
4508                 if ( !is_null( $ns ) ) {
4509                         $where['page_namespace'] = $ns;
4510                 }
4511
4512                 $res = $dbr->select(
4513                         array( 'redirect', 'page' ),
4514                         array( 'page_namespace', 'page_title' ),
4515                         $where,
4516                         __METHOD__
4517                 );
4518
4519                 foreach ( $res as $row ) {
4520                         $redirs[] = self::newFromRow( $row );
4521                 }
4522                 return $redirs;
4523         }
4524
4525         /**
4526          * Check if this Title is a valid redirect target
4527          *
4528          * @return bool
4529          */
4530         public function isValidRedirectTarget() {
4531                 global $wgInvalidRedirectTargets;
4532
4533                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4534                 if ( $this->isSpecial( 'Userlogout' ) ) {
4535                         return false;
4536                 }
4537
4538                 foreach ( $wgInvalidRedirectTargets as $target ) {
4539                         if ( $this->isSpecial( $target ) ) {
4540                                 return false;
4541                         }
4542                 }
4543
4544                 return true;
4545         }
4546
4547         /**
4548          * Get a backlink cache object
4549          *
4550          * @return BacklinkCache
4551          */
4552         public function getBacklinkCache() {
4553                 return BacklinkCache::get( $this );
4554         }
4555
4556         /**
4557          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4558          *
4559          * @return bool
4560          */
4561         public function canUseNoindex() {
4562                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4563
4564                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4565                         ? $wgContentNamespaces
4566                         : $wgExemptFromUserRobotsControl;
4567
4568                 return !in_array( $this->mNamespace, $bannedNamespaces );
4569
4570         }
4571
4572         /**
4573          * Returns the raw sort key to be used for categories, with the specified
4574          * prefix.  This will be fed to Collation::getSortKey() to get a
4575          * binary sortkey that can be used for actual sorting.
4576          *
4577          * @param string $prefix The prefix to be used, specified using
4578          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4579          *   prefix.
4580          * @return string
4581          */
4582         public function getCategorySortkey( $prefix = '' ) {
4583                 $unprefixed = $this->getText();
4584
4585                 // Anything that uses this hook should only depend
4586                 // on the Title object passed in, and should probably
4587                 // tell the users to run updateCollations.php --force
4588                 // in order to re-sort existing category relations.
4589                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4590                 if ( $prefix !== '' ) {
4591                         # Separate with a line feed, so the unprefixed part is only used as
4592                         # a tiebreaker when two pages have the exact same prefix.
4593                         # In UCA, tab is the only character that can sort above LF
4594                         # so we strip both of them from the original prefix.
4595                         $prefix = strtr( $prefix, "\n\t", '  ' );
4596                         return "$prefix\n$unprefixed";
4597                 }
4598                 return $unprefixed;
4599         }
4600
4601         /**
4602          * Get the language in which the content of this page is written in
4603          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4604          * e.g. $wgLang (such as special pages, which are in the user language).
4605          *
4606          * @since 1.18
4607          * @return Language
4608          */
4609         public function getPageLanguage() {
4610                 global $wgLang, $wgLanguageCode;
4611                 if ( $this->isSpecialPage() ) {
4612                         // special pages are in the user language
4613                         return $wgLang;
4614                 }
4615
4616                 // Checking if DB language is set
4617                 if ( $this->mDbPageLanguage ) {
4618                         return wfGetLangObj( $this->mDbPageLanguage );
4619                 }
4620
4621                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4622                         // Note that this may depend on user settings, so the cache should
4623                         // be only per-request.
4624                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4625                         // content to determine the page language!
4626                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4627                         // tests.
4628                         $contentHandler = ContentHandler::getForTitle( $this );
4629                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4630                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4631                 } else {
4632                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4633                 }
4634
4635                 return $langObj;
4636         }
4637
4638         /**
4639          * Get the language in which the content of this page is written when
4640          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4641          * e.g. $wgLang (such as special pages, which are in the user language).
4642          *
4643          * @since 1.20
4644          * @return Language
4645          */
4646         public function getPageViewLanguage() {
4647                 global $wgLang;
4648
4649                 if ( $this->isSpecialPage() ) {
4650                         // If the user chooses a variant, the content is actually
4651                         // in a language whose code is the variant code.
4652                         $variant = $wgLang->getPreferredVariant();
4653                         if ( $wgLang->getCode() !== $variant ) {
4654                                 return Language::factory( $variant );
4655                         }
4656
4657                         return $wgLang;
4658                 }
4659
4660                 // @note Can't be cached persistently, depends on user settings.
4661                 // @note ContentHandler::getPageViewLanguage() may need to load the
4662                 //   content to determine the page language!
4663                 $contentHandler = ContentHandler::getForTitle( $this );
4664                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4665                 return $pageLang;
4666         }
4667
4668         /**
4669          * Get a list of rendered edit notices for this page.
4670          *
4671          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4672          * they will already be wrapped in paragraphs.
4673          *
4674          * @since 1.21
4675          * @param int $oldid Revision ID that's being edited
4676          * @return array
4677          */
4678         public function getEditNotices( $oldid = 0 ) {
4679                 $notices = array();
4680
4681                 // Optional notice for the entire namespace
4682                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4683                 $msg = wfMessage( $editnotice_ns );
4684                 if ( $msg->exists() ) {
4685                         $html = $msg->parseAsBlock();
4686                         // Edit notices may have complex logic, but output nothing (T91715)
4687                         if ( trim( $html ) !== '' ) {
4688                                 $notices[$editnotice_ns] = Html::rawElement(
4689                                         'div',
4690                                         array( 'class' => array(
4691                                                 'mw-editnotice',
4692                                                 'mw-editnotice-namespace',
4693                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4694                                         ) ),
4695                                         $html
4696                                 );
4697                         }
4698                 }
4699
4700                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4701                         // Optional notice for page itself and any parent page
4702                         $parts = explode( '/', $this->getDBkey() );
4703                         $editnotice_base = $editnotice_ns;
4704                         while ( count( $parts ) > 0 ) {
4705                                 $editnotice_base .= '-' . array_shift( $parts );
4706                                 $msg = wfMessage( $editnotice_base );
4707                                 if ( $msg->exists() ) {
4708                                         $html = $msg->parseAsBlock();
4709                                         if ( trim( $html ) !== '' ) {
4710                                                 $notices[$editnotice_base] = Html::rawElement(
4711                                                         'div',
4712                                                         array( 'class' => array(
4713                                                                 'mw-editnotice',
4714                                                                 'mw-editnotice-base',
4715                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4716                                                         ) ),
4717                                                         $html
4718                                                 );
4719                                         }
4720                                 }
4721                         }
4722                 } else {
4723                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4724                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4725                         $msg = wfMessage( $editnoticeText );
4726                         if ( $msg->exists() ) {
4727                                 $html = $msg->parseAsBlock();
4728                                 if ( trim( $html ) !== '' ) {
4729                                         $notices[$editnoticeText] = Html::rawElement(
4730                                                 'div',
4731                                                 array( 'class' => array(
4732                                                         'mw-editnotice',
4733                                                         'mw-editnotice-page',
4734                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4735                                                 ) ),
4736                                                 $html
4737                                         );
4738                                 }
4739                         }
4740                 }
4741
4742                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4743                 return $notices;
4744         }
4745 }