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 InvalidArgumentException
 260          * @return Title|null Title or null on an error.
 261          */
 262         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 263                 if ( is_object( $text ) ) {
 264                         throw new InvalidArgumentException( '$text must be a string.' );
 265                 } elseif ( !is_string( $text ) ) {
 266                         wfWarn( __METHOD__ . ': $text must be a string. This will throw an InvalidArgumentException in future.' );
 267                 }
 268
 269                 $cache = self::getTitleCache();
 270
 271                 /**
 272                  * Wiki pages often contain multiple links to the same page.
 273                  * Title normalization and parsing can become expensive on
 274                  * pages with many links, so we can save a little time by
 275                  * caching them.
 276                  *
 277                  * In theory these are value objects and won't get changed...
 278                  */
 279                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 280                         return $cache->get( $text );
 281                 }
 282
 283                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 284                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 285
 286                 $t = new Title();
 287                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 288                 $t->mDefaultNamespace = intval( $defaultNamespace );
 289
 290                 if ( $t->secureAndSplit() ) {
 291                         if ( $defaultNamespace == NS_MAIN ) {
 292                                 $cache->set( $text, $t );
 293                         }
 294                         return $t;
 295                 } else {
 296                         return null;
 297                 }
 298         }
 299
 300         /**
 301          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 302          *
 303          * Example of wrong and broken code:
 304          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 305          *
 306          * Example of right code:
 307          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 308          *
 309          * Create a new Title from URL-encoded text. Ensures that
 310          * the given title's length does not exceed the maximum.
 311          *
 312          * @param string $url The title, as might be taken from a URL
 313          * @return Title|null The new object, or null on an error
 314          */
 315         public static function newFromURL( $url ) {
 316                 $t = new Title();
 317
 318                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 319                 # but some URLs used it as a space replacement and they still come
 320                 # from some external search tools.
 321                 if ( strpos( self::legalChars(), '+' ) === false ) {
 322                         $url = str_replace( '+', ' ', $url );
 323                 }
 324
 325                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * @return MapCacheLRU
 335          */
 336         private static function getTitleCache() {
 337                 if ( self::$titleCache == null ) {
 338                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 339                 }
 340                 return self::$titleCache;
 341         }
 342
 343         /**
 344          * Returns a list of fields that are to be selected for initializing Title
 345          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 346          * whether to include page_content_model.
 347          *
 348          * @return array
 349          */
 350         protected static function getSelectFields() {
 351                 global $wgContentHandlerUseDB;
 352
 353                 $fields = array(
 354                         'page_namespace', 'page_title', 'page_id',
 355                         'page_len', 'page_is_redirect', 'page_latest',
 356                 );
 357
 358                 if ( $wgContentHandlerUseDB ) {
 359                         $fields[] = 'page_content_model';
 360                 }
 361
 362                 return $fields;
 363         }
 364
 365         /**
 366          * Create a new Title from an article ID
 367          *
 368          * @param int $id The page_id corresponding to the Title to create
 369          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 370          * @return Title|null The new object, or null on an error
 371          */
 372         public static function newFromID( $id, $flags = 0 ) {
 373                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 374                 $row = $db->selectRow(
 375                         'page',
 376                         self::getSelectFields(),
 377                         array( 'page_id' => $id ),
 378                         __METHOD__
 379                 );
 380                 if ( $row !== false ) {
 381                         $title = Title::newFromRow( $row );
 382                 } else {
 383                         $title = null;
 384                 }
 385                 return $title;
 386         }
 387
 388         /**
 389          * Make an array of titles from an array of IDs
 390          *
 391          * @param int[] $ids Array of IDs
 392          * @return Title[] Array of Titles
 393          */
 394         public static function newFromIDs( $ids ) {
 395                 if ( !count( $ids ) ) {
 396                         return array();
 397                 }
 398                 $dbr = wfGetDB( DB_SLAVE );
 399
 400                 $res = $dbr->select(
 401                         'page',
 402                         self::getSelectFields(),
 403                         array( 'page_id' => $ids ),
 404                         __METHOD__
 405                 );
 406
 407                 $titles = array();
 408                 foreach ( $res as $row ) {
 409                         $titles[] = Title::newFromRow( $row );
 410                 }
 411                 return $titles;
 412         }
 413
 414         /**
 415          * Make a Title object from a DB row
 416          *
 417          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 418          * @return Title Corresponding Title
 419          */
 420         public static function newFromRow( $row ) {
 421                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 422                 $t->loadFromRow( $row );
 423                 return $t;
 424         }
 425
 426         /**
 427          * Load Title object fields from a DB row.
 428          * If false is given, the title will be treated as non-existing.
 429          *
 430          * @param stdClass|bool $row Database row
 431          */
 432         public function loadFromRow( $row ) {
 433                 if ( $row ) { // page found
 434                         if ( isset( $row->page_id ) ) {
 435                                 $this->mArticleID = (int)$row->page_id;
 436                         }
 437                         if ( isset( $row->page_len ) ) {
 438                                 $this->mLength = (int)$row->page_len;
 439                         }
 440                         if ( isset( $row->page_is_redirect ) ) {
 441                                 $this->mRedirect = (bool)$row->page_is_redirect;
 442                         }
 443                         if ( isset( $row->page_latest ) ) {
 444                                 $this->mLatestID = (int)$row->page_latest;
 445                         }
 446                         if ( isset( $row->page_content_model ) ) {
 447                                 $this->mContentModel = strval( $row->page_content_model );
 448                         } else {
 449                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 450                         }
 451                         if ( isset( $row->page_lang ) ) {
 452                                 $this->mDbPageLanguage = (string)$row->page_lang;
 453                         }
 454                 } else { // page not found
 455                         $this->mArticleID = 0;
 456                         $this->mLength = 0;
 457                         $this->mRedirect = false;
 458                         $this->mLatestID = 0;
 459                         $this->mContentModel = false; # initialized lazily in getContentModel()
 460                 }
 461         }
 462
 463         /**
 464          * Create a new Title from a namespace index and a DB key.
 465          * It's assumed that $ns and $title are *valid*, for instance when
 466          * they came directly from the database or a special page name.
 467          * For convenience, spaces are converted to underscores so that
 468          * eg user_text fields can be used directly.
 469          *
 470          * @param int $ns The namespace of the article
 471          * @param string $title The unprefixed database key form
 472          * @param string $fragment The link fragment (after the "#")
 473          * @param string $interwiki The interwiki prefix
 474          * @return Title The new object
 475          */
 476         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 477                 $t = new Title();
 478                 $t->mInterwiki = $interwiki;
 479                 $t->mFragment = $fragment;
 480                 $t->mNamespace = $ns = intval( $ns );
 481                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 482                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 483                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 484                 $t->mTextform = str_replace( '_', ' ', $title );
 485                 $t->mContentModel = false; # initialized lazily in getContentModel()
 486                 return $t;
 487         }
 488
 489         /**
 490          * Create a new Title from a namespace index and a DB key.
 491          * The parameters will be checked for validity, which is a bit slower
 492          * than makeTitle() but safer for user-provided data.
 493          *
 494          * @param int $ns The namespace of the article
 495          * @param string $title Database key form
 496          * @param string $fragment The link fragment (after the "#")
 497          * @param string $interwiki Interwiki prefix
 498          * @return Title The new object, or null on an error
 499          */
 500         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 501                 if ( !MWNamespace::exists( $ns ) ) {
 502                         return null;
 503                 }
 504
 505                 $t = new Title();
 506                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 507                 if ( $t->secureAndSplit() ) {
 508                         return $t;
 509                 } else {
 510                         return null;
 511                 }
 512         }
 513
 514         /**
 515          * Create a new Title for the Main Page
 516          *
 517          * @return Title The new object
 518          */
 519         public static function newMainPage() {
 520                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 521                 // Don't give fatal errors if the message is broken
 522                 if ( !$title ) {
 523                         $title = Title::newFromText( 'Main Page' );
 524                 }
 525                 return $title;
 526         }
 527
 528         /**
 529          * Extract a redirect destination from a string and return the
 530          * Title, or null if the text doesn't contain a valid redirect
 531          * This will only return the very next target, useful for
 532          * the redirect table and other checks that don't need full recursion
 533          *
 534          * @param string $text Text with possible redirect
 535          * @return Title The corresponding Title
 536          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 537          */
 538         public static function newFromRedirect( $text ) {
 539                 ContentHandler::deprecated( __METHOD__, '1.21' );
 540
 541                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 542                 return $content->getRedirectTarget();
 543         }
 544
 545         /**
 546          * Extract a redirect destination from a string and return the
 547          * Title, or null if the text doesn't contain a valid redirect
 548          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 549          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 550          *
 551          * @param string $text Text with possible redirect
 552          * @return Title
 553          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 554          */
 555         public static function newFromRedirectRecurse( $text ) {
 556                 ContentHandler::deprecated( __METHOD__, '1.21' );
 557
 558                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 559                 return $content->getUltimateRedirectTarget();
 560         }
 561
 562         /**
 563          * Extract a redirect destination from a string and return an
 564          * array of Titles, or null if the text doesn't contain a valid redirect
 565          * The last element in the array is the final destination after all redirects
 566          * have been resolved (up to $wgMaxRedirects times)
 567          *
 568          * @param string $text Text with possible redirect
 569          * @return Title[] Array of Titles, with the destination last
 570          * @deprecated since 1.21, use Content::getRedirectChain instead.
 571          */
 572         public static function newFromRedirectArray( $text ) {
 573                 ContentHandler::deprecated( __METHOD__, '1.21' );
 574
 575                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 576                 return $content->getRedirectChain();
 577         }
 578
 579         /**
 580          * Get the prefixed DB key associated with an ID
 581          *
 582          * @param int $id The page_id of the article
 583          * @return Title|null An object representing the article, or null if no such article was found
 584          */
 585         public static function nameOf( $id ) {
 586                 $dbr = wfGetDB( DB_SLAVE );
 587
 588                 $s = $dbr->selectRow(
 589                         'page',
 590                         array( 'page_namespace', 'page_title' ),
 591                         array( 'page_id' => $id ),
 592                         __METHOD__
 593                 );
 594                 if ( $s === false ) {
 595                         return null;
 596                 }
 597
 598                 $n = self::makeName( $s->page_namespace, $s->page_title );
 599                 return $n;
 600         }
 601
 602         /**
 603          * Get a regex character class describing the legal characters in a link
 604          *
 605          * @return string The list of characters, not delimited
 606          */
 607         public static function legalChars() {
 608                 global $wgLegalTitleChars;
 609                 return $wgLegalTitleChars;
 610         }
 611
 612         /**
 613          * Returns a simple regex that will match on characters and sequences invalid in titles.
 614          * Note that this doesn't pick up many things that could be wrong with titles, but that
 615          * replacing this regex with something valid will make many titles valid.
 616          *
 617          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 618          *
 619          * @return string Regex string
 620          */
 621         static function getTitleInvalidRegex() {
 622                 wfDeprecated( __METHOD__, '1.25' );
 623                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 624         }
 625
 626         /**
 627          * Utility method for converting a character sequence from bytes to Unicode.
 628          *
 629          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 630          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 631          *
 632          * @param string $byteClass
 633          * @return string
 634          */
 635         public static function convertByteClassToUnicodeClass( $byteClass ) {
 636                 $length = strlen( $byteClass );
 637                 // Input token queue
 638                 $x0 = $x1 = $x2 = '';
 639                 // Decoded queue
 640                 $d0 = $d1 = $d2 = '';
 641                 // Decoded integer codepoints
 642                 $ord0 = $ord1 = $ord2 = 0;
 643                 // Re-encoded queue
 644                 $r0 = $r1 = $r2 = '';
 645                 // Output
 646                 $out = '';
 647                 // Flags
 648                 $allowUnicode = false;
 649                 for ( $pos = 0; $pos < $length; $pos++ ) {
 650                         // Shift the queues down
 651                         $x2 = $x1;
 652                         $x1 = $x0;
 653                         $d2 = $d1;
 654                         $d1 = $d0;
 655                         $ord2 = $ord1;
 656                         $ord1 = $ord0;
 657                         $r2 = $r1;
 658                         $r1 = $r0;
 659                         // Load the current input token and decoded values
 660                         $inChar = $byteClass[$pos];
 661                         if ( $inChar == '\\' ) {
 662                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 663                                         $x0 = $inChar . $m[0];
 664                                         $d0 = chr( hexdec( $m[1] ) );
 665                                         $pos += strlen( $m[0] );
 666                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 667                                         $x0 = $inChar . $m[0];
 668                                         $d0 = chr( octdec( $m[0] ) );
 669                                         $pos += strlen( $m[0] );
 670                                 } elseif ( $pos + 1 >= $length ) {
 671                                         $x0 = $d0 = '\\';
 672                                 } else {
 673                                         $d0 = $byteClass[$pos + 1];
 674                                         $x0 = $inChar . $d0;
 675                                         $pos += 1;
 676                                 }
 677                         } else {
 678                                 $x0 = $d0 = $inChar;
 679                         }
 680                         $ord0 = ord( $d0 );
 681                         // Load the current re-encoded value
 682                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 683                                 $r0 = sprintf( '\x%02x', $ord0 );
 684                         } elseif ( $ord0 >= 0x80 ) {
 685                                 // Allow unicode if a single high-bit character appears
 686                                 $r0 = sprintf( '\x%02x', $ord0 );
 687                                 $allowUnicode = true;
 688                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 689                                 $r0 = '\\' . $d0;
 690                         } else {
 691                                 $r0 = $d0;
 692                         }
 693                         // Do the output
 694                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 695                                 // Range
 696                                 if ( $ord2 > $ord0 ) {
 697                                         // Empty range
 698                                 } elseif ( $ord0 >= 0x80 ) {
 699                                         // Unicode range
 700                                         $allowUnicode = true;
 701                                         if ( $ord2 < 0x80 ) {
 702                                                 // Keep the non-unicode section of the range
 703                                                 $out .= "$r2-\\x7F";
 704                                         }
 705                                 } else {
 706                                         // Normal range
 707                                         $out .= "$r2-$r0";
 708                                 }
 709                                 // Reset state to the initial value
 710                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 711                         } elseif ( $ord2 < 0x80 ) {
 712                                 // ASCII character
 713                                 $out .= $r2;
 714                         }
 715                 }
 716                 if ( $ord1 < 0x80 ) {
 717                         $out .= $r1;
 718                 }
 719                 if ( $ord0 < 0x80 ) {
 720                         $out .= $r0;
 721                 }
 722                 if ( $allowUnicode ) {
 723                         $out .= '\u0080-\uFFFF';
 724                 }
 725                 return $out;
 726         }
 727
 728         /**
 729          * Make a prefixed DB key from a DB key and a namespace index
 730          *
 731          * @param int $ns Numerical representation of the namespace
 732          * @param string $title The DB key form the title
 733          * @param string $fragment The link fragment (after the "#")
 734          * @param string $interwiki The interwiki prefix
 735          * @param bool $canoncialNamespace If true, use the canonical name for
 736          *   $ns instead of the localized version.
 737          * @return string The prefixed form of the title
 738          */
 739         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 740                 $canoncialNamespace = false
 741         ) {
 742                 global $wgContLang;
 743
 744                 if ( $canoncialNamespace ) {
 745                         $namespace = MWNamespace::getCanonicalName( $ns );
 746                 } else {
 747                         $namespace = $wgContLang->getNsText( $ns );
 748                 }
 749                 $name = $namespace == '' ? $title : "$namespace:$title";
 750                 if ( strval( $interwiki ) != '' ) {
 751                         $name = "$interwiki:$name";
 752                 }
 753                 if ( strval( $fragment ) != '' ) {
 754                         $name .= '#' . $fragment;
 755                 }
 756                 return $name;
 757         }
 758
 759         /**
 760          * Escape a text fragment, say from a link, for a URL
 761          *
 762          * @param string $fragment Containing a URL or link fragment (after the "#")
 763          * @return string Escaped string
 764          */
 765         static function escapeFragmentForURL( $fragment ) {
 766                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 767                 # fragments appear not to work in IE (at least up to 7) or in at least
 768                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 769                 # to care if they aren't encoded.
 770                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 771         }
 772
 773         /**
 774          * Callback for usort() to do title sorts by (namespace, title)
 775          *
 776          * @param Title $a
 777          * @param Title $b
 778          *
 779          * @return int Result of string comparison, or namespace comparison
 780          */
 781         public static function compare( $a, $b ) {
 782                 if ( $a->getNamespace() == $b->getNamespace() ) {
 783                         return strcmp( $a->getText(), $b->getText() );
 784                 } else {
 785                         return $a->getNamespace() - $b->getNamespace();
 786                 }
 787         }
 788
 789         /**
 790          * Determine whether the object refers to a page within
 791          * this project (either this wiki or a wiki with a local
 792          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 793          *
 794          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 795          */
 796         public function isLocal() {
 797                 if ( $this->isExternal() ) {
 798                         $iw = Interwiki::fetch( $this->mInterwiki );
 799                         if ( $iw ) {
 800                                 return $iw->isLocal();
 801                         }
 802                 }
 803                 return true;
 804         }
 805
 806         /**
 807          * Is this Title interwiki?
 808          *
 809          * @return bool
 810          */
 811         public function isExternal() {
 812                 return $this->mInterwiki !== '';
 813         }
 814
 815         /**
 816          * Get the interwiki prefix
 817          *
 818          * Use Title::isExternal to check if a interwiki is set
 819          *
 820          * @return string Interwiki prefix
 821          */
 822         public function getInterwiki() {
 823                 return $this->mInterwiki;
 824         }
 825
 826         /**
 827          * Was this a local interwiki link?
 828          *
 829          * @return bool
 830          */
 831         public function wasLocalInterwiki() {
 832                 return $this->mLocalInterwiki;
 833         }
 834
 835         /**
 836          * Determine whether the object refers to a page within
 837          * this project and is transcludable.
 838          *
 839          * @return bool True if this is transcludable
 840          */
 841         public function isTrans() {
 842                 if ( !$this->isExternal() ) {
 843                         return false;
 844                 }
 845
 846                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 847         }
 848
 849         /**
 850          * Returns the DB name of the distant wiki which owns the object.
 851          *
 852          * @return string The DB name
 853          */
 854         public function getTransWikiID() {
 855                 if ( !$this->isExternal() ) {
 856                         return false;
 857                 }
 858
 859                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 860         }
 861
 862         /**
 863          * Get a TitleValue object representing this Title.
 864          *
 865          * @note Not all valid Titles have a corresponding valid TitleValue
 866          * (e.g. TitleValues cannot represent page-local links that have a
 867          * fragment but no title text).
 868          *
 869          * @return TitleValue|null
 870          */
 871         public function getTitleValue() {
 872                 if ( $this->mTitleValue === null ) {
 873                         try {
 874                                 $this->mTitleValue = new TitleValue(
 875                                         $this->getNamespace(),
 876                                         $this->getDBkey(),
 877                                         $this->getFragment() );
 878                         } catch ( InvalidArgumentException $ex ) {
 879                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 880                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 881                         }
 882                 }
 883
 884                 return $this->mTitleValue;
 885         }
 886
 887         /**
 888          * Get the text form (spaces not underscores) of the main part
 889          *
 890          * @return string Main part of the title
 891          */
 892         public function getText() {
 893                 return $this->mTextform;
 894         }
 895
 896         /**
 897          * Get the URL-encoded form of the main part
 898          *
 899          * @return string Main part of the title, URL-encoded
 900          */
 901         public function getPartialURL() {
 902                 return $this->mUrlform;
 903         }
 904
 905         /**
 906          * Get the main part with underscores
 907          *
 908          * @return string Main part of the title, with underscores
 909          */
 910         public function getDBkey() {
 911                 return $this->mDbkeyform;
 912         }
 913
 914         /**
 915          * Get the DB key with the initial letter case as specified by the user
 916          *
 917          * @return string DB key
 918          */
 919         function getUserCaseDBKey() {
 920                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 921                         return $this->mUserCaseDBKey;
 922                 } else {
 923                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 924                         return $this->mDbkeyform;
 925                 }
 926         }
 927
 928         /**
 929          * Get the namespace index, i.e. one of the NS_xxxx constants.
 930          *
 931          * @return int Namespace index
 932          */
 933         public function getNamespace() {
 934                 return $this->mNamespace;
 935         }
 936
 937         /**
 938          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 939          *
 940          * @throws MWException
 941          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 942          * @return string Content model id
 943          */
 944         public function getContentModel( $flags = 0 ) {
 945                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 946                         $linkCache = LinkCache::singleton();
 947                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 948                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 949                 }
 950
 951                 if ( !$this->mContentModel ) {
 952                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 953                 }
 954
 955                 if ( !$this->mContentModel ) {
 956                         throw new MWException( 'Failed to determine content model!' );
 957                 }
 958
 959                 return $this->mContentModel;
 960         }
 961
 962         /**
 963          * Convenience method for checking a title's content model name
 964          *
 965          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 966          * @return bool True if $this->getContentModel() == $id
 967          */
 968         public function hasContentModel( $id ) {
 969                 return $this->getContentModel() == $id;
 970         }
 971
 972         /**
 973          * Get the namespace text
 974          *
 975          * @return string Namespace text
 976          */
 977         public function getNsText() {
 978                 if ( $this->isExternal() ) {
 979                         // This probably shouldn't even happen. ohh man, oh yuck.
 980                         // But for interwiki transclusion it sometimes does.
 981                         // Shit. Shit shit shit.
 982                         //
 983                         // Use the canonical namespaces if possible to try to
 984                         // resolve a foreign namespace.
 985                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 986                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 987                         }
 988                 }
 989
 990                 try {
 991                         $formatter = self::getTitleFormatter();
 992                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 993                 } catch ( InvalidArgumentException $ex ) {
 994                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 995                         return false;
 996                 }
 997         }
 998
 999         /**
1000          * Get the namespace text of the subject (rather than talk) page
1001          *
1002          * @return string Namespace text
1003          */
1004         public function getSubjectNsText() {
1005                 global $wgContLang;
1006                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1007         }
1008
1009         /**
1010          * Get the namespace text of the talk page
1011          *
1012          * @return string Namespace text
1013          */
1014         public function getTalkNsText() {
1015                 global $wgContLang;
1016                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1017         }
1018
1019         /**
1020          * Could this title have a corresponding talk page?
1021          *
1022          * @return bool
1023          */
1024         public function canTalk() {
1025                 return MWNamespace::canTalk( $this->mNamespace );
1026         }
1027
1028         /**
1029          * Is this in a namespace that allows actual pages?
1030          *
1031          * @return bool
1032          */
1033         public function canExist() {
1034                 return $this->mNamespace >= NS_MAIN;
1035         }
1036
1037         /**
1038          * Can this title be added to a user's watchlist?
1039          *
1040          * @return bool
1041          */
1042         public function isWatchable() {
1043                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1044         }
1045
1046         /**
1047          * Returns true if this is a special page.
1048          *
1049          * @return bool
1050          */
1051         public function isSpecialPage() {
1052                 return $this->getNamespace() == NS_SPECIAL;
1053         }
1054
1055         /**
1056          * Returns true if this title resolves to the named special page
1057          *
1058          * @param string $name The special page name
1059          * @return bool
1060          */
1061         public function isSpecial( $name ) {
1062                 if ( $this->isSpecialPage() ) {
1063                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1064                         if ( $name == $thisName ) {
1065                                 return true;
1066                         }
1067                 }
1068                 return false;
1069         }
1070
1071         /**
1072          * If the Title refers to a special page alias which is not the local default, resolve
1073          * the alias, and localise the name as necessary.  Otherwise, return $this
1074          *
1075          * @return Title
1076          */
1077         public function fixSpecialName() {
1078                 if ( $this->isSpecialPage() ) {
1079                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1080                         if ( $canonicalName ) {
1081                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1082                                 if ( $localName != $this->mDbkeyform ) {
1083                                         return Title::makeTitle( NS_SPECIAL, $localName );
1084                                 }
1085                         }
1086                 }
1087                 return $this;
1088         }
1089
1090         /**
1091          * Returns true if the title is inside the specified namespace.
1092          *
1093          * Please make use of this instead of comparing to getNamespace()
1094          * This function is much more resistant to changes we may make
1095          * to namespaces than code that makes direct comparisons.
1096          * @param int $ns The namespace
1097          * @return bool
1098          * @since 1.19
1099          */
1100         public function inNamespace( $ns ) {
1101                 return MWNamespace::equals( $this->getNamespace(), $ns );
1102         }
1103
1104         /**
1105          * Returns true if the title is inside one of the specified namespaces.
1106          *
1107          * @param int $namespaces,... The namespaces to check for
1108          * @return bool
1109          * @since 1.19
1110          */
1111         public function inNamespaces( /* ... */ ) {
1112                 $namespaces = func_get_args();
1113                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1114                         $namespaces = $namespaces[0];
1115                 }
1116
1117                 foreach ( $namespaces as $ns ) {
1118                         if ( $this->inNamespace( $ns ) ) {
1119                                 return true;
1120                         }
1121                 }
1122
1123                 return false;
1124         }
1125
1126         /**
1127          * Returns true if the title has the same subject namespace as the
1128          * namespace specified.
1129          * For example this method will take NS_USER and return true if namespace
1130          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1131          * as their subject namespace.
1132          *
1133          * This is MUCH simpler than individually testing for equivalence
1134          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1135          * @since 1.19
1136          * @param int $ns
1137          * @return bool
1138          */
1139         public function hasSubjectNamespace( $ns ) {
1140                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1141         }
1142
1143         /**
1144          * Is this Title in a namespace which contains content?
1145          * In other words, is this a content page, for the purposes of calculating
1146          * statistics, etc?
1147          *
1148          * @return bool
1149          */
1150         public function isContentPage() {
1151                 return MWNamespace::isContent( $this->getNamespace() );
1152         }
1153
1154         /**
1155          * Would anybody with sufficient privileges be able to move this page?
1156          * Some pages just aren't movable.
1157          *
1158          * @return bool
1159          */
1160         public function isMovable() {
1161                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1162                         // Interwiki title or immovable namespace. Hooks don't get to override here
1163                         return false;
1164                 }
1165
1166                 $result = true;
1167                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1168                 return $result;
1169         }
1170
1171         /**
1172          * Is this the mainpage?
1173          * @note Title::newFromText seems to be sufficiently optimized by the title
1174          * cache that we don't need to over-optimize by doing direct comparisons and
1175          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1176          * ends up reporting something differently than $title->isMainPage();
1177          *
1178          * @since 1.18
1179          * @return bool
1180          */
1181         public function isMainPage() {
1182                 return $this->equals( Title::newMainPage() );
1183         }
1184
1185         /**
1186          * Is this a subpage?
1187          *
1188          * @return bool
1189          */
1190         public function isSubpage() {
1191                 return MWNamespace::hasSubpages( $this->mNamespace )
1192                         ? strpos( $this->getText(), '/' ) !== false
1193                         : false;
1194         }
1195
1196         /**
1197          * Is this a conversion table for the LanguageConverter?
1198          *
1199          * @return bool
1200          */
1201         public function isConversionTable() {
1202                 // @todo ConversionTable should become a separate content model.
1203
1204                 return $this->getNamespace() == NS_MEDIAWIKI &&
1205                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1206         }
1207
1208         /**
1209          * Does that page contain wikitext, or it is JS, CSS or whatever?
1210          *
1211          * @return bool
1212          */
1213         public function isWikitextPage() {
1214                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1215         }
1216
1217         /**
1218          * Could this page contain custom CSS or JavaScript for the global UI.
1219          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1220          * or CONTENT_MODEL_JAVASCRIPT.
1221          *
1222          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1223          * for that!
1224          *
1225          * Note that this method should not return true for pages that contain and
1226          * show "inactive" CSS or JS.
1227          *
1228          * @return bool
1229          */
1230         public function isCssOrJsPage() {
1231                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1232                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1233                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1234
1235                 # @note This hook is also called in ContentHandler::getDefaultModel.
1236                 #   It's called here again to make sure hook functions can force this
1237                 #   method to return true even outside the MediaWiki namespace.
1238
1239                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1240
1241                 return $isCssOrJsPage;
1242         }
1243
1244         /**
1245          * Is this a .css or .js subpage of a user page?
1246          * @return bool
1247          */
1248         public function isCssJsSubpage() {
1249                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1250                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1251                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1252         }
1253
1254         /**
1255          * Trim down a .css or .js subpage title to get the corresponding skin name
1256          *
1257          * @return string Containing skin name from .css or .js subpage title
1258          */
1259         public function getSkinFromCssJsSubpage() {
1260                 $subpage = explode( '/', $this->mTextform );
1261                 $subpage = $subpage[count( $subpage ) - 1];
1262                 $lastdot = strrpos( $subpage, '.' );
1263                 if ( $lastdot === false ) {
1264                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1265                 }
1266                 return substr( $subpage, 0, $lastdot );
1267         }
1268
1269         /**
1270          * Is this a .css subpage of a user page?
1271          *
1272          * @return bool
1273          */
1274         public function isCssSubpage() {
1275                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1276                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1277         }
1278
1279         /**
1280          * Is this a .js subpage of a user page?
1281          *
1282          * @return bool
1283          */
1284         public function isJsSubpage() {
1285                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1286                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1287         }
1288
1289         /**
1290          * Is this a talk page of some sort?
1291          *
1292          * @return bool
1293          */
1294         public function isTalkPage() {
1295                 return MWNamespace::isTalk( $this->getNamespace() );
1296         }
1297
1298         /**
1299          * Get a Title object associated with the talk page of this article
1300          *
1301          * @return Title The object for the talk page
1302          */
1303         public function getTalkPage() {
1304                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1305         }
1306
1307         /**
1308          * Get a title object associated with the subject page of this
1309          * talk page
1310          *
1311          * @return Title The object for the subject page
1312          */
1313         public function getSubjectPage() {
1314                 // Is this the same title?
1315                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1316                 if ( $this->getNamespace() == $subjectNS ) {
1317                         return $this;
1318                 }
1319                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1320         }
1321
1322         /**
1323          * Get the other title for this page, if this is a subject page
1324          * get the talk page, if it is a subject page get the talk page
1325          *
1326          * @since 1.25
1327          * @throws MWException
1328          * @return Title
1329          */
1330         public function getOtherPage() {
1331                 if ( $this->isSpecialPage() ) {
1332                         throw new MWException( 'Special pages cannot have other pages' );
1333                 }
1334                 if ( $this->isTalkPage() ) {
1335                         return $this->getSubjectPage();
1336                 } else {
1337                         return $this->getTalkPage();
1338                 }
1339         }
1340
1341         /**
1342          * Get the default namespace index, for when there is no namespace
1343          *
1344          * @return int Default namespace index
1345          */
1346         public function getDefaultNamespace() {
1347                 return $this->mDefaultNamespace;
1348         }
1349
1350         /**
1351          * Get the Title fragment (i.e.\ the bit after the #) in text form
1352          *
1353          * Use Title::hasFragment to check for a fragment
1354          *
1355          * @return string Title fragment
1356          */
1357         public function getFragment() {
1358                 return $this->mFragment;
1359         }
1360
1361         /**
1362          * Check if a Title fragment is set
1363          *
1364          * @return bool
1365          * @since 1.23
1366          */
1367         public function hasFragment() {
1368                 return $this->mFragment !== '';
1369         }
1370
1371         /**
1372          * Get the fragment in URL form, including the "#" character if there is one
1373          * @return string Fragment in URL form
1374          */
1375         public function getFragmentForURL() {
1376                 if ( !$this->hasFragment() ) {
1377                         return '';
1378                 } else {
1379                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1380                 }
1381         }
1382
1383         /**
1384          * Set the fragment for this title. Removes the first character from the
1385          * specified fragment before setting, so it assumes you're passing it with
1386          * an initial "#".
1387          *
1388          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1389          * Still in active use privately.
1390          *
1391          * @param string $fragment Text
1392          */
1393         public function setFragment( $fragment ) {
1394                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1395         }
1396
1397         /**
1398          * Prefix some arbitrary text with the namespace or interwiki prefix
1399          * of this object
1400          *
1401          * @param string $name The text
1402          * @return string The prefixed text
1403          */
1404         private function prefix( $name ) {
1405                 $p = '';
1406                 if ( $this->isExternal() ) {
1407                         $p = $this->mInterwiki . ':';
1408                 }
1409
1410                 if ( 0 != $this->mNamespace ) {
1411                         $p .= $this->getNsText() . ':';
1412                 }
1413                 return $p . $name;
1414         }
1415
1416         /**
1417          * Get the prefixed database key form
1418          *
1419          * @return string The prefixed title, with underscores and
1420          *  any interwiki and namespace prefixes
1421          */
1422         public function getPrefixedDBkey() {
1423                 $s = $this->prefix( $this->mDbkeyform );
1424                 $s = str_replace( ' ', '_', $s );
1425                 return $s;
1426         }
1427
1428         /**
1429          * Get the prefixed title with spaces.
1430          * This is the form usually used for display
1431          *
1432          * @return string The prefixed title, with spaces
1433          */
1434         public function getPrefixedText() {
1435                 if ( $this->mPrefixedText === null ) {
1436                         $s = $this->prefix( $this->mTextform );
1437                         $s = str_replace( '_', ' ', $s );
1438                         $this->mPrefixedText = $s;
1439                 }
1440                 return $this->mPrefixedText;
1441         }
1442
1443         /**
1444          * Return a string representation of this title
1445          *
1446          * @return string Representation of this title
1447          */
1448         public function __toString() {
1449                 return $this->getPrefixedText();
1450         }
1451
1452         /**
1453          * Get the prefixed title with spaces, plus any fragment
1454          * (part beginning with '#')
1455          *
1456          * @return string The prefixed title, with spaces and the fragment, including '#'
1457          */
1458         public function getFullText() {
1459                 $text = $this->getPrefixedText();
1460                 if ( $this->hasFragment() ) {
1461                         $text .= '#' . $this->getFragment();
1462                 }
1463                 return $text;
1464         }
1465
1466         /**
1467          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1468          *
1469          * @par Example:
1470          * @code
1471          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1472          * # returns: 'Foo'
1473          * @endcode
1474          *
1475          * @return string Root name
1476          * @since 1.20
1477          */
1478         public function getRootText() {
1479                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1480                         return $this->getText();
1481                 }
1482
1483                 return strtok( $this->getText(), '/' );
1484         }
1485
1486         /**
1487          * Get the root page name title, i.e. the leftmost part before any slashes
1488          *
1489          * @par Example:
1490          * @code
1491          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1492          * # returns: Title{User:Foo}
1493          * @endcode
1494          *
1495          * @return Title Root title
1496          * @since 1.20
1497          */
1498         public function getRootTitle() {
1499                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1500         }
1501
1502         /**
1503          * Get the base page name without a namespace, i.e. the part before the subpage name
1504          *
1505          * @par Example:
1506          * @code
1507          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1508          * # returns: 'Foo/Bar'
1509          * @endcode
1510          *
1511          * @return string Base name
1512          */
1513         public function getBaseText() {
1514                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1515                         return $this->getText();
1516                 }
1517
1518                 $parts = explode( '/', $this->getText() );
1519                 # Don't discard the real title if there's no subpage involved
1520                 if ( count( $parts ) > 1 ) {
1521                         unset( $parts[count( $parts ) - 1] );
1522                 }
1523                 return implode( '/', $parts );
1524         }
1525
1526         /**
1527          * Get the base page name title, i.e. the part before the subpage name
1528          *
1529          * @par Example:
1530          * @code
1531          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1532          * # returns: Title{User:Foo/Bar}
1533          * @endcode
1534          *
1535          * @return Title Base title
1536          * @since 1.20
1537          */
1538         public function getBaseTitle() {
1539                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1540         }
1541
1542         /**
1543          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1544          *
1545          * @par Example:
1546          * @code
1547          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1548          * # returns: "Baz"
1549          * @endcode
1550          *
1551          * @return string Subpage name
1552          */
1553         public function getSubpageText() {
1554                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1555                         return $this->mTextform;
1556                 }
1557                 $parts = explode( '/', $this->mTextform );
1558                 return $parts[count( $parts ) - 1];
1559         }
1560
1561         /**
1562          * Get the title for a subpage of the current page
1563          *
1564          * @par Example:
1565          * @code
1566          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1567          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1568          * @endcode
1569          *
1570          * @param string $text The subpage name to add to the title
1571          * @return Title Subpage title
1572          * @since 1.20
1573          */
1574         public function getSubpage( $text ) {
1575                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1576         }
1577
1578         /**
1579          * Get a URL-encoded form of the subpage text
1580          *
1581          * @return string URL-encoded subpage name
1582          */
1583         public function getSubpageUrlForm() {
1584                 $text = $this->getSubpageText();
1585                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1586                 return $text;
1587         }
1588
1589         /**
1590          * Get a URL-encoded title (not an actual URL) including interwiki
1591          *
1592          * @return string The URL-encoded form
1593          */
1594         public function getPrefixedURL() {
1595                 $s = $this->prefix( $this->mDbkeyform );
1596                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1597                 return $s;
1598         }
1599
1600         /**
1601          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1602          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1603          * second argument named variant. This was deprecated in favor
1604          * of passing an array of option with a "variant" key
1605          * Once $query2 is removed for good, this helper can be dropped
1606          * and the wfArrayToCgi moved to getLocalURL();
1607          *
1608          * @since 1.19 (r105919)
1609          * @param array|string $query
1610          * @param bool $query2
1611          * @return string
1612          */
1613         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1614                 if ( $query2 !== false ) {
1615                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1616                                 "method called with a second parameter is deprecated. Add your " .
1617                                 "parameter to an array passed as the first parameter.", "1.19" );
1618                 }
1619                 if ( is_array( $query ) ) {
1620                         $query = wfArrayToCgi( $query );
1621                 }
1622                 if ( $query2 ) {
1623                         if ( is_string( $query2 ) ) {
1624                                 // $query2 is a string, we will consider this to be
1625                                 // a deprecated $variant argument and add it to the query
1626                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1627                         } else {
1628                                 $query2 = wfArrayToCgi( $query2 );
1629                         }
1630                         // If we have $query content add a & to it first
1631                         if ( $query ) {
1632                                 $query .= '&';
1633                         }
1634                         // Now append the queries together
1635                         $query .= $query2;
1636                 }
1637                 return $query;
1638         }
1639
1640         /**
1641          * Get a real URL referring to this title, with interwiki link and
1642          * fragment
1643          *
1644          * @see self::getLocalURL for the arguments.
1645          * @see wfExpandUrl
1646          * @param array|string $query
1647          * @param bool $query2
1648          * @param string $proto Protocol type to use in URL
1649          * @return string The URL
1650          */
1651         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1652                 $query = self::fixUrlQueryArgs( $query, $query2 );
1653
1654                 # Hand off all the decisions on urls to getLocalURL
1655                 $url = $this->getLocalURL( $query );
1656
1657                 # Expand the url to make it a full url. Note that getLocalURL has the
1658                 # potential to output full urls for a variety of reasons, so we use
1659                 # wfExpandUrl instead of simply prepending $wgServer
1660                 $url = wfExpandUrl( $url, $proto );
1661
1662                 # Finally, add the fragment.
1663                 $url .= $this->getFragmentForURL();
1664
1665                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1666                 return $url;
1667         }
1668
1669         /**
1670          * Get a URL with no fragment or server name (relative URL) from a Title object.
1671          * If this page is generated with action=render, however,
1672          * $wgServer is prepended to make an absolute URL.
1673          *
1674          * @see self::getFullURL to always get an absolute URL.
1675          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1676          *  valid to link, locally, to the current Title.
1677          * @see self::newFromText to produce a Title object.
1678          *
1679          * @param string|array $query An optional query string,
1680          *   not used for interwiki links. Can be specified as an associative array as well,
1681          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1682          *   Some query patterns will trigger various shorturl path replacements.
1683          * @param array $query2 An optional secondary query array. This one MUST
1684          *   be an array. If a string is passed it will be interpreted as a deprecated
1685          *   variant argument and urlencoded into a variant= argument.
1686          *   This second query argument will be added to the $query
1687          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1688          *   pair in the first parameter array instead.
1689          *
1690          * @return string String of the URL.
1691          */
1692         public function getLocalURL( $query = '', $query2 = false ) {
1693                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1694
1695                 $query = self::fixUrlQueryArgs( $query, $query2 );
1696
1697                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1698                 if ( $interwiki ) {
1699                         $namespace = $this->getNsText();
1700                         if ( $namespace != '' ) {
1701                                 # Can this actually happen? Interwikis shouldn't be parsed.
1702                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1703                                 $namespace .= ':';
1704                         }
1705                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1706                         $url = wfAppendQuery( $url, $query );
1707                 } else {
1708                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1709                         if ( $query == '' ) {
1710                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1711                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1712                         } else {
1713                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1714                                 $url = false;
1715                                 $matches = array();
1716
1717                                 if ( !empty( $wgActionPaths )
1718                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1719                                 ) {
1720                                         $action = urldecode( $matches[2] );
1721                                         if ( isset( $wgActionPaths[$action] ) ) {
1722                                                 $query = $matches[1];
1723                                                 if ( isset( $matches[4] ) ) {
1724                                                         $query .= $matches[4];
1725                                                 }
1726                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1727                                                 if ( $query != '' ) {
1728                                                         $url = wfAppendQuery( $url, $query );
1729                                                 }
1730                                         }
1731                                 }
1732
1733                                 if ( $url === false
1734                                         && $wgVariantArticlePath
1735                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1736                                         && $this->getPageLanguage()->hasVariants()
1737                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1738                                 ) {
1739                                         $variant = urldecode( $matches[1] );
1740                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1741                                                 // Only do the variant replacement if the given variant is a valid
1742                                                 // variant for the page's language.
1743                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1744                                                 $url = str_replace( '$1', $dbkey, $url );
1745                                         }
1746                                 }
1747
1748                                 if ( $url === false ) {
1749                                         if ( $query == '-' ) {
1750                                                 $query = '';
1751                                         }
1752                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1753                                 }
1754                         }
1755
1756                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1757
1758                         // @todo FIXME: This causes breakage in various places when we
1759                         // actually expected a local URL and end up with dupe prefixes.
1760                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1761                                 $url = $wgServer . $url;
1762                         }
1763                 }
1764                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1765                 return $url;
1766         }
1767
1768         /**
1769          * Get a URL that's the simplest URL that will be valid to link, locally,
1770          * to the current Title.  It includes the fragment, but does not include
1771          * the server unless action=render is used (or the link is external).  If
1772          * there's a fragment but the prefixed text is empty, we just return a link
1773          * to the fragment.
1774          *
1775          * The result obviously should not be URL-escaped, but does need to be
1776          * HTML-escaped if it's being output in HTML.
1777          *
1778          * @param array $query
1779          * @param bool $query2
1780          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1781          * @see self::getLocalURL for the arguments.
1782          * @return string The URL
1783          */
1784         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1785                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1786                         $ret = $this->getFullURL( $query, $query2, $proto );
1787                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1788                         $ret = $this->getFragmentForURL();
1789                 } else {
1790                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1791                 }
1792                 return $ret;
1793         }
1794
1795         /**
1796          * Get the URL form for an internal link.
1797          * - Used in various Squid-related code, in case we have a different
1798          * internal hostname for the server from the exposed one.
1799          *
1800          * This uses $wgInternalServer to qualify the path, or $wgServer
1801          * if $wgInternalServer is not set. If the server variable used is
1802          * protocol-relative, the URL will be expanded to http://
1803          *
1804          * @see self::getLocalURL for the arguments.
1805          * @return string The URL
1806          */
1807         public function getInternalURL( $query = '', $query2 = false ) {
1808                 global $wgInternalServer, $wgServer;
1809                 $query = self::fixUrlQueryArgs( $query, $query2 );
1810                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1811                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1812                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1813                 return $url;
1814         }
1815
1816         /**
1817          * Get the URL for a canonical link, for use in things like IRC and
1818          * e-mail notifications. Uses $wgCanonicalServer and the
1819          * GetCanonicalURL hook.
1820          *
1821          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1822          *
1823          * @see self::getLocalURL for the arguments.
1824          * @return string The URL
1825          * @since 1.18
1826          */
1827         public function getCanonicalURL( $query = '', $query2 = false ) {
1828                 $query = self::fixUrlQueryArgs( $query, $query2 );
1829                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1830                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1831                 return $url;
1832         }
1833
1834         /**
1835          * Get the edit URL for this Title
1836          *
1837          * @return string The URL, or a null string if this is an interwiki link
1838          */
1839         public function getEditURL() {
1840                 if ( $this->isExternal() ) {
1841                         return '';
1842                 }
1843                 $s = $this->getLocalURL( 'action=edit' );
1844
1845                 return $s;
1846         }
1847
1848         /**
1849          * Is $wgUser watching this page?
1850          *
1851          * @deprecated since 1.20; use User::isWatched() instead.
1852          * @return bool
1853          */
1854         public function userIsWatching() {
1855                 global $wgUser;
1856
1857                 if ( is_null( $this->mWatched ) ) {
1858                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1859                                 $this->mWatched = false;
1860                         } else {
1861                                 $this->mWatched = $wgUser->isWatched( $this );
1862                         }
1863                 }
1864                 return $this->mWatched;
1865         }
1866
1867         /**
1868          * Can $user perform $action on this page?
1869          * This skips potentially expensive cascading permission checks
1870          * as well as avoids expensive error formatting
1871          *
1872          * Suitable for use for nonessential UI controls in common cases, but
1873          * _not_ for functional access control.
1874          *
1875          * May provide false positives, but should never provide a false negative.
1876          *
1877          * @param string $action Action that permission needs to be checked for
1878          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1879          * @return bool
1880          */
1881         public function quickUserCan( $action, $user = null ) {
1882                 return $this->userCan( $action, $user, false );
1883         }
1884
1885         /**
1886          * Can $user perform $action on this page?
1887          *
1888          * @param string $action Action that permission needs to be checked for
1889          * @param User $user User to check (since 1.19); $wgUser will be used if not
1890          *   provided.
1891          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1892          * @return bool
1893          */
1894         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1895                 if ( !$user instanceof User ) {
1896                         global $wgUser;
1897                         $user = $wgUser;
1898                 }
1899
1900                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1901         }
1902
1903         /**
1904          * Can $user perform $action on this page?
1905          *
1906          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1907          *
1908          * @param string $action Action that permission needs to be checked for
1909          * @param User $user User to check
1910          * @param string $rigor One of (quick,full,secure)
1911          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1912          *   - full   : does cheap and expensive checks possibly from a slave
1913          *   - secure : does cheap and expensive checks, using the master as needed
1914          * @param bool $short Set this to true to stop after the first permission error.
1915          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1916          *   whose corresponding errors may be ignored.
1917          * @return array Array of arguments to wfMessage to explain permissions problems.
1918          */
1919         public function getUserPermissionsErrors(
1920                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1921         ) {
1922                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1923
1924                 // Remove the errors being ignored.
1925                 foreach ( $errors as $index => $error ) {
1926                         $error_key = is_array( $error ) ? $error[0] : $error;
1927
1928                         if ( in_array( $error_key, $ignoreErrors ) ) {
1929                                 unset( $errors[$index] );
1930                         }
1931                 }
1932
1933                 return $errors;
1934         }
1935
1936         /**
1937          * Permissions checks that fail most often, and which are easiest to test.
1938          *
1939          * @param string $action The action to check
1940          * @param User $user User to check
1941          * @param array $errors List of current errors
1942          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1943          * @param bool $short Short circuit on first error
1944          *
1945          * @return array List of errors
1946          */
1947         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1948                 if ( !Hooks::run( 'TitleQuickPermissions',
1949                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1950                 ) {
1951                         return $errors;
1952                 }
1953
1954                 if ( $action == 'create' ) {
1955                         if (
1956                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1957                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1958                         ) {
1959                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1960                         }
1961                 } elseif ( $action == 'move' ) {
1962                         if ( !$user->isAllowed( 'move-rootuserpages' )
1963                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1964                                 // Show user page-specific message only if the user can move other pages
1965                                 $errors[] = array( 'cant-move-user-page' );
1966                         }
1967
1968                         // Check if user is allowed to move files if it's a file
1969                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1970                                 $errors[] = array( 'movenotallowedfile' );
1971                         }
1972
1973                         // Check if user is allowed to move category pages if it's a category page
1974                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1975                                 $errors[] = array( 'cant-move-category-page' );
1976                         }
1977
1978                         if ( !$user->isAllowed( 'move' ) ) {
1979                                 // User can't move anything
1980                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1981                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1982                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1983                                         // custom message if logged-in users without any special rights can move
1984                                         $errors[] = array( 'movenologintext' );
1985                                 } else {
1986                                         $errors[] = array( 'movenotallowed' );
1987                                 }
1988                         }
1989                 } elseif ( $action == 'move-target' ) {
1990                         if ( !$user->isAllowed( 'move' ) ) {
1991                                 // User can't move anything
1992                                 $errors[] = array( 'movenotallowed' );
1993                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1994                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1995                                 // Show user page-specific message only if the user can move other pages
1996                                 $errors[] = array( 'cant-move-to-user-page' );
1997                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1998                                         && $this->mNamespace == NS_CATEGORY ) {
1999                                 // Show category page-specific message only if the user can move other pages
2000                                 $errors[] = array( 'cant-move-to-category-page' );
2001                         }
2002                 } elseif ( !$user->isAllowed( $action ) ) {
2003                         $errors[] = $this->missingPermissionError( $action, $short );
2004                 }
2005
2006                 return $errors;
2007         }
2008
2009         /**
2010          * Add the resulting error code to the errors array
2011          *
2012          * @param array $errors List of current errors
2013          * @param array $result Result of errors
2014          *
2015          * @return array List of errors
2016          */
2017         private function resultToError( $errors, $result ) {
2018                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2019                         // A single array representing an error
2020                         $errors[] = $result;
2021                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2022                         // A nested array representing multiple errors
2023                         $errors = array_merge( $errors, $result );
2024                 } elseif ( $result !== '' && is_string( $result ) ) {
2025                         // A string representing a message-id
2026                         $errors[] = array( $result );
2027                 } elseif ( $result === false ) {
2028                         // a generic "We don't want them to do that"
2029                         $errors[] = array( 'badaccess-group0' );
2030                 }
2031                 return $errors;
2032         }
2033
2034         /**
2035          * Check various permission hooks
2036          *
2037          * @param string $action The action to check
2038          * @param User $user User to check
2039          * @param array $errors List of current errors
2040          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2041          * @param bool $short Short circuit on first error
2042          *
2043          * @return array List of errors
2044          */
2045         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2046                 // Use getUserPermissionsErrors instead
2047                 $result = '';
2048                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2049                         return $result ? array() : array( array( 'badaccess-group0' ) );
2050                 }
2051                 // Check getUserPermissionsErrors hook
2052                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2053                         $errors = $this->resultToError( $errors, $result );
2054                 }
2055                 // Check getUserPermissionsErrorsExpensive hook
2056                 if (
2057                         $rigor !== 'quick'
2058                         && !( $short && count( $errors ) > 0 )
2059                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2060                 ) {
2061                         $errors = $this->resultToError( $errors, $result );
2062                 }
2063
2064                 return $errors;
2065         }
2066
2067         /**
2068          * Check permissions on special pages & namespaces
2069          *
2070          * @param string $action The action to check
2071          * @param User $user User to check
2072          * @param array $errors List of current errors
2073          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2074          * @param bool $short Short circuit on first error
2075          *
2076          * @return array List of errors
2077          */
2078         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2079                 # Only 'createaccount' can be performed on special pages,
2080                 # which don't actually exist in the DB.
2081                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2082                         $errors[] = array( 'ns-specialprotected' );
2083                 }
2084
2085                 # Check $wgNamespaceProtection for restricted namespaces
2086                 if ( $this->isNamespaceProtected( $user ) ) {
2087                         $ns = $this->mNamespace == NS_MAIN ?
2088                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2089                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2090                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2091                 }
2092
2093                 return $errors;
2094         }
2095
2096         /**
2097          * Check CSS/JS sub-page permissions
2098          *
2099          * @param string $action The action to check
2100          * @param User $user User to check
2101          * @param array $errors List of current errors
2102          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2103          * @param bool $short Short circuit on first error
2104          *
2105          * @return array List of errors
2106          */
2107         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2108                 # Protect css/js subpages of user pages
2109                 # XXX: this might be better using restrictions
2110                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2111                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2112                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2113                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2114                                         $errors[] = array( 'mycustomcssprotected', $action );
2115                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2116                                         $errors[] = array( 'mycustomjsprotected', $action );
2117                                 }
2118                         } else {
2119                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2120                                         $errors[] = array( 'customcssprotected', $action );
2121                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2122                                         $errors[] = array( 'customjsprotected', $action );
2123                                 }
2124                         }
2125                 }
2126
2127                 return $errors;
2128         }
2129
2130         /**
2131          * Check against page_restrictions table requirements on this
2132          * page. The user must possess all required rights for this
2133          * action.
2134          *
2135          * @param string $action The action to check
2136          * @param User $user User to check
2137          * @param array $errors List of current errors
2138          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2139          * @param bool $short Short circuit on first error
2140          *
2141          * @return array List of errors
2142          */
2143         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2144                 foreach ( $this->getRestrictions( $action ) as $right ) {
2145                         // Backwards compatibility, rewrite sysop -> editprotected
2146                         if ( $right == 'sysop' ) {
2147                                 $right = 'editprotected';
2148                         }
2149                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2150                         if ( $right == 'autoconfirmed' ) {
2151                                 $right = 'editsemiprotected';
2152                         }
2153                         if ( $right == '' ) {
2154                                 continue;
2155                         }
2156                         if ( !$user->isAllowed( $right ) ) {
2157                                 $errors[] = array( 'protectedpagetext', $right, $action );
2158                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2159                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2160                         }
2161                 }
2162
2163                 return $errors;
2164         }
2165
2166         /**
2167          * Check restrictions on cascading pages.
2168          *
2169          * @param string $action The action to check
2170          * @param User $user User to check
2171          * @param array $errors List of current errors
2172          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2173          * @param bool $short Short circuit on first error
2174          *
2175          * @return array List of errors
2176          */
2177         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2178                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2179                         # We /could/ use the protection level on the source page, but it's
2180                         # fairly ugly as we have to establish a precedence hierarchy for pages
2181                         # included by multiple cascade-protected pages. So just restrict
2182                         # it to people with 'protect' permission, as they could remove the
2183                         # protection anyway.
2184                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2185                         # Cascading protection depends on more than this page...
2186                         # Several cascading protected pages may include this page...
2187                         # Check each cascading level
2188                         # This is only for protection restrictions, not for all actions
2189                         if ( isset( $restrictions[$action] ) ) {
2190                                 foreach ( $restrictions[$action] as $right ) {
2191                                         // Backwards compatibility, rewrite sysop -> editprotected
2192                                         if ( $right == 'sysop' ) {
2193                                                 $right = 'editprotected';
2194                                         }
2195                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2196                                         if ( $right == 'autoconfirmed' ) {
2197                                                 $right = 'editsemiprotected';
2198                                         }
2199                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2200                                                 $pages = '';
2201                                                 foreach ( $cascadingSources as $page ) {
2202                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2203                                                 }
2204                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2205                                         }
2206                                 }
2207                         }
2208                 }
2209
2210                 return $errors;
2211         }
2212
2213         /**
2214          * Check action permissions not already checked in checkQuickPermissions
2215          *
2216          * @param string $action The action to check
2217          * @param User $user User to check
2218          * @param array $errors List of current errors
2219          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2220          * @param bool $short Short circuit on first error
2221          *
2222          * @return array List of errors
2223          */
2224         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2225                 global $wgDeleteRevisionsLimit, $wgLang;
2226
2227                 if ( $action == 'protect' ) {
2228                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2229                                 // If they can't edit, they shouldn't protect.
2230                                 $errors[] = array( 'protect-cantedit' );
2231                         }
2232                 } elseif ( $action == 'create' ) {
2233                         $title_protection = $this->getTitleProtection();
2234                         if ( $title_protection ) {
2235                                 if ( $title_protection['permission'] == ''
2236                                         || !$user->isAllowed( $title_protection['permission'] )
2237                                 ) {
2238                                         $errors[] = array(
2239                                                 'titleprotected',
2240                                                 User::whoIs( $title_protection['user'] ),
2241                                                 $title_protection['reason']
2242                                         );
2243                                 }
2244                         }
2245                 } elseif ( $action == 'move' ) {
2246                         // Check for immobile pages
2247                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2248                                 // Specific message for this case
2249                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2250                         } elseif ( !$this->isMovable() ) {
2251                                 // Less specific message for rarer cases
2252                                 $errors[] = array( 'immobile-source-page' );
2253                         }
2254                 } elseif ( $action == 'move-target' ) {
2255                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2256                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2257                         } elseif ( !$this->isMovable() ) {
2258                                 $errors[] = array( 'immobile-target-page' );
2259                         }
2260                 } elseif ( $action == 'delete' ) {
2261                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2262                         if ( !$tempErrors ) {
2263                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2264                                         $user, $tempErrors, $rigor, true );
2265                         }
2266                         if ( $tempErrors ) {
2267                                 // If protection keeps them from editing, they shouldn't be able to delete.
2268                                 $errors[] = array( 'deleteprotected' );
2269                         }
2270                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2271                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2272                         ) {
2273                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2274                         }
2275                 }
2276                 return $errors;
2277         }
2278
2279         /**
2280          * Check that the user isn't blocked from editing.
2281          *
2282          * @param string $action The action to check
2283          * @param User $user User to check
2284          * @param array $errors List of current errors
2285          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2286          * @param bool $short Short circuit on first error
2287          *
2288          * @return array List of errors
2289          */
2290         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2291                 // Account creation blocks handled at userlogin.
2292                 // Unblocking handled in SpecialUnblock
2293                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2294                         return $errors;
2295                 }
2296
2297                 global $wgEmailConfirmToEdit;
2298
2299                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2300                         $errors[] = array( 'confirmedittext' );
2301                 }
2302
2303                 $useSlave = ( $rigor !== 'secure' );
2304                 if ( ( $action == 'edit' || $action == 'create' )
2305                         && !$user->isBlockedFrom( $this, $useSlave )
2306                 ) {
2307                         // Don't block the user from editing their own talk page unless they've been
2308                         // explicitly blocked from that too.
2309                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2310                         // @todo FIXME: Pass the relevant context into this function.
2311                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2312                 }
2313
2314                 return $errors;
2315         }
2316
2317         /**
2318          * Check that the user is allowed to read this page.
2319          *
2320          * @param string $action The action to check
2321          * @param User $user User to check
2322          * @param array $errors List of current errors
2323          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2324          * @param bool $short Short circuit on first error
2325          *
2326          * @return array List of errors
2327          */
2328         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2329                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2330
2331                 $whitelisted = false;
2332                 if ( User::isEveryoneAllowed( 'read' ) ) {
2333                         # Shortcut for public wikis, allows skipping quite a bit of code
2334                         $whitelisted = true;
2335                 } elseif ( $user->isAllowed( 'read' ) ) {
2336                         # If the user is allowed to read pages, he is allowed to read all pages
2337                         $whitelisted = true;
2338                 } elseif ( $this->isSpecial( 'Userlogin' )
2339                         || $this->isSpecial( 'ChangePassword' )
2340                         || $this->isSpecial( 'PasswordReset' )
2341                 ) {
2342                         # Always grant access to the login page.
2343                         # Even anons need to be able to log in.
2344                         $whitelisted = true;
2345                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2346                         # Time to check the whitelist
2347                         # Only do these checks is there's something to check against
2348                         $name = $this->getPrefixedText();
2349                         $dbName = $this->getPrefixedDBkey();
2350
2351                         // Check for explicit whitelisting with and without underscores
2352                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2353                                 $whitelisted = true;
2354                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2355                                 # Old settings might have the title prefixed with
2356                                 # a colon for main-namespace pages
2357                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2358                                         $whitelisted = true;
2359                                 }
2360                         } elseif ( $this->isSpecialPage() ) {
2361                                 # If it's a special page, ditch the subpage bit and check again
2362                                 $name = $this->getDBkey();
2363                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2364                                 if ( $name ) {
2365                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2366                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2367                                                 $whitelisted = true;
2368                                         }
2369                                 }
2370                         }
2371                 }
2372
2373                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2374                         $name = $this->getPrefixedText();
2375                         // Check for regex whitelisting
2376                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2377                                 if ( preg_match( $listItem, $name ) ) {
2378                                         $whitelisted = true;
2379                                         break;
2380                                 }
2381                         }
2382                 }
2383
2384                 if ( !$whitelisted ) {
2385                         # If the title is not whitelisted, give extensions a chance to do so...
2386                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2387                         if ( !$whitelisted ) {
2388                                 $errors[] = $this->missingPermissionError( $action, $short );
2389                         }
2390                 }
2391
2392                 return $errors;
2393         }
2394
2395         /**
2396          * Get a description array when the user doesn't have the right to perform
2397          * $action (i.e. when User::isAllowed() returns false)
2398          *
2399          * @param string $action The action to check
2400          * @param bool $short Short circuit on first error
2401          * @return array List of errors
2402          */
2403         private function missingPermissionError( $action, $short ) {
2404                 // We avoid expensive display logic for quickUserCan's and such
2405                 if ( $short ) {
2406                         return array( 'badaccess-group0' );
2407                 }
2408
2409                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2410                         User::getGroupsWithPermission( $action ) );
2411
2412                 if ( count( $groups ) ) {
2413                         global $wgLang;
2414                         return array(
2415                                 'badaccess-groups',
2416                                 $wgLang->commaList( $groups ),
2417                                 count( $groups )
2418                         );
2419                 } else {
2420                         return array( 'badaccess-group0' );
2421                 }
2422         }
2423
2424         /**
2425          * Can $user perform $action on this page? This is an internal function,
2426          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2427          * checks on wfReadOnly() and blocks)
2428          *
2429          * @param string $action Action that permission needs to be checked for
2430          * @param User $user User to check
2431          * @param string $rigor One of (quick,full,secure)
2432          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2433          *   - full   : does cheap and expensive checks possibly from a slave
2434          *   - secure : does cheap and expensive checks, using the master as needed
2435          * @param bool $short Set this to true to stop after the first permission error.
2436          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2437          */
2438         protected function getUserPermissionsErrorsInternal(
2439                 $action, $user, $rigor = 'secure', $short = false
2440         ) {
2441                 if ( $rigor === true ) {
2442                         $rigor = 'secure'; // b/c
2443                 } elseif ( $rigor === false ) {
2444                         $rigor = 'quick'; // b/c
2445                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2446                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2447                 }
2448
2449                 # Read has special handling
2450                 if ( $action == 'read' ) {
2451                         $checks = array(
2452                                 'checkPermissionHooks',
2453                                 'checkReadPermissions',
2454                         );
2455                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2456                 # here as it will lead to duplicate error messages. This is okay to do
2457                 # since anywhere that checks for create will also check for edit, and
2458                 # those checks are called for edit.
2459                 } elseif ( $action == 'create' ) {
2460                         $checks = array(
2461                                 'checkQuickPermissions',
2462                                 'checkPermissionHooks',
2463                                 'checkPageRestrictions',
2464                                 'checkCascadingSourcesRestrictions',
2465                                 'checkActionPermissions',
2466                                 'checkUserBlock'
2467                         );
2468                 } else {
2469                         $checks = array(
2470                                 'checkQuickPermissions',
2471                                 'checkPermissionHooks',
2472                                 'checkSpecialsAndNSPermissions',
2473                                 'checkCSSandJSPermissions',
2474                                 'checkPageRestrictions',
2475                                 'checkCascadingSourcesRestrictions',
2476                                 'checkActionPermissions',
2477                                 'checkUserBlock'
2478                         );
2479                 }
2480
2481                 $errors = array();
2482                 while ( count( $checks ) > 0 &&
2483                                 !( $short && count( $errors ) > 0 ) ) {
2484                         $method = array_shift( $checks );
2485                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2486                 }
2487
2488                 return $errors;
2489         }
2490
2491         /**
2492          * Get a filtered list of all restriction types supported by this wiki.
2493          * @param bool $exists True to get all restriction types that apply to
2494          * titles that do exist, False for all restriction types that apply to
2495          * titles that do not exist
2496          * @return array
2497          */
2498         public static function getFilteredRestrictionTypes( $exists = true ) {
2499                 global $wgRestrictionTypes;
2500                 $types = $wgRestrictionTypes;
2501                 if ( $exists ) {
2502                         # Remove the create restriction for existing titles
2503                         $types = array_diff( $types, array( 'create' ) );
2504                 } else {
2505                         # Only the create and upload restrictions apply to non-existing titles
2506                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2507                 }
2508                 return $types;
2509         }
2510
2511         /**
2512          * Returns restriction types for the current Title
2513          *
2514          * @return array Applicable restriction types
2515          */
2516         public function getRestrictionTypes() {
2517                 if ( $this->isSpecialPage() ) {
2518                         return array();
2519                 }
2520
2521                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2522
2523                 if ( $this->getNamespace() != NS_FILE ) {
2524                         # Remove the upload restriction for non-file titles
2525                         $types = array_diff( $types, array( 'upload' ) );
2526                 }
2527
2528                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2529
2530                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2531                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2532
2533                 return $types;
2534         }
2535
2536         /**
2537          * Is this title subject to title protection?
2538          * Title protection is the one applied against creation of such title.
2539          *
2540          * @return array|bool An associative array representing any existent title
2541          *   protection, or false if there's none.
2542          */
2543         public function getTitleProtection() {
2544                 // Can't protect pages in special namespaces
2545                 if ( $this->getNamespace() < 0 ) {
2546                         return false;
2547                 }
2548
2549                 // Can't protect pages that exist.
2550                 if ( $this->exists() ) {
2551                         return false;
2552                 }
2553
2554                 if ( $this->mTitleProtection === null ) {
2555                         $dbr = wfGetDB( DB_SLAVE );
2556                         $res = $dbr->select(
2557                                 'protected_titles',
2558                                 array(
2559                                         'user' => 'pt_user',
2560                                         'reason' => 'pt_reason',
2561                                         'expiry' => 'pt_expiry',
2562                                         'permission' => 'pt_create_perm'
2563                                 ),
2564                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2565                                 __METHOD__
2566                         );
2567
2568                         // fetchRow returns false if there are no rows.
2569                         $row = $dbr->fetchRow( $res );
2570                         if ( $row ) {
2571                                 if ( $row['permission'] == 'sysop' ) {
2572                                         $row['permission'] = 'editprotected'; // B/C
2573                                 }
2574                                 if ( $row['permission'] == 'autoconfirmed' ) {
2575                                         $row['permission'] = 'editsemiprotected'; // B/C
2576                                 }
2577                         }
2578                         $this->mTitleProtection = $row;
2579                 }
2580                 return $this->mTitleProtection;
2581         }
2582
2583         /**
2584          * Remove any title protection due to page existing
2585          */
2586         public function deleteTitleProtection() {
2587                 $dbw = wfGetDB( DB_MASTER );
2588
2589                 $dbw->delete(
2590                         'protected_titles',
2591                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2592                         __METHOD__
2593                 );
2594                 $this->mTitleProtection = false;
2595         }
2596
2597         /**
2598          * Is this page "semi-protected" - the *only* protection levels are listed
2599          * in $wgSemiprotectedRestrictionLevels?
2600          *
2601          * @param string $action Action to check (default: edit)
2602          * @return bool
2603          */
2604         public function isSemiProtected( $action = 'edit' ) {
2605                 global $wgSemiprotectedRestrictionLevels;
2606
2607                 $restrictions = $this->getRestrictions( $action );
2608                 $semi = $wgSemiprotectedRestrictionLevels;
2609                 if ( !$restrictions || !$semi ) {
2610                         // Not protected, or all protection is full protection
2611                         return false;
2612                 }
2613
2614                 // Remap autoconfirmed to editsemiprotected for BC
2615                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2616                         $semi[$key] = 'editsemiprotected';
2617                 }
2618                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2619                         $restrictions[$key] = 'editsemiprotected';
2620                 }
2621
2622                 return !array_diff( $restrictions, $semi );
2623         }
2624
2625         /**
2626          * Does the title correspond to a protected article?
2627          *
2628          * @param string $action The action the page is protected from,
2629          * by default checks all actions.
2630          * @return bool
2631          */
2632         public function isProtected( $action = '' ) {
2633                 global $wgRestrictionLevels;
2634
2635                 $restrictionTypes = $this->getRestrictionTypes();
2636
2637                 # Special pages have inherent protection
2638                 if ( $this->isSpecialPage() ) {
2639                         return true;
2640                 }
2641
2642                 # Check regular protection levels
2643                 foreach ( $restrictionTypes as $type ) {
2644                         if ( $action == $type || $action == '' ) {
2645                                 $r = $this->getRestrictions( $type );
2646                                 foreach ( $wgRestrictionLevels as $level ) {
2647                                         if ( in_array( $level, $r ) && $level != '' ) {
2648                                                 return true;
2649                                         }
2650                                 }
2651                         }
2652                 }
2653
2654                 return false;
2655         }
2656
2657         /**
2658          * Determines if $user is unable to edit this page because it has been protected
2659          * by $wgNamespaceProtection.
2660          *
2661          * @param User $user User object to check permissions
2662          * @return bool
2663          */
2664         public function isNamespaceProtected( User $user ) {
2665                 global $wgNamespaceProtection;
2666
2667                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2668                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2669                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2670                                         return true;
2671                                 }
2672                         }
2673                 }
2674                 return false;
2675         }
2676
2677         /**
2678          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2679          *
2680          * @return bool If the page is subject to cascading restrictions.
2681          */
2682         public function isCascadeProtected() {
2683                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2684                 return ( $sources > 0 );
2685         }
2686
2687         /**
2688          * Determines whether cascading protection sources have already been loaded from
2689          * the database.
2690          *
2691          * @param bool $getPages True to check if the pages are loaded, or false to check
2692          * if the status is loaded.
2693          * @return bool Whether or not the specified information has been loaded
2694          * @since 1.23
2695          */
2696         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2697                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2698         }
2699
2700         /**
2701          * Cascading protection: Get the source of any cascading restrictions on this page.
2702          *
2703          * @param bool $getPages Whether or not to retrieve the actual pages
2704          *        that the restrictions have come from and the actual restrictions
2705          *        themselves.
2706          * @return array Two elements: First is an array of Title objects of the
2707          *        pages from which cascading restrictions have come, false for
2708          *        none, or true if such restrictions exist but $getPages was not
2709          *        set. Second is an array like that returned by
2710          *        Title::getAllRestrictions(), or an empty array if $getPages is
2711          *        false.
2712          */
2713         public function getCascadeProtectionSources( $getPages = true ) {
2714                 global $wgContLang;
2715                 $pagerestrictions = array();
2716
2717                 if ( $this->mCascadeSources !== null && $getPages ) {
2718                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2719                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2720                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2721                 }
2722
2723                 $dbr = wfGetDB( DB_SLAVE );
2724
2725                 if ( $this->getNamespace() == NS_FILE ) {
2726                         $tables = array( 'imagelinks', 'page_restrictions' );
2727                         $where_clauses = array(
2728                                 'il_to' => $this->getDBkey(),
2729                                 'il_from=pr_page',
2730                                 'pr_cascade' => 1
2731                         );
2732                 } else {
2733                         $tables = array( 'templatelinks', 'page_restrictions' );
2734                         $where_clauses = array(
2735                                 'tl_namespace' => $this->getNamespace(),
2736                                 'tl_title' => $this->getDBkey(),
2737                                 'tl_from=pr_page',
2738                                 'pr_cascade' => 1
2739                         );
2740                 }
2741
2742                 if ( $getPages ) {
2743                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2744                                 'pr_expiry', 'pr_type', 'pr_level' );
2745                         $where_clauses[] = 'page_id=pr_page';
2746                         $tables[] = 'page';
2747                 } else {
2748                         $cols = array( 'pr_expiry' );
2749                 }
2750
2751                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2752
2753                 $sources = $getPages ? array() : false;
2754                 $now = wfTimestampNow();
2755
2756                 foreach ( $res as $row ) {
2757                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2758                         if ( $expiry > $now ) {
2759                                 if ( $getPages ) {
2760                                         $page_id = $row->pr_page;
2761                                         $page_ns = $row->page_namespace;
2762                                         $page_title = $row->page_title;
2763                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2764                                         # Add groups needed for each restriction type if its not already there
2765                                         # Make sure this restriction type still exists
2766
2767                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2768                                                 $pagerestrictions[$row->pr_type] = array();
2769                                         }
2770
2771                                         if (
2772                                                 isset( $pagerestrictions[$row->pr_type] )
2773                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2774                                         ) {
2775                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2776                                         }
2777                                 } else {
2778                                         $sources = true;
2779                                 }
2780                         }
2781                 }
2782
2783                 if ( $getPages ) {
2784                         $this->mCascadeSources = $sources;
2785                         $this->mCascadingRestrictions = $pagerestrictions;
2786                 } else {
2787                         $this->mHasCascadingRestrictions = $sources;
2788                 }
2789
2790                 return array( $sources, $pagerestrictions );
2791         }
2792
2793         /**
2794          * Accessor for mRestrictionsLoaded
2795          *
2796          * @return bool Whether or not the page's restrictions have already been
2797          * loaded from the database
2798          * @since 1.23
2799          */
2800         public function areRestrictionsLoaded() {
2801                 return $this->mRestrictionsLoaded;
2802         }
2803
2804         /**
2805          * Accessor/initialisation for mRestrictions
2806          *
2807          * @param string $action Action that permission needs to be checked for
2808          * @return array Restriction levels needed to take the action. All levels are
2809          *     required. Note that restriction levels are normally user rights, but 'sysop'
2810          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2811          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2812          */
2813         public function getRestrictions( $action ) {
2814                 if ( !$this->mRestrictionsLoaded ) {
2815                         $this->loadRestrictions();
2816                 }
2817                 return isset( $this->mRestrictions[$action] )
2818                                 ? $this->mRestrictions[$action]
2819                                 : array();
2820         }
2821
2822         /**
2823          * Accessor/initialisation for mRestrictions
2824          *
2825          * @return array Keys are actions, values are arrays as returned by
2826          *     Title::getRestrictions()
2827          * @since 1.23
2828          */
2829         public function getAllRestrictions() {
2830                 if ( !$this->mRestrictionsLoaded ) {
2831                         $this->loadRestrictions();
2832                 }
2833                 return $this->mRestrictions;
2834         }
2835
2836         /**
2837          * Get the expiry time for the restriction against a given action
2838          *
2839          * @param string $action
2840          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2841          *     or not protected at all, or false if the action is not recognised.
2842          */
2843         public function getRestrictionExpiry( $action ) {
2844                 if ( !$this->mRestrictionsLoaded ) {
2845                         $this->loadRestrictions();
2846                 }
2847                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2848         }
2849
2850         /**
2851          * Returns cascading restrictions for the current article
2852          *
2853          * @return bool
2854          */
2855         function areRestrictionsCascading() {
2856                 if ( !$this->mRestrictionsLoaded ) {
2857                         $this->loadRestrictions();
2858                 }
2859
2860                 return $this->mCascadeRestriction;
2861         }
2862
2863         /**
2864          * Loads a string into mRestrictions array
2865          *
2866          * @param ResultWrapper $res Resource restrictions as an SQL result.
2867          * @param string $oldFashionedRestrictions Comma-separated list of page
2868          *        restrictions from page table (pre 1.10)
2869          */
2870         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2871                 $rows = array();
2872
2873                 foreach ( $res as $row ) {
2874                         $rows[] = $row;
2875                 }
2876
2877                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2878         }
2879
2880         /**
2881          * Compiles list of active page restrictions from both page table (pre 1.10)
2882          * and page_restrictions table for this existing page.
2883          * Public for usage by LiquidThreads.
2884          *
2885          * @param array $rows Array of db result objects
2886          * @param string $oldFashionedRestrictions Comma-separated list of page
2887          *   restrictions from page table (pre 1.10)
2888          */
2889         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2890                 global $wgContLang;
2891                 $dbr = wfGetDB( DB_SLAVE );
2892
2893                 $restrictionTypes = $this->getRestrictionTypes();
2894
2895                 foreach ( $restrictionTypes as $type ) {
2896                         $this->mRestrictions[$type] = array();
2897                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2898                 }
2899
2900                 $this->mCascadeRestriction = false;
2901
2902                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2903
2904                 if ( $oldFashionedRestrictions === null ) {
2905                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2906                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2907                 }
2908
2909                 if ( $oldFashionedRestrictions != '' ) {
2910
2911                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2912                                 $temp = explode( '=', trim( $restrict ) );
2913                                 if ( count( $temp ) == 1 ) {
2914                                         // old old format should be treated as edit/move restriction
2915                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2916                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2917                                 } else {
2918                                         $restriction = trim( $temp[1] );
2919                                         if ( $restriction != '' ) { //some old entries are empty
2920                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2921                                         }
2922                                 }
2923                         }
2924
2925                         $this->mOldRestrictions = true;
2926
2927                 }
2928
2929                 if ( count( $rows ) ) {
2930                         # Current system - load second to make them override.
2931                         $now = wfTimestampNow();
2932
2933                         # Cycle through all the restrictions.
2934                         foreach ( $rows as $row ) {
2935
2936                                 // Don't take care of restrictions types that aren't allowed
2937                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2938                                         continue;
2939                                 }
2940
2941                                 // This code should be refactored, now that it's being used more generally,
2942                                 // But I don't really see any harm in leaving it in Block for now -werdna
2943                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2944
2945                                 // Only apply the restrictions if they haven't expired!
2946                                 if ( !$expiry || $expiry > $now ) {
2947                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2948                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2949
2950                                         $this->mCascadeRestriction |= $row->pr_cascade;
2951                                 }
2952                         }
2953                 }
2954
2955                 $this->mRestrictionsLoaded = true;
2956         }
2957
2958         /**
2959          * Load restrictions from the page_restrictions table
2960          *
2961          * @param string $oldFashionedRestrictions Comma-separated list of page
2962          *   restrictions from page table (pre 1.10)
2963          */
2964         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2965                 global $wgContLang;
2966                 if ( !$this->mRestrictionsLoaded ) {
2967                         if ( $this->exists() ) {
2968                                 $dbr = wfGetDB( DB_SLAVE );
2969
2970                                 $res = $dbr->select(
2971                                         'page_restrictions',
2972                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2973                                         array( 'pr_page' => $this->getArticleID() ),
2974                                         __METHOD__
2975                                 );
2976
2977                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2978                         } else {
2979                                 $title_protection = $this->getTitleProtection();
2980
2981                                 if ( $title_protection ) {
2982                                         $now = wfTimestampNow();
2983                                         $expiry = $wgContLang->formatExpiry( $title_protection['expiry'], TS_MW );
2984
2985                                         if ( !$expiry || $expiry > $now ) {
2986                                                 // Apply the restrictions
2987                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2988                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
2989                                         } else { // Get rid of the old restrictions
2990                                                 $this->mTitleProtection = false;
2991                                         }
2992                                 } else {
2993                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2994                                 }
2995                                 $this->mRestrictionsLoaded = true;
2996                         }
2997                 }
2998         }
2999
3000         /**
3001          * Flush the protection cache in this object and force reload from the database.
3002          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3003          */
3004         public function flushRestrictions() {
3005                 $this->mRestrictionsLoaded = false;
3006                 $this->mTitleProtection = null;
3007         }
3008
3009         /**
3010          * Purge expired restrictions from the page_restrictions table
3011          */
3012         static function purgeExpiredRestrictions() {
3013                 if ( wfReadOnly() ) {
3014                         return;
3015                 }
3016
3017                 $method = __METHOD__;
3018                 $dbw = wfGetDB( DB_MASTER );
3019                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3020                         $dbw->delete(
3021                                 'page_restrictions',
3022                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3023                                 $method
3024                         );
3025                         $dbw->delete(
3026                                 'protected_titles',
3027                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3028                                 $method
3029                         );
3030                 } );
3031         }
3032
3033         /**
3034          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3035          *
3036          * @return bool
3037          */
3038         public function hasSubpages() {
3039                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3040                         # Duh
3041                         return false;
3042                 }
3043
3044                 # We dynamically add a member variable for the purpose of this method
3045                 # alone to cache the result.  There's no point in having it hanging
3046                 # around uninitialized in every Title object; therefore we only add it
3047                 # if needed and don't declare it statically.
3048                 if ( $this->mHasSubpages === null ) {
3049                         $this->mHasSubpages = false;
3050                         $subpages = $this->getSubpages( 1 );
3051                         if ( $subpages instanceof TitleArray ) {
3052                                 $this->mHasSubpages = (bool)$subpages->count();
3053                         }
3054                 }
3055
3056                 return $this->mHasSubpages;
3057         }
3058
3059         /**
3060          * Get all subpages of this page.
3061          *
3062          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3063          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3064          *  doesn't allow subpages
3065          */
3066         public function getSubpages( $limit = -1 ) {
3067                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3068                         return array();
3069                 }
3070
3071                 $dbr = wfGetDB( DB_SLAVE );
3072                 $conds['page_namespace'] = $this->getNamespace();
3073                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3074                 $options = array();
3075                 if ( $limit > -1 ) {
3076                         $options['LIMIT'] = $limit;
3077                 }
3078                 $this->mSubpages = TitleArray::newFromResult(
3079                         $dbr->select( 'page',
3080                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3081                                 $conds,
3082                                 __METHOD__,
3083                                 $options
3084                         )
3085                 );
3086                 return $this->mSubpages;
3087         }
3088
3089         /**
3090          * Is there a version of this page in the deletion archive?
3091          *
3092          * @return int The number of archived revisions
3093          */
3094         public function isDeleted() {
3095                 if ( $this->getNamespace() < 0 ) {
3096                         $n = 0;
3097                 } else {
3098                         $dbr = wfGetDB( DB_SLAVE );
3099
3100                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3101                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3102                                 __METHOD__
3103                         );
3104                         if ( $this->getNamespace() == NS_FILE ) {
3105                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3106                                         array( 'fa_name' => $this->getDBkey() ),
3107                                         __METHOD__
3108                                 );
3109                         }
3110                 }
3111                 return (int)$n;
3112         }
3113
3114         /**
3115          * Is there a version of this page in the deletion archive?
3116          *
3117          * @return bool
3118          */
3119         public function isDeletedQuick() {
3120                 if ( $this->getNamespace() < 0 ) {
3121                         return false;
3122                 }
3123                 $dbr = wfGetDB( DB_SLAVE );
3124                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3125                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3126                         __METHOD__
3127                 );
3128                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3129                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3130                                 array( 'fa_name' => $this->getDBkey() ),
3131                                 __METHOD__
3132                         );
3133                 }
3134                 return $deleted;
3135         }
3136
3137         /**
3138          * Get the article ID for this Title from the link cache,
3139          * adding it if necessary
3140          *
3141          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3142          *  for update
3143          * @return int The ID
3144          */
3145         public function getArticleID( $flags = 0 ) {
3146                 if ( $this->getNamespace() < 0 ) {
3147                         $this->mArticleID = 0;
3148                         return $this->mArticleID;
3149                 }
3150                 $linkCache = LinkCache::singleton();
3151                 if ( $flags & self::GAID_FOR_UPDATE ) {
3152                         $oldUpdate = $linkCache->forUpdate( true );
3153                         $linkCache->clearLink( $this );
3154                         $this->mArticleID = $linkCache->addLinkObj( $this );
3155                         $linkCache->forUpdate( $oldUpdate );
3156                 } else {
3157                         if ( -1 == $this->mArticleID ) {
3158                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3159                         }
3160                 }
3161                 return $this->mArticleID;
3162         }
3163
3164         /**
3165          * Is this an article that is a redirect page?
3166          * Uses link cache, adding it if necessary
3167          *
3168          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3169          * @return bool
3170          */
3171         public function isRedirect( $flags = 0 ) {
3172                 if ( !is_null( $this->mRedirect ) ) {
3173                         return $this->mRedirect;
3174                 }
3175                 if ( !$this->getArticleID( $flags ) ) {
3176                         $this->mRedirect = false;
3177                         return $this->mRedirect;
3178                 }
3179
3180                 $linkCache = LinkCache::singleton();
3181                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3182                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3183                 if ( $cached === null ) {
3184                         # Trust LinkCache's state over our own
3185                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3186                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3187                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3188                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3189                         # LinkCache to refresh its data from the master.
3190                         $this->mRedirect = false;
3191                         return $this->mRedirect;
3192                 }
3193
3194                 $this->mRedirect = (bool)$cached;
3195
3196                 return $this->mRedirect;
3197         }
3198
3199         /**
3200          * What is the length of this page?
3201          * Uses link cache, adding it if necessary
3202          *
3203          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3204          * @return int
3205          */
3206         public function getLength( $flags = 0 ) {
3207                 if ( $this->mLength != -1 ) {
3208                         return $this->mLength;
3209                 }
3210                 if ( !$this->getArticleID( $flags ) ) {
3211                         $this->mLength = 0;
3212                         return $this->mLength;
3213                 }
3214                 $linkCache = LinkCache::singleton();
3215                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3216                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3217                 if ( $cached === null ) {
3218                         # Trust LinkCache's state over our own, as for isRedirect()
3219                         $this->mLength = 0;
3220                         return $this->mLength;
3221                 }
3222
3223                 $this->mLength = intval( $cached );
3224
3225                 return $this->mLength;
3226         }
3227
3228         /**
3229          * What is the page_latest field for this page?
3230          *
3231          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3232          * @return int Int or 0 if the page doesn't exist
3233          */
3234         public function getLatestRevID( $flags = 0 ) {
3235                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3236                         return intval( $this->mLatestID );
3237                 }
3238                 if ( !$this->getArticleID( $flags ) ) {
3239                         $this->mLatestID = 0;
3240                         return $this->mLatestID;
3241                 }
3242                 $linkCache = LinkCache::singleton();
3243                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3244                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3245                 if ( $cached === null ) {
3246                         # Trust LinkCache's state over our own, as for isRedirect()
3247                         $this->mLatestID = 0;
3248                         return $this->mLatestID;
3249                 }
3250
3251                 $this->mLatestID = intval( $cached );
3252
3253                 return $this->mLatestID;
3254         }
3255
3256         /**
3257          * This clears some fields in this object, and clears any associated
3258          * keys in the "bad links" section of the link cache.
3259          *
3260          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3261          * loading of the new page_id. It's also called from
3262          * WikiPage::doDeleteArticleReal()
3263          *
3264          * @param int $newid The new Article ID
3265          */
3266         public function resetArticleID( $newid ) {
3267                 $linkCache = LinkCache::singleton();
3268                 $linkCache->clearLink( $this );
3269
3270                 if ( $newid === false ) {
3271                         $this->mArticleID = -1;
3272                 } else {
3273                         $this->mArticleID = intval( $newid );
3274                 }
3275                 $this->mRestrictionsLoaded = false;
3276                 $this->mRestrictions = array();
3277                 $this->mRedirect = null;
3278                 $this->mLength = -1;
3279                 $this->mLatestID = false;
3280                 $this->mContentModel = false;
3281                 $this->mEstimateRevisions = null;
3282                 $this->mPageLanguage = false;
3283                 $this->mDbPageLanguage = null;
3284                 $this->mIsBigDeletion = null;
3285         }
3286
3287         /**
3288          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3289          *
3290          * @param string $text Containing title to capitalize
3291          * @param int $ns Namespace index, defaults to NS_MAIN
3292          * @return string Containing capitalized title
3293          */
3294         public static function capitalize( $text, $ns = NS_MAIN ) {
3295                 global $wgContLang;
3296
3297                 if ( MWNamespace::isCapitalized( $ns ) ) {
3298                         return $wgContLang->ucfirst( $text );
3299                 } else {
3300                         return $text;
3301                 }
3302         }
3303
3304         /**
3305          * Secure and split - main initialisation function for this object
3306          *
3307          * Assumes that mDbkeyform has been set, and is urldecoded
3308          * and uses underscores, but not otherwise munged.  This function
3309          * removes illegal characters, splits off the interwiki and
3310          * namespace prefixes, sets the other forms, and canonicalizes
3311          * everything.
3312          *
3313          * @return bool True on success
3314          */
3315         private function secureAndSplit() {
3316                 # Initialisation
3317                 $this->mInterwiki = '';
3318                 $this->mFragment = '';
3319                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3320
3321                 $dbkey = $this->mDbkeyform;
3322
3323                 try {
3324                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3325                         //        the parsing code with Title, while avoiding massive refactoring.
3326                         // @todo: get rid of secureAndSplit, refactor parsing code.
3327                         $titleParser = self::getTitleParser();
3328                         $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3329                 } catch ( MalformedTitleException $ex ) {
3330                         return false;
3331                 }
3332
3333                 # Fill fields
3334                 $this->setFragment( '#' . $parts['fragment'] );
3335                 $this->mInterwiki = $parts['interwiki'];
3336                 $this->mLocalInterwiki = $parts['local_interwiki'];
3337                 $this->mNamespace = $parts['namespace'];
3338                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3339
3340                 $this->mDbkeyform = $parts['dbkey'];
3341                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3342                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3343
3344                 # We already know that some pages won't be in the database!
3345                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3346                         $this->mArticleID = 0;
3347                 }
3348
3349                 return true;
3350         }
3351
3352         /**
3353          * Get an array of Title objects linking to this Title
3354          * Also stores the IDs in the link cache.
3355          *
3356          * WARNING: do not use this function on arbitrary user-supplied titles!
3357          * On heavily-used templates it will max out the memory.
3358          *
3359          * @param array $options May be FOR UPDATE
3360          * @param string $table Table name
3361          * @param string $prefix Fields prefix
3362          * @return Title[] Array of Title objects linking here
3363          */
3364         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3365                 if ( count( $options ) > 0 ) {
3366                         $db = wfGetDB( DB_MASTER );
3367                 } else {
3368                         $db = wfGetDB( DB_SLAVE );
3369                 }
3370
3371                 $res = $db->select(
3372                         array( 'page', $table ),
3373                         self::getSelectFields(),
3374                         array(
3375                                 "{$prefix}_from=page_id",
3376                                 "{$prefix}_namespace" => $this->getNamespace(),
3377                                 "{$prefix}_title" => $this->getDBkey() ),
3378                         __METHOD__,
3379                         $options
3380                 );
3381
3382                 $retVal = array();
3383                 if ( $res->numRows() ) {
3384                         $linkCache = LinkCache::singleton();
3385                         foreach ( $res as $row ) {
3386                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3387                                 if ( $titleObj ) {
3388                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3389                                         $retVal[] = $titleObj;
3390                                 }
3391                         }
3392                 }
3393                 return $retVal;
3394         }
3395
3396         /**
3397          * Get an array of Title objects using this Title as a template
3398          * Also stores the IDs in the link cache.
3399          *
3400          * WARNING: do not use this function on arbitrary user-supplied titles!
3401          * On heavily-used templates it will max out the memory.
3402          *
3403          * @param array $options May be FOR UPDATE
3404          * @return Title[] Array of Title the Title objects linking here
3405          */
3406         public function getTemplateLinksTo( $options = array() ) {
3407                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3408         }
3409
3410         /**
3411          * Get an array of Title objects linked from this Title
3412          * Also stores the IDs in the link cache.
3413          *
3414          * WARNING: do not use this function on arbitrary user-supplied titles!
3415          * On heavily-used templates it will max out the memory.
3416          *
3417          * @param array $options May be FOR UPDATE
3418          * @param string $table Table name
3419          * @param string $prefix Fields prefix
3420          * @return array Array of Title objects linking here
3421          */
3422         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3423                 global $wgContentHandlerUseDB;
3424
3425                 $id = $this->getArticleID();
3426
3427                 # If the page doesn't exist; there can't be any link from this page
3428                 if ( !$id ) {
3429                         return array();
3430                 }
3431
3432                 if ( count( $options ) > 0 ) {
3433                         $db = wfGetDB( DB_MASTER );
3434                 } else {
3435                         $db = wfGetDB( DB_SLAVE );
3436                 }
3437
3438                 $namespaceFiled = "{$prefix}_namespace";
3439                 $titleField = "{$prefix}_title";
3440
3441                 $fields = array(
3442                         $namespaceFiled,
3443                         $titleField,
3444                         'page_id',
3445                         'page_len',
3446                         'page_is_redirect',
3447                         'page_latest'
3448                 );
3449
3450                 if ( $wgContentHandlerUseDB ) {
3451                         $fields[] = 'page_content_model';
3452                 }
3453
3454                 $res = $db->select(
3455                         array( $table, 'page' ),
3456                         $fields,
3457                         array( "{$prefix}_from" => $id ),
3458                         __METHOD__,
3459                         $options,
3460                         array( 'page' => array(
3461                                 'LEFT JOIN',
3462                                 array( "page_namespace=$namespaceFiled", "page_title=$titleField" )
3463                         ) )
3464                 );
3465
3466                 $retVal = array();
3467                 if ( $res->numRows() ) {
3468                         $linkCache = LinkCache::singleton();
3469                         foreach ( $res as $row ) {
3470                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3471                                 if ( $titleObj ) {
3472                                         if ( $row->page_id ) {
3473                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3474                                         } else {
3475                                                 $linkCache->addBadLinkObj( $titleObj );
3476                                         }
3477                                         $retVal[] = $titleObj;
3478                                 }
3479                         }
3480                 }
3481                 return $retVal;
3482         }
3483
3484         /**
3485          * Get an array of Title objects used on this Title as a template
3486          * Also stores the IDs in the link cache.
3487          *
3488          * WARNING: do not use this function on arbitrary user-supplied titles!
3489          * On heavily-used templates it will max out the memory.
3490          *
3491          * @param array $options May be FOR UPDATE
3492          * @return Title[] Array of Title the Title objects used here
3493          */
3494         public function getTemplateLinksFrom( $options = array() ) {
3495                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3496         }
3497
3498         /**
3499          * Get an array of Title objects referring to non-existent articles linked
3500          * from this page.
3501          *
3502          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3503          *   should use redirect table in this case).
3504          * @return Title[] Array of Title the Title objects
3505          */
3506         public function getBrokenLinksFrom() {
3507                 if ( $this->getArticleID() == 0 ) {
3508                         # All links from article ID 0 are false positives
3509                         return array();
3510                 }
3511
3512                 $dbr = wfGetDB( DB_SLAVE );
3513                 $res = $dbr->select(
3514                         array( 'page', 'pagelinks' ),
3515                         array( 'pl_namespace', 'pl_title' ),
3516                         array(
3517                                 'pl_from' => $this->getArticleID(),
3518                                 'page_namespace IS NULL'
3519                         ),
3520                         __METHOD__, array(),
3521                         array(
3522                                 'page' => array(
3523                                         'LEFT JOIN',
3524                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3525                                 )
3526                         )
3527                 );
3528
3529                 $retVal = array();
3530                 foreach ( $res as $row ) {
3531                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3532                 }
3533                 return $retVal;
3534         }
3535
3536         /**
3537          * Get a list of URLs to purge from the Squid cache when this
3538          * page changes
3539          *
3540          * @return string[] Array of String the URLs
3541          */
3542         public function getSquidURLs() {
3543                 $urls = array(
3544                         $this->getInternalURL(),
3545                         $this->getInternalURL( 'action=history' )
3546                 );
3547
3548                 $pageLang = $this->getPageLanguage();
3549                 if ( $pageLang->hasVariants() ) {
3550                         $variants = $pageLang->getVariants();
3551                         foreach ( $variants as $vCode ) {
3552                                 $urls[] = $this->getInternalURL( '', $vCode );
3553                         }
3554                 }
3555
3556                 // If we are looking at a css/js user subpage, purge the action=raw.
3557                 if ( $this->isJsSubpage() ) {
3558                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3559                 } elseif ( $this->isCssSubpage() ) {
3560                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3561                 }
3562
3563                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3564                 return $urls;
3565         }
3566
3567         /**
3568          * Purge all applicable Squid URLs
3569          */
3570         public function purgeSquid() {
3571                 global $wgUseSquid;
3572                 if ( $wgUseSquid ) {
3573                         $urls = $this->getSquidURLs();
3574                         $u = new SquidUpdate( $urls );
3575                         $u->doUpdate();
3576                 }
3577         }
3578
3579         /**
3580          * Move this page without authentication
3581          *
3582          * @deprecated since 1.25 use MovePage class instead
3583          * @param Title $nt The new page Title
3584          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3585          */
3586         public function moveNoAuth( &$nt ) {
3587                 wfDeprecated( __METHOD__, '1.25' );
3588                 return $this->moveTo( $nt, false );
3589         }
3590
3591         /**
3592          * Check whether a given move operation would be valid.
3593          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3594          *
3595          * @deprecated since 1.25, use MovePage's methods instead
3596          * @param Title $nt The new title
3597          * @param bool $auth Whether to check user permissions (uses $wgUser)
3598          * @param string $reason Is the log summary of the move, used for spam checking
3599          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3600          */
3601         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3602                 global $wgUser;
3603
3604                 if ( !( $nt instanceof Title ) ) {
3605                         // Normally we'd add this to $errors, but we'll get
3606                         // lots of syntax errors if $nt is not an object
3607                         return array( array( 'badtitletext' ) );
3608                 }
3609
3610                 $mp = new MovePage( $this, $nt );
3611                 $errors = $mp->isValidMove()->getErrorsArray();
3612                 if ( $auth ) {
3613                         $errors = wfMergeErrorArrays(
3614                                 $errors,
3615                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3616                         );
3617                 }
3618
3619                 return $errors ? : true;
3620         }
3621
3622         /**
3623          * Check if the requested move target is a valid file move target
3624          * @todo move this to MovePage
3625          * @param Title $nt Target title
3626          * @return array List of errors
3627          */
3628         protected function validateFileMoveOperation( $nt ) {
3629                 global $wgUser;
3630
3631                 $errors = array();
3632
3633                 $destFile = wfLocalFile( $nt );
3634                 $destFile->load( File::READ_LATEST );
3635                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3636                         && !$destFile->exists() && wfFindFile( $nt )
3637                 ) {
3638                         $errors[] = array( 'file-exists-sharedrepo' );
3639                 }
3640
3641                 return $errors;
3642         }
3643
3644         /**
3645          * Move a title to a new location
3646          *
3647          * @deprecated since 1.25, use the MovePage class instead
3648          * @param Title $nt The new title
3649          * @param bool $auth Indicates whether $wgUser's permissions
3650          *  should be checked
3651          * @param string $reason The reason for the move
3652          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3653          *  Ignored if the user doesn't have the suppressredirect right.
3654          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3655          */
3656         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3657                 global $wgUser;
3658                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3659                 if ( is_array( $err ) ) {
3660                         // Auto-block user's IP if the account was "hard" blocked
3661                         $wgUser->spreadAnyEditBlock();
3662                         return $err;
3663                 }
3664                 // Check suppressredirect permission
3665                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3666                         $createRedirect = true;
3667                 }
3668
3669                 $mp = new MovePage( $this, $nt );
3670                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3671                 if ( $status->isOK() ) {
3672                         return true;
3673                 } else {
3674                         return $status->getErrorsArray();
3675                 }
3676         }
3677
3678         /**
3679          * Move this page's subpages to be subpages of $nt
3680          *
3681          * @param Title $nt Move target
3682          * @param bool $auth Whether $wgUser's permissions should be checked
3683          * @param string $reason The reason for the move
3684          * @param bool $createRedirect Whether to create redirects from the old subpages to
3685          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3686          * @return array Array with old page titles as keys, and strings (new page titles) or
3687          *     arrays (errors) as values, or an error array with numeric indices if no pages
3688          *     were moved
3689          */
3690         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3691                 global $wgMaximumMovedPages;
3692                 // Check permissions
3693                 if ( !$this->userCan( 'move-subpages' ) ) {
3694                         return array( 'cant-move-subpages' );
3695                 }
3696                 // Do the source and target namespaces support subpages?
3697                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3698                         return array( 'namespace-nosubpages',
3699                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3700                 }
3701                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3702                         return array( 'namespace-nosubpages',
3703                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3704                 }
3705
3706                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3707                 $retval = array();
3708                 $count = 0;
3709                 foreach ( $subpages as $oldSubpage ) {
3710                         $count++;
3711                         if ( $count > $wgMaximumMovedPages ) {
3712                                 $retval[$oldSubpage->getPrefixedText()] =
3713                                                 array( 'movepage-max-pages',
3714                                                         $wgMaximumMovedPages );
3715                                 break;
3716                         }
3717
3718                         // We don't know whether this function was called before
3719                         // or after moving the root page, so check both
3720                         // $this and $nt
3721                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3722                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3723                         ) {
3724                                 // When moving a page to a subpage of itself,
3725                                 // don't move it twice
3726                                 continue;
3727                         }
3728                         $newPageName = preg_replace(
3729                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3730                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3731                                         $oldSubpage->getDBkey() );
3732                         if ( $oldSubpage->isTalkPage() ) {
3733                                 $newNs = $nt->getTalkPage()->getNamespace();
3734                         } else {
3735                                 $newNs = $nt->getSubjectPage()->getNamespace();
3736                         }
3737                         # Bug 14385: we need makeTitleSafe because the new page names may
3738                         # be longer than 255 characters.
3739                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3740
3741                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3742                         if ( $success === true ) {
3743                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3744                         } else {
3745                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3746                         }
3747                 }
3748                 return $retval;
3749         }
3750
3751         /**
3752          * Checks if this page is just a one-rev redirect.
3753          * Adds lock, so don't use just for light purposes.
3754          *
3755          * @return bool
3756          */
3757         public function isSingleRevRedirect() {
3758                 global $wgContentHandlerUseDB;
3759
3760                 $dbw = wfGetDB( DB_MASTER );
3761
3762                 # Is it a redirect?
3763                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3764                 if ( $wgContentHandlerUseDB ) {
3765                         $fields[] = 'page_content_model';
3766                 }
3767
3768                 $row = $dbw->selectRow( 'page',
3769                         $fields,
3770                         $this->pageCond(),
3771                         __METHOD__,
3772                         array( 'FOR UPDATE' )
3773                 );
3774                 # Cache some fields we may want
3775                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3776                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3777                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3778                 $this->mContentModel = $row && isset( $row->page_content_model )
3779                         ? strval( $row->page_content_model )
3780                         : false;
3781
3782                 if ( !$this->mRedirect ) {
3783                         return false;
3784                 }
3785                 # Does the article have a history?
3786                 $row = $dbw->selectField( array( 'page', 'revision' ),
3787                         'rev_id',
3788                         array( 'page_namespace' => $this->getNamespace(),
3789                                 'page_title' => $this->getDBkey(),
3790                                 'page_id=rev_page',
3791                                 'page_latest != rev_id'
3792                         ),
3793                         __METHOD__,
3794                         array( 'FOR UPDATE' )
3795                 );
3796                 # Return true if there was no history
3797                 return ( $row === false );
3798         }
3799
3800         /**
3801          * Checks if $this can be moved to a given Title
3802          * - Selects for update, so don't call it unless you mean business
3803          *
3804          * @deprecated since 1.25, use MovePage's methods instead
3805          * @param Title $nt The new title to check
3806          * @return bool
3807          */
3808         public function isValidMoveTarget( $nt ) {
3809                 # Is it an existing file?
3810                 if ( $nt->getNamespace() == NS_FILE ) {
3811                         $file = wfLocalFile( $nt );
3812                         $file->load( File::READ_LATEST );
3813                         if ( $file->exists() ) {
3814                                 wfDebug( __METHOD__ . ": file exists\n" );
3815                                 return false;
3816                         }
3817                 }
3818                 # Is it a redirect with no history?
3819                 if ( !$nt->isSingleRevRedirect() ) {
3820                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3821                         return false;
3822                 }
3823                 # Get the article text
3824                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3825                 if ( !is_object( $rev ) ) {
3826                         return false;
3827                 }
3828                 $content = $rev->getContent();
3829                 # Does the redirect point to the source?
3830                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3831                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3832
3833                 if ( $redirTitle ) {
3834                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3835                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3836                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3837                                 return false;
3838                         } else {
3839                                 return true;
3840                         }
3841                 } else {
3842                         # Fail safe (not a redirect after all. strange.)
3843                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3844                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3845                         return false;
3846                 }
3847         }
3848
3849         /**
3850          * Get categories to which this Title belongs and return an array of
3851          * categories' names.
3852          *
3853          * @return array Array of parents in the form:
3854          *        $parent => $currentarticle
3855          */
3856         public function getParentCategories() {
3857                 global $wgContLang;
3858
3859                 $data = array();
3860
3861                 $titleKey = $this->getArticleID();
3862
3863                 if ( $titleKey === 0 ) {
3864                         return $data;
3865                 }
3866
3867                 $dbr = wfGetDB( DB_SLAVE );
3868
3869                 $res = $dbr->select(
3870                         'categorylinks',
3871                         'cl_to',
3872                         array( 'cl_from' => $titleKey ),
3873                         __METHOD__
3874                 );
3875
3876                 if ( $res->numRows() > 0 ) {
3877                         foreach ( $res as $row ) {
3878                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3879                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3880                         }
3881                 }
3882                 return $data;
3883         }
3884
3885         /**
3886          * Get a tree of parent categories
3887          *
3888          * @param array $children Array with the children in the keys, to check for circular refs
3889          * @return array Tree of parent categories
3890          */
3891         public function getParentCategoryTree( $children = array() ) {
3892                 $stack = array();
3893                 $parents = $this->getParentCategories();
3894
3895                 if ( $parents ) {
3896                         foreach ( $parents as $parent => $current ) {
3897                                 if ( array_key_exists( $parent, $children ) ) {
3898                                         # Circular reference
3899                                         $stack[$parent] = array();
3900                                 } else {
3901                                         $nt = Title::newFromText( $parent );
3902                                         if ( $nt ) {
3903                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3904                                         }
3905                                 }
3906                         }
3907                 }
3908
3909                 return $stack;
3910         }
3911
3912         /**
3913          * Get an associative array for selecting this title from
3914          * the "page" table
3915          *
3916          * @return array Array suitable for the $where parameter of DB::select()
3917          */
3918         public function pageCond() {
3919                 if ( $this->mArticleID > 0 ) {
3920                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3921                         return array( 'page_id' => $this->mArticleID );
3922                 } else {
3923                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3924                 }
3925         }
3926
3927         /**
3928          * Get the revision ID of the previous revision
3929          *
3930          * @param int $revId Revision ID. Get the revision that was before this one.
3931          * @param int $flags Title::GAID_FOR_UPDATE
3932          * @return int|bool Old revision ID, or false if none exists
3933          */
3934         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3935                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3936                 $revId = $db->selectField( 'revision', 'rev_id',
3937                         array(
3938                                 'rev_page' => $this->getArticleID( $flags ),
3939                                 'rev_id < ' . intval( $revId )
3940                         ),
3941                         __METHOD__,
3942                         array( 'ORDER BY' => 'rev_id DESC' )
3943                 );
3944
3945                 if ( $revId === false ) {
3946                         return false;
3947                 } else {
3948                         return intval( $revId );
3949                 }
3950         }
3951
3952         /**
3953          * Get the revision ID of the next revision
3954          *
3955          * @param int $revId Revision ID. Get the revision that was after this one.
3956          * @param int $flags Title::GAID_FOR_UPDATE
3957          * @return int|bool Next revision ID, or false if none exists
3958          */
3959         public function getNextRevisionID( $revId, $flags = 0 ) {
3960                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3961                 $revId = $db->selectField( 'revision', 'rev_id',
3962                         array(
3963                                 'rev_page' => $this->getArticleID( $flags ),
3964                                 'rev_id > ' . intval( $revId )
3965                         ),
3966                         __METHOD__,
3967                         array( 'ORDER BY' => 'rev_id' )
3968                 );
3969
3970                 if ( $revId === false ) {
3971                         return false;
3972                 } else {
3973                         return intval( $revId );
3974                 }
3975         }
3976
3977         /**
3978          * Get the first revision of the page
3979          *
3980          * @param int $flags Title::GAID_FOR_UPDATE
3981          * @return Revision|null If page doesn't exist
3982          */
3983         public function getFirstRevision( $flags = 0 ) {
3984                 $pageId = $this->getArticleID( $flags );
3985                 if ( $pageId ) {
3986                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3987                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3988                                 array( 'rev_page' => $pageId ),
3989                                 __METHOD__,
3990                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3991                         );
3992                         if ( $row ) {
3993                                 return new Revision( $row );
3994                         }
3995                 }
3996                 return null;
3997         }
3998
3999         /**
4000          * Get the oldest revision timestamp of this page
4001          *
4002          * @param int $flags Title::GAID_FOR_UPDATE
4003          * @return string MW timestamp
4004          */
4005         public function getEarliestRevTime( $flags = 0 ) {
4006                 $rev = $this->getFirstRevision( $flags );
4007                 return $rev ? $rev->getTimestamp() : null;
4008         }
4009
4010         /**
4011          * Check if this is a new page
4012          *
4013          * @return bool
4014          */
4015         public function isNewPage() {
4016                 $dbr = wfGetDB( DB_SLAVE );
4017                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4018         }
4019
4020         /**
4021          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4022          *
4023          * @return bool
4024          */
4025         public function isBigDeletion() {
4026                 global $wgDeleteRevisionsLimit;
4027
4028                 if ( !$wgDeleteRevisionsLimit ) {
4029                         return false;
4030                 }
4031
4032                 if ( $this->mIsBigDeletion === null ) {
4033                         $dbr = wfGetDB( DB_SLAVE );
4034
4035                         $revCount = $dbr->selectRowCount(
4036                                 'revision',
4037                                 '1',
4038                                 array( 'rev_page' => $this->getArticleID() ),
4039                                 __METHOD__,
4040                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4041                         );
4042
4043                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4044                 }
4045
4046                 return $this->mIsBigDeletion;
4047         }
4048
4049         /**
4050          * Get the approximate revision count of this page.
4051          *
4052          * @return int
4053          */
4054         public function estimateRevisionCount() {
4055                 if ( !$this->exists() ) {
4056                         return 0;
4057                 }
4058
4059                 if ( $this->mEstimateRevisions === null ) {
4060                         $dbr = wfGetDB( DB_SLAVE );
4061                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4062                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4063                 }
4064
4065                 return $this->mEstimateRevisions;
4066         }
4067
4068         /**
4069          * Get the number of revisions between the given revision.
4070          * Used for diffs and other things that really need it.
4071          *
4072          * @param int|Revision $old Old revision or rev ID (first before range)
4073          * @param int|Revision $new New revision or rev ID (first after range)
4074          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4075          * @return int Number of revisions between these revisions.
4076          */
4077         public function countRevisionsBetween( $old, $new, $max = null ) {
4078                 if ( !( $old instanceof Revision ) ) {
4079                         $old = Revision::newFromTitle( $this, (int)$old );
4080                 }
4081                 if ( !( $new instanceof Revision ) ) {
4082                         $new = Revision::newFromTitle( $this, (int)$new );
4083                 }
4084                 if ( !$old || !$new ) {
4085                         return 0; // nothing to compare
4086                 }
4087                 $dbr = wfGetDB( DB_SLAVE );
4088                 $conds = array(
4089                         'rev_page' => $this->getArticleID(),
4090                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4091                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4092                 );
4093                 if ( $max !== null ) {
4094                         return $dbr->selectRowCount( 'revision', '1',
4095                                 $conds,
4096                                 __METHOD__,
4097                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4098                         );
4099                 } else {
4100                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4101                 }
4102         }
4103
4104         /**
4105          * Get the authors between the given revisions or revision IDs.
4106          * Used for diffs and other things that really need it.
4107          *
4108          * @since 1.23
4109          *
4110          * @param int|Revision $old Old revision or rev ID (first before range by default)
4111          * @param int|Revision $new New revision or rev ID (first after range by default)
4112          * @param int $limit Maximum number of authors
4113          * @param string|array $options (Optional): Single option, or an array of options:
4114          *     'include_old' Include $old in the range; $new is excluded.
4115          *     'include_new' Include $new in the range; $old is excluded.
4116          *     'include_both' Include both $old and $new in the range.
4117          *     Unknown option values are ignored.
4118          * @return array|null Names of revision authors in the range; null if not both revisions exist
4119          */
4120         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4121                 if ( !( $old instanceof Revision ) ) {
4122                         $old = Revision::newFromTitle( $this, (int)$old );
4123                 }
4124                 if ( !( $new instanceof Revision ) ) {
4125                         $new = Revision::newFromTitle( $this, (int)$new );
4126                 }
4127                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4128                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4129                 // in the sanity check below?
4130                 if ( !$old || !$new ) {
4131                         return null; // nothing to compare
4132                 }
4133                 $authors = array();
4134                 $old_cmp = '>';
4135                 $new_cmp = '<';
4136                 $options = (array)$options;
4137                 if ( in_array( 'include_old', $options ) ) {
4138                         $old_cmp = '>=';
4139                 }
4140                 if ( in_array( 'include_new', $options ) ) {
4141                         $new_cmp = '<=';
4142                 }
4143                 if ( in_array( 'include_both', $options ) ) {
4144                         $old_cmp = '>=';
4145                         $new_cmp = '<=';
4146                 }
4147                 // No DB query needed if $old and $new are the same or successive revisions:
4148                 if ( $old->getId() === $new->getId() ) {
4149                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4150                                 array() :
4151                                 array( $old->getUserText( Revision::RAW ) );
4152                 } elseif ( $old->getId() === $new->getParentId() ) {
4153                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4154                                 $authors[] = $old->getUserText( Revision::RAW );
4155                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4156                                         $authors[] = $new->getUserText( Revision::RAW );
4157                                 }
4158                         } elseif ( $old_cmp === '>=' ) {
4159                                 $authors[] = $old->getUserText( Revision::RAW );
4160                         } elseif ( $new_cmp === '<=' ) {
4161                                 $authors[] = $new->getUserText( Revision::RAW );
4162                         }
4163                         return $authors;
4164                 }
4165                 $dbr = wfGetDB( DB_SLAVE );
4166                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4167                         array(
4168                                 'rev_page' => $this->getArticleID(),
4169                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4170                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4171                         ), __METHOD__,
4172                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4173                 );
4174                 foreach ( $res as $row ) {
4175                         $authors[] = $row->rev_user_text;
4176                 }
4177                 return $authors;
4178         }
4179
4180         /**
4181          * Get the number of authors between the given revisions or revision IDs.
4182          * Used for diffs and other things that really need it.
4183          *
4184          * @param int|Revision $old Old revision or rev ID (first before range by default)
4185          * @param int|Revision $new New revision or rev ID (first after range by default)
4186          * @param int $limit Maximum number of authors
4187          * @param string|array $options (Optional): Single option, or an array of options:
4188          *     'include_old' Include $old in the range; $new is excluded.
4189          *     'include_new' Include $new in the range; $old is excluded.
4190          *     'include_both' Include both $old and $new in the range.
4191          *     Unknown option values are ignored.
4192          * @return int Number of revision authors in the range; zero if not both revisions exist
4193          */
4194         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4195                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4196                 return $authors ? count( $authors ) : 0;
4197         }
4198
4199         /**
4200          * Compare with another title.
4201          *
4202          * @param Title $title
4203          * @return bool
4204          */
4205         public function equals( Title $title ) {
4206                 // Note: === is necessary for proper matching of number-like titles.
4207                 return $this->getInterwiki() === $title->getInterwiki()
4208                         && $this->getNamespace() == $title->getNamespace()
4209                         && $this->getDBkey() === $title->getDBkey();
4210         }
4211
4212         /**
4213          * Check if this title is a subpage of another title
4214          *
4215          * @param Title $title
4216          * @return bool
4217          */
4218         public function isSubpageOf( Title $title ) {
4219                 return $this->getInterwiki() === $title->getInterwiki()
4220                         && $this->getNamespace() == $title->getNamespace()
4221                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4222         }
4223
4224         /**
4225          * Check if page exists.  For historical reasons, this function simply
4226          * checks for the existence of the title in the page table, and will
4227          * thus return false for interwiki links, special pages and the like.
4228          * If you want to know if a title can be meaningfully viewed, you should
4229          * probably call the isKnown() method instead.
4230          *
4231          * @return bool
4232          */
4233         public function exists() {
4234                 $exists = $this->getArticleID() != 0;
4235                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4236                 return $exists;
4237         }
4238
4239         /**
4240          * Should links to this title be shown as potentially viewable (i.e. as
4241          * "bluelinks"), even if there's no record by this title in the page
4242          * table?
4243          *
4244          * This function is semi-deprecated for public use, as well as somewhat
4245          * misleadingly named.  You probably just want to call isKnown(), which
4246          * calls this function internally.
4247          *
4248          * (ISSUE: Most of these checks are cheap, but the file existence check
4249          * can potentially be quite expensive.  Including it here fixes a lot of
4250          * existing code, but we might want to add an optional parameter to skip
4251          * it and any other expensive checks.)
4252          *
4253          * @return bool
4254          */
4255         public function isAlwaysKnown() {
4256                 $isKnown = null;
4257
4258                 /**
4259                  * Allows overriding default behavior for determining if a page exists.
4260                  * If $isKnown is kept as null, regular checks happen. If it's
4261                  * a boolean, this value is returned by the isKnown method.
4262                  *
4263                  * @since 1.20
4264                  *
4265                  * @param Title $title
4266                  * @param bool|null $isKnown
4267                  */
4268                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4269
4270                 if ( !is_null( $isKnown ) ) {
4271                         return $isKnown;
4272                 }
4273
4274                 if ( $this->isExternal() ) {
4275                         return true;  // any interwiki link might be viewable, for all we know
4276                 }
4277
4278                 switch ( $this->mNamespace ) {
4279                         case NS_MEDIA:
4280                         case NS_FILE:
4281                                 // file exists, possibly in a foreign repo
4282                                 return (bool)wfFindFile( $this );
4283                         case NS_SPECIAL:
4284                                 // valid special page
4285                                 return SpecialPageFactory::exists( $this->getDBkey() );
4286                         case NS_MAIN:
4287                                 // selflink, possibly with fragment
4288                                 return $this->mDbkeyform == '';
4289                         case NS_MEDIAWIKI:
4290                                 // known system message
4291                                 return $this->hasSourceText() !== false;
4292                         default:
4293                                 return false;
4294                 }
4295         }
4296
4297         /**
4298          * Does this title refer to a page that can (or might) be meaningfully
4299          * viewed?  In particular, this function may be used to determine if
4300          * links to the title should be rendered as "bluelinks" (as opposed to
4301          * "redlinks" to non-existent pages).
4302          * Adding something else to this function will cause inconsistency
4303          * since LinkHolderArray calls isAlwaysKnown() and does its own
4304          * page existence check.
4305          *
4306          * @return bool
4307          */
4308         public function isKnown() {
4309                 return $this->isAlwaysKnown() || $this->exists();
4310         }
4311
4312         /**
4313          * Does this page have source text?
4314          *
4315          * @return bool
4316          */
4317         public function hasSourceText() {
4318                 if ( $this->exists() ) {
4319                         return true;
4320                 }
4321
4322                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4323                         // If the page doesn't exist but is a known system message, default
4324                         // message content will be displayed, same for language subpages-
4325                         // Use always content language to avoid loading hundreds of languages
4326                         // to get the link color.
4327                         global $wgContLang;
4328                         list( $name, ) = MessageCache::singleton()->figureMessage(
4329                                 $wgContLang->lcfirst( $this->getText() )
4330                         );
4331                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4332                         return $message->exists();
4333                 }
4334
4335                 return false;
4336         }
4337
4338         /**
4339          * Get the default message text or false if the message doesn't exist
4340          *
4341          * @return string|bool
4342          */
4343         public function getDefaultMessageText() {
4344                 global $wgContLang;
4345
4346                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4347                         return false;
4348                 }
4349
4350                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4351                         $wgContLang->lcfirst( $this->getText() )
4352                 );
4353                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4354
4355                 if ( $message->exists() ) {
4356                         return $message->plain();
4357                 } else {
4358                         return false;
4359                 }
4360         }
4361
4362         /**
4363          * Updates page_touched for this page; called from LinksUpdate.php
4364          *
4365          * @return bool True if the update succeeded
4366          */
4367         public function invalidateCache() {
4368                 if ( wfReadOnly() ) {
4369                         return false;
4370                 }
4371
4372                 if ( $this->mArticleID === 0 ) {
4373                         return true; // avoid gap locking if we know it's not there
4374                 }
4375
4376                 $method = __METHOD__;
4377                 $dbw = wfGetDB( DB_MASTER );
4378                 $conds = $this->pageCond();
4379                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method ) {
4380                         $dbw->update(
4381                                 'page',
4382                                 array( 'page_touched' => $dbw->timestamp() ),
4383                                 $conds,
4384                                 $method
4385                         );
4386                 } );
4387
4388                 return true;
4389         }
4390
4391         /**
4392          * Update page_touched timestamps and send squid purge messages for
4393          * pages linking to this title. May be sent to the job queue depending
4394          * on the number of links. Typically called on create and delete.
4395          */
4396         public function touchLinks() {
4397                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4398                 $u->doUpdate();
4399
4400                 if ( $this->getNamespace() == NS_CATEGORY ) {
4401                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4402                         $u->doUpdate();
4403                 }
4404         }
4405
4406         /**
4407          * Get the last touched timestamp
4408          *
4409          * @param DatabaseBase $db Optional db
4410          * @return string Last-touched timestamp
4411          */
4412         public function getTouched( $db = null ) {
4413                 if ( $db === null ) {
4414                         $db = wfGetDB( DB_SLAVE );
4415                 }
4416                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4417                 return $touched;
4418         }
4419
4420         /**
4421          * Get the timestamp when this page was updated since the user last saw it.
4422          *
4423          * @param User $user
4424          * @return string|null
4425          */
4426         public function getNotificationTimestamp( $user = null ) {
4427                 global $wgUser, $wgShowUpdatedMarker;
4428                 // Assume current user if none given
4429                 if ( !$user ) {
4430                         $user = $wgUser;
4431                 }
4432                 // Check cache first
4433                 $uid = $user->getId();
4434                 // avoid isset here, as it'll return false for null entries
4435                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4436                         return $this->mNotificationTimestamp[$uid];
4437                 }
4438                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4439                         $this->mNotificationTimestamp[$uid] = false;
4440                         return $this->mNotificationTimestamp[$uid];
4441                 }
4442                 // Don't cache too much!
4443                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4444                         $this->mNotificationTimestamp = array();
4445                 }
4446                 $dbr = wfGetDB( DB_SLAVE );
4447                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4448                         'wl_notificationtimestamp',
4449                         array(
4450                                 'wl_user' => $user->getId(),
4451                                 'wl_namespace' => $this->getNamespace(),
4452                                 'wl_title' => $this->getDBkey(),
4453                         ),
4454                         __METHOD__
4455                 );
4456                 return $this->mNotificationTimestamp[$uid];
4457         }
4458
4459         /**
4460          * Generate strings used for xml 'id' names in monobook tabs
4461          *
4462          * @param string $prepend Defaults to 'nstab-'
4463          * @return string XML 'id' name
4464          */
4465         public function getNamespaceKey( $prepend = 'nstab-' ) {
4466                 global $wgContLang;
4467                 // Gets the subject namespace if this title
4468                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4469                 // Checks if canonical namespace name exists for namespace
4470                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4471                         // Uses canonical namespace name
4472                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4473                 } else {
4474                         // Uses text of namespace
4475                         $namespaceKey = $this->getSubjectNsText();
4476                 }
4477                 // Makes namespace key lowercase
4478                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4479                 // Uses main
4480                 if ( $namespaceKey == '' ) {
4481                         $namespaceKey = 'main';
4482                 }
4483                 // Changes file to image for backwards compatibility
4484                 if ( $namespaceKey == 'file' ) {
4485                         $namespaceKey = 'image';
4486                 }
4487                 return $prepend . $namespaceKey;
4488         }
4489
4490         /**
4491          * Get all extant redirects to this Title
4492          *
4493          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4494          * @return Title[] Array of Title redirects to this title
4495          */
4496         public function getRedirectsHere( $ns = null ) {
4497                 $redirs = array();
4498
4499                 $dbr = wfGetDB( DB_SLAVE );
4500                 $where = array(
4501                         'rd_namespace' => $this->getNamespace(),
4502                         'rd_title' => $this->getDBkey(),
4503                         'rd_from = page_id'
4504                 );
4505                 if ( $this->isExternal() ) {
4506                         $where['rd_interwiki'] = $this->getInterwiki();
4507                 } else {
4508                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4509                 }
4510                 if ( !is_null( $ns ) ) {
4511                         $where['page_namespace'] = $ns;
4512                 }
4513
4514                 $res = $dbr->select(
4515                         array( 'redirect', 'page' ),
4516                         array( 'page_namespace', 'page_title' ),
4517                         $where,
4518                         __METHOD__
4519                 );
4520
4521                 foreach ( $res as $row ) {
4522                         $redirs[] = self::newFromRow( $row );
4523                 }
4524                 return $redirs;
4525         }
4526
4527         /**
4528          * Check if this Title is a valid redirect target
4529          *
4530          * @return bool
4531          */
4532         public function isValidRedirectTarget() {
4533                 global $wgInvalidRedirectTargets;
4534
4535                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4536                 if ( $this->isSpecial( 'Userlogout' ) ) {
4537                         return false;
4538                 }
4539
4540                 foreach ( $wgInvalidRedirectTargets as $target ) {
4541                         if ( $this->isSpecial( $target ) ) {
4542                                 return false;
4543                         }
4544                 }
4545
4546                 return true;
4547         }
4548
4549         /**
4550          * Get a backlink cache object
4551          *
4552          * @return BacklinkCache
4553          */
4554         public function getBacklinkCache() {
4555                 return BacklinkCache::get( $this );
4556         }
4557
4558         /**
4559          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4560          *
4561          * @return bool
4562          */
4563         public function canUseNoindex() {
4564                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4565
4566                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4567                         ? $wgContentNamespaces
4568                         : $wgExemptFromUserRobotsControl;
4569
4570                 return !in_array( $this->mNamespace, $bannedNamespaces );
4571
4572         }
4573
4574         /**
4575          * Returns the raw sort key to be used for categories, with the specified
4576          * prefix.  This will be fed to Collation::getSortKey() to get a
4577          * binary sortkey that can be used for actual sorting.
4578          *
4579          * @param string $prefix The prefix to be used, specified using
4580          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4581          *   prefix.
4582          * @return string
4583          */
4584         public function getCategorySortkey( $prefix = '' ) {
4585                 $unprefixed = $this->getText();
4586
4587                 // Anything that uses this hook should only depend
4588                 // on the Title object passed in, and should probably
4589                 // tell the users to run updateCollations.php --force
4590                 // in order to re-sort existing category relations.
4591                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4592                 if ( $prefix !== '' ) {
4593                         # Separate with a line feed, so the unprefixed part is only used as
4594                         # a tiebreaker when two pages have the exact same prefix.
4595                         # In UCA, tab is the only character that can sort above LF
4596                         # so we strip both of them from the original prefix.
4597                         $prefix = strtr( $prefix, "\n\t", '  ' );
4598                         return "$prefix\n$unprefixed";
4599                 }
4600                 return $unprefixed;
4601         }
4602
4603         /**
4604          * Get the language in which the content of this page is written in
4605          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4606          * e.g. $wgLang (such as special pages, which are in the user language).
4607          *
4608          * @since 1.18
4609          * @return Language
4610          */
4611         public function getPageLanguage() {
4612                 global $wgLang, $wgLanguageCode;
4613                 if ( $this->isSpecialPage() ) {
4614                         // special pages are in the user language
4615                         return $wgLang;
4616                 }
4617
4618                 // Checking if DB language is set
4619                 if ( $this->mDbPageLanguage ) {
4620                         return wfGetLangObj( $this->mDbPageLanguage );
4621                 }
4622
4623                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4624                         // Note that this may depend on user settings, so the cache should
4625                         // be only per-request.
4626                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4627                         // content to determine the page language!
4628                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4629                         // tests.
4630                         $contentHandler = ContentHandler::getForTitle( $this );
4631                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4632                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4633                 } else {
4634                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4635                 }
4636
4637                 return $langObj;
4638         }
4639
4640         /**
4641          * Get the language in which the content of this page is written when
4642          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4643          * e.g. $wgLang (such as special pages, which are in the user language).
4644          *
4645          * @since 1.20
4646          * @return Language
4647          */
4648         public function getPageViewLanguage() {
4649                 global $wgLang;
4650
4651                 if ( $this->isSpecialPage() ) {
4652                         // If the user chooses a variant, the content is actually
4653                         // in a language whose code is the variant code.
4654                         $variant = $wgLang->getPreferredVariant();
4655                         if ( $wgLang->getCode() !== $variant ) {
4656                                 return Language::factory( $variant );
4657                         }
4658
4659                         return $wgLang;
4660                 }
4661
4662                 // @note Can't be cached persistently, depends on user settings.
4663                 // @note ContentHandler::getPageViewLanguage() may need to load the
4664                 //   content to determine the page language!
4665                 $contentHandler = ContentHandler::getForTitle( $this );
4666                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4667                 return $pageLang;
4668         }
4669
4670         /**
4671          * Get a list of rendered edit notices for this page.
4672          *
4673          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4674          * they will already be wrapped in paragraphs.
4675          *
4676          * @since 1.21
4677          * @param int $oldid Revision ID that's being edited
4678          * @return array
4679          */
4680         public function getEditNotices( $oldid = 0 ) {
4681                 $notices = array();
4682
4683                 // Optional notice for the entire namespace
4684                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4685                 $msg = wfMessage( $editnotice_ns );
4686                 if ( $msg->exists() ) {
4687                         $html = $msg->parseAsBlock();
4688                         // Edit notices may have complex logic, but output nothing (T91715)
4689                         if ( trim( $html ) !== '' ) {
4690                                 $notices[$editnotice_ns] = Html::rawElement(
4691                                         'div',
4692                                         array( 'class' => array(
4693                                                 'mw-editnotice',
4694                                                 'mw-editnotice-namespace',
4695                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4696                                         ) ),
4697                                         $html
4698                                 );
4699                         }
4700                 }
4701
4702                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4703                         // Optional notice for page itself and any parent page
4704                         $parts = explode( '/', $this->getDBkey() );
4705                         $editnotice_base = $editnotice_ns;
4706                         while ( count( $parts ) > 0 ) {
4707                                 $editnotice_base .= '-' . array_shift( $parts );
4708                                 $msg = wfMessage( $editnotice_base );
4709                                 if ( $msg->exists() ) {
4710                                         $html = $msg->parseAsBlock();
4711                                         if ( trim( $html ) !== '' ) {
4712                                                 $notices[$editnotice_base] = Html::rawElement(
4713                                                         'div',
4714                                                         array( 'class' => array(
4715                                                                 'mw-editnotice',
4716                                                                 'mw-editnotice-base',
4717                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4718                                                         ) ),
4719                                                         $html
4720                                                 );
4721                                         }
4722                                 }
4723                         }
4724                 } else {
4725                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4726                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4727                         $msg = wfMessage( $editnoticeText );
4728                         if ( $msg->exists() ) {
4729                                 $html = $msg->parseAsBlock();
4730                                 if ( trim( $html ) !== '' ) {
4731                                         $notices[$editnoticeText] = Html::rawElement(
4732                                                 'div',
4733                                                 array( 'class' => array(
4734                                                         'mw-editnotice',
4735                                                         'mw-editnotice-page',
4736                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4737                                                 ) ),
4738                                                 $html
4739                                         );
4740                                 }
4741                         }
4742                 }
4743
4744                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4745                 return $notices;
4746         }
4747 }