includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  */
  33 class Title {
  34         /** @var MapCacheLRU */
  35         static private $titleCache = null;
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         /** @var string Text form (spaces not underscores) of the main part */
  58         public $mTextform = '';
  59
  60         /** @var string URL-encoded form of the main part */
  61         public $mUrlform = '';
  62
  63         /** @var string Main part with underscores */
  64         public $mDbkeyform = '';
  65
  66         /** @var string Database key with the initial letter in the case specified by the user */
  67         protected $mUserCaseDBKey;
  68
  69         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  70         public $mNamespace = NS_MAIN;
  71
  72         /** @var string Interwiki prefix */
  73         public $mInterwiki = '';
  74
  75         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  76         private $mLocalInterwiki = false;
  77
  78         /** @var string Title fragment (i.e. the bit after the #) */
  79         public $mFragment = '';
  80
  81         /** @var int Article ID, fetched from the link cache on demand */
  82         public $mArticleID = -1;
  83
  84         /** @var bool|int ID of most recent revision */
  85         protected $mLatestID = false;
  86
  87         /**
  88          * @var bool|string ID of the page's content model, i.e. one of the
  89          *   CONTENT_MODEL_XXX constants
  90          */
  91         public $mContentModel = false;
  92
  93         /** @var int Estimated number of revisions; null of not loaded */
  94         private $mEstimateRevisions;
  95
  96         /** @var array Array of groups allowed to edit this article */
  97         public $mRestrictions = array();
  98
  99         /** @var bool */
 100         protected $mOldRestrictions = false;
 101
 102         /** @var bool Cascade restrictions on this page to included templates and images? */
 103         public $mCascadeRestriction;
 104
 105         /** Caching the results of getCascadeProtectionSources */
 106         public $mCascadingRestrictions;
 107
 108         /** @var array When do the restrictions on this page expire? */
 109         protected $mRestrictionsExpiry = array();
 110
 111         /** @var bool Are cascading restrictions in effect on this page? */
 112         protected $mHasCascadingRestrictions;
 113
 114         /** @var array Where are the cascading restrictions coming from on this page? */
 115         public $mCascadeSources;
 116
 117         /** @var bool Boolean for initialisation on demand */
 118         public $mRestrictionsLoaded = false;
 119
 120         /** @var string Text form including namespace/interwiki, initialised on demand */
 121         protected $mPrefixedText = null;
 122
 123         /** @var mixed Cached value for getTitleProtection (create protection) */
 124         public $mTitleProtection;
 125
 126         /**
 127          * @var int Namespace index when there is no namespace. Don't change the
 128          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 129          *   Zero except in {{transclusion}} tags.
 130          */
 131         public $mDefaultNamespace = NS_MAIN;
 132
 133         /**
 134          * @var bool Is $wgUser watching this page? null if unfilled, accessed
 135          * through userIsWatching()
 136          */
 137         protected $mWatched = null;
 138
 139         /** @var int The page length, 0 for special pages */
 140         protected $mLength = -1;
 141
 142         /** @var null Is the article at this title a redirect? */
 143         public $mRedirect = null;
 144
 145         /** @var array Associative array of user ID -> timestamp/false */
 146         private $mNotificationTimestamp = array();
 147
 148         /** @var bool Whether a page has any subpages */
 149         private $mHasSubpages;
 150
 151         /** @var bool The (string) language code of the page's language and content code. */
 152         private $mPageLanguage = false;
 153
 154         /** @var string The page language code from the database */
 155         private $mDbPageLanguage = null;
 156
 157         /** @var TitleValue A corresponding TitleValue object */
 158         private $mTitleValue = null;
 159
 160         /** @var bool Would deleting this page be a big deletion? */
 161         private $mIsBigDeletion = null;
 162         // @}
 163
 164         /**
 165          * B/C kludge: provide a TitleParser for use by Title.
 166          * Ideally, Title would have no methods that need this.
 167          * Avoid usage of this singleton by using TitleValue
 168          * and the associated services when possible.
 169          *
 170          * @return TitleParser
 171          */
 172         private static function getTitleParser() {
 173                 global $wgContLang, $wgLocalInterwikis;
 174
 175                 static $titleCodec = null;
 176                 static $titleCodecFingerprint = null;
 177
 178                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 179                 // make sure we are using the right one. To detect changes over the course
 180                 // of a request, we remember a fingerprint of the config used to create the
 181                 // codec singleton, and re-create it if the fingerprint doesn't match.
 182                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 183
 184                 if ( $fingerprint !== $titleCodecFingerprint ) {
 185                         $titleCodec = null;
 186                 }
 187
 188                 if ( !$titleCodec ) {
 189                         $titleCodec = new MediaWikiTitleCodec(
 190                                 $wgContLang,
 191                                 GenderCache::singleton(),
 192                                 $wgLocalInterwikis
 193                         );
 194                         $titleCodecFingerprint = $fingerprint;
 195                 }
 196
 197                 return $titleCodec;
 198         }
 199
 200         /**
 201          * B/C kludge: provide a TitleParser for use by Title.
 202          * Ideally, Title would have no methods that need this.
 203          * Avoid usage of this singleton by using TitleValue
 204          * and the associated services when possible.
 205          *
 206          * @return TitleFormatter
 207          */
 208         private static function getTitleFormatter() {
 209                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 210                 //      which implements TitleFormatter.
 211                 return self::getTitleParser();
 212         }
 213
 214         function __construct() {
 215         }
 216
 217         /**
 218          * Create a new Title from a prefixed DB key
 219          *
 220          * @param string $key The database key, which has underscores
 221          *      instead of spaces, possibly including namespace and
 222          *      interwiki prefixes
 223          * @return Title|null Title, or null on an error
 224          */
 225         public static function newFromDBkey( $key ) {
 226                 $t = new Title();
 227                 $t->mDbkeyform = $key;
 228                 if ( $t->secureAndSplit() ) {
 229                         return $t;
 230                 } else {
 231                         return null;
 232                 }
 233         }
 234
 235         /**
 236          * Create a new Title from a TitleValue
 237          *
 238          * @param TitleValue $titleValue Assumed to be safe.
 239          *
 240          * @return Title
 241          */
 242         public static function newFromTitleValue( TitleValue $titleValue ) {
 243                 return self::makeTitle(
 244                         $titleValue->getNamespace(),
 245                         $titleValue->getText(),
 246                         $titleValue->getFragment() );
 247         }
 248
 249         /**
 250          * Create a new Title from text, such as what one would find in a link. De-
 251          * codes any HTML entities in the text.
 252          *
 253          * @param string $text The link text; spaces, prefixes, and an
 254          *   initial ':' indicating the main namespace are accepted.
 255          * @param int $defaultNamespace The namespace to use if none is specified
 256          *   by a prefix.  If you want to force a specific namespace even if
 257          *   $text might begin with a namespace prefix, use makeTitle() or
 258          *   makeTitleSafe().
 259          * @throws MWException
 260          * @return Title|null Title or null on an error.
 261          */
 262         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 263                 if ( is_object( $text ) ) {
 264                         throw new MWException( 'Title::newFromText given an object' );
 265                 }
 266
 267                 $cache = self::getTitleCache();
 268
 269                 /**
 270                  * Wiki pages often contain multiple links to the same page.
 271                  * Title normalization and parsing can become expensive on
 272                  * pages with many links, so we can save a little time by
 273                  * caching them.
 274                  *
 275                  * In theory these are value objects and won't get changed...
 276                  */
 277                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 278                         return $cache->get( $text );
 279                 }
 280
 281                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 282                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 283
 284                 $t = new Title();
 285                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 286                 $t->mDefaultNamespace = intval( $defaultNamespace );
 287
 288                 if ( $t->secureAndSplit() ) {
 289                         if ( $defaultNamespace == NS_MAIN ) {
 290                                 $cache->set( $text, $t );
 291                         }
 292                         return $t;
 293                 } else {
 294                         return null;
 295                 }
 296         }
 297
 298         /**
 299          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 300          *
 301          * Example of wrong and broken code:
 302          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 303          *
 304          * Example of right code:
 305          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 306          *
 307          * Create a new Title from URL-encoded text. Ensures that
 308          * the given title's length does not exceed the maximum.
 309          *
 310          * @param string $url The title, as might be taken from a URL
 311          * @return Title|null The new object, or null on an error
 312          */
 313         public static function newFromURL( $url ) {
 314                 $t = new Title();
 315
 316                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 317                 # but some URLs used it as a space replacement and they still come
 318                 # from some external search tools.
 319                 if ( strpos( self::legalChars(), '+' ) === false ) {
 320                         $url = str_replace( '+', ' ', $url );
 321                 }
 322
 323                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 324                 if ( $t->secureAndSplit() ) {
 325                         return $t;
 326                 } else {
 327                         return null;
 328                 }
 329         }
 330
 331         /**
 332          * @return MapCacheLRU
 333          */
 334         private static function getTitleCache() {
 335                 if ( self::$titleCache == null ) {
 336                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 337                 }
 338                 return self::$titleCache;
 339         }
 340
 341         /**
 342          * Returns a list of fields that are to be selected for initializing Title
 343          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 344          * whether to include page_content_model.
 345          *
 346          * @return array
 347          */
 348         protected static function getSelectFields() {
 349                 global $wgContentHandlerUseDB;
 350
 351                 $fields = array(
 352                         'page_namespace', 'page_title', 'page_id',
 353                         'page_len', 'page_is_redirect', 'page_latest',
 354                 );
 355
 356                 if ( $wgContentHandlerUseDB ) {
 357                         $fields[] = 'page_content_model';
 358                 }
 359
 360                 return $fields;
 361         }
 362
 363         /**
 364          * Create a new Title from an article ID
 365          *
 366          * @param int $id The page_id corresponding to the Title to create
 367          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 368          * @return Title|null The new object, or null on an error
 369          */
 370         public static function newFromID( $id, $flags = 0 ) {
 371                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 372                 $row = $db->selectRow(
 373                         'page',
 374                         self::getSelectFields(),
 375                         array( 'page_id' => $id ),
 376                         __METHOD__
 377                 );
 378                 if ( $row !== false ) {
 379                         $title = Title::newFromRow( $row );
 380                 } else {
 381                         $title = null;
 382                 }
 383                 return $title;
 384         }
 385
 386         /**
 387          * Make an array of titles from an array of IDs
 388          *
 389          * @param int[] $ids Array of IDs
 390          * @return Title[] Array of Titles
 391          */
 392         public static function newFromIDs( $ids ) {
 393                 if ( !count( $ids ) ) {
 394                         return array();
 395                 }
 396                 $dbr = wfGetDB( DB_SLAVE );
 397
 398                 $res = $dbr->select(
 399                         'page',
 400                         self::getSelectFields(),
 401                         array( 'page_id' => $ids ),
 402                         __METHOD__
 403                 );
 404
 405                 $titles = array();
 406                 foreach ( $res as $row ) {
 407                         $titles[] = Title::newFromRow( $row );
 408                 }
 409                 return $titles;
 410         }
 411
 412         /**
 413          * Make a Title object from a DB row
 414          *
 415          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 416          * @return Title Corresponding Title
 417          */
 418         public static function newFromRow( $row ) {
 419                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 420                 $t->loadFromRow( $row );
 421                 return $t;
 422         }
 423
 424         /**
 425          * Load Title object fields from a DB row.
 426          * If false is given, the title will be treated as non-existing.
 427          *
 428          * @param stdClass|bool $row Database row
 429          */
 430         public function loadFromRow( $row ) {
 431                 if ( $row ) { // page found
 432                         if ( isset( $row->page_id ) ) {
 433                                 $this->mArticleID = (int)$row->page_id;
 434                         }
 435                         if ( isset( $row->page_len ) ) {
 436                                 $this->mLength = (int)$row->page_len;
 437                         }
 438                         if ( isset( $row->page_is_redirect ) ) {
 439                                 $this->mRedirect = (bool)$row->page_is_redirect;
 440                         }
 441                         if ( isset( $row->page_latest ) ) {
 442                                 $this->mLatestID = (int)$row->page_latest;
 443                         }
 444                         if ( isset( $row->page_content_model ) ) {
 445                                 $this->mContentModel = strval( $row->page_content_model );
 446                         } else {
 447                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 448                         }
 449                         if ( isset( $row->page_lang ) ) {
 450                                 $this->mDbPageLanguage = (string)$row->page_lang;
 451                         }
 452                 } else { // page not found
 453                         $this->mArticleID = 0;
 454                         $this->mLength = 0;
 455                         $this->mRedirect = false;
 456                         $this->mLatestID = 0;
 457                         $this->mContentModel = false; # initialized lazily in getContentModel()
 458                 }
 459         }
 460
 461         /**
 462          * Create a new Title from a namespace index and a DB key.
 463          * It's assumed that $ns and $title are *valid*, for instance when
 464          * they came directly from the database or a special page name.
 465          * For convenience, spaces are converted to underscores so that
 466          * eg user_text fields can be used directly.
 467          *
 468          * @param int $ns The namespace of the article
 469          * @param string $title The unprefixed database key form
 470          * @param string $fragment The link fragment (after the "#")
 471          * @param string $interwiki The interwiki prefix
 472          * @return Title The new object
 473          */
 474         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 475                 $t = new Title();
 476                 $t->mInterwiki = $interwiki;
 477                 $t->mFragment = $fragment;
 478                 $t->mNamespace = $ns = intval( $ns );
 479                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 480                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 481                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 482                 $t->mTextform = str_replace( '_', ' ', $title );
 483                 $t->mContentModel = false; # initialized lazily in getContentModel()
 484                 return $t;
 485         }
 486
 487         /**
 488          * Create a new Title from a namespace index and a DB key.
 489          * The parameters will be checked for validity, which is a bit slower
 490          * than makeTitle() but safer for user-provided data.
 491          *
 492          * @param int $ns The namespace of the article
 493          * @param string $title Database key form
 494          * @param string $fragment The link fragment (after the "#")
 495          * @param string $interwiki Interwiki prefix
 496          * @return Title The new object, or null on an error
 497          */
 498         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 499                 if ( !MWNamespace::exists( $ns ) ) {
 500                         return null;
 501                 }
 502
 503                 $t = new Title();
 504                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 505                 if ( $t->secureAndSplit() ) {
 506                         return $t;
 507                 } else {
 508                         return null;
 509                 }
 510         }
 511
 512         /**
 513          * Create a new Title for the Main Page
 514          *
 515          * @return Title The new object
 516          */
 517         public static function newMainPage() {
 518                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 519                 // Don't give fatal errors if the message is broken
 520                 if ( !$title ) {
 521                         $title = Title::newFromText( 'Main Page' );
 522                 }
 523                 return $title;
 524         }
 525
 526         /**
 527          * Extract a redirect destination from a string and return the
 528          * Title, or null if the text doesn't contain a valid redirect
 529          * This will only return the very next target, useful for
 530          * the redirect table and other checks that don't need full recursion
 531          *
 532          * @param string $text Text with possible redirect
 533          * @return Title The corresponding Title
 534          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 535          */
 536         public static function newFromRedirect( $text ) {
 537                 ContentHandler::deprecated( __METHOD__, '1.21' );
 538
 539                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 540                 return $content->getRedirectTarget();
 541         }
 542
 543         /**
 544          * Extract a redirect destination from a string and return the
 545          * Title, or null if the text doesn't contain a valid redirect
 546          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 547          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 548          *
 549          * @param string $text Text with possible redirect
 550          * @return Title
 551          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 552          */
 553         public static function newFromRedirectRecurse( $text ) {
 554                 ContentHandler::deprecated( __METHOD__, '1.21' );
 555
 556                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 557                 return $content->getUltimateRedirectTarget();
 558         }
 559
 560         /**
 561          * Extract a redirect destination from a string and return an
 562          * array of Titles, or null if the text doesn't contain a valid redirect
 563          * The last element in the array is the final destination after all redirects
 564          * have been resolved (up to $wgMaxRedirects times)
 565          *
 566          * @param string $text Text with possible redirect
 567          * @return Title[] Array of Titles, with the destination last
 568          * @deprecated since 1.21, use Content::getRedirectChain instead.
 569          */
 570         public static function newFromRedirectArray( $text ) {
 571                 ContentHandler::deprecated( __METHOD__, '1.21' );
 572
 573                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 574                 return $content->getRedirectChain();
 575         }
 576
 577         /**
 578          * Get the prefixed DB key associated with an ID
 579          *
 580          * @param int $id The page_id of the article
 581          * @return Title|null An object representing the article, or null if no such article was found
 582          */
 583         public static function nameOf( $id ) {
 584                 $dbr = wfGetDB( DB_SLAVE );
 585
 586                 $s = $dbr->selectRow(
 587                         'page',
 588                         array( 'page_namespace', 'page_title' ),
 589                         array( 'page_id' => $id ),
 590                         __METHOD__
 591                 );
 592                 if ( $s === false ) {
 593                         return null;
 594                 }
 595
 596                 $n = self::makeName( $s->page_namespace, $s->page_title );
 597                 return $n;
 598         }
 599
 600         /**
 601          * Get a regex character class describing the legal characters in a link
 602          *
 603          * @return string The list of characters, not delimited
 604          */
 605         public static function legalChars() {
 606                 global $wgLegalTitleChars;
 607                 return $wgLegalTitleChars;
 608         }
 609
 610         /**
 611          * Returns a simple regex that will match on characters and sequences invalid in titles.
 612          * Note that this doesn't pick up many things that could be wrong with titles, but that
 613          * replacing this regex with something valid will make many titles valid.
 614          *
 615          * @todo move this into MediaWikiTitleCodec
 616          *
 617          * @return string Regex string
 618          */
 619         static function getTitleInvalidRegex() {
 620                 static $rxTc = false;
 621                 if ( !$rxTc ) {
 622                         # Matching titles will be held as illegal.
 623                         $rxTc = '/' .
 624                                 # Any character not allowed is forbidden...
 625                                 '[^' . self::legalChars() . ']' .
 626                                 # URL percent encoding sequences interfere with the ability
 627                                 # to round-trip titles -- you can't link to them consistently.
 628                                 '|%[0-9A-Fa-f]{2}' .
 629                                 # XML/HTML character references produce similar issues.
 630                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 631                                 '|&#[0-9]+;' .
 632                                 '|&#x[0-9A-Fa-f]+;' .
 633                                 '/S';
 634                 }
 635
 636                 return $rxTc;
 637         }
 638
 639         /**
 640          * Utility method for converting a character sequence from bytes to Unicode.
 641          *
 642          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 643          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 644          *
 645          * @param string $byteClass
 646          * @return string
 647          */
 648         public static function convertByteClassToUnicodeClass( $byteClass ) {
 649                 $length = strlen( $byteClass );
 650                 // Input token queue
 651                 $x0 = $x1 = $x2 = '';
 652                 // Decoded queue
 653                 $d0 = $d1 = $d2 = '';
 654                 // Decoded integer codepoints
 655                 $ord0 = $ord1 = $ord2 = 0;
 656                 // Re-encoded queue
 657                 $r0 = $r1 = $r2 = '';
 658                 // Output
 659                 $out = '';
 660                 // Flags
 661                 $allowUnicode = false;
 662                 for ( $pos = 0; $pos < $length; $pos++ ) {
 663                         // Shift the queues down
 664                         $x2 = $x1;
 665                         $x1 = $x0;
 666                         $d2 = $d1;
 667                         $d1 = $d0;
 668                         $ord2 = $ord1;
 669                         $ord1 = $ord0;
 670                         $r2 = $r1;
 671                         $r1 = $r0;
 672                         // Load the current input token and decoded values
 673                         $inChar = $byteClass[$pos];
 674                         if ( $inChar == '\\' ) {
 675                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 676                                         $x0 = $inChar . $m[0];
 677                                         $d0 = chr( hexdec( $m[1] ) );
 678                                         $pos += strlen( $m[0] );
 679                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 680                                         $x0 = $inChar . $m[0];
 681                                         $d0 = chr( octdec( $m[0] ) );
 682                                         $pos += strlen( $m[0] );
 683                                 } elseif ( $pos + 1 >= $length ) {
 684                                         $x0 = $d0 = '\\';
 685                                 } else {
 686                                         $d0 = $byteClass[$pos + 1];
 687                                         $x0 = $inChar . $d0;
 688                                         $pos += 1;
 689                                 }
 690                         } else {
 691                                 $x0 = $d0 = $inChar;
 692                         }
 693                         $ord0 = ord( $d0 );
 694                         // Load the current re-encoded value
 695                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 696                                 $r0 = sprintf( '\x%02x', $ord0 );
 697                         } elseif ( $ord0 >= 0x80 ) {
 698                                 // Allow unicode if a single high-bit character appears
 699                                 $r0 = sprintf( '\x%02x', $ord0 );
 700                                 $allowUnicode = true;
 701                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 702                                 $r0 = '\\' . $d0;
 703                         } else {
 704                                 $r0 = $d0;
 705                         }
 706                         // Do the output
 707                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 708                                 // Range
 709                                 if ( $ord2 > $ord0 ) {
 710                                         // Empty range
 711                                 } elseif ( $ord0 >= 0x80 ) {
 712                                         // Unicode range
 713                                         $allowUnicode = true;
 714                                         if ( $ord2 < 0x80 ) {
 715                                                 // Keep the non-unicode section of the range
 716                                                 $out .= "$r2-\\x7F";
 717                                         }
 718                                 } else {
 719                                         // Normal range
 720                                         $out .= "$r2-$r0";
 721                                 }
 722                                 // Reset state to the initial value
 723                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 724                         } elseif ( $ord2 < 0x80 ) {
 725                                 // ASCII character
 726                                 $out .= $r2;
 727                         }
 728                 }
 729                 if ( $ord1 < 0x80 ) {
 730                         $out .= $r1;
 731                 }
 732                 if ( $ord0 < 0x80 ) {
 733                         $out .= $r0;
 734                 }
 735                 if ( $allowUnicode ) {
 736                         $out .= '\u0080-\uFFFF';
 737                 }
 738                 return $out;
 739         }
 740
 741         /**
 742          * Make a prefixed DB key from a DB key and a namespace index
 743          *
 744          * @param int $ns Numerical representation of the namespace
 745          * @param string $title The DB key form the title
 746          * @param string $fragment The link fragment (after the "#")
 747          * @param string $interwiki The interwiki prefix
 748          * @param bool $canoncialNamespace If true, use the canonical name for
 749          *   $ns instead of the localized version.
 750          * @return string The prefixed form of the title
 751          */
 752         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 753                 $canoncialNamespace = false
 754         ) {
 755                 global $wgContLang;
 756
 757                 if ( $canoncialNamespace ) {
 758                         $namespace = MWNamespace::getCanonicalName( $ns );
 759                 } else {
 760                         $namespace = $wgContLang->getNsText( $ns );
 761                 }
 762                 $name = $namespace == '' ? $title : "$namespace:$title";
 763                 if ( strval( $interwiki ) != '' ) {
 764                         $name = "$interwiki:$name";
 765                 }
 766                 if ( strval( $fragment ) != '' ) {
 767                         $name .= '#' . $fragment;
 768                 }
 769                 return $name;
 770         }
 771
 772         /**
 773          * Escape a text fragment, say from a link, for a URL
 774          *
 775          * @param string $fragment Containing a URL or link fragment (after the "#")
 776          * @return string Escaped string
 777          */
 778         static function escapeFragmentForURL( $fragment ) {
 779                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 780                 # fragments appear not to work in IE (at least up to 7) or in at least
 781                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 782                 # to care if they aren't encoded.
 783                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 784         }
 785
 786         /**
 787          * Callback for usort() to do title sorts by (namespace, title)
 788          *
 789          * @param Title $a
 790          * @param Title $b
 791          *
 792          * @return int Result of string comparison, or namespace comparison
 793          */
 794         public static function compare( $a, $b ) {
 795                 if ( $a->getNamespace() == $b->getNamespace() ) {
 796                         return strcmp( $a->getText(), $b->getText() );
 797                 } else {
 798                         return $a->getNamespace() - $b->getNamespace();
 799                 }
 800         }
 801
 802         /**
 803          * Determine whether the object refers to a page within
 804          * this project (either this wiki or a wiki with a local
 805          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 806          *
 807          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 808          */
 809         public function isLocal() {
 810                 if ( $this->isExternal() ) {
 811                         $iw = Interwiki::fetch( $this->mInterwiki );
 812                         if ( $iw ) {
 813                                 return $iw->isLocal();
 814                         }
 815                 }
 816                 return true;
 817         }
 818
 819         /**
 820          * Is this Title interwiki?
 821          *
 822          * @return bool
 823          */
 824         public function isExternal() {
 825                 return $this->mInterwiki !== '';
 826         }
 827
 828         /**
 829          * Get the interwiki prefix
 830          *
 831          * Use Title::isExternal to check if a interwiki is set
 832          *
 833          * @return string Interwiki prefix
 834          */
 835         public function getInterwiki() {
 836                 return $this->mInterwiki;
 837         }
 838
 839         /**
 840          * Was this a local interwiki link?
 841          *
 842          * @return bool
 843          */
 844         public function wasLocalInterwiki() {
 845                 return $this->mLocalInterwiki;
 846         }
 847
 848         /**
 849          * Determine whether the object refers to a page within
 850          * this project and is transcludable.
 851          *
 852          * @return bool True if this is transcludable
 853          */
 854         public function isTrans() {
 855                 if ( !$this->isExternal() ) {
 856                         return false;
 857                 }
 858
 859                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 860         }
 861
 862         /**
 863          * Returns the DB name of the distant wiki which owns the object.
 864          *
 865          * @return string The DB name
 866          */
 867         public function getTransWikiID() {
 868                 if ( !$this->isExternal() ) {
 869                         return false;
 870                 }
 871
 872                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 873         }
 874
 875         /**
 876          * Get a TitleValue object representing this Title.
 877          *
 878          * @note Not all valid Titles have a corresponding valid TitleValue
 879          * (e.g. TitleValues cannot represent page-local links that have a
 880          * fragment but no title text).
 881          *
 882          * @return TitleValue|null
 883          */
 884         public function getTitleValue() {
 885                 if ( $this->mTitleValue === null ) {
 886                         try {
 887                                 $this->mTitleValue = new TitleValue(
 888                                         $this->getNamespace(),
 889                                         $this->getDBkey(),
 890                                         $this->getFragment() );
 891                         } catch ( InvalidArgumentException $ex ) {
 892                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 893                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 894                         }
 895                 }
 896
 897                 return $this->mTitleValue;
 898         }
 899
 900         /**
 901          * Get the text form (spaces not underscores) of the main part
 902          *
 903          * @return string Main part of the title
 904          */
 905         public function getText() {
 906                 return $this->mTextform;
 907         }
 908
 909         /**
 910          * Get the URL-encoded form of the main part
 911          *
 912          * @return string Main part of the title, URL-encoded
 913          */
 914         public function getPartialURL() {
 915                 return $this->mUrlform;
 916         }
 917
 918         /**
 919          * Get the main part with underscores
 920          *
 921          * @return string Main part of the title, with underscores
 922          */
 923         public function getDBkey() {
 924                 return $this->mDbkeyform;
 925         }
 926
 927         /**
 928          * Get the DB key with the initial letter case as specified by the user
 929          *
 930          * @return string DB key
 931          */
 932         function getUserCaseDBKey() {
 933                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 934                         return $this->mUserCaseDBKey;
 935                 } else {
 936                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 937                         return $this->mDbkeyform;
 938                 }
 939         }
 940
 941         /**
 942          * Get the namespace index, i.e. one of the NS_xxxx constants.
 943          *
 944          * @return int Namespace index
 945          */
 946         public function getNamespace() {
 947                 return $this->mNamespace;
 948         }
 949
 950         /**
 951          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 952          *
 953          * @throws MWException
 954          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 955          * @return string Content model id
 956          */
 957         public function getContentModel( $flags = 0 ) {
 958                 # Calling getArticleID() loads the field from cache as needed
 959                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 960                         $linkCache = LinkCache::singleton();
 961                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 962                 }
 963
 964                 if ( !$this->mContentModel ) {
 965                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 966                 }
 967
 968                 if ( !$this->mContentModel ) {
 969                         throw new MWException( 'Failed to determine content model!' );
 970                 }
 971
 972                 return $this->mContentModel;
 973         }
 974
 975         /**
 976          * Convenience method for checking a title's content model name
 977          *
 978          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 979          * @return bool True if $this->getContentModel() == $id
 980          */
 981         public function hasContentModel( $id ) {
 982                 return $this->getContentModel() == $id;
 983         }
 984
 985         /**
 986          * Get the namespace text
 987          *
 988          * @return string Namespace text
 989          */
 990         public function getNsText() {
 991                 if ( $this->isExternal() ) {
 992                         // This probably shouldn't even happen. ohh man, oh yuck.
 993                         // But for interwiki transclusion it sometimes does.
 994                         // Shit. Shit shit shit.
 995                         //
 996                         // Use the canonical namespaces if possible to try to
 997                         // resolve a foreign namespace.
 998                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 999                                 return MWNamespace::getCanonicalName( $this->mNamespace );
1000                         }
1001                 }
1002
1003                 try {
1004                         $formatter = self::getTitleFormatter();
1005                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
1006                 } catch ( InvalidArgumentException $ex ) {
1007                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1008                         return false;
1009                 }
1010         }
1011
1012         /**
1013          * Get the namespace text of the subject (rather than talk) page
1014          *
1015          * @return string Namespace text
1016          */
1017         public function getSubjectNsText() {
1018                 global $wgContLang;
1019                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1020         }
1021
1022         /**
1023          * Get the namespace text of the talk page
1024          *
1025          * @return string Namespace text
1026          */
1027         public function getTalkNsText() {
1028                 global $wgContLang;
1029                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1030         }
1031
1032         /**
1033          * Could this title have a corresponding talk page?
1034          *
1035          * @return bool
1036          */
1037         public function canTalk() {
1038                 return MWNamespace::canTalk( $this->mNamespace );
1039         }
1040
1041         /**
1042          * Is this in a namespace that allows actual pages?
1043          *
1044          * @return bool
1045          */
1046         public function canExist() {
1047                 return $this->mNamespace >= NS_MAIN;
1048         }
1049
1050         /**
1051          * Can this title be added to a user's watchlist?
1052          *
1053          * @return bool
1054          */
1055         public function isWatchable() {
1056                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1057         }
1058
1059         /**
1060          * Returns true if this is a special page.
1061          *
1062          * @return bool
1063          */
1064         public function isSpecialPage() {
1065                 return $this->getNamespace() == NS_SPECIAL;
1066         }
1067
1068         /**
1069          * Returns true if this title resolves to the named special page
1070          *
1071          * @param string $name The special page name
1072          * @return bool
1073          */
1074         public function isSpecial( $name ) {
1075                 if ( $this->isSpecialPage() ) {
1076                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1077                         if ( $name == $thisName ) {
1078                                 return true;
1079                         }
1080                 }
1081                 return false;
1082         }
1083
1084         /**
1085          * If the Title refers to a special page alias which is not the local default, resolve
1086          * the alias, and localise the name as necessary.  Otherwise, return $this
1087          *
1088          * @return Title
1089          */
1090         public function fixSpecialName() {
1091                 if ( $this->isSpecialPage() ) {
1092                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1093                         if ( $canonicalName ) {
1094                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1095                                 if ( $localName != $this->mDbkeyform ) {
1096                                         return Title::makeTitle( NS_SPECIAL, $localName );
1097                                 }
1098                         }
1099                 }
1100                 return $this;
1101         }
1102
1103         /**
1104          * Returns true if the title is inside the specified namespace.
1105          *
1106          * Please make use of this instead of comparing to getNamespace()
1107          * This function is much more resistant to changes we may make
1108          * to namespaces than code that makes direct comparisons.
1109          * @param int $ns The namespace
1110          * @return bool
1111          * @since 1.19
1112          */
1113         public function inNamespace( $ns ) {
1114                 return MWNamespace::equals( $this->getNamespace(), $ns );
1115         }
1116
1117         /**
1118          * Returns true if the title is inside one of the specified namespaces.
1119          *
1120          * @param int $namespaces,... The namespaces to check for
1121          * @return bool
1122          * @since 1.19
1123          */
1124         public function inNamespaces( /* ... */ ) {
1125                 $namespaces = func_get_args();
1126                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1127                         $namespaces = $namespaces[0];
1128                 }
1129
1130                 foreach ( $namespaces as $ns ) {
1131                         if ( $this->inNamespace( $ns ) ) {
1132                                 return true;
1133                         }
1134                 }
1135
1136                 return false;
1137         }
1138
1139         /**
1140          * Returns true if the title has the same subject namespace as the
1141          * namespace specified.
1142          * For example this method will take NS_USER and return true if namespace
1143          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1144          * as their subject namespace.
1145          *
1146          * This is MUCH simpler than individually testing for equivalence
1147          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1148          * @since 1.19
1149          * @param int $ns
1150          * @return bool
1151          */
1152         public function hasSubjectNamespace( $ns ) {
1153                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1154         }
1155
1156         /**
1157          * Is this Title in a namespace which contains content?
1158          * In other words, is this a content page, for the purposes of calculating
1159          * statistics, etc?
1160          *
1161          * @return bool
1162          */
1163         public function isContentPage() {
1164                 return MWNamespace::isContent( $this->getNamespace() );
1165         }
1166
1167         /**
1168          * Would anybody with sufficient privileges be able to move this page?
1169          * Some pages just aren't movable.
1170          *
1171          * @return bool
1172          */
1173         public function isMovable() {
1174                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1175                         // Interwiki title or immovable namespace. Hooks don't get to override here
1176                         return false;
1177                 }
1178
1179                 $result = true;
1180                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1181                 return $result;
1182         }
1183
1184         /**
1185          * Is this the mainpage?
1186          * @note Title::newFromText seems to be sufficiently optimized by the title
1187          * cache that we don't need to over-optimize by doing direct comparisons and
1188          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1189          * ends up reporting something differently than $title->isMainPage();
1190          *
1191          * @since 1.18
1192          * @return bool
1193          */
1194         public function isMainPage() {
1195                 return $this->equals( Title::newMainPage() );
1196         }
1197
1198         /**
1199          * Is this a subpage?
1200          *
1201          * @return bool
1202          */
1203         public function isSubpage() {
1204                 return MWNamespace::hasSubpages( $this->mNamespace )
1205                         ? strpos( $this->getText(), '/' ) !== false
1206                         : false;
1207         }
1208
1209         /**
1210          * Is this a conversion table for the LanguageConverter?
1211          *
1212          * @return bool
1213          */
1214         public function isConversionTable() {
1215                 // @todo ConversionTable should become a separate content model.
1216
1217                 return $this->getNamespace() == NS_MEDIAWIKI &&
1218                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1219         }
1220
1221         /**
1222          * Does that page contain wikitext, or it is JS, CSS or whatever?
1223          *
1224          * @return bool
1225          */
1226         public function isWikitextPage() {
1227                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1228         }
1229
1230         /**
1231          * Could this page contain custom CSS or JavaScript for the global UI.
1232          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1233          * or CONTENT_MODEL_JAVASCRIPT.
1234          *
1235          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1236          * for that!
1237          *
1238          * Note that this method should not return true for pages that contain and
1239          * show "inactive" CSS or JS.
1240          *
1241          * @return bool
1242          */
1243         public function isCssOrJsPage() {
1244                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1245                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1246                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1247
1248                 # @note This hook is also called in ContentHandler::getDefaultModel.
1249                 #   It's called here again to make sure hook functions can force this
1250                 #   method to return true even outside the MediaWiki namespace.
1251
1252                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1253
1254                 return $isCssOrJsPage;
1255         }
1256
1257         /**
1258          * Is this a .css or .js subpage of a user page?
1259          * @return bool
1260          */
1261         public function isCssJsSubpage() {
1262                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1263                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1264                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1265         }
1266
1267         /**
1268          * Trim down a .css or .js subpage title to get the corresponding skin name
1269          *
1270          * @return string Containing skin name from .css or .js subpage title
1271          */
1272         public function getSkinFromCssJsSubpage() {
1273                 $subpage = explode( '/', $this->mTextform );
1274                 $subpage = $subpage[count( $subpage ) - 1];
1275                 $lastdot = strrpos( $subpage, '.' );
1276                 if ( $lastdot === false ) {
1277                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1278                 }
1279                 return substr( $subpage, 0, $lastdot );
1280         }
1281
1282         /**
1283          * Is this a .css subpage of a user page?
1284          *
1285          * @return bool
1286          */
1287         public function isCssSubpage() {
1288                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1289                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1290         }
1291
1292         /**
1293          * Is this a .js subpage of a user page?
1294          *
1295          * @return bool
1296          */
1297         public function isJsSubpage() {
1298                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1299                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1300         }
1301
1302         /**
1303          * Is this a talk page of some sort?
1304          *
1305          * @return bool
1306          */
1307         public function isTalkPage() {
1308                 return MWNamespace::isTalk( $this->getNamespace() );
1309         }
1310
1311         /**
1312          * Get a Title object associated with the talk page of this article
1313          *
1314          * @return Title The object for the talk page
1315          */
1316         public function getTalkPage() {
1317                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1318         }
1319
1320         /**
1321          * Get a title object associated with the subject page of this
1322          * talk page
1323          *
1324          * @return Title The object for the subject page
1325          */
1326         public function getSubjectPage() {
1327                 // Is this the same title?
1328                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1329                 if ( $this->getNamespace() == $subjectNS ) {
1330                         return $this;
1331                 }
1332                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1333         }
1334
1335         /**
1336          * Get the default namespace index, for when there is no namespace
1337          *
1338          * @return int Default namespace index
1339          */
1340         public function getDefaultNamespace() {
1341                 return $this->mDefaultNamespace;
1342         }
1343
1344         /**
1345          * Get the Title fragment (i.e.\ the bit after the #) in text form
1346          *
1347          * Use Title::hasFragment to check for a fragment
1348          *
1349          * @return string Title fragment
1350          */
1351         public function getFragment() {
1352                 return $this->mFragment;
1353         }
1354
1355         /**
1356          * Check if a Title fragment is set
1357          *
1358          * @return bool
1359          * @since 1.23
1360          */
1361         public function hasFragment() {
1362                 return $this->mFragment !== '';
1363         }
1364
1365         /**
1366          * Get the fragment in URL form, including the "#" character if there is one
1367          * @return string Fragment in URL form
1368          */
1369         public function getFragmentForURL() {
1370                 if ( !$this->hasFragment() ) {
1371                         return '';
1372                 } else {
1373                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1374                 }
1375         }
1376
1377         /**
1378          * Set the fragment for this title. Removes the first character from the
1379          * specified fragment before setting, so it assumes you're passing it with
1380          * an initial "#".
1381          *
1382          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1383          * Still in active use privately.
1384          *
1385          * @param string $fragment Text
1386          */
1387         public function setFragment( $fragment ) {
1388                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1389         }
1390
1391         /**
1392          * Prefix some arbitrary text with the namespace or interwiki prefix
1393          * of this object
1394          *
1395          * @param string $name The text
1396          * @return string The prefixed text
1397          */
1398         private function prefix( $name ) {
1399                 $p = '';
1400                 if ( $this->isExternal() ) {
1401                         $p = $this->mInterwiki . ':';
1402                 }
1403
1404                 if ( 0 != $this->mNamespace ) {
1405                         $p .= $this->getNsText() . ':';
1406                 }
1407                 return $p . $name;
1408         }
1409
1410         /**
1411          * Get the prefixed database key form
1412          *
1413          * @return string The prefixed title, with underscores and
1414          *  any interwiki and namespace prefixes
1415          */
1416         public function getPrefixedDBkey() {
1417                 $s = $this->prefix( $this->mDbkeyform );
1418                 $s = str_replace( ' ', '_', $s );
1419                 return $s;
1420         }
1421
1422         /**
1423          * Get the prefixed title with spaces.
1424          * This is the form usually used for display
1425          *
1426          * @return string The prefixed title, with spaces
1427          */
1428         public function getPrefixedText() {
1429                 if ( $this->mPrefixedText === null ) {
1430                         $s = $this->prefix( $this->mTextform );
1431                         $s = str_replace( '_', ' ', $s );
1432                         $this->mPrefixedText = $s;
1433                 }
1434                 return $this->mPrefixedText;
1435         }
1436
1437         /**
1438          * Return a string representation of this title
1439          *
1440          * @return string Representation of this title
1441          */
1442         public function __toString() {
1443                 return $this->getPrefixedText();
1444         }
1445
1446         /**
1447          * Get the prefixed title with spaces, plus any fragment
1448          * (part beginning with '#')
1449          *
1450          * @return string The prefixed title, with spaces and the fragment, including '#'
1451          */
1452         public function getFullText() {
1453                 $text = $this->getPrefixedText();
1454                 if ( $this->hasFragment() ) {
1455                         $text .= '#' . $this->getFragment();
1456                 }
1457                 return $text;
1458         }
1459
1460         /**
1461          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1462          *
1463          * @par Example:
1464          * @code
1465          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1466          * # returns: 'Foo'
1467          * @endcode
1468          *
1469          * @return string Root name
1470          * @since 1.20
1471          */
1472         public function getRootText() {
1473                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1474                         return $this->getText();
1475                 }
1476
1477                 return strtok( $this->getText(), '/' );
1478         }
1479
1480         /**
1481          * Get the root page name title, i.e. the leftmost part before any slashes
1482          *
1483          * @par Example:
1484          * @code
1485          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1486          * # returns: Title{User:Foo}
1487          * @endcode
1488          *
1489          * @return Title Root title
1490          * @since 1.20
1491          */
1492         public function getRootTitle() {
1493                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1494         }
1495
1496         /**
1497          * Get the base page name without a namespace, i.e. the part before the subpage name
1498          *
1499          * @par Example:
1500          * @code
1501          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1502          * # returns: 'Foo/Bar'
1503          * @endcode
1504          *
1505          * @return string Base name
1506          */
1507         public function getBaseText() {
1508                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1509                         return $this->getText();
1510                 }
1511
1512                 $parts = explode( '/', $this->getText() );
1513                 # Don't discard the real title if there's no subpage involved
1514                 if ( count( $parts ) > 1 ) {
1515                         unset( $parts[count( $parts ) - 1] );
1516                 }
1517                 return implode( '/', $parts );
1518         }
1519
1520         /**
1521          * Get the base page name title, i.e. the part before the subpage name
1522          *
1523          * @par Example:
1524          * @code
1525          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1526          * # returns: Title{User:Foo/Bar}
1527          * @endcode
1528          *
1529          * @return Title Base title
1530          * @since 1.20
1531          */
1532         public function getBaseTitle() {
1533                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1534         }
1535
1536         /**
1537          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1538          *
1539          * @par Example:
1540          * @code
1541          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1542          * # returns: "Baz"
1543          * @endcode
1544          *
1545          * @return string Subpage name
1546          */
1547         public function getSubpageText() {
1548                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1549                         return $this->mTextform;
1550                 }
1551                 $parts = explode( '/', $this->mTextform );
1552                 return $parts[count( $parts ) - 1];
1553         }
1554
1555         /**
1556          * Get the title for a subpage of the current page
1557          *
1558          * @par Example:
1559          * @code
1560          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1561          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1562          * @endcode
1563          *
1564          * @param string $text The subpage name to add to the title
1565          * @return Title Subpage title
1566          * @since 1.20
1567          */
1568         public function getSubpage( $text ) {
1569                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1570         }
1571
1572         /**
1573          * Get a URL-encoded form of the subpage text
1574          *
1575          * @return string URL-encoded subpage name
1576          */
1577         public function getSubpageUrlForm() {
1578                 $text = $this->getSubpageText();
1579                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1580                 return $text;
1581         }
1582
1583         /**
1584          * Get a URL-encoded title (not an actual URL) including interwiki
1585          *
1586          * @return string The URL-encoded form
1587          */
1588         public function getPrefixedURL() {
1589                 $s = $this->prefix( $this->mDbkeyform );
1590                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1591                 return $s;
1592         }
1593
1594         /**
1595          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1596          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1597          * second argument named variant. This was deprecated in favor
1598          * of passing an array of option with a "variant" key
1599          * Once $query2 is removed for good, this helper can be dropped
1600          * and the wfArrayToCgi moved to getLocalURL();
1601          *
1602          * @since 1.19 (r105919)
1603          * @param array|string $query
1604          * @param bool $query2
1605          * @return string
1606          */
1607         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1608                 if ( $query2 !== false ) {
1609                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1610                                 "method called with a second parameter is deprecated. Add your " .
1611                                 "parameter to an array passed as the first parameter.", "1.19" );
1612                 }
1613                 if ( is_array( $query ) ) {
1614                         $query = wfArrayToCgi( $query );
1615                 }
1616                 if ( $query2 ) {
1617                         if ( is_string( $query2 ) ) {
1618                                 // $query2 is a string, we will consider this to be
1619                                 // a deprecated $variant argument and add it to the query
1620                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1621                         } else {
1622                                 $query2 = wfArrayToCgi( $query2 );
1623                         }
1624                         // If we have $query content add a & to it first
1625                         if ( $query ) {
1626                                 $query .= '&';
1627                         }
1628                         // Now append the queries together
1629                         $query .= $query2;
1630                 }
1631                 return $query;
1632         }
1633
1634         /**
1635          * Get a real URL referring to this title, with interwiki link and
1636          * fragment
1637          *
1638          * @see self::getLocalURL for the arguments.
1639          * @see wfExpandUrl
1640          * @param array|string $query
1641          * @param bool $query2
1642          * @param string $proto Protocol type to use in URL
1643          * @return string The URL
1644          */
1645         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1646                 $query = self::fixUrlQueryArgs( $query, $query2 );
1647
1648                 # Hand off all the decisions on urls to getLocalURL
1649                 $url = $this->getLocalURL( $query );
1650
1651                 # Expand the url to make it a full url. Note that getLocalURL has the
1652                 # potential to output full urls for a variety of reasons, so we use
1653                 # wfExpandUrl instead of simply prepending $wgServer
1654                 $url = wfExpandUrl( $url, $proto );
1655
1656                 # Finally, add the fragment.
1657                 $url .= $this->getFragmentForURL();
1658
1659                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1660                 return $url;
1661         }
1662
1663         /**
1664          * Get a URL with no fragment or server name (relative URL) from a Title object.
1665          * If this page is generated with action=render, however,
1666          * $wgServer is prepended to make an absolute URL.
1667          *
1668          * @see self::getFullURL to always get an absolute URL.
1669          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1670          *  valid to link, locally, to the current Title.
1671          * @see self::newFromText to produce a Title object.
1672          *
1673          * @param string|array $query An optional query string,
1674          *   not used for interwiki links. Can be specified as an associative array as well,
1675          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1676          *   Some query patterns will trigger various shorturl path replacements.
1677          * @param array $query2 An optional secondary query array. This one MUST
1678          *   be an array. If a string is passed it will be interpreted as a deprecated
1679          *   variant argument and urlencoded into a variant= argument.
1680          *   This second query argument will be added to the $query
1681          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1682          *   pair in the first parameter array instead.
1683          *
1684          * @return string String of the URL.
1685          */
1686         public function getLocalURL( $query = '', $query2 = false ) {
1687                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1688
1689                 $query = self::fixUrlQueryArgs( $query, $query2 );
1690
1691                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1692                 if ( $interwiki ) {
1693                         $namespace = $this->getNsText();
1694                         if ( $namespace != '' ) {
1695                                 # Can this actually happen? Interwikis shouldn't be parsed.
1696                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1697                                 $namespace .= ':';
1698                         }
1699                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1700                         $url = wfAppendQuery( $url, $query );
1701                 } else {
1702                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1703                         if ( $query == '' ) {
1704                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1705                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1706                         } else {
1707                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1708                                 $url = false;
1709                                 $matches = array();
1710
1711                                 if ( !empty( $wgActionPaths )
1712                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1713                                 ) {
1714                                         $action = urldecode( $matches[2] );
1715                                         if ( isset( $wgActionPaths[$action] ) ) {
1716                                                 $query = $matches[1];
1717                                                 if ( isset( $matches[4] ) ) {
1718                                                         $query .= $matches[4];
1719                                                 }
1720                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1721                                                 if ( $query != '' ) {
1722                                                         $url = wfAppendQuery( $url, $query );
1723                                                 }
1724                                         }
1725                                 }
1726
1727                                 if ( $url === false
1728                                         && $wgVariantArticlePath
1729                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1730                                         && $this->getPageLanguage()->hasVariants()
1731                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1732                                 ) {
1733                                         $variant = urldecode( $matches[1] );
1734                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1735                                                 // Only do the variant replacement if the given variant is a valid
1736                                                 // variant for the page's language.
1737                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1738                                                 $url = str_replace( '$1', $dbkey, $url );
1739                                         }
1740                                 }
1741
1742                                 if ( $url === false ) {
1743                                         if ( $query == '-' ) {
1744                                                 $query = '';
1745                                         }
1746                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1747                                 }
1748                         }
1749
1750                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1751
1752                         // @todo FIXME: This causes breakage in various places when we
1753                         // actually expected a local URL and end up with dupe prefixes.
1754                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1755                                 $url = $wgServer . $url;
1756                         }
1757                 }
1758                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1759                 return $url;
1760         }
1761
1762         /**
1763          * Get a URL that's the simplest URL that will be valid to link, locally,
1764          * to the current Title.  It includes the fragment, but does not include
1765          * the server unless action=render is used (or the link is external).  If
1766          * there's a fragment but the prefixed text is empty, we just return a link
1767          * to the fragment.
1768          *
1769          * The result obviously should not be URL-escaped, but does need to be
1770          * HTML-escaped if it's being output in HTML.
1771          *
1772          * @param array $query
1773          * @param bool $query2
1774          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1775          * @see self::getLocalURL for the arguments.
1776          * @return string The URL
1777          */
1778         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1779                 wfProfileIn( __METHOD__ );
1780                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1781                         $ret = $this->getFullURL( $query, $query2, $proto );
1782                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1783                         $ret = $this->getFragmentForURL();
1784                 } else {
1785                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1786                 }
1787                 wfProfileOut( __METHOD__ );
1788                 return $ret;
1789         }
1790
1791         /**
1792          * Get the URL form for an internal link.
1793          * - Used in various Squid-related code, in case we have a different
1794          * internal hostname for the server from the exposed one.
1795          *
1796          * This uses $wgInternalServer to qualify the path, or $wgServer
1797          * if $wgInternalServer is not set. If the server variable used is
1798          * protocol-relative, the URL will be expanded to http://
1799          *
1800          * @see self::getLocalURL for the arguments.
1801          * @return string The URL
1802          */
1803         public function getInternalURL( $query = '', $query2 = false ) {
1804                 global $wgInternalServer, $wgServer;
1805                 $query = self::fixUrlQueryArgs( $query, $query2 );
1806                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1807                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1808                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1809                 return $url;
1810         }
1811
1812         /**
1813          * Get the URL for a canonical link, for use in things like IRC and
1814          * e-mail notifications. Uses $wgCanonicalServer and the
1815          * GetCanonicalURL hook.
1816          *
1817          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1818          *
1819          * @see self::getLocalURL for the arguments.
1820          * @return string The URL
1821          * @since 1.18
1822          */
1823         public function getCanonicalURL( $query = '', $query2 = false ) {
1824                 $query = self::fixUrlQueryArgs( $query, $query2 );
1825                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1826                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1827                 return $url;
1828         }
1829
1830         /**
1831          * Get the edit URL for this Title
1832          *
1833          * @return string The URL, or a null string if this is an interwiki link
1834          */
1835         public function getEditURL() {
1836                 if ( $this->isExternal() ) {
1837                         return '';
1838                 }
1839                 $s = $this->getLocalURL( 'action=edit' );
1840
1841                 return $s;
1842         }
1843
1844         /**
1845          * Is $wgUser watching this page?
1846          *
1847          * @deprecated since 1.20; use User::isWatched() instead.
1848          * @return bool
1849          */
1850         public function userIsWatching() {
1851                 global $wgUser;
1852
1853                 if ( is_null( $this->mWatched ) ) {
1854                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1855                                 $this->mWatched = false;
1856                         } else {
1857                                 $this->mWatched = $wgUser->isWatched( $this );
1858                         }
1859                 }
1860                 return $this->mWatched;
1861         }
1862
1863         /**
1864          * Can $user perform $action on this page?
1865          * This skips potentially expensive cascading permission checks
1866          * as well as avoids expensive error formatting
1867          *
1868          * Suitable for use for nonessential UI controls in common cases, but
1869          * _not_ for functional access control.
1870          *
1871          * May provide false positives, but should never provide a false negative.
1872          *
1873          * @param string $action Action that permission needs to be checked for
1874          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1875          * @return bool
1876          */
1877         public function quickUserCan( $action, $user = null ) {
1878                 return $this->userCan( $action, $user, false );
1879         }
1880
1881         /**
1882          * Can $user perform $action on this page?
1883          *
1884          * @param string $action Action that permission needs to be checked for
1885          * @param User $user User to check (since 1.19); $wgUser will be used if not
1886          *   provided.
1887          * @param bool $doExpensiveQueries Set this to false to avoid doing
1888          *   unnecessary queries.
1889          * @return bool
1890          */
1891         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1892                 if ( !$user instanceof User ) {
1893                         global $wgUser;
1894                         $user = $wgUser;
1895                 }
1896
1897                 return !count( $this->getUserPermissionsErrorsInternal(
1898                         $action, $user, $doExpensiveQueries, true ) );
1899         }
1900
1901         /**
1902          * Can $user perform $action on this page?
1903          *
1904          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1905          *
1906          * @param string $action Action that permission needs to be checked for
1907          * @param User $user User to check
1908          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1909          *   queries by skipping checks for cascading protections and user blocks.
1910          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1911          *   whose corresponding errors may be ignored.
1912          * @return array Array of arguments to wfMessage to explain permissions problems.
1913          */
1914         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true,
1915                 $ignoreErrors = array()
1916         ) {
1917                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1918
1919                 // Remove the errors being ignored.
1920                 foreach ( $errors as $index => $error ) {
1921                         $error_key = is_array( $error ) ? $error[0] : $error;
1922
1923                         if ( in_array( $error_key, $ignoreErrors ) ) {
1924                                 unset( $errors[$index] );
1925                         }
1926                 }
1927
1928                 return $errors;
1929         }
1930
1931         /**
1932          * Permissions checks that fail most often, and which are easiest to test.
1933          *
1934          * @param string $action The action to check
1935          * @param User $user User to check
1936          * @param array $errors List of current errors
1937          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1938          * @param bool $short Short circuit on first error
1939          *
1940          * @return array List of errors
1941          */
1942         private function checkQuickPermissions( $action, $user, $errors,
1943                 $doExpensiveQueries, $short
1944         ) {
1945                 if ( !Hooks::run( 'TitleQuickPermissions',
1946                         array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) )
1947                 ) {
1948                         return $errors;
1949                 }
1950
1951                 if ( $action == 'create' ) {
1952                         if (
1953                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1954                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1955                         ) {
1956                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1957                         }
1958                 } elseif ( $action == 'move' ) {
1959                         if ( !$user->isAllowed( 'move-rootuserpages' )
1960                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1961                                 // Show user page-specific message only if the user can move other pages
1962                                 $errors[] = array( 'cant-move-user-page' );
1963                         }
1964
1965                         // Check if user is allowed to move files if it's a file
1966                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1967                                 $errors[] = array( 'movenotallowedfile' );
1968                         }
1969
1970                         // Check if user is allowed to move category pages if it's a category page
1971                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1972                                 $errors[] = array( 'cant-move-category-page' );
1973                         }
1974
1975                         if ( !$user->isAllowed( 'move' ) ) {
1976                                 // User can't move anything
1977                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1978                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1979                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1980                                         // custom message if logged-in users without any special rights can move
1981                                         $errors[] = array( 'movenologintext' );
1982                                 } else {
1983                                         $errors[] = array( 'movenotallowed' );
1984                                 }
1985                         }
1986                 } elseif ( $action == 'move-target' ) {
1987                         if ( !$user->isAllowed( 'move' ) ) {
1988                                 // User can't move anything
1989                                 $errors[] = array( 'movenotallowed' );
1990                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1991                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1992                                 // Show user page-specific message only if the user can move other pages
1993                                 $errors[] = array( 'cant-move-to-user-page' );
1994                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1995                                         && $this->mNamespace == NS_CATEGORY ) {
1996                                 // Show category page-specific message only if the user can move other pages
1997                                 $errors[] = array( 'cant-move-to-category-page' );
1998                         }
1999                 } elseif ( !$user->isAllowed( $action ) ) {
2000                         $errors[] = $this->missingPermissionError( $action, $short );
2001                 }
2002
2003                 return $errors;
2004         }
2005
2006         /**
2007          * Add the resulting error code to the errors array
2008          *
2009          * @param array $errors List of current errors
2010          * @param array $result Result of errors
2011          *
2012          * @return array List of errors
2013          */
2014         private function resultToError( $errors, $result ) {
2015                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2016                         // A single array representing an error
2017                         $errors[] = $result;
2018                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2019                         // A nested array representing multiple errors
2020                         $errors = array_merge( $errors, $result );
2021                 } elseif ( $result !== '' && is_string( $result ) ) {
2022                         // A string representing a message-id
2023                         $errors[] = array( $result );
2024                 } elseif ( $result === false ) {
2025                         // a generic "We don't want them to do that"
2026                         $errors[] = array( 'badaccess-group0' );
2027                 }
2028                 return $errors;
2029         }
2030
2031         /**
2032          * Check various permission hooks
2033          *
2034          * @param string $action The action to check
2035          * @param User $user User to check
2036          * @param array $errors List of current errors
2037          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2038          * @param bool $short Short circuit on first error
2039          *
2040          * @return array List of errors
2041          */
2042         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
2043                 // Use getUserPermissionsErrors instead
2044                 $result = '';
2045                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2046                         return $result ? array() : array( array( 'badaccess-group0' ) );
2047                 }
2048                 // Check getUserPermissionsErrors hook
2049                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2050                         $errors = $this->resultToError( $errors, $result );
2051                 }
2052                 // Check getUserPermissionsErrorsExpensive hook
2053                 if (
2054                         $doExpensiveQueries
2055                         && !( $short && count( $errors ) > 0 )
2056                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2057                 ) {
2058                         $errors = $this->resultToError( $errors, $result );
2059                 }
2060
2061                 return $errors;
2062         }
2063
2064         /**
2065          * Check permissions on special pages & namespaces
2066          *
2067          * @param string $action The action to check
2068          * @param User $user User to check
2069          * @param array $errors List of current errors
2070          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2071          * @param bool $short Short circuit on first error
2072          *
2073          * @return array List of errors
2074          */
2075         private function checkSpecialsAndNSPermissions( $action, $user, $errors,
2076                 $doExpensiveQueries, $short
2077         ) {
2078                 # Only 'createaccount' can be performed on special pages,
2079                 # which don't actually exist in the DB.
2080                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2081                         $errors[] = array( 'ns-specialprotected' );
2082                 }
2083
2084                 # Check $wgNamespaceProtection for restricted namespaces
2085                 if ( $this->isNamespaceProtected( $user ) ) {
2086                         $ns = $this->mNamespace == NS_MAIN ?
2087                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2088                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2089                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2090                 }
2091
2092                 return $errors;
2093         }
2094
2095         /**
2096          * Check CSS/JS sub-page permissions
2097          *
2098          * @param string $action The action to check
2099          * @param User $user User to check
2100          * @param array $errors List of current errors
2101          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2102          * @param bool $short Short circuit on first error
2103          *
2104          * @return array List of errors
2105          */
2106         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2107                 # Protect css/js subpages of user pages
2108                 # XXX: this might be better using restrictions
2109                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2110                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2111                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2112                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2113                                         $errors[] = array( 'mycustomcssprotected', $action );
2114                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2115                                         $errors[] = array( 'mycustomjsprotected', $action );
2116                                 }
2117                         } else {
2118                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2119                                         $errors[] = array( 'customcssprotected', $action );
2120                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2121                                         $errors[] = array( 'customjsprotected', $action );
2122                                 }
2123                         }
2124                 }
2125
2126                 return $errors;
2127         }
2128
2129         /**
2130          * Check against page_restrictions table requirements on this
2131          * page. The user must possess all required rights for this
2132          * action.
2133          *
2134          * @param string $action The action to check
2135          * @param User $user User to check
2136          * @param array $errors List of current errors
2137          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2138          * @param bool $short Short circuit on first error
2139          *
2140          * @return array List of errors
2141          */
2142         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2143                 foreach ( $this->getRestrictions( $action ) as $right ) {
2144                         // Backwards compatibility, rewrite sysop -> editprotected
2145                         if ( $right == 'sysop' ) {
2146                                 $right = 'editprotected';
2147                         }
2148                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2149                         if ( $right == 'autoconfirmed' ) {
2150                                 $right = 'editsemiprotected';
2151                         }
2152                         if ( $right == '' ) {
2153                                 continue;
2154                         }
2155                         if ( !$user->isAllowed( $right ) ) {
2156                                 $errors[] = array( 'protectedpagetext', $right, $action );
2157                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2158                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2159                         }
2160                 }
2161
2162                 return $errors;
2163         }
2164
2165         /**
2166          * Check restrictions on cascading pages.
2167          *
2168          * @param string $action The action to check
2169          * @param User $user User to check
2170          * @param array $errors List of current errors
2171          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2172          * @param bool $short Short circuit on first error
2173          *
2174          * @return array List of errors
2175          */
2176         private function checkCascadingSourcesRestrictions( $action, $user, $errors,
2177                 $doExpensiveQueries, $short
2178         ) {
2179                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2180                         # We /could/ use the protection level on the source page, but it's
2181                         # fairly ugly as we have to establish a precedence hierarchy for pages
2182                         # included by multiple cascade-protected pages. So just restrict
2183                         # it to people with 'protect' permission, as they could remove the
2184                         # protection anyway.
2185                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2186                         # Cascading protection depends on more than this page...
2187                         # Several cascading protected pages may include this page...
2188                         # Check each cascading level
2189                         # This is only for protection restrictions, not for all actions
2190                         if ( isset( $restrictions[$action] ) ) {
2191                                 foreach ( $restrictions[$action] as $right ) {
2192                                         // Backwards compatibility, rewrite sysop -> editprotected
2193                                         if ( $right == 'sysop' ) {
2194                                                 $right = 'editprotected';
2195                                         }
2196                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2197                                         if ( $right == 'autoconfirmed' ) {
2198                                                 $right = 'editsemiprotected';
2199                                         }
2200                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2201                                                 $pages = '';
2202                                                 foreach ( $cascadingSources as $page ) {
2203                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2204                                                 }
2205                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2206                                         }
2207                                 }
2208                         }
2209                 }
2210
2211                 return $errors;
2212         }
2213
2214         /**
2215          * Check action permissions not already checked in checkQuickPermissions
2216          *
2217          * @param string $action The action to check
2218          * @param User $user User to check
2219          * @param array $errors List of current errors
2220          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2221          * @param bool $short Short circuit on first error
2222          *
2223          * @return array List of errors
2224          */
2225         private function checkActionPermissions( $action, $user, $errors,
2226                 $doExpensiveQueries, $short
2227         ) {
2228                 global $wgDeleteRevisionsLimit, $wgLang;
2229
2230                 if ( $action == 'protect' ) {
2231                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit',
2232                                 $user, $doExpensiveQueries, true ) )
2233                         ) {
2234                                 // If they can't edit, they shouldn't protect.
2235                                 $errors[] = array( 'protect-cantedit' );
2236                         }
2237                 } elseif ( $action == 'create' ) {
2238                         $title_protection = $this->getTitleProtection();
2239                         if ( $title_protection ) {
2240                                 if ( $title_protection['permission'] == ''
2241                                         || !$user->isAllowed( $title_protection['permission'] )
2242                                 ) {
2243                                         $errors[] = array(
2244                                                 'titleprotected',
2245                                                 User::whoIs( $title_protection['user'] ),
2246                                                 $title_protection['reason']
2247                                         );
2248                                 }
2249                         }
2250                 } elseif ( $action == 'move' ) {
2251                         // Check for immobile pages
2252                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2253                                 // Specific message for this case
2254                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2255                         } elseif ( !$this->isMovable() ) {
2256                                 // Less specific message for rarer cases
2257                                 $errors[] = array( 'immobile-source-page' );
2258                         }
2259                 } elseif ( $action == 'move-target' ) {
2260                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2261                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2262                         } elseif ( !$this->isMovable() ) {
2263                                 $errors[] = array( 'immobile-target-page' );
2264                         }
2265                 } elseif ( $action == 'delete' ) {
2266                         $tempErrors = $this->checkPageRestrictions( 'edit',
2267                                 $user, array(), $doExpensiveQueries, true );
2268                         if ( !$tempErrors ) {
2269                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2270                                         $user, $tempErrors, $doExpensiveQueries, true );
2271                         }
2272                         if ( $tempErrors ) {
2273                                 // If protection keeps them from editing, they shouldn't be able to delete.
2274                                 $errors[] = array( 'deleteprotected' );
2275                         }
2276                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2277                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2278                         ) {
2279                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2280                         }
2281                 }
2282                 return $errors;
2283         }
2284
2285         /**
2286          * Check that the user isn't blocked from editing.
2287          *
2288          * @param string $action The action to check
2289          * @param User $user User to check
2290          * @param array $errors List of current errors
2291          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2292          * @param bool $short Short circuit on first error
2293          *
2294          * @return array List of errors
2295          */
2296         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2297                 // Account creation blocks handled at userlogin.
2298                 // Unblocking handled in SpecialUnblock
2299                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2300                         return $errors;
2301                 }
2302
2303                 global $wgEmailConfirmToEdit;
2304
2305                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2306                         $errors[] = array( 'confirmedittext' );
2307                 }
2308
2309                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2310                         // Don't block the user from editing their own talk page unless they've been
2311                         // explicitly blocked from that too.
2312                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2313                         // @todo FIXME: Pass the relevant context into this function.
2314                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2315                 }
2316
2317                 return $errors;
2318         }
2319
2320         /**
2321          * Check that the user is allowed to read this page.
2322          *
2323          * @param string $action The action to check
2324          * @param User $user User to check
2325          * @param array $errors List of current errors
2326          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2327          * @param bool $short Short circuit on first error
2328          *
2329          * @return array List of errors
2330          */
2331         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2332                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2333
2334                 $whitelisted = false;
2335                 if ( User::isEveryoneAllowed( 'read' ) ) {
2336                         # Shortcut for public wikis, allows skipping quite a bit of code
2337                         $whitelisted = true;
2338                 } elseif ( $user->isAllowed( 'read' ) ) {
2339                         # If the user is allowed to read pages, he is allowed to read all pages
2340                         $whitelisted = true;
2341                 } elseif ( $this->isSpecial( 'Userlogin' )
2342                         || $this->isSpecial( 'ChangePassword' )
2343                         || $this->isSpecial( 'PasswordReset' )
2344                 ) {
2345                         # Always grant access to the login page.
2346                         # Even anons need to be able to log in.
2347                         $whitelisted = true;
2348                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2349                         # Time to check the whitelist
2350                         # Only do these checks is there's something to check against
2351                         $name = $this->getPrefixedText();
2352                         $dbName = $this->getPrefixedDBkey();
2353
2354                         // Check for explicit whitelisting with and without underscores
2355                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2356                                 $whitelisted = true;
2357                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2358                                 # Old settings might have the title prefixed with
2359                                 # a colon for main-namespace pages
2360                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2361                                         $whitelisted = true;
2362                                 }
2363                         } elseif ( $this->isSpecialPage() ) {
2364                                 # If it's a special page, ditch the subpage bit and check again
2365                                 $name = $this->getDBkey();
2366                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2367                                 if ( $name ) {
2368                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2369                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2370                                                 $whitelisted = true;
2371                                         }
2372                                 }
2373                         }
2374                 }
2375
2376                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2377                         $name = $this->getPrefixedText();
2378                         // Check for regex whitelisting
2379                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2380                                 if ( preg_match( $listItem, $name ) ) {
2381                                         $whitelisted = true;
2382                                         break;
2383                                 }
2384                         }
2385                 }
2386
2387                 if ( !$whitelisted ) {
2388                         # If the title is not whitelisted, give extensions a chance to do so...
2389                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2390                         if ( !$whitelisted ) {
2391                                 $errors[] = $this->missingPermissionError( $action, $short );
2392                         }
2393                 }
2394
2395                 return $errors;
2396         }
2397
2398         /**
2399          * Get a description array when the user doesn't have the right to perform
2400          * $action (i.e. when User::isAllowed() returns false)
2401          *
2402          * @param string $action The action to check
2403          * @param bool $short Short circuit on first error
2404          * @return array List of errors
2405          */
2406         private function missingPermissionError( $action, $short ) {
2407                 // We avoid expensive display logic for quickUserCan's and such
2408                 if ( $short ) {
2409                         return array( 'badaccess-group0' );
2410                 }
2411
2412                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2413                         User::getGroupsWithPermission( $action ) );
2414
2415                 if ( count( $groups ) ) {
2416                         global $wgLang;
2417                         return array(
2418                                 'badaccess-groups',
2419                                 $wgLang->commaList( $groups ),
2420                                 count( $groups )
2421                         );
2422                 } else {
2423                         return array( 'badaccess-group0' );
2424                 }
2425         }
2426
2427         /**
2428          * Can $user perform $action on this page? This is an internal function,
2429          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2430          * checks on wfReadOnly() and blocks)
2431          *
2432          * @param string $action Action that permission needs to be checked for
2433          * @param User $user User to check
2434          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
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( $action, $user,
2439                 $doExpensiveQueries = true, $short = false
2440         ) {
2441                 wfProfileIn( __METHOD__ );
2442
2443                 # Read has special handling
2444                 if ( $action == 'read' ) {
2445                         $checks = array(
2446                                 'checkPermissionHooks',
2447                                 'checkReadPermissions',
2448                         );
2449                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2450                 # here as it will lead to duplicate error messages. This is okay to do
2451                 # since anywhere that checks for create will also check for edit, and
2452                 # those checks are called for edit.
2453                 } elseif ( $action == 'create' ) {
2454                         $checks = array(
2455                                 'checkQuickPermissions',
2456                                 'checkPermissionHooks',
2457                                 'checkPageRestrictions',
2458                                 'checkCascadingSourcesRestrictions',
2459                                 'checkActionPermissions',
2460                                 'checkUserBlock'
2461                         );
2462                 } else {
2463                         $checks = array(
2464                                 'checkQuickPermissions',
2465                                 'checkPermissionHooks',
2466                                 'checkSpecialsAndNSPermissions',
2467                                 'checkCSSandJSPermissions',
2468                                 'checkPageRestrictions',
2469                                 'checkCascadingSourcesRestrictions',
2470                                 'checkActionPermissions',
2471                                 'checkUserBlock'
2472                         );
2473                 }
2474
2475                 $errors = array();
2476                 while ( count( $checks ) > 0 &&
2477                                 !( $short && count( $errors ) > 0 ) ) {
2478                         $method = array_shift( $checks );
2479                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2480                 }
2481
2482                 wfProfileOut( __METHOD__ );
2483                 return $errors;
2484         }
2485
2486         /**
2487          * Get a filtered list of all restriction types supported by this wiki.
2488          * @param bool $exists True to get all restriction types that apply to
2489          * titles that do exist, False for all restriction types that apply to
2490          * titles that do not exist
2491          * @return array
2492          */
2493         public static function getFilteredRestrictionTypes( $exists = true ) {
2494                 global $wgRestrictionTypes;
2495                 $types = $wgRestrictionTypes;
2496                 if ( $exists ) {
2497                         # Remove the create restriction for existing titles
2498                         $types = array_diff( $types, array( 'create' ) );
2499                 } else {
2500                         # Only the create and upload restrictions apply to non-existing titles
2501                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2502                 }
2503                 return $types;
2504         }
2505
2506         /**
2507          * Returns restriction types for the current Title
2508          *
2509          * @return array Applicable restriction types
2510          */
2511         public function getRestrictionTypes() {
2512                 if ( $this->isSpecialPage() ) {
2513                         return array();
2514                 }
2515
2516                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2517
2518                 if ( $this->getNamespace() != NS_FILE ) {
2519                         # Remove the upload restriction for non-file titles
2520                         $types = array_diff( $types, array( 'upload' ) );
2521                 }
2522
2523                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2524
2525                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2526                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2527
2528                 return $types;
2529         }
2530
2531         /**
2532          * Is this title subject to title protection?
2533          * Title protection is the one applied against creation of such title.
2534          *
2535          * @return array|bool An associative array representing any existent title
2536          *   protection, or false if there's none.
2537          */
2538         public function getTitleProtection() {
2539                 // Can't protect pages in special namespaces
2540                 if ( $this->getNamespace() < 0 ) {
2541                         return false;
2542                 }
2543
2544                 // Can't protect pages that exist.
2545                 if ( $this->exists() ) {
2546                         return false;
2547                 }
2548
2549                 if ( $this->mTitleProtection === null ) {
2550                         $dbr = wfGetDB( DB_SLAVE );
2551                         $res = $dbr->select(
2552                                 'protected_titles',
2553                                 array(
2554                                         'user' => 'pt_user',
2555                                         'reason' => 'pt_reason',
2556                                         'expiry' => 'pt_expiry',
2557                                         'permission' => 'pt_create_perm'
2558                                 ),
2559                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2560                                 __METHOD__
2561                         );
2562
2563                         // fetchRow returns false if there are no rows.
2564                         $row = $dbr->fetchRow( $res );
2565                         if ( $row ) {
2566                                 if ( $row['permission'] == 'sysop' ) {
2567                                         $row['permission'] = 'editprotected'; // B/C
2568                                 }
2569                                 if ( $row['permission'] == 'autoconfirmed' ) {
2570                                         $row['permission'] = 'editsemiprotected'; // B/C
2571                                 }
2572                         }
2573                         $this->mTitleProtection = $row;
2574                 }
2575                 return $this->mTitleProtection;
2576         }
2577
2578         /**
2579          * Remove any title protection due to page existing
2580          */
2581         public function deleteTitleProtection() {
2582                 $dbw = wfGetDB( DB_MASTER );
2583
2584                 $dbw->delete(
2585                         'protected_titles',
2586                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2587                         __METHOD__
2588                 );
2589                 $this->mTitleProtection = false;
2590         }
2591
2592         /**
2593          * Is this page "semi-protected" - the *only* protection levels are listed
2594          * in $wgSemiprotectedRestrictionLevels?
2595          *
2596          * @param string $action Action to check (default: edit)
2597          * @return bool
2598          */
2599         public function isSemiProtected( $action = 'edit' ) {
2600                 global $wgSemiprotectedRestrictionLevels;
2601
2602                 $restrictions = $this->getRestrictions( $action );
2603                 $semi = $wgSemiprotectedRestrictionLevels;
2604                 if ( !$restrictions || !$semi ) {
2605                         // Not protected, or all protection is full protection
2606                         return false;
2607                 }
2608
2609                 // Remap autoconfirmed to editsemiprotected for BC
2610                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2611                         $semi[$key] = 'editsemiprotected';
2612                 }
2613                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2614                         $restrictions[$key] = 'editsemiprotected';
2615                 }
2616
2617                 return !array_diff( $restrictions, $semi );
2618         }
2619
2620         /**
2621          * Does the title correspond to a protected article?
2622          *
2623          * @param string $action The action the page is protected from,
2624          * by default checks all actions.
2625          * @return bool
2626          */
2627         public function isProtected( $action = '' ) {
2628                 global $wgRestrictionLevels;
2629
2630                 $restrictionTypes = $this->getRestrictionTypes();
2631
2632                 # Special pages have inherent protection
2633                 if ( $this->isSpecialPage() ) {
2634                         return true;
2635                 }
2636
2637                 # Check regular protection levels
2638                 foreach ( $restrictionTypes as $type ) {
2639                         if ( $action == $type || $action == '' ) {
2640                                 $r = $this->getRestrictions( $type );
2641                                 foreach ( $wgRestrictionLevels as $level ) {
2642                                         if ( in_array( $level, $r ) && $level != '' ) {
2643                                                 return true;
2644                                         }
2645                                 }
2646                         }
2647                 }
2648
2649                 return false;
2650         }
2651
2652         /**
2653          * Determines if $user is unable to edit this page because it has been protected
2654          * by $wgNamespaceProtection.
2655          *
2656          * @param User $user User object to check permissions
2657          * @return bool
2658          */
2659         public function isNamespaceProtected( User $user ) {
2660                 global $wgNamespaceProtection;
2661
2662                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2663                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2664                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2665                                         return true;
2666                                 }
2667                         }
2668                 }
2669                 return false;
2670         }
2671
2672         /**
2673          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2674          *
2675          * @return bool If the page is subject to cascading restrictions.
2676          */
2677         public function isCascadeProtected() {
2678                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2679                 return ( $sources > 0 );
2680         }
2681
2682         /**
2683          * Determines whether cascading protection sources have already been loaded from
2684          * the database.
2685          *
2686          * @param bool $getPages True to check if the pages are loaded, or false to check
2687          * if the status is loaded.
2688          * @return bool Whether or not the specified information has been loaded
2689          * @since 1.23
2690          */
2691         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2692                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2693         }
2694
2695         /**
2696          * Cascading protection: Get the source of any cascading restrictions on this page.
2697          *
2698          * @param bool $getPages Whether or not to retrieve the actual pages
2699          *        that the restrictions have come from and the actual restrictions
2700          *        themselves.
2701          * @return array Two elements: First is an array of Title objects of the
2702          *        pages from which cascading restrictions have come, false for
2703          *        none, or true if such restrictions exist but $getPages was not
2704          *        set. Second is an array like that returned by
2705          *        Title::getAllRestrictions(), or an empty array if $getPages is
2706          *        false.
2707          */
2708         public function getCascadeProtectionSources( $getPages = true ) {
2709                 global $wgContLang;
2710                 $pagerestrictions = array();
2711
2712                 if ( $this->mCascadeSources !== null && $getPages ) {
2713                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2714                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2715                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2716                 }
2717
2718                 wfProfileIn( __METHOD__ );
2719
2720                 $dbr = wfGetDB( DB_SLAVE );
2721
2722                 if ( $this->getNamespace() == NS_FILE ) {
2723                         $tables = array( 'imagelinks', 'page_restrictions' );
2724                         $where_clauses = array(
2725                                 'il_to' => $this->getDBkey(),
2726                                 'il_from=pr_page',
2727                                 'pr_cascade' => 1
2728                         );
2729                 } else {
2730                         $tables = array( 'templatelinks', 'page_restrictions' );
2731                         $where_clauses = array(
2732                                 'tl_namespace' => $this->getNamespace(),
2733                                 'tl_title' => $this->getDBkey(),
2734                                 'tl_from=pr_page',
2735                                 'pr_cascade' => 1
2736                         );
2737                 }
2738
2739                 if ( $getPages ) {
2740                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2741                                 'pr_expiry', 'pr_type', 'pr_level' );
2742                         $where_clauses[] = 'page_id=pr_page';
2743                         $tables[] = 'page';
2744                 } else {
2745                         $cols = array( 'pr_expiry' );
2746                 }
2747
2748                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2749
2750                 $sources = $getPages ? array() : false;
2751                 $now = wfTimestampNow();
2752                 $purgeExpired = false;
2753
2754                 foreach ( $res as $row ) {
2755                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2756                         if ( $expiry > $now ) {
2757                                 if ( $getPages ) {
2758                                         $page_id = $row->pr_page;
2759                                         $page_ns = $row->page_namespace;
2760                                         $page_title = $row->page_title;
2761                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2762                                         # Add groups needed for each restriction type if its not already there
2763                                         # Make sure this restriction type still exists
2764
2765                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2766                                                 $pagerestrictions[$row->pr_type] = array();
2767                                         }
2768
2769                                         if (
2770                                                 isset( $pagerestrictions[$row->pr_type] )
2771                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2772                                         ) {
2773                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2774                                         }
2775                                 } else {
2776                                         $sources = true;
2777                                 }
2778                         } else {
2779                                 // Trigger lazy purge of expired restrictions from the db
2780                                 $purgeExpired = true;
2781                         }
2782                 }
2783                 if ( $purgeExpired ) {
2784                         Title::purgeExpiredRestrictions();
2785                 }
2786
2787                 if ( $getPages ) {
2788                         $this->mCascadeSources = $sources;
2789                         $this->mCascadingRestrictions = $pagerestrictions;
2790                 } else {
2791                         $this->mHasCascadingRestrictions = $sources;
2792                 }
2793
2794                 wfProfileOut( __METHOD__ );
2795                 return array( $sources, $pagerestrictions );
2796         }
2797
2798         /**
2799          * Accessor for mRestrictionsLoaded
2800          *
2801          * @return bool Whether or not the page's restrictions have already been
2802          * loaded from the database
2803          * @since 1.23
2804          */
2805         public function areRestrictionsLoaded() {
2806                 return $this->mRestrictionsLoaded;
2807         }
2808
2809         /**
2810          * Accessor/initialisation for mRestrictions
2811          *
2812          * @param string $action Action that permission needs to be checked for
2813          * @return array Restriction levels needed to take the action. All levels are
2814          *     required. Note that restriction levels are normally user rights, but 'sysop'
2815          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2816          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2817          */
2818         public function getRestrictions( $action ) {
2819                 if ( !$this->mRestrictionsLoaded ) {
2820                         $this->loadRestrictions();
2821                 }
2822                 return isset( $this->mRestrictions[$action] )
2823                                 ? $this->mRestrictions[$action]
2824                                 : array();
2825         }
2826
2827         /**
2828          * Accessor/initialisation for mRestrictions
2829          *
2830          * @return array Keys are actions, values are arrays as returned by
2831          *     Title::getRestrictions()
2832          * @since 1.23
2833          */
2834         public function getAllRestrictions() {
2835                 if ( !$this->mRestrictionsLoaded ) {
2836                         $this->loadRestrictions();
2837                 }
2838                 return $this->mRestrictions;
2839         }
2840
2841         /**
2842          * Get the expiry time for the restriction against a given action
2843          *
2844          * @param string $action
2845          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2846          *     or not protected at all, or false if the action is not recognised.
2847          */
2848         public function getRestrictionExpiry( $action ) {
2849                 if ( !$this->mRestrictionsLoaded ) {
2850                         $this->loadRestrictions();
2851                 }
2852                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2853         }
2854
2855         /**
2856          * Returns cascading restrictions for the current article
2857          *
2858          * @return bool
2859          */
2860         function areRestrictionsCascading() {
2861                 if ( !$this->mRestrictionsLoaded ) {
2862                         $this->loadRestrictions();
2863                 }
2864
2865                 return $this->mCascadeRestriction;
2866         }
2867
2868         /**
2869          * Loads a string into mRestrictions array
2870          *
2871          * @param ResultWrapper $res Resource restrictions as an SQL result.
2872          * @param string $oldFashionedRestrictions Comma-separated list of page
2873          *        restrictions from page table (pre 1.10)
2874          */
2875         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2876                 $rows = array();
2877
2878                 foreach ( $res as $row ) {
2879                         $rows[] = $row;
2880                 }
2881
2882                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2883         }
2884
2885         /**
2886          * Compiles list of active page restrictions from both page table (pre 1.10)
2887          * and page_restrictions table for this existing page.
2888          * Public for usage by LiquidThreads.
2889          *
2890          * @param array $rows Array of db result objects
2891          * @param string $oldFashionedRestrictions Comma-separated list of page
2892          *   restrictions from page table (pre 1.10)
2893          */
2894         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2895                 global $wgContLang;
2896                 $dbr = wfGetDB( DB_SLAVE );
2897
2898                 $restrictionTypes = $this->getRestrictionTypes();
2899
2900                 foreach ( $restrictionTypes as $type ) {
2901                         $this->mRestrictions[$type] = array();
2902                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2903                 }
2904
2905                 $this->mCascadeRestriction = false;
2906
2907                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2908
2909                 if ( $oldFashionedRestrictions === null ) {
2910                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2911                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2912                 }
2913
2914                 if ( $oldFashionedRestrictions != '' ) {
2915
2916                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2917                                 $temp = explode( '=', trim( $restrict ) );
2918                                 if ( count( $temp ) == 1 ) {
2919                                         // old old format should be treated as edit/move restriction
2920                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2921                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2922                                 } else {
2923                                         $restriction = trim( $temp[1] );
2924                                         if ( $restriction != '' ) { //some old entries are empty
2925                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2926                                         }
2927                                 }
2928                         }
2929
2930                         $this->mOldRestrictions = true;
2931
2932                 }
2933
2934                 if ( count( $rows ) ) {
2935                         # Current system - load second to make them override.
2936                         $now = wfTimestampNow();
2937                         $purgeExpired = false;
2938
2939                         # Cycle through all the restrictions.
2940                         foreach ( $rows as $row ) {
2941
2942                                 // Don't take care of restrictions types that aren't allowed
2943                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2944                                         continue;
2945                                 }
2946
2947                                 // This code should be refactored, now that it's being used more generally,
2948                                 // But I don't really see any harm in leaving it in Block for now -werdna
2949                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2950
2951                                 // Only apply the restrictions if they haven't expired!
2952                                 if ( !$expiry || $expiry > $now ) {
2953                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2954                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2955
2956                                         $this->mCascadeRestriction |= $row->pr_cascade;
2957                                 } else {
2958                                         // Trigger a lazy purge of expired restrictions
2959                                         $purgeExpired = true;
2960                                 }
2961                         }
2962
2963                         if ( $purgeExpired ) {
2964                                 Title::purgeExpiredRestrictions();
2965                         }
2966                 }
2967
2968                 $this->mRestrictionsLoaded = true;
2969         }
2970
2971         /**
2972          * Load restrictions from the page_restrictions table
2973          *
2974          * @param string $oldFashionedRestrictions Comma-separated list of page
2975          *   restrictions from page table (pre 1.10)
2976          */
2977         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2978                 global $wgContLang;
2979                 if ( !$this->mRestrictionsLoaded ) {
2980                         if ( $this->exists() ) {
2981                                 $dbr = wfGetDB( DB_SLAVE );
2982
2983                                 $res = $dbr->select(
2984                                         'page_restrictions',
2985                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2986                                         array( 'pr_page' => $this->getArticleID() ),
2987                                         __METHOD__
2988                                 );
2989
2990                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2991                         } else {
2992                                 $title_protection = $this->getTitleProtection();
2993
2994                                 if ( $title_protection ) {
2995                                         $now = wfTimestampNow();
2996                                         $expiry = $wgContLang->formatExpiry( $title_protection['expiry'], TS_MW );
2997
2998                                         if ( !$expiry || $expiry > $now ) {
2999                                                 // Apply the restrictions
3000                                                 $this->mRestrictionsExpiry['create'] = $expiry;
3001                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
3002                                         } else { // Get rid of the old restrictions
3003                                                 Title::purgeExpiredRestrictions();
3004                                                 $this->mTitleProtection = false;
3005                                         }
3006                                 } else {
3007                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
3008                                 }
3009                                 $this->mRestrictionsLoaded = true;
3010                         }
3011                 }
3012         }
3013
3014         /**
3015          * Flush the protection cache in this object and force reload from the database.
3016          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3017          */
3018         public function flushRestrictions() {
3019                 $this->mRestrictionsLoaded = false;
3020                 $this->mTitleProtection = null;
3021         }
3022
3023         /**
3024          * Purge expired restrictions from the page_restrictions table
3025          */
3026         static function purgeExpiredRestrictions() {
3027                 if ( wfReadOnly() ) {
3028                         return;
3029                 }
3030
3031                 $method = __METHOD__;
3032                 $dbw = wfGetDB( DB_MASTER );
3033                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3034                         $dbw->delete(
3035                                 'page_restrictions',
3036                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3037                                 $method
3038                         );
3039                         $dbw->delete(
3040                                 'protected_titles',
3041                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3042                                 $method
3043                         );
3044                 } );
3045         }
3046
3047         /**
3048          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3049          *
3050          * @return bool
3051          */
3052         public function hasSubpages() {
3053                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3054                         # Duh
3055                         return false;
3056                 }
3057
3058                 # We dynamically add a member variable for the purpose of this method
3059                 # alone to cache the result.  There's no point in having it hanging
3060                 # around uninitialized in every Title object; therefore we only add it
3061                 # if needed and don't declare it statically.
3062                 if ( $this->mHasSubpages === null ) {
3063                         $this->mHasSubpages = false;
3064                         $subpages = $this->getSubpages( 1 );
3065                         if ( $subpages instanceof TitleArray ) {
3066                                 $this->mHasSubpages = (bool)$subpages->count();
3067                         }
3068                 }
3069
3070                 return $this->mHasSubpages;
3071         }
3072
3073         /**
3074          * Get all subpages of this page.
3075          *
3076          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3077          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3078          *  doesn't allow subpages
3079          */
3080         public function getSubpages( $limit = -1 ) {
3081                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3082                         return array();
3083                 }
3084
3085                 $dbr = wfGetDB( DB_SLAVE );
3086                 $conds['page_namespace'] = $this->getNamespace();
3087                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3088                 $options = array();
3089                 if ( $limit > -1 ) {
3090                         $options['LIMIT'] = $limit;
3091                 }
3092                 $this->mSubpages = TitleArray::newFromResult(
3093                         $dbr->select( 'page',
3094                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3095                                 $conds,
3096                                 __METHOD__,
3097                                 $options
3098                         )
3099                 );
3100                 return $this->mSubpages;
3101         }
3102
3103         /**
3104          * Is there a version of this page in the deletion archive?
3105          *
3106          * @return int The number of archived revisions
3107          */
3108         public function isDeleted() {
3109                 if ( $this->getNamespace() < 0 ) {
3110                         $n = 0;
3111                 } else {
3112                         $dbr = wfGetDB( DB_SLAVE );
3113
3114                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3115                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3116                                 __METHOD__
3117                         );
3118                         if ( $this->getNamespace() == NS_FILE ) {
3119                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3120                                         array( 'fa_name' => $this->getDBkey() ),
3121                                         __METHOD__
3122                                 );
3123                         }
3124                 }
3125                 return (int)$n;
3126         }
3127
3128         /**
3129          * Is there a version of this page in the deletion archive?
3130          *
3131          * @return bool
3132          */
3133         public function isDeletedQuick() {
3134                 if ( $this->getNamespace() < 0 ) {
3135                         return false;
3136                 }
3137                 $dbr = wfGetDB( DB_SLAVE );
3138                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3139                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3140                         __METHOD__
3141                 );
3142                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3143                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3144                                 array( 'fa_name' => $this->getDBkey() ),
3145                                 __METHOD__
3146                         );
3147                 }
3148                 return $deleted;
3149         }
3150
3151         /**
3152          * Get the article ID for this Title from the link cache,
3153          * adding it if necessary
3154          *
3155          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3156          *  for update
3157          * @return int The ID
3158          */
3159         public function getArticleID( $flags = 0 ) {
3160                 if ( $this->getNamespace() < 0 ) {
3161                         $this->mArticleID = 0;
3162                         return $this->mArticleID;
3163                 }
3164                 $linkCache = LinkCache::singleton();
3165                 if ( $flags & self::GAID_FOR_UPDATE ) {
3166                         $oldUpdate = $linkCache->forUpdate( true );
3167                         $linkCache->clearLink( $this );
3168                         $this->mArticleID = $linkCache->addLinkObj( $this );
3169                         $linkCache->forUpdate( $oldUpdate );
3170                 } else {
3171                         if ( -1 == $this->mArticleID ) {
3172                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3173                         }
3174                 }
3175                 return $this->mArticleID;
3176         }
3177
3178         /**
3179          * Is this an article that is a redirect page?
3180          * Uses link cache, adding it if necessary
3181          *
3182          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3183          * @return bool
3184          */
3185         public function isRedirect( $flags = 0 ) {
3186                 if ( !is_null( $this->mRedirect ) ) {
3187                         return $this->mRedirect;
3188                 }
3189                 # Calling getArticleID() loads the field from cache as needed
3190                 if ( !$this->getArticleID( $flags ) ) {
3191                         $this->mRedirect = false;
3192                         return $this->mRedirect;
3193                 }
3194
3195                 $linkCache = LinkCache::singleton();
3196                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3197                 if ( $cached === null ) {
3198                         # Trust LinkCache's state over our own
3199                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3200                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3201                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3202                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3203                         # LinkCache to refresh its data from the master.
3204                         $this->mRedirect = false;
3205                         return $this->mRedirect;
3206                 }
3207
3208                 $this->mRedirect = (bool)$cached;
3209
3210                 return $this->mRedirect;
3211         }
3212
3213         /**
3214          * What is the length of this page?
3215          * Uses link cache, adding it if necessary
3216          *
3217          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3218          * @return int
3219          */
3220         public function getLength( $flags = 0 ) {
3221                 if ( $this->mLength != -1 ) {
3222                         return $this->mLength;
3223                 }
3224                 # Calling getArticleID() loads the field from cache as needed
3225                 if ( !$this->getArticleID( $flags ) ) {
3226                         $this->mLength = 0;
3227                         return $this->mLength;
3228                 }
3229                 $linkCache = LinkCache::singleton();
3230                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3231                 if ( $cached === null ) {
3232                         # Trust LinkCache's state over our own, as for isRedirect()
3233                         $this->mLength = 0;
3234                         return $this->mLength;
3235                 }
3236
3237                 $this->mLength = intval( $cached );
3238
3239                 return $this->mLength;
3240         }
3241
3242         /**
3243          * What is the page_latest field for this page?
3244          *
3245          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3246          * @return int Int or 0 if the page doesn't exist
3247          */
3248         public function getLatestRevID( $flags = 0 ) {
3249                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3250                         return intval( $this->mLatestID );
3251                 }
3252                 # Calling getArticleID() loads the field from cache as needed
3253                 if ( !$this->getArticleID( $flags ) ) {
3254                         $this->mLatestID = 0;
3255                         return $this->mLatestID;
3256                 }
3257                 $linkCache = LinkCache::singleton();
3258                 $linkCache->addLinkObj( $this );
3259                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3260                 if ( $cached === null ) {
3261                         # Trust LinkCache's state over our own, as for isRedirect()
3262                         $this->mLatestID = 0;
3263                         return $this->mLatestID;
3264                 }
3265
3266                 $this->mLatestID = intval( $cached );
3267
3268                 return $this->mLatestID;
3269         }
3270
3271         /**
3272          * This clears some fields in this object, and clears any associated
3273          * keys in the "bad links" section of the link cache.
3274          *
3275          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3276          * loading of the new page_id. It's also called from
3277          * WikiPage::doDeleteArticleReal()
3278          *
3279          * @param int $newid The new Article ID
3280          */
3281         public function resetArticleID( $newid ) {
3282                 $linkCache = LinkCache::singleton();
3283                 $linkCache->clearLink( $this );
3284
3285                 if ( $newid === false ) {
3286                         $this->mArticleID = -1;
3287                 } else {
3288                         $this->mArticleID = intval( $newid );
3289                 }
3290                 $this->mRestrictionsLoaded = false;
3291                 $this->mRestrictions = array();
3292                 $this->mRedirect = null;
3293                 $this->mLength = -1;
3294                 $this->mLatestID = false;
3295                 $this->mContentModel = false;
3296                 $this->mEstimateRevisions = null;
3297                 $this->mPageLanguage = false;
3298                 $this->mDbPageLanguage = null;
3299                 $this->mIsBigDeletion = null;
3300         }
3301
3302         /**
3303          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3304          *
3305          * @param string $text Containing title to capitalize
3306          * @param int $ns Namespace index, defaults to NS_MAIN
3307          * @return string Containing capitalized title
3308          */
3309         public static function capitalize( $text, $ns = NS_MAIN ) {
3310                 global $wgContLang;
3311
3312                 if ( MWNamespace::isCapitalized( $ns ) ) {
3313                         return $wgContLang->ucfirst( $text );
3314                 } else {
3315                         return $text;
3316                 }
3317         }
3318
3319         /**
3320          * Secure and split - main initialisation function for this object
3321          *
3322          * Assumes that mDbkeyform has been set, and is urldecoded
3323          * and uses underscores, but not otherwise munged.  This function
3324          * removes illegal characters, splits off the interwiki and
3325          * namespace prefixes, sets the other forms, and canonicalizes
3326          * everything.
3327          *
3328          * @return bool True on success
3329          */
3330         private function secureAndSplit() {
3331                 # Initialisation
3332                 $this->mInterwiki = '';
3333                 $this->mFragment = '';
3334                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3335
3336                 $dbkey = $this->mDbkeyform;
3337
3338                 try {
3339                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3340                         //        the parsing code with Title, while avoiding massive refactoring.
3341                         // @todo: get rid of secureAndSplit, refactor parsing code.
3342                         $titleParser = self::getTitleParser();
3343                         $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3344                 } catch ( MalformedTitleException $ex ) {
3345                         return false;
3346                 }
3347
3348                 # Fill fields
3349                 $this->setFragment( '#' . $parts['fragment'] );
3350                 $this->mInterwiki = $parts['interwiki'];
3351                 $this->mLocalInterwiki = $parts['local_interwiki'];
3352                 $this->mNamespace = $parts['namespace'];
3353                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3354
3355                 $this->mDbkeyform = $parts['dbkey'];
3356                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3357                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3358
3359                 # We already know that some pages won't be in the database!
3360                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3361                         $this->mArticleID = 0;
3362                 }
3363
3364                 return true;
3365         }
3366
3367         /**
3368          * Get an array of Title objects linking to this Title
3369          * Also stores the IDs in the link cache.
3370          *
3371          * WARNING: do not use this function on arbitrary user-supplied titles!
3372          * On heavily-used templates it will max out the memory.
3373          *
3374          * @param array $options May be FOR UPDATE
3375          * @param string $table Table name
3376          * @param string $prefix Fields prefix
3377          * @return Title[] Array of Title objects linking here
3378          */
3379         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3380                 if ( count( $options ) > 0 ) {
3381                         $db = wfGetDB( DB_MASTER );
3382                 } else {
3383                         $db = wfGetDB( DB_SLAVE );
3384                 }
3385
3386                 $res = $db->select(
3387                         array( 'page', $table ),
3388                         self::getSelectFields(),
3389                         array(
3390                                 "{$prefix}_from=page_id",
3391                                 "{$prefix}_namespace" => $this->getNamespace(),
3392                                 "{$prefix}_title" => $this->getDBkey() ),
3393                         __METHOD__,
3394                         $options
3395                 );
3396
3397                 $retVal = array();
3398                 if ( $res->numRows() ) {
3399                         $linkCache = LinkCache::singleton();
3400                         foreach ( $res as $row ) {
3401                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3402                                 if ( $titleObj ) {
3403                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3404                                         $retVal[] = $titleObj;
3405                                 }
3406                         }
3407                 }
3408                 return $retVal;
3409         }
3410
3411         /**
3412          * Get an array of Title objects using this Title as a template
3413          * Also stores the IDs in the link cache.
3414          *
3415          * WARNING: do not use this function on arbitrary user-supplied titles!
3416          * On heavily-used templates it will max out the memory.
3417          *
3418          * @param array $options May be FOR UPDATE
3419          * @return Title[] Array of Title the Title objects linking here
3420          */
3421         public function getTemplateLinksTo( $options = array() ) {
3422                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3423         }
3424
3425         /**
3426          * Get an array of Title objects linked from this Title
3427          * Also stores the IDs in the link cache.
3428          *
3429          * WARNING: do not use this function on arbitrary user-supplied titles!
3430          * On heavily-used templates it will max out the memory.
3431          *
3432          * @param array $options May be FOR UPDATE
3433          * @param string $table Table name
3434          * @param string $prefix Fields prefix
3435          * @return array Array of Title objects linking here
3436          */
3437         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3438                 global $wgContentHandlerUseDB;
3439
3440                 $id = $this->getArticleID();
3441
3442                 # If the page doesn't exist; there can't be any link from this page
3443                 if ( !$id ) {
3444                         return array();
3445                 }
3446
3447                 if ( count( $options ) > 0 ) {
3448                         $db = wfGetDB( DB_MASTER );
3449                 } else {
3450                         $db = wfGetDB( DB_SLAVE );
3451                 }
3452
3453                 $namespaceFiled = "{$prefix}_namespace";
3454                 $titleField = "{$prefix}_title";
3455
3456                 $fields = array(
3457                         $namespaceFiled,
3458                         $titleField,
3459                         'page_id',
3460                         'page_len',
3461                         'page_is_redirect',
3462                         'page_latest'
3463                 );
3464
3465                 if ( $wgContentHandlerUseDB ) {
3466                         $fields[] = 'page_content_model';
3467                 }
3468
3469                 $res = $db->select(
3470                         array( $table, 'page' ),
3471                         $fields,
3472                         array( "{$prefix}_from" => $id ),
3473                         __METHOD__,
3474                         $options,
3475                         array( 'page' => array(
3476                                 'LEFT JOIN',
3477                                 array( "page_namespace=$namespaceFiled", "page_title=$titleField" )
3478                         ) )
3479                 );
3480
3481                 $retVal = array();
3482                 if ( $res->numRows() ) {
3483                         $linkCache = LinkCache::singleton();
3484                         foreach ( $res as $row ) {
3485                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3486                                 if ( $titleObj ) {
3487                                         if ( $row->page_id ) {
3488                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3489                                         } else {
3490                                                 $linkCache->addBadLinkObj( $titleObj );
3491                                         }
3492                                         $retVal[] = $titleObj;
3493                                 }
3494                         }
3495                 }
3496                 return $retVal;
3497         }
3498
3499         /**
3500          * Get an array of Title objects used on this Title as a template
3501          * Also stores the IDs in the link cache.
3502          *
3503          * WARNING: do not use this function on arbitrary user-supplied titles!
3504          * On heavily-used templates it will max out the memory.
3505          *
3506          * @param array $options May be FOR UPDATE
3507          * @return Title[] Array of Title the Title objects used here
3508          */
3509         public function getTemplateLinksFrom( $options = array() ) {
3510                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3511         }
3512
3513         /**
3514          * Get an array of Title objects referring to non-existent articles linked
3515          * from this page.
3516          *
3517          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3518          *   should use redirect table in this case).
3519          * @return Title[] Array of Title the Title objects
3520          */
3521         public function getBrokenLinksFrom() {
3522                 if ( $this->getArticleID() == 0 ) {
3523                         # All links from article ID 0 are false positives
3524                         return array();
3525                 }
3526
3527                 $dbr = wfGetDB( DB_SLAVE );
3528                 $res = $dbr->select(
3529                         array( 'page', 'pagelinks' ),
3530                         array( 'pl_namespace', 'pl_title' ),
3531                         array(
3532                                 'pl_from' => $this->getArticleID(),
3533                                 'page_namespace IS NULL'
3534                         ),
3535                         __METHOD__, array(),
3536                         array(
3537                                 'page' => array(
3538                                         'LEFT JOIN',
3539                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3540                                 )
3541                         )
3542                 );
3543
3544                 $retVal = array();
3545                 foreach ( $res as $row ) {
3546                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3547                 }
3548                 return $retVal;
3549         }
3550
3551         /**
3552          * Get a list of URLs to purge from the Squid cache when this
3553          * page changes
3554          *
3555          * @return string[] Array of String the URLs
3556          */
3557         public function getSquidURLs() {
3558                 $urls = array(
3559                         $this->getInternalURL(),
3560                         $this->getInternalURL( 'action=history' )
3561                 );
3562
3563                 $pageLang = $this->getPageLanguage();
3564                 if ( $pageLang->hasVariants() ) {
3565                         $variants = $pageLang->getVariants();
3566                         foreach ( $variants as $vCode ) {
3567                                 $urls[] = $this->getInternalURL( '', $vCode );
3568                         }
3569                 }
3570
3571                 // If we are looking at a css/js user subpage, purge the action=raw.
3572                 if ( $this->isJsSubpage() ) {
3573                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3574                 } elseif ( $this->isCssSubpage() ) {
3575                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3576                 }
3577
3578                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3579                 return $urls;
3580         }
3581
3582         /**
3583          * Purge all applicable Squid URLs
3584          */
3585         public function purgeSquid() {
3586                 global $wgUseSquid;
3587                 if ( $wgUseSquid ) {
3588                         $urls = $this->getSquidURLs();
3589                         $u = new SquidUpdate( $urls );
3590                         $u->doUpdate();
3591                 }
3592         }
3593
3594         /**
3595          * Move this page without authentication
3596          *
3597          * @deprecated since 1.25 use MovePage class instead
3598          * @param Title $nt The new page Title
3599          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3600          */
3601         public function moveNoAuth( &$nt ) {
3602                 wfDeprecated( __METHOD__, '1.25' );
3603                 return $this->moveTo( $nt, false );
3604         }
3605
3606         /**
3607          * Check whether a given move operation would be valid.
3608          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3609          *
3610          * @deprecated since 1.25, use MovePage's methods instead
3611          * @param Title $nt The new title
3612          * @param bool $auth Ignored
3613          * @param string $reason Is the log summary of the move, used for spam checking
3614          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3615          */
3616         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3617                 global $wgUser;
3618
3619                 if ( !( $nt instanceof Title ) ) {
3620                         // Normally we'd add this to $errors, but we'll get
3621                         // lots of syntax errors if $nt is not an object
3622                         return array( array( 'badtitletext' ) );
3623                 }
3624
3625                 $mp = new MovePage( $this, $nt );
3626                 $errors = wfMergeErrorArrays(
3627                         $mp->isValidMove()->getErrorsArray(),
3628                         $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3629                 );
3630
3631                 return $errors ? : true;
3632         }
3633
3634         /**
3635          * Check if the requested move target is a valid file move target
3636          * @todo move this to MovePage
3637          * @param Title $nt Target title
3638          * @return array List of errors
3639          */
3640         protected function validateFileMoveOperation( $nt ) {
3641                 global $wgUser;
3642
3643                 $errors = array();
3644
3645                 $destFile = wfLocalFile( $nt );
3646                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3647                         $errors[] = array( 'file-exists-sharedrepo' );
3648                 }
3649
3650                 return $errors;
3651         }
3652
3653         /**
3654          * Move a title to a new location
3655          *
3656          * @deprecated since 1.25, use the MovePage class instead
3657          * @param Title $nt The new title
3658          * @param bool $auth Indicates whether $wgUser's permissions
3659          *  should be checked
3660          * @param string $reason The reason for the move
3661          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3662          *  Ignored if the user doesn't have the suppressredirect right.
3663          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3664          */
3665         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3666                 global $wgUser;
3667                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3668                 if ( is_array( $err ) ) {
3669                         // Auto-block user's IP if the account was "hard" blocked
3670                         $wgUser->spreadAnyEditBlock();
3671                         return $err;
3672                 }
3673                 // Check suppressredirect permission
3674                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3675                         $createRedirect = true;
3676                 }
3677
3678                 $mp = new MovePage( $this, $nt );
3679                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3680                 if ( $status->isOK() ) {
3681                         return true;
3682                 } else {
3683                         return $status->getErrorsArray();
3684                 }
3685         }
3686
3687         /**
3688          * Move this page's subpages to be subpages of $nt
3689          *
3690          * @param Title $nt Move target
3691          * @param bool $auth Whether $wgUser's permissions should be checked
3692          * @param string $reason The reason for the move
3693          * @param bool $createRedirect Whether to create redirects from the old subpages to
3694          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3695          * @return array Array with old page titles as keys, and strings (new page titles) or
3696          *     arrays (errors) as values, or an error array with numeric indices if no pages
3697          *     were moved
3698          */
3699         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3700                 global $wgMaximumMovedPages;
3701                 // Check permissions
3702                 if ( !$this->userCan( 'move-subpages' ) ) {
3703                         return array( 'cant-move-subpages' );
3704                 }
3705                 // Do the source and target namespaces support subpages?
3706                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3707                         return array( 'namespace-nosubpages',
3708                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3709                 }
3710                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3711                         return array( 'namespace-nosubpages',
3712                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3713                 }
3714
3715                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3716                 $retval = array();
3717                 $count = 0;
3718                 foreach ( $subpages as $oldSubpage ) {
3719                         $count++;
3720                         if ( $count > $wgMaximumMovedPages ) {
3721                                 $retval[$oldSubpage->getPrefixedText()] =
3722                                                 array( 'movepage-max-pages',
3723                                                         $wgMaximumMovedPages );
3724                                 break;
3725                         }
3726
3727                         // We don't know whether this function was called before
3728                         // or after moving the root page, so check both
3729                         // $this and $nt
3730                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3731                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3732                         ) {
3733                                 // When moving a page to a subpage of itself,
3734                                 // don't move it twice
3735                                 continue;
3736                         }
3737                         $newPageName = preg_replace(
3738                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3739                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3740                                         $oldSubpage->getDBkey() );
3741                         if ( $oldSubpage->isTalkPage() ) {
3742                                 $newNs = $nt->getTalkPage()->getNamespace();
3743                         } else {
3744                                 $newNs = $nt->getSubjectPage()->getNamespace();
3745                         }
3746                         # Bug 14385: we need makeTitleSafe because the new page names may
3747                         # be longer than 255 characters.
3748                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3749
3750                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3751                         if ( $success === true ) {
3752                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3753                         } else {
3754                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3755                         }
3756                 }
3757                 return $retval;
3758         }
3759
3760         /**
3761          * Checks if this page is just a one-rev redirect.
3762          * Adds lock, so don't use just for light purposes.
3763          *
3764          * @return bool
3765          */
3766         public function isSingleRevRedirect() {
3767                 global $wgContentHandlerUseDB;
3768
3769                 $dbw = wfGetDB( DB_MASTER );
3770
3771                 # Is it a redirect?
3772                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3773                 if ( $wgContentHandlerUseDB ) {
3774                         $fields[] = 'page_content_model';
3775                 }
3776
3777                 $row = $dbw->selectRow( 'page',
3778                         $fields,
3779                         $this->pageCond(),
3780                         __METHOD__,
3781                         array( 'FOR UPDATE' )
3782                 );
3783                 # Cache some fields we may want
3784                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3785                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3786                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3787                 $this->mContentModel = $row && isset( $row->page_content_model )
3788                         ? strval( $row->page_content_model )
3789                         : false;
3790
3791                 if ( !$this->mRedirect ) {
3792                         return false;
3793                 }
3794                 # Does the article have a history?
3795                 $row = $dbw->selectField( array( 'page', 'revision' ),
3796                         'rev_id',
3797                         array( 'page_namespace' => $this->getNamespace(),
3798                                 'page_title' => $this->getDBkey(),
3799                                 'page_id=rev_page',
3800                                 'page_latest != rev_id'
3801                         ),
3802                         __METHOD__,
3803                         array( 'FOR UPDATE' )
3804                 );
3805                 # Return true if there was no history
3806                 return ( $row === false );
3807         }
3808
3809         /**
3810          * Checks if $this can be moved to a given Title
3811          * - Selects for update, so don't call it unless you mean business
3812          *
3813          * @deprecated since 1.25, use MovePage's methods instead
3814          * @param Title $nt The new title to check
3815          * @return bool
3816          */
3817         public function isValidMoveTarget( $nt ) {
3818                 # Is it an existing file?
3819                 if ( $nt->getNamespace() == NS_FILE ) {
3820                         $file = wfLocalFile( $nt );
3821                         if ( $file->exists() ) {
3822                                 wfDebug( __METHOD__ . ": file exists\n" );
3823                                 return false;
3824                         }
3825                 }
3826                 # Is it a redirect with no history?
3827                 if ( !$nt->isSingleRevRedirect() ) {
3828                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3829                         return false;
3830                 }
3831                 # Get the article text
3832                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3833                 if ( !is_object( $rev ) ) {
3834                         return false;
3835                 }
3836                 $content = $rev->getContent();
3837                 # Does the redirect point to the source?
3838                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3839                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3840
3841                 if ( $redirTitle ) {
3842                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3843                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3844                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3845                                 return false;
3846                         } else {
3847                                 return true;
3848                         }
3849                 } else {
3850                         # Fail safe (not a redirect after all. strange.)
3851                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3852                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3853                         return false;
3854                 }
3855         }
3856
3857         /**
3858          * Get categories to which this Title belongs and return an array of
3859          * categories' names.
3860          *
3861          * @return array Array of parents in the form:
3862          *        $parent => $currentarticle
3863          */
3864         public function getParentCategories() {
3865                 global $wgContLang;
3866
3867                 $data = array();
3868
3869                 $titleKey = $this->getArticleID();
3870
3871                 if ( $titleKey === 0 ) {
3872                         return $data;
3873                 }
3874
3875                 $dbr = wfGetDB( DB_SLAVE );
3876
3877                 $res = $dbr->select(
3878                         'categorylinks',
3879                         'cl_to',
3880                         array( 'cl_from' => $titleKey ),
3881                         __METHOD__
3882                 );
3883
3884                 if ( $res->numRows() > 0 ) {
3885                         foreach ( $res as $row ) {
3886                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3887                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3888                         }
3889                 }
3890                 return $data;
3891         }
3892
3893         /**
3894          * Get a tree of parent categories
3895          *
3896          * @param array $children Array with the children in the keys, to check for circular refs
3897          * @return array Tree of parent categories
3898          */
3899         public function getParentCategoryTree( $children = array() ) {
3900                 $stack = array();
3901                 $parents = $this->getParentCategories();
3902
3903                 if ( $parents ) {
3904                         foreach ( $parents as $parent => $current ) {
3905                                 if ( array_key_exists( $parent, $children ) ) {
3906                                         # Circular reference
3907                                         $stack[$parent] = array();
3908                                 } else {
3909                                         $nt = Title::newFromText( $parent );
3910                                         if ( $nt ) {
3911                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3912                                         }
3913                                 }
3914                         }
3915                 }
3916
3917                 return $stack;
3918         }
3919
3920         /**
3921          * Get an associative array for selecting this title from
3922          * the "page" table
3923          *
3924          * @return array Array suitable for the $where parameter of DB::select()
3925          */
3926         public function pageCond() {
3927                 if ( $this->mArticleID > 0 ) {
3928                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3929                         return array( 'page_id' => $this->mArticleID );
3930                 } else {
3931                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3932                 }
3933         }
3934
3935         /**
3936          * Get the revision ID of the previous revision
3937          *
3938          * @param int $revId Revision ID. Get the revision that was before this one.
3939          * @param int $flags Title::GAID_FOR_UPDATE
3940          * @return int|bool Old revision ID, or false if none exists
3941          */
3942         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3943                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3944                 $revId = $db->selectField( 'revision', 'rev_id',
3945                         array(
3946                                 'rev_page' => $this->getArticleID( $flags ),
3947                                 'rev_id < ' . intval( $revId )
3948                         ),
3949                         __METHOD__,
3950                         array( 'ORDER BY' => 'rev_id DESC' )
3951                 );
3952
3953                 if ( $revId === false ) {
3954                         return false;
3955                 } else {
3956                         return intval( $revId );
3957                 }
3958         }
3959
3960         /**
3961          * Get the revision ID of the next revision
3962          *
3963          * @param int $revId Revision ID. Get the revision that was after this one.
3964          * @param int $flags Title::GAID_FOR_UPDATE
3965          * @return int|bool Next revision ID, or false if none exists
3966          */
3967         public function getNextRevisionID( $revId, $flags = 0 ) {
3968                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3969                 $revId = $db->selectField( 'revision', 'rev_id',
3970                         array(
3971                                 'rev_page' => $this->getArticleID( $flags ),
3972                                 'rev_id > ' . intval( $revId )
3973                         ),
3974                         __METHOD__,
3975                         array( 'ORDER BY' => 'rev_id' )
3976                 );
3977
3978                 if ( $revId === false ) {
3979                         return false;
3980                 } else {
3981                         return intval( $revId );
3982                 }
3983         }
3984
3985         /**
3986          * Get the first revision of the page
3987          *
3988          * @param int $flags Title::GAID_FOR_UPDATE
3989          * @return Revision|null If page doesn't exist
3990          */
3991         public function getFirstRevision( $flags = 0 ) {
3992                 $pageId = $this->getArticleID( $flags );
3993                 if ( $pageId ) {
3994                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3995                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3996                                 array( 'rev_page' => $pageId ),
3997                                 __METHOD__,
3998                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3999                         );
4000                         if ( $row ) {
4001                                 return new Revision( $row );
4002                         }
4003                 }
4004                 return null;
4005         }
4006
4007         /**
4008          * Get the oldest revision timestamp of this page
4009          *
4010          * @param int $flags Title::GAID_FOR_UPDATE
4011          * @return string MW timestamp
4012          */
4013         public function getEarliestRevTime( $flags = 0 ) {
4014                 $rev = $this->getFirstRevision( $flags );
4015                 return $rev ? $rev->getTimestamp() : null;
4016         }
4017
4018         /**
4019          * Check if this is a new page
4020          *
4021          * @return bool
4022          */
4023         public function isNewPage() {
4024                 $dbr = wfGetDB( DB_SLAVE );
4025                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4026         }
4027
4028         /**
4029          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4030          *
4031          * @return bool
4032          */
4033         public function isBigDeletion() {
4034                 global $wgDeleteRevisionsLimit;
4035
4036                 if ( !$wgDeleteRevisionsLimit ) {
4037                         return false;
4038                 }
4039
4040                 if ( $this->mIsBigDeletion === null ) {
4041                         $dbr = wfGetDB( DB_SLAVE );
4042
4043                         $innerQuery = $dbr->selectSQLText(
4044                                 'revision',
4045                                 '1',
4046                                 array( 'rev_page' => $this->getArticleID() ),
4047                                 __METHOD__,
4048                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4049                         );
4050
4051                         $revCount = $dbr->query(
4052                                 'SELECT COUNT(*) FROM (' . $innerQuery . ') AS innerQuery',
4053                                 __METHOD__
4054                         );
4055                         $revCount = $revCount->fetchRow();
4056                         $revCount = $revCount['COUNT(*)'];
4057
4058                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4059                 }
4060
4061                 return $this->mIsBigDeletion;
4062         }
4063
4064         /**
4065          * Get the approximate revision count of this page.
4066          *
4067          * @return int
4068          */
4069         public function estimateRevisionCount() {
4070                 if ( !$this->exists() ) {
4071                         return 0;
4072                 }
4073
4074                 if ( $this->mEstimateRevisions === null ) {
4075                         $dbr = wfGetDB( DB_SLAVE );
4076                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4077                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4078                 }
4079
4080                 return $this->mEstimateRevisions;
4081         }
4082
4083         /**
4084          * Get the number of revisions between the given revision.
4085          * Used for diffs and other things that really need it.
4086          *
4087          * @param int|Revision $old Old revision or rev ID (first before range)
4088          * @param int|Revision $new New revision or rev ID (first after range)
4089          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4090          * @return int Number of revisions between these revisions.
4091          */
4092         public function countRevisionsBetween( $old, $new, $max = null ) {
4093                 if ( !( $old instanceof Revision ) ) {
4094                         $old = Revision::newFromTitle( $this, (int)$old );
4095                 }
4096                 if ( !( $new instanceof Revision ) ) {
4097                         $new = Revision::newFromTitle( $this, (int)$new );
4098                 }
4099                 if ( !$old || !$new ) {
4100                         return 0; // nothing to compare
4101                 }
4102                 $dbr = wfGetDB( DB_SLAVE );
4103                 $conds = array(
4104                         'rev_page' => $this->getArticleID(),
4105                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4106                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4107                 );
4108                 if ( $max !== null ) {
4109                         $res = $dbr->select( 'revision', '1',
4110                                 $conds,
4111                                 __METHOD__,
4112                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4113                         );
4114                         return $res->numRows();
4115                 } else {
4116                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4117                 }
4118         }
4119
4120         /**
4121          * Get the authors between the given revisions or revision IDs.
4122          * Used for diffs and other things that really need it.
4123          *
4124          * @since 1.23
4125          *
4126          * @param int|Revision $old Old revision or rev ID (first before range by default)
4127          * @param int|Revision $new New revision or rev ID (first after range by default)
4128          * @param int $limit Maximum number of authors
4129          * @param string|array $options (Optional): Single option, or an array of options:
4130          *     'include_old' Include $old in the range; $new is excluded.
4131          *     'include_new' Include $new in the range; $old is excluded.
4132          *     'include_both' Include both $old and $new in the range.
4133          *     Unknown option values are ignored.
4134          * @return array|null Names of revision authors in the range; null if not both revisions exist
4135          */
4136         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4137                 if ( !( $old instanceof Revision ) ) {
4138                         $old = Revision::newFromTitle( $this, (int)$old );
4139                 }
4140                 if ( !( $new instanceof Revision ) ) {
4141                         $new = Revision::newFromTitle( $this, (int)$new );
4142                 }
4143                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4144                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4145                 // in the sanity check below?
4146                 if ( !$old || !$new ) {
4147                         return null; // nothing to compare
4148                 }
4149                 $authors = array();
4150                 $old_cmp = '>';
4151                 $new_cmp = '<';
4152                 $options = (array)$options;
4153                 if ( in_array( 'include_old', $options ) ) {
4154                         $old_cmp = '>=';
4155                 }
4156                 if ( in_array( 'include_new', $options ) ) {
4157                         $new_cmp = '<=';
4158                 }
4159                 if ( in_array( 'include_both', $options ) ) {
4160                         $old_cmp = '>=';
4161                         $new_cmp = '<=';
4162                 }
4163                 // No DB query needed if $old and $new are the same or successive revisions:
4164                 if ( $old->getId() === $new->getId() ) {
4165                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4166                 } elseif ( $old->getId() === $new->getParentId() ) {
4167                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4168                                 $authors[] = $old->getRawUserText();
4169                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4170                                         $authors[] = $new->getRawUserText();
4171                                 }
4172                         } elseif ( $old_cmp === '>=' ) {
4173                                 $authors[] = $old->getRawUserText();
4174                         } elseif ( $new_cmp === '<=' ) {
4175                                 $authors[] = $new->getRawUserText();
4176                         }
4177                         return $authors;
4178                 }
4179                 $dbr = wfGetDB( DB_SLAVE );
4180                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4181                         array(
4182                                 'rev_page' => $this->getArticleID(),
4183                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4184                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4185                         ), __METHOD__,
4186                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4187                 );
4188                 foreach ( $res as $row ) {
4189                         $authors[] = $row->rev_user_text;
4190                 }
4191                 return $authors;
4192         }
4193
4194         /**
4195          * Get the number of authors between the given revisions or revision IDs.
4196          * Used for diffs and other things that really need it.
4197          *
4198          * @param int|Revision $old Old revision or rev ID (first before range by default)
4199          * @param int|Revision $new New revision or rev ID (first after range by default)
4200          * @param int $limit Maximum number of authors
4201          * @param string|array $options (Optional): Single option, or an array of options:
4202          *     'include_old' Include $old in the range; $new is excluded.
4203          *     'include_new' Include $new in the range; $old is excluded.
4204          *     'include_both' Include both $old and $new in the range.
4205          *     Unknown option values are ignored.
4206          * @return int Number of revision authors in the range; zero if not both revisions exist
4207          */
4208         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4209                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4210                 return $authors ? count( $authors ) : 0;
4211         }
4212
4213         /**
4214          * Compare with another title.
4215          *
4216          * @param Title $title
4217          * @return bool
4218          */
4219         public function equals( Title $title ) {
4220                 // Note: === is necessary for proper matching of number-like titles.
4221                 return $this->getInterwiki() === $title->getInterwiki()
4222                         && $this->getNamespace() == $title->getNamespace()
4223                         && $this->getDBkey() === $title->getDBkey();
4224         }
4225
4226         /**
4227          * Check if this title is a subpage of another title
4228          *
4229          * @param Title $title
4230          * @return bool
4231          */
4232         public function isSubpageOf( Title $title ) {
4233                 return $this->getInterwiki() === $title->getInterwiki()
4234                         && $this->getNamespace() == $title->getNamespace()
4235                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4236         }
4237
4238         /**
4239          * Check if page exists.  For historical reasons, this function simply
4240          * checks for the existence of the title in the page table, and will
4241          * thus return false for interwiki links, special pages and the like.
4242          * If you want to know if a title can be meaningfully viewed, you should
4243          * probably call the isKnown() method instead.
4244          *
4245          * @return bool
4246          */
4247         public function exists() {
4248                 $exists = $this->getArticleID() != 0;
4249                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4250                 return $exists;
4251         }
4252
4253         /**
4254          * Should links to this title be shown as potentially viewable (i.e. as
4255          * "bluelinks"), even if there's no record by this title in the page
4256          * table?
4257          *
4258          * This function is semi-deprecated for public use, as well as somewhat
4259          * misleadingly named.  You probably just want to call isKnown(), which
4260          * calls this function internally.
4261          *
4262          * (ISSUE: Most of these checks are cheap, but the file existence check
4263          * can potentially be quite expensive.  Including it here fixes a lot of
4264          * existing code, but we might want to add an optional parameter to skip
4265          * it and any other expensive checks.)
4266          *
4267          * @return bool
4268          */
4269         public function isAlwaysKnown() {
4270                 $isKnown = null;
4271
4272                 /**
4273                  * Allows overriding default behavior for determining if a page exists.
4274                  * If $isKnown is kept as null, regular checks happen. If it's
4275                  * a boolean, this value is returned by the isKnown method.
4276                  *
4277                  * @since 1.20
4278                  *
4279                  * @param Title $title
4280                  * @param bool|null $isKnown
4281                  */
4282                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4283
4284                 if ( !is_null( $isKnown ) ) {
4285                         return $isKnown;
4286                 }
4287
4288                 if ( $this->isExternal() ) {
4289                         return true;  // any interwiki link might be viewable, for all we know
4290                 }
4291
4292                 switch ( $this->mNamespace ) {
4293                         case NS_MEDIA:
4294                         case NS_FILE:
4295                                 // file exists, possibly in a foreign repo
4296                                 return (bool)wfFindFile( $this );
4297                         case NS_SPECIAL:
4298                                 // valid special page
4299                                 return SpecialPageFactory::exists( $this->getDBkey() );
4300                         case NS_MAIN:
4301                                 // selflink, possibly with fragment
4302                                 return $this->mDbkeyform == '';
4303                         case NS_MEDIAWIKI:
4304                                 // known system message
4305                                 return $this->hasSourceText() !== false;
4306                         default:
4307                                 return false;
4308                 }
4309         }
4310
4311         /**
4312          * Does this title refer to a page that can (or might) be meaningfully
4313          * viewed?  In particular, this function may be used to determine if
4314          * links to the title should be rendered as "bluelinks" (as opposed to
4315          * "redlinks" to non-existent pages).
4316          * Adding something else to this function will cause inconsistency
4317          * since LinkHolderArray calls isAlwaysKnown() and does its own
4318          * page existence check.
4319          *
4320          * @return bool
4321          */
4322         public function isKnown() {
4323                 return $this->isAlwaysKnown() || $this->exists();
4324         }
4325
4326         /**
4327          * Does this page have source text?
4328          *
4329          * @return bool
4330          */
4331         public function hasSourceText() {
4332                 if ( $this->exists() ) {
4333                         return true;
4334                 }
4335
4336                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4337                         // If the page doesn't exist but is a known system message, default
4338                         // message content will be displayed, same for language subpages-
4339                         // Use always content language to avoid loading hundreds of languages
4340                         // to get the link color.
4341                         global $wgContLang;
4342                         list( $name, ) = MessageCache::singleton()->figureMessage(
4343                                 $wgContLang->lcfirst( $this->getText() )
4344                         );
4345                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4346                         return $message->exists();
4347                 }
4348
4349                 return false;
4350         }
4351
4352         /**
4353          * Get the default message text or false if the message doesn't exist
4354          *
4355          * @return string|bool
4356          */
4357         public function getDefaultMessageText() {
4358                 global $wgContLang;
4359
4360                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4361                         return false;
4362                 }
4363
4364                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4365                         $wgContLang->lcfirst( $this->getText() )
4366                 );
4367                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4368
4369                 if ( $message->exists() ) {
4370                         return $message->plain();
4371                 } else {
4372                         return false;
4373                 }
4374         }
4375
4376         /**
4377          * Updates page_touched for this page; called from LinksUpdate.php
4378          *
4379          * @return bool True if the update succeeded
4380          */
4381         public function invalidateCache() {
4382                 if ( wfReadOnly() ) {
4383                         return false;
4384                 }
4385
4386                 if ( $this->mArticleID === 0 ) {
4387                         return true; // avoid gap locking if we know it's not there
4388                 }
4389
4390                 $method = __METHOD__;
4391                 $dbw = wfGetDB( DB_MASTER );
4392                 $conds = $this->pageCond();
4393                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method ) {
4394                         $dbw->update(
4395                                 'page',
4396                                 array( 'page_touched' => $dbw->timestamp() ),
4397                                 $conds,
4398                                 $method
4399                         );
4400                 } );
4401
4402                 return true;
4403         }
4404
4405         /**
4406          * Update page_touched timestamps and send squid purge messages for
4407          * pages linking to this title. May be sent to the job queue depending
4408          * on the number of links. Typically called on create and delete.
4409          */
4410         public function touchLinks() {
4411                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4412                 $u->doUpdate();
4413
4414                 if ( $this->getNamespace() == NS_CATEGORY ) {
4415                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4416                         $u->doUpdate();
4417                 }
4418         }
4419
4420         /**
4421          * Get the last touched timestamp
4422          *
4423          * @param DatabaseBase $db Optional db
4424          * @return string Last-touched timestamp
4425          */
4426         public function getTouched( $db = null ) {
4427                 if ( $db === null ) {
4428                         $db = wfGetDB( DB_SLAVE );
4429                 }
4430                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4431                 return $touched;
4432         }
4433
4434         /**
4435          * Get the timestamp when this page was updated since the user last saw it.
4436          *
4437          * @param User $user
4438          * @return string|null
4439          */
4440         public function getNotificationTimestamp( $user = null ) {
4441                 global $wgUser, $wgShowUpdatedMarker;
4442                 // Assume current user if none given
4443                 if ( !$user ) {
4444                         $user = $wgUser;
4445                 }
4446                 // Check cache first
4447                 $uid = $user->getId();
4448                 // avoid isset here, as it'll return false for null entries
4449                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4450                         return $this->mNotificationTimestamp[$uid];
4451                 }
4452                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4453                         $this->mNotificationTimestamp[$uid] = false;
4454                         return $this->mNotificationTimestamp[$uid];
4455                 }
4456                 // Don't cache too much!
4457                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4458                         $this->mNotificationTimestamp = array();
4459                 }
4460                 $dbr = wfGetDB( DB_SLAVE );
4461                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4462                         'wl_notificationtimestamp',
4463                         array(
4464                                 'wl_user' => $user->getId(),
4465                                 'wl_namespace' => $this->getNamespace(),
4466                                 'wl_title' => $this->getDBkey(),
4467                         ),
4468                         __METHOD__
4469                 );
4470                 return $this->mNotificationTimestamp[$uid];
4471         }
4472
4473         /**
4474          * Generate strings used for xml 'id' names in monobook tabs
4475          *
4476          * @param string $prepend Defaults to 'nstab-'
4477          * @return string XML 'id' name
4478          */
4479         public function getNamespaceKey( $prepend = 'nstab-' ) {
4480                 global $wgContLang;
4481                 // Gets the subject namespace if this title
4482                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4483                 // Checks if canonical namespace name exists for namespace
4484                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4485                         // Uses canonical namespace name
4486                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4487                 } else {
4488                         // Uses text of namespace
4489                         $namespaceKey = $this->getSubjectNsText();
4490                 }
4491                 // Makes namespace key lowercase
4492                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4493                 // Uses main
4494                 if ( $namespaceKey == '' ) {
4495                         $namespaceKey = 'main';
4496                 }
4497                 // Changes file to image for backwards compatibility
4498                 if ( $namespaceKey == 'file' ) {
4499                         $namespaceKey = 'image';
4500                 }
4501                 return $prepend . $namespaceKey;
4502         }
4503
4504         /**
4505          * Get all extant redirects to this Title
4506          *
4507          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4508          * @return Title[] Array of Title redirects to this title
4509          */
4510         public function getRedirectsHere( $ns = null ) {
4511                 $redirs = array();
4512
4513                 $dbr = wfGetDB( DB_SLAVE );
4514                 $where = array(
4515                         'rd_namespace' => $this->getNamespace(),
4516                         'rd_title' => $this->getDBkey(),
4517                         'rd_from = page_id'
4518                 );
4519                 if ( $this->isExternal() ) {
4520                         $where['rd_interwiki'] = $this->getInterwiki();
4521                 } else {
4522                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4523                 }
4524                 if ( !is_null( $ns ) ) {
4525                         $where['page_namespace'] = $ns;
4526                 }
4527
4528                 $res = $dbr->select(
4529                         array( 'redirect', 'page' ),
4530                         array( 'page_namespace', 'page_title' ),
4531                         $where,
4532                         __METHOD__
4533                 );
4534
4535                 foreach ( $res as $row ) {
4536                         $redirs[] = self::newFromRow( $row );
4537                 }
4538                 return $redirs;
4539         }
4540
4541         /**
4542          * Check if this Title is a valid redirect target
4543          *
4544          * @return bool
4545          */
4546         public function isValidRedirectTarget() {
4547                 global $wgInvalidRedirectTargets;
4548
4549                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4550                 if ( $this->isSpecial( 'Userlogout' ) ) {
4551                         return false;
4552                 }
4553
4554                 foreach ( $wgInvalidRedirectTargets as $target ) {
4555                         if ( $this->isSpecial( $target ) ) {
4556                                 return false;
4557                         }
4558                 }
4559
4560                 return true;
4561         }
4562
4563         /**
4564          * Get a backlink cache object
4565          *
4566          * @return BacklinkCache
4567          */
4568         public function getBacklinkCache() {
4569                 return BacklinkCache::get( $this );
4570         }
4571
4572         /**
4573          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4574          *
4575          * @return bool
4576          */
4577         public function canUseNoindex() {
4578                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4579
4580                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4581                         ? $wgContentNamespaces
4582                         : $wgExemptFromUserRobotsControl;
4583
4584                 return !in_array( $this->mNamespace, $bannedNamespaces );
4585
4586         }
4587
4588         /**
4589          * Returns the raw sort key to be used for categories, with the specified
4590          * prefix.  This will be fed to Collation::getSortKey() to get a
4591          * binary sortkey that can be used for actual sorting.
4592          *
4593          * @param string $prefix The prefix to be used, specified using
4594          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4595          *   prefix.
4596          * @return string
4597          */
4598         public function getCategorySortkey( $prefix = '' ) {
4599                 $unprefixed = $this->getText();
4600
4601                 // Anything that uses this hook should only depend
4602                 // on the Title object passed in, and should probably
4603                 // tell the users to run updateCollations.php --force
4604                 // in order to re-sort existing category relations.
4605                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4606                 if ( $prefix !== '' ) {
4607                         # Separate with a line feed, so the unprefixed part is only used as
4608                         # a tiebreaker when two pages have the exact same prefix.
4609                         # In UCA, tab is the only character that can sort above LF
4610                         # so we strip both of them from the original prefix.
4611                         $prefix = strtr( $prefix, "\n\t", '  ' );
4612                         return "$prefix\n$unprefixed";
4613                 }
4614                 return $unprefixed;
4615         }
4616
4617         /**
4618          * Get the language in which the content of this page is written in
4619          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4620          * e.g. $wgLang (such as special pages, which are in the user language).
4621          *
4622          * @since 1.18
4623          * @return Language
4624          */
4625         public function getPageLanguage() {
4626                 global $wgLang, $wgLanguageCode;
4627                 wfProfileIn( __METHOD__ );
4628                 if ( $this->isSpecialPage() ) {
4629                         // special pages are in the user language
4630                         wfProfileOut( __METHOD__ );
4631                         return $wgLang;
4632                 }
4633
4634                 // Checking if DB language is set
4635                 if ( $this->mDbPageLanguage ) {
4636                         wfProfileOut( __METHOD__ );
4637                         return wfGetLangObj( $this->mDbPageLanguage );
4638                 }
4639
4640                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4641                         // Note that this may depend on user settings, so the cache should
4642                         // be only per-request.
4643                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4644                         // content to determine the page language!
4645                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4646                         // tests.
4647                         $contentHandler = ContentHandler::getForTitle( $this );
4648                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4649                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4650                 } else {
4651                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4652                 }
4653
4654                 wfProfileOut( __METHOD__ );
4655                 return $langObj;
4656         }
4657
4658         /**
4659          * Get the language in which the content of this page is written when
4660          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4661          * e.g. $wgLang (such as special pages, which are in the user language).
4662          *
4663          * @since 1.20
4664          * @return Language
4665          */
4666         public function getPageViewLanguage() {
4667                 global $wgLang;
4668
4669                 if ( $this->isSpecialPage() ) {
4670                         // If the user chooses a variant, the content is actually
4671                         // in a language whose code is the variant code.
4672                         $variant = $wgLang->getPreferredVariant();
4673                         if ( $wgLang->getCode() !== $variant ) {
4674                                 return Language::factory( $variant );
4675                         }
4676
4677                         return $wgLang;
4678                 }
4679
4680                 // @note Can't be cached persistently, depends on user settings.
4681                 // @note ContentHandler::getPageViewLanguage() may need to load the
4682                 //   content to determine the page language!
4683                 $contentHandler = ContentHandler::getForTitle( $this );
4684                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4685                 return $pageLang;
4686         }
4687
4688         /**
4689          * Get a list of rendered edit notices for this page.
4690          *
4691          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4692          * they will already be wrapped in paragraphs.
4693          *
4694          * @since 1.21
4695          * @param int $oldid Revision ID that's being edited
4696          * @return array
4697          */
4698         public function getEditNotices( $oldid = 0 ) {
4699                 $notices = array();
4700
4701                 # Optional notices on a per-namespace and per-page basis
4702                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4703                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4704                 if ( $editnotice_ns_message->exists() ) {
4705                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4706                 }
4707                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4708                         $parts = explode( '/', $this->getDBkey() );
4709                         $editnotice_base = $editnotice_ns;
4710                         while ( count( $parts ) > 0 ) {
4711                                 $editnotice_base .= '-' . array_shift( $parts );
4712                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4713                                 if ( $editnotice_base_msg->exists() ) {
4714                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4715                                 }
4716                         }
4717                 } else {
4718                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4719                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4720                         $editnoticeMsg = wfMessage( $editnoticeText );
4721                         if ( $editnoticeMsg->exists() ) {
4722                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4723                         }
4724                 }
4725
4726                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4727                 return $notices;
4728         }
4729 }