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 string|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
 229                 try {
 230                         $t->secureAndSplit();
 231                         return $t;
 232                 } catch ( MalformedTitleException $ex ) {
 233                         return null;
 234                 }
 235         }
 236
 237         /**
 238          * Create a new Title from a TitleValue
 239          *
 240          * @param TitleValue $titleValue Assumed to be safe.
 241          *
 242          * @return Title
 243          */
 244         public static function newFromTitleValue( TitleValue $titleValue ) {
 245                 return self::makeTitle(
 246                         $titleValue->getNamespace(),
 247                         $titleValue->getText(),
 248                         $titleValue->getFragment() );
 249         }
 250
 251         /**
 252          * Create a new Title from text, such as what one would find in a link. De-
 253          * codes any HTML entities in the text.
 254          *
 255          * @param string $text The link text; spaces, prefixes, and an
 256          *   initial ':' indicating the main namespace are accepted.
 257          * @param int $defaultNamespace The namespace to use if none is specified
 258          *   by a prefix.  If you want to force a specific namespace even if
 259          *   $text might begin with a namespace prefix, use makeTitle() or
 260          *   makeTitleSafe().
 261          * @throws InvalidArgumentException
 262          * @return Title|null Title or null on an error.
 263          */
 264         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 265                 if ( is_object( $text ) ) {
 266                         throw new InvalidArgumentException( '$text must be a string.' );
 267                 } elseif ( !is_string( $text ) ) {
 268                         wfDebugLog( 'T76305', wfGetAllCallers( 5 ) );
 269                         wfWarn(
 270                                 __METHOD__ . ': $text must be a string. ' .
 271                                         'This will throw an InvalidArgumentException in future.',
 272                                 2
 273                         );
 274                 }
 275
 276                 try {
 277                         return Title::newFromTextThrow( $text, $defaultNamespace );
 278                 } catch ( MalformedTitleException $ex ) {
 279                         return null;
 280                 }
 281         }
 282
 283         /**
 284          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 285          * rather than returning null.
 286          *
 287          * The exception subclasses encode detailed information about why the title is invalid.
 288          *
 289          * @see Title::newFromText
 290          *
 291          * @since 1.25
 292          * @param string $text Title text to check
 293          * @param int $defaultNamespace
 294          * @throws MalformedTitleException If the title is invalid
 295          * @return Title
 296          */
 297         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 298                 if ( is_object( $text ) ) {
 299                         throw new MWException( 'Title::newFromTextThrow given an object' );
 300                 }
 301
 302                 $cache = self::getTitleCache();
 303
 304                 /**
 305                  * Wiki pages often contain multiple links to the same page.
 306                  * Title normalization and parsing can become expensive on
 307                  * pages with many links, so we can save a little time by
 308                  * caching them.
 309                  *
 310                  * In theory these are value objects and won't get changed...
 311                  */
 312                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 313                         return $cache->get( $text );
 314                 }
 315
 316                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 317                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 318
 319                 $t = new Title();
 320                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 321                 $t->mDefaultNamespace = intval( $defaultNamespace );
 322
 323                 $t->secureAndSplit();
 324                 if ( $defaultNamespace == NS_MAIN ) {
 325                         $cache->set( $text, $t );
 326                 }
 327                 return $t;
 328         }
 329
 330         /**
 331          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 332          *
 333          * Example of wrong and broken code:
 334          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 335          *
 336          * Example of right code:
 337          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 338          *
 339          * Create a new Title from URL-encoded text. Ensures that
 340          * the given title's length does not exceed the maximum.
 341          *
 342          * @param string $url The title, as might be taken from a URL
 343          * @return Title|null The new object, or null on an error
 344          */
 345         public static function newFromURL( $url ) {
 346                 $t = new Title();
 347
 348                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 349                 # but some URLs used it as a space replacement and they still come
 350                 # from some external search tools.
 351                 if ( strpos( self::legalChars(), '+' ) === false ) {
 352                         $url = strtr( $url, '+', ' ' );
 353                 }
 354
 355                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 356
 357                 try {
 358                         $t->secureAndSplit();
 359                         return $t;
 360                 } catch ( MalformedTitleException $ex ) {
 361                         return null;
 362                 }
 363         }
 364
 365         /**
 366          * @return MapCacheLRU
 367          */
 368         private static function getTitleCache() {
 369                 if ( self::$titleCache == null ) {
 370                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 371                 }
 372                 return self::$titleCache;
 373         }
 374
 375         /**
 376          * Returns a list of fields that are to be selected for initializing Title
 377          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 378          * whether to include page_content_model.
 379          *
 380          * @return array
 381          */
 382         protected static function getSelectFields() {
 383                 global $wgContentHandlerUseDB;
 384
 385                 $fields = array(
 386                         'page_namespace', 'page_title', 'page_id',
 387                         'page_len', 'page_is_redirect', 'page_latest',
 388                 );
 389
 390                 if ( $wgContentHandlerUseDB ) {
 391                         $fields[] = 'page_content_model';
 392                 }
 393
 394                 return $fields;
 395         }
 396
 397         /**
 398          * Create a new Title from an article ID
 399          *
 400          * @param int $id The page_id corresponding to the Title to create
 401          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 402          * @return Title|null The new object, or null on an error
 403          */
 404         public static function newFromID( $id, $flags = 0 ) {
 405                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 406                 $row = $db->selectRow(
 407                         'page',
 408                         self::getSelectFields(),
 409                         array( 'page_id' => $id ),
 410                         __METHOD__
 411                 );
 412                 if ( $row !== false ) {
 413                         $title = Title::newFromRow( $row );
 414                 } else {
 415                         $title = null;
 416                 }
 417                 return $title;
 418         }
 419
 420         /**
 421          * Make an array of titles from an array of IDs
 422          *
 423          * @param int[] $ids Array of IDs
 424          * @return Title[] Array of Titles
 425          */
 426         public static function newFromIDs( $ids ) {
 427                 if ( !count( $ids ) ) {
 428                         return array();
 429                 }
 430                 $dbr = wfGetDB( DB_SLAVE );
 431
 432                 $res = $dbr->select(
 433                         'page',
 434                         self::getSelectFields(),
 435                         array( 'page_id' => $ids ),
 436                         __METHOD__
 437                 );
 438
 439                 $titles = array();
 440                 foreach ( $res as $row ) {
 441                         $titles[] = Title::newFromRow( $row );
 442                 }
 443                 return $titles;
 444         }
 445
 446         /**
 447          * Make a Title object from a DB row
 448          *
 449          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 450          * @return Title Corresponding Title
 451          */
 452         public static function newFromRow( $row ) {
 453                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 454                 $t->loadFromRow( $row );
 455                 return $t;
 456         }
 457
 458         /**
 459          * Load Title object fields from a DB row.
 460          * If false is given, the title will be treated as non-existing.
 461          *
 462          * @param stdClass|bool $row Database row
 463          */
 464         public function loadFromRow( $row ) {
 465                 if ( $row ) { // page found
 466                         if ( isset( $row->page_id ) ) {
 467                                 $this->mArticleID = (int)$row->page_id;
 468                         }
 469                         if ( isset( $row->page_len ) ) {
 470                                 $this->mLength = (int)$row->page_len;
 471                         }
 472                         if ( isset( $row->page_is_redirect ) ) {
 473                                 $this->mRedirect = (bool)$row->page_is_redirect;
 474                         }
 475                         if ( isset( $row->page_latest ) ) {
 476                                 $this->mLatestID = (int)$row->page_latest;
 477                         }
 478                         if ( isset( $row->page_content_model ) ) {
 479                                 $this->mContentModel = strval( $row->page_content_model );
 480                         } else {
 481                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 482                         }
 483                         if ( isset( $row->page_lang ) ) {
 484                                 $this->mDbPageLanguage = (string)$row->page_lang;
 485                         }
 486                         if ( isset( $row->page_restrictions ) ) {
 487                                 $this->mOldRestrictions = $row->page_restrictions;
 488                         }
 489                 } else { // page not found
 490                         $this->mArticleID = 0;
 491                         $this->mLength = 0;
 492                         $this->mRedirect = false;
 493                         $this->mLatestID = 0;
 494                         $this->mContentModel = false; # initialized lazily in getContentModel()
 495                 }
 496         }
 497
 498         /**
 499          * Create a new Title from a namespace index and a DB key.
 500          * It's assumed that $ns and $title are *valid*, for instance when
 501          * they came directly from the database or a special page name.
 502          * For convenience, spaces are converted to underscores so that
 503          * eg user_text fields can be used directly.
 504          *
 505          * @param int $ns The namespace of the article
 506          * @param string $title The unprefixed database key form
 507          * @param string $fragment The link fragment (after the "#")
 508          * @param string $interwiki The interwiki prefix
 509          * @return Title The new object
 510          */
 511         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 512                 $t = new Title();
 513                 $t->mInterwiki = $interwiki;
 514                 $t->mFragment = $fragment;
 515                 $t->mNamespace = $ns = intval( $ns );
 516                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 517                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 518                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 519                 $t->mTextform = strtr( $title, '_', ' ' );
 520                 $t->mContentModel = false; # initialized lazily in getContentModel()
 521                 return $t;
 522         }
 523
 524         /**
 525          * Create a new Title from a namespace index and a DB key.
 526          * The parameters will be checked for validity, which is a bit slower
 527          * than makeTitle() but safer for user-provided data.
 528          *
 529          * @param int $ns The namespace of the article
 530          * @param string $title Database key form
 531          * @param string $fragment The link fragment (after the "#")
 532          * @param string $interwiki Interwiki prefix
 533          * @return Title|null The new object, or null on an error
 534          */
 535         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 536                 if ( !MWNamespace::exists( $ns ) ) {
 537                         return null;
 538                 }
 539
 540                 $t = new Title();
 541                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 542
 543                 try {
 544                         $t->secureAndSplit();
 545                         return $t;
 546                 } catch ( MalformedTitleException $ex ) {
 547                         return null;
 548                 }
 549         }
 550
 551         /**
 552          * Create a new Title for the Main Page
 553          *
 554          * @return Title The new object
 555          */
 556         public static function newMainPage() {
 557                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 558                 // Don't give fatal errors if the message is broken
 559                 if ( !$title ) {
 560                         $title = Title::newFromText( 'Main Page' );
 561                 }
 562                 return $title;
 563         }
 564
 565         /**
 566          * Extract a redirect destination from a string and return the
 567          * Title, or null if the text doesn't contain a valid redirect
 568          * This will only return the very next target, useful for
 569          * the redirect table and other checks that don't need full recursion
 570          *
 571          * @param string $text Text with possible redirect
 572          * @return Title The corresponding Title
 573          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 574          */
 575         public static function newFromRedirect( $text ) {
 576                 ContentHandler::deprecated( __METHOD__, '1.21' );
 577
 578                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 579                 return $content->getRedirectTarget();
 580         }
 581
 582         /**
 583          * Extract a redirect destination from a string and return the
 584          * Title, or null if the text doesn't contain a valid redirect
 585          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 586          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 587          *
 588          * @param string $text Text with possible redirect
 589          * @return Title
 590          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 591          */
 592         public static function newFromRedirectRecurse( $text ) {
 593                 ContentHandler::deprecated( __METHOD__, '1.21' );
 594
 595                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 596                 return $content->getUltimateRedirectTarget();
 597         }
 598
 599         /**
 600          * Extract a redirect destination from a string and return an
 601          * array of Titles, or null if the text doesn't contain a valid redirect
 602          * The last element in the array is the final destination after all redirects
 603          * have been resolved (up to $wgMaxRedirects times)
 604          *
 605          * @param string $text Text with possible redirect
 606          * @return Title[] Array of Titles, with the destination last
 607          * @deprecated since 1.21, use Content::getRedirectChain instead.
 608          */
 609         public static function newFromRedirectArray( $text ) {
 610                 ContentHandler::deprecated( __METHOD__, '1.21' );
 611
 612                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 613                 return $content->getRedirectChain();
 614         }
 615
 616         /**
 617          * Get the prefixed DB key associated with an ID
 618          *
 619          * @param int $id The page_id of the article
 620          * @return Title|null An object representing the article, or null if no such article was found
 621          */
 622         public static function nameOf( $id ) {
 623                 $dbr = wfGetDB( DB_SLAVE );
 624
 625                 $s = $dbr->selectRow(
 626                         'page',
 627                         array( 'page_namespace', 'page_title' ),
 628                         array( 'page_id' => $id ),
 629                         __METHOD__
 630                 );
 631                 if ( $s === false ) {
 632                         return null;
 633                 }
 634
 635                 $n = self::makeName( $s->page_namespace, $s->page_title );
 636                 return $n;
 637         }
 638
 639         /**
 640          * Get a regex character class describing the legal characters in a link
 641          *
 642          * @return string The list of characters, not delimited
 643          */
 644         public static function legalChars() {
 645                 global $wgLegalTitleChars;
 646                 return $wgLegalTitleChars;
 647         }
 648
 649         /**
 650          * Returns a simple regex that will match on characters and sequences invalid in titles.
 651          * Note that this doesn't pick up many things that could be wrong with titles, but that
 652          * replacing this regex with something valid will make many titles valid.
 653          *
 654          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 655          *
 656          * @return string Regex string
 657          */
 658         static function getTitleInvalidRegex() {
 659                 wfDeprecated( __METHOD__, '1.25' );
 660                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 661         }
 662
 663         /**
 664          * Utility method for converting a character sequence from bytes to Unicode.
 665          *
 666          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 667          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 668          *
 669          * @param string $byteClass
 670          * @return string
 671          */
 672         public static function convertByteClassToUnicodeClass( $byteClass ) {
 673                 $length = strlen( $byteClass );
 674                 // Input token queue
 675                 $x0 = $x1 = $x2 = '';
 676                 // Decoded queue
 677                 $d0 = $d1 = $d2 = '';
 678                 // Decoded integer codepoints
 679                 $ord0 = $ord1 = $ord2 = 0;
 680                 // Re-encoded queue
 681                 $r0 = $r1 = $r2 = '';
 682                 // Output
 683                 $out = '';
 684                 // Flags
 685                 $allowUnicode = false;
 686                 for ( $pos = 0; $pos < $length; $pos++ ) {
 687                         // Shift the queues down
 688                         $x2 = $x1;
 689                         $x1 = $x0;
 690                         $d2 = $d1;
 691                         $d1 = $d0;
 692                         $ord2 = $ord1;
 693                         $ord1 = $ord0;
 694                         $r2 = $r1;
 695                         $r1 = $r0;
 696                         // Load the current input token and decoded values
 697                         $inChar = $byteClass[$pos];
 698                         if ( $inChar == '\\' ) {
 699                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 700                                         $x0 = $inChar . $m[0];
 701                                         $d0 = chr( hexdec( $m[1] ) );
 702                                         $pos += strlen( $m[0] );
 703                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 704                                         $x0 = $inChar . $m[0];
 705                                         $d0 = chr( octdec( $m[0] ) );
 706                                         $pos += strlen( $m[0] );
 707                                 } elseif ( $pos + 1 >= $length ) {
 708                                         $x0 = $d0 = '\\';
 709                                 } else {
 710                                         $d0 = $byteClass[$pos + 1];
 711                                         $x0 = $inChar . $d0;
 712                                         $pos += 1;
 713                                 }
 714                         } else {
 715                                 $x0 = $d0 = $inChar;
 716                         }
 717                         $ord0 = ord( $d0 );
 718                         // Load the current re-encoded value
 719                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 720                                 $r0 = sprintf( '\x%02x', $ord0 );
 721                         } elseif ( $ord0 >= 0x80 ) {
 722                                 // Allow unicode if a single high-bit character appears
 723                                 $r0 = sprintf( '\x%02x', $ord0 );
 724                                 $allowUnicode = true;
 725                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 726                                 $r0 = '\\' . $d0;
 727                         } else {
 728                                 $r0 = $d0;
 729                         }
 730                         // Do the output
 731                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 732                                 // Range
 733                                 if ( $ord2 > $ord0 ) {
 734                                         // Empty range
 735                                 } elseif ( $ord0 >= 0x80 ) {
 736                                         // Unicode range
 737                                         $allowUnicode = true;
 738                                         if ( $ord2 < 0x80 ) {
 739                                                 // Keep the non-unicode section of the range
 740                                                 $out .= "$r2-\\x7F";
 741                                         }
 742                                 } else {
 743                                         // Normal range
 744                                         $out .= "$r2-$r0";
 745                                 }
 746                                 // Reset state to the initial value
 747                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 748                         } elseif ( $ord2 < 0x80 ) {
 749                                 // ASCII character
 750                                 $out .= $r2;
 751                         }
 752                 }
 753                 if ( $ord1 < 0x80 ) {
 754                         $out .= $r1;
 755                 }
 756                 if ( $ord0 < 0x80 ) {
 757                         $out .= $r0;
 758                 }
 759                 if ( $allowUnicode ) {
 760                         $out .= '\u0080-\uFFFF';
 761                 }
 762                 return $out;
 763         }
 764
 765         /**
 766          * Make a prefixed DB key from a DB key and a namespace index
 767          *
 768          * @param int $ns Numerical representation of the namespace
 769          * @param string $title The DB key form the title
 770          * @param string $fragment The link fragment (after the "#")
 771          * @param string $interwiki The interwiki prefix
 772          * @param bool $canoncialNamespace If true, use the canonical name for
 773          *   $ns instead of the localized version.
 774          * @return string The prefixed form of the title
 775          */
 776         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 777                 $canoncialNamespace = false
 778         ) {
 779                 global $wgContLang;
 780
 781                 if ( $canoncialNamespace ) {
 782                         $namespace = MWNamespace::getCanonicalName( $ns );
 783                 } else {
 784                         $namespace = $wgContLang->getNsText( $ns );
 785                 }
 786                 $name = $namespace == '' ? $title : "$namespace:$title";
 787                 if ( strval( $interwiki ) != '' ) {
 788                         $name = "$interwiki:$name";
 789                 }
 790                 if ( strval( $fragment ) != '' ) {
 791                         $name .= '#' . $fragment;
 792                 }
 793                 return $name;
 794         }
 795
 796         /**
 797          * Escape a text fragment, say from a link, for a URL
 798          *
 799          * @param string $fragment Containing a URL or link fragment (after the "#")
 800          * @return string Escaped string
 801          */
 802         static function escapeFragmentForURL( $fragment ) {
 803                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 804                 # fragments appear not to work in IE (at least up to 7) or in at least
 805                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 806                 # to care if they aren't encoded.
 807                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 808         }
 809
 810         /**
 811          * Callback for usort() to do title sorts by (namespace, title)
 812          *
 813          * @param Title $a
 814          * @param Title $b
 815          *
 816          * @return int Result of string comparison, or namespace comparison
 817          */
 818         public static function compare( $a, $b ) {
 819                 if ( $a->getNamespace() == $b->getNamespace() ) {
 820                         return strcmp( $a->getText(), $b->getText() );
 821                 } else {
 822                         return $a->getNamespace() - $b->getNamespace();
 823                 }
 824         }
 825
 826         /**
 827          * Determine whether the object refers to a page within
 828          * this project (either this wiki or a wiki with a local
 829          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 830          *
 831          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 832          */
 833         public function isLocal() {
 834                 if ( $this->isExternal() ) {
 835                         $iw = Interwiki::fetch( $this->mInterwiki );
 836                         if ( $iw ) {
 837                                 return $iw->isLocal();
 838                         }
 839                 }
 840                 return true;
 841         }
 842
 843         /**
 844          * Is this Title interwiki?
 845          *
 846          * @return bool
 847          */
 848         public function isExternal() {
 849                 return $this->mInterwiki !== '';
 850         }
 851
 852         /**
 853          * Get the interwiki prefix
 854          *
 855          * Use Title::isExternal to check if a interwiki is set
 856          *
 857          * @return string Interwiki prefix
 858          */
 859         public function getInterwiki() {
 860                 return $this->mInterwiki;
 861         }
 862
 863         /**
 864          * Was this a local interwiki link?
 865          *
 866          * @return bool
 867          */
 868         public function wasLocalInterwiki() {
 869                 return $this->mLocalInterwiki;
 870         }
 871
 872         /**
 873          * Determine whether the object refers to a page within
 874          * this project and is transcludable.
 875          *
 876          * @return bool True if this is transcludable
 877          */
 878         public function isTrans() {
 879                 if ( !$this->isExternal() ) {
 880                         return false;
 881                 }
 882
 883                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 884         }
 885
 886         /**
 887          * Returns the DB name of the distant wiki which owns the object.
 888          *
 889          * @return string The DB name
 890          */
 891         public function getTransWikiID() {
 892                 if ( !$this->isExternal() ) {
 893                         return false;
 894                 }
 895
 896                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 897         }
 898
 899         /**
 900          * Get a TitleValue object representing this Title.
 901          *
 902          * @note Not all valid Titles have a corresponding valid TitleValue
 903          * (e.g. TitleValues cannot represent page-local links that have a
 904          * fragment but no title text).
 905          *
 906          * @return TitleValue|null
 907          */
 908         public function getTitleValue() {
 909                 if ( $this->mTitleValue === null ) {
 910                         try {
 911                                 $this->mTitleValue = new TitleValue(
 912                                         $this->getNamespace(),
 913                                         $this->getDBkey(),
 914                                         $this->getFragment() );
 915                         } catch ( InvalidArgumentException $ex ) {
 916                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 917                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 918                         }
 919                 }
 920
 921                 return $this->mTitleValue;
 922         }
 923
 924         /**
 925          * Get the text form (spaces not underscores) of the main part
 926          *
 927          * @return string Main part of the title
 928          */
 929         public function getText() {
 930                 return $this->mTextform;
 931         }
 932
 933         /**
 934          * Get the URL-encoded form of the main part
 935          *
 936          * @return string Main part of the title, URL-encoded
 937          */
 938         public function getPartialURL() {
 939                 return $this->mUrlform;
 940         }
 941
 942         /**
 943          * Get the main part with underscores
 944          *
 945          * @return string Main part of the title, with underscores
 946          */
 947         public function getDBkey() {
 948                 return $this->mDbkeyform;
 949         }
 950
 951         /**
 952          * Get the DB key with the initial letter case as specified by the user
 953          *
 954          * @return string DB key
 955          */
 956         function getUserCaseDBKey() {
 957                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 958                         return $this->mUserCaseDBKey;
 959                 } else {
 960                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 961                         return $this->mDbkeyform;
 962                 }
 963         }
 964
 965         /**
 966          * Get the namespace index, i.e. one of the NS_xxxx constants.
 967          *
 968          * @return int Namespace index
 969          */
 970         public function getNamespace() {
 971                 return $this->mNamespace;
 972         }
 973
 974         /**
 975          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 976          *
 977          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 978          * @return string Content model id
 979          */
 980         public function getContentModel( $flags = 0 ) {
 981                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 982                         $linkCache = LinkCache::singleton();
 983                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 984                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 985                 }
 986
 987                 if ( !$this->mContentModel ) {
 988                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 989                 }
 990
 991                 return $this->mContentModel;
 992         }
 993
 994         /**
 995          * Convenience method for checking a title's content model name
 996          *
 997          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 998          * @return bool True if $this->getContentModel() == $id
 999          */
1000         public function hasContentModel( $id ) {
1001                 return $this->getContentModel() == $id;
1002         }
1003
1004         /**
1005          * Get the namespace text
1006          *
1007          * @return string Namespace text
1008          */
1009         public function getNsText() {
1010                 if ( $this->isExternal() ) {
1011                         // This probably shouldn't even happen. ohh man, oh yuck.
1012                         // But for interwiki transclusion it sometimes does.
1013                         // Shit. Shit shit shit.
1014                         //
1015                         // Use the canonical namespaces if possible to try to
1016                         // resolve a foreign namespace.
1017                         if ( MWNamespace::exists( $this->mNamespace ) ) {
1018                                 return MWNamespace::getCanonicalName( $this->mNamespace );
1019                         }
1020                 }
1021
1022                 try {
1023                         $formatter = self::getTitleFormatter();
1024                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
1025                 } catch ( InvalidArgumentException $ex ) {
1026                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1027                         return false;
1028                 }
1029         }
1030
1031         /**
1032          * Get the namespace text of the subject (rather than talk) page
1033          *
1034          * @return string Namespace text
1035          */
1036         public function getSubjectNsText() {
1037                 global $wgContLang;
1038                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1039         }
1040
1041         /**
1042          * Get the namespace text of the talk page
1043          *
1044          * @return string Namespace text
1045          */
1046         public function getTalkNsText() {
1047                 global $wgContLang;
1048                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1049         }
1050
1051         /**
1052          * Could this title have a corresponding talk page?
1053          *
1054          * @return bool
1055          */
1056         public function canTalk() {
1057                 return MWNamespace::canTalk( $this->mNamespace );
1058         }
1059
1060         /**
1061          * Is this in a namespace that allows actual pages?
1062          *
1063          * @return bool
1064          */
1065         public function canExist() {
1066                 return $this->mNamespace >= NS_MAIN;
1067         }
1068
1069         /**
1070          * Can this title be added to a user's watchlist?
1071          *
1072          * @return bool
1073          */
1074         public function isWatchable() {
1075                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1076         }
1077
1078         /**
1079          * Returns true if this is a special page.
1080          *
1081          * @return bool
1082          */
1083         public function isSpecialPage() {
1084                 return $this->getNamespace() == NS_SPECIAL;
1085         }
1086
1087         /**
1088          * Returns true if this title resolves to the named special page
1089          *
1090          * @param string $name The special page name
1091          * @return bool
1092          */
1093         public function isSpecial( $name ) {
1094                 if ( $this->isSpecialPage() ) {
1095                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1096                         if ( $name == $thisName ) {
1097                                 return true;
1098                         }
1099                 }
1100                 return false;
1101         }
1102
1103         /**
1104          * If the Title refers to a special page alias which is not the local default, resolve
1105          * the alias, and localise the name as necessary.  Otherwise, return $this
1106          *
1107          * @return Title
1108          */
1109         public function fixSpecialName() {
1110                 if ( $this->isSpecialPage() ) {
1111                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1112                         if ( $canonicalName ) {
1113                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1114                                 if ( $localName != $this->mDbkeyform ) {
1115                                         return Title::makeTitle( NS_SPECIAL, $localName );
1116                                 }
1117                         }
1118                 }
1119                 return $this;
1120         }
1121
1122         /**
1123          * Returns true if the title is inside the specified namespace.
1124          *
1125          * Please make use of this instead of comparing to getNamespace()
1126          * This function is much more resistant to changes we may make
1127          * to namespaces than code that makes direct comparisons.
1128          * @param int $ns The namespace
1129          * @return bool
1130          * @since 1.19
1131          */
1132         public function inNamespace( $ns ) {
1133                 return MWNamespace::equals( $this->getNamespace(), $ns );
1134         }
1135
1136         /**
1137          * Returns true if the title is inside one of the specified namespaces.
1138          *
1139          * @param int $namespaces,... The namespaces to check for
1140          * @return bool
1141          * @since 1.19
1142          */
1143         public function inNamespaces( /* ... */ ) {
1144                 $namespaces = func_get_args();
1145                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1146                         $namespaces = $namespaces[0];
1147                 }
1148
1149                 foreach ( $namespaces as $ns ) {
1150                         if ( $this->inNamespace( $ns ) ) {
1151                                 return true;
1152                         }
1153                 }
1154
1155                 return false;
1156         }
1157
1158         /**
1159          * Returns true if the title has the same subject namespace as the
1160          * namespace specified.
1161          * For example this method will take NS_USER and return true if namespace
1162          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1163          * as their subject namespace.
1164          *
1165          * This is MUCH simpler than individually testing for equivalence
1166          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1167          * @since 1.19
1168          * @param int $ns
1169          * @return bool
1170          */
1171         public function hasSubjectNamespace( $ns ) {
1172                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1173         }
1174
1175         /**
1176          * Is this Title in a namespace which contains content?
1177          * In other words, is this a content page, for the purposes of calculating
1178          * statistics, etc?
1179          *
1180          * @return bool
1181          */
1182         public function isContentPage() {
1183                 return MWNamespace::isContent( $this->getNamespace() );
1184         }
1185
1186         /**
1187          * Would anybody with sufficient privileges be able to move this page?
1188          * Some pages just aren't movable.
1189          *
1190          * @return bool
1191          */
1192         public function isMovable() {
1193                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1194                         // Interwiki title or immovable namespace. Hooks don't get to override here
1195                         return false;
1196                 }
1197
1198                 $result = true;
1199                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1200                 return $result;
1201         }
1202
1203         /**
1204          * Is this the mainpage?
1205          * @note Title::newFromText seems to be sufficiently optimized by the title
1206          * cache that we don't need to over-optimize by doing direct comparisons and
1207          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1208          * ends up reporting something differently than $title->isMainPage();
1209          *
1210          * @since 1.18
1211          * @return bool
1212          */
1213         public function isMainPage() {
1214                 return $this->equals( Title::newMainPage() );
1215         }
1216
1217         /**
1218          * Is this a subpage?
1219          *
1220          * @return bool
1221          */
1222         public function isSubpage() {
1223                 return MWNamespace::hasSubpages( $this->mNamespace )
1224                         ? strpos( $this->getText(), '/' ) !== false
1225                         : false;
1226         }
1227
1228         /**
1229          * Is this a conversion table for the LanguageConverter?
1230          *
1231          * @return bool
1232          */
1233         public function isConversionTable() {
1234                 // @todo ConversionTable should become a separate content model.
1235
1236                 return $this->getNamespace() == NS_MEDIAWIKI &&
1237                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1238         }
1239
1240         /**
1241          * Does that page contain wikitext, or it is JS, CSS or whatever?
1242          *
1243          * @return bool
1244          */
1245         public function isWikitextPage() {
1246                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1247         }
1248
1249         /**
1250          * Could this page contain custom CSS or JavaScript for the global UI.
1251          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1252          * or CONTENT_MODEL_JAVASCRIPT.
1253          *
1254          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1255          * for that!
1256          *
1257          * Note that this method should not return true for pages that contain and
1258          * show "inactive" CSS or JS.
1259          *
1260          * @return bool
1261          */
1262         public function isCssOrJsPage() {
1263                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1264                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1265                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1266
1267                 # @note This hook is also called in ContentHandler::getDefaultModel.
1268                 #   It's called here again to make sure hook functions can force this
1269                 #   method to return true even outside the MediaWiki namespace.
1270
1271                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1272
1273                 return $isCssOrJsPage;
1274         }
1275
1276         /**
1277          * Is this a .css or .js subpage of a user page?
1278          * @return bool
1279          */
1280         public function isCssJsSubpage() {
1281                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1282                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1283                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1284         }
1285
1286         /**
1287          * Trim down a .css or .js subpage title to get the corresponding skin name
1288          *
1289          * @return string Containing skin name from .css or .js subpage title
1290          */
1291         public function getSkinFromCssJsSubpage() {
1292                 $subpage = explode( '/', $this->mTextform );
1293                 $subpage = $subpage[count( $subpage ) - 1];
1294                 $lastdot = strrpos( $subpage, '.' );
1295                 if ( $lastdot === false ) {
1296                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1297                 }
1298                 return substr( $subpage, 0, $lastdot );
1299         }
1300
1301         /**
1302          * Is this a .css subpage of a user page?
1303          *
1304          * @return bool
1305          */
1306         public function isCssSubpage() {
1307                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1308                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1309         }
1310
1311         /**
1312          * Is this a .js subpage of a user page?
1313          *
1314          * @return bool
1315          */
1316         public function isJsSubpage() {
1317                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1318                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1319         }
1320
1321         /**
1322          * Is this a talk page of some sort?
1323          *
1324          * @return bool
1325          */
1326         public function isTalkPage() {
1327                 return MWNamespace::isTalk( $this->getNamespace() );
1328         }
1329
1330         /**
1331          * Get a Title object associated with the talk page of this article
1332          *
1333          * @return Title The object for the talk page
1334          */
1335         public function getTalkPage() {
1336                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1337         }
1338
1339         /**
1340          * Get a title object associated with the subject page of this
1341          * talk page
1342          *
1343          * @return Title The object for the subject page
1344          */
1345         public function getSubjectPage() {
1346                 // Is this the same title?
1347                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1348                 if ( $this->getNamespace() == $subjectNS ) {
1349                         return $this;
1350                 }
1351                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1352         }
1353
1354         /**
1355          * Get the other title for this page, if this is a subject page
1356          * get the talk page, if it is a subject page get the talk page
1357          *
1358          * @since 1.25
1359          * @throws MWException
1360          * @return Title
1361          */
1362         public function getOtherPage() {
1363                 if ( $this->isSpecialPage() ) {
1364                         throw new MWException( 'Special pages cannot have other pages' );
1365                 }
1366                 if ( $this->isTalkPage() ) {
1367                         return $this->getSubjectPage();
1368                 } else {
1369                         return $this->getTalkPage();
1370                 }
1371         }
1372
1373         /**
1374          * Get the default namespace index, for when there is no namespace
1375          *
1376          * @return int Default namespace index
1377          */
1378         public function getDefaultNamespace() {
1379                 return $this->mDefaultNamespace;
1380         }
1381
1382         /**
1383          * Get the Title fragment (i.e.\ the bit after the #) in text form
1384          *
1385          * Use Title::hasFragment to check for a fragment
1386          *
1387          * @return string Title fragment
1388          */
1389         public function getFragment() {
1390                 return $this->mFragment;
1391         }
1392
1393         /**
1394          * Check if a Title fragment is set
1395          *
1396          * @return bool
1397          * @since 1.23
1398          */
1399         public function hasFragment() {
1400                 return $this->mFragment !== '';
1401         }
1402
1403         /**
1404          * Get the fragment in URL form, including the "#" character if there is one
1405          * @return string Fragment in URL form
1406          */
1407         public function getFragmentForURL() {
1408                 if ( !$this->hasFragment() ) {
1409                         return '';
1410                 } else {
1411                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1412                 }
1413         }
1414
1415         /**
1416          * Set the fragment for this title. Removes the first character from the
1417          * specified fragment before setting, so it assumes you're passing it with
1418          * an initial "#".
1419          *
1420          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1421          * Still in active use privately.
1422          *
1423          * @param string $fragment Text
1424          */
1425         public function setFragment( $fragment ) {
1426                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1427         }
1428
1429         /**
1430          * Prefix some arbitrary text with the namespace or interwiki prefix
1431          * of this object
1432          *
1433          * @param string $name The text
1434          * @return string The prefixed text
1435          */
1436         private function prefix( $name ) {
1437                 $p = '';
1438                 if ( $this->isExternal() ) {
1439                         $p = $this->mInterwiki . ':';
1440                 }
1441
1442                 if ( 0 != $this->mNamespace ) {
1443                         $p .= $this->getNsText() . ':';
1444                 }
1445                 return $p . $name;
1446         }
1447
1448         /**
1449          * Get the prefixed database key form
1450          *
1451          * @return string The prefixed title, with underscores and
1452          *  any interwiki and namespace prefixes
1453          */
1454         public function getPrefixedDBkey() {
1455                 $s = $this->prefix( $this->mDbkeyform );
1456                 $s = strtr( $s, ' ', '_' );
1457                 return $s;
1458         }
1459
1460         /**
1461          * Get the prefixed title with spaces.
1462          * This is the form usually used for display
1463          *
1464          * @return string The prefixed title, with spaces
1465          */
1466         public function getPrefixedText() {
1467                 if ( $this->mPrefixedText === null ) {
1468                         $s = $this->prefix( $this->mTextform );
1469                         $s = strtr( $s, '_', ' ' );
1470                         $this->mPrefixedText = $s;
1471                 }
1472                 return $this->mPrefixedText;
1473         }
1474
1475         /**
1476          * Return a string representation of this title
1477          *
1478          * @return string Representation of this title
1479          */
1480         public function __toString() {
1481                 return $this->getPrefixedText();
1482         }
1483
1484         /**
1485          * Get the prefixed title with spaces, plus any fragment
1486          * (part beginning with '#')
1487          *
1488          * @return string The prefixed title, with spaces and the fragment, including '#'
1489          */
1490         public function getFullText() {
1491                 $text = $this->getPrefixedText();
1492                 if ( $this->hasFragment() ) {
1493                         $text .= '#' . $this->getFragment();
1494                 }
1495                 return $text;
1496         }
1497
1498         /**
1499          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1500          *
1501          * @par Example:
1502          * @code
1503          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1504          * # returns: 'Foo'
1505          * @endcode
1506          *
1507          * @return string Root name
1508          * @since 1.20
1509          */
1510         public function getRootText() {
1511                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1512                         return $this->getText();
1513                 }
1514
1515                 return strtok( $this->getText(), '/' );
1516         }
1517
1518         /**
1519          * Get the root page name title, i.e. the leftmost part before any slashes
1520          *
1521          * @par Example:
1522          * @code
1523          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1524          * # returns: Title{User:Foo}
1525          * @endcode
1526          *
1527          * @return Title Root title
1528          * @since 1.20
1529          */
1530         public function getRootTitle() {
1531                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1532         }
1533
1534         /**
1535          * Get the base page name without a namespace, i.e. the part before the subpage name
1536          *
1537          * @par Example:
1538          * @code
1539          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1540          * # returns: 'Foo/Bar'
1541          * @endcode
1542          *
1543          * @return string Base name
1544          */
1545         public function getBaseText() {
1546                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1547                         return $this->getText();
1548                 }
1549
1550                 $parts = explode( '/', $this->getText() );
1551                 # Don't discard the real title if there's no subpage involved
1552                 if ( count( $parts ) > 1 ) {
1553                         unset( $parts[count( $parts ) - 1] );
1554                 }
1555                 return implode( '/', $parts );
1556         }
1557
1558         /**
1559          * Get the base page name title, i.e. the part before the subpage name
1560          *
1561          * @par Example:
1562          * @code
1563          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1564          * # returns: Title{User:Foo/Bar}
1565          * @endcode
1566          *
1567          * @return Title Base title
1568          * @since 1.20
1569          */
1570         public function getBaseTitle() {
1571                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1572         }
1573
1574         /**
1575          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1576          *
1577          * @par Example:
1578          * @code
1579          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1580          * # returns: "Baz"
1581          * @endcode
1582          *
1583          * @return string Subpage name
1584          */
1585         public function getSubpageText() {
1586                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1587                         return $this->mTextform;
1588                 }
1589                 $parts = explode( '/', $this->mTextform );
1590                 return $parts[count( $parts ) - 1];
1591         }
1592
1593         /**
1594          * Get the title for a subpage of the current page
1595          *
1596          * @par Example:
1597          * @code
1598          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1599          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1600          * @endcode
1601          *
1602          * @param string $text The subpage name to add to the title
1603          * @return Title Subpage title
1604          * @since 1.20
1605          */
1606         public function getSubpage( $text ) {
1607                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1608         }
1609
1610         /**
1611          * Get a URL-encoded form of the subpage text
1612          *
1613          * @return string URL-encoded subpage name
1614          */
1615         public function getSubpageUrlForm() {
1616                 $text = $this->getSubpageText();
1617                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1618                 return $text;
1619         }
1620
1621         /**
1622          * Get a URL-encoded title (not an actual URL) including interwiki
1623          *
1624          * @return string The URL-encoded form
1625          */
1626         public function getPrefixedURL() {
1627                 $s = $this->prefix( $this->mDbkeyform );
1628                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1629                 return $s;
1630         }
1631
1632         /**
1633          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1634          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1635          * second argument named variant. This was deprecated in favor
1636          * of passing an array of option with a "variant" key
1637          * Once $query2 is removed for good, this helper can be dropped
1638          * and the wfArrayToCgi moved to getLocalURL();
1639          *
1640          * @since 1.19 (r105919)
1641          * @param array|string $query
1642          * @param bool $query2
1643          * @return string
1644          */
1645         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1646                 if ( $query2 !== false ) {
1647                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1648                                 "method called with a second parameter is deprecated. Add your " .
1649                                 "parameter to an array passed as the first parameter.", "1.19" );
1650                 }
1651                 if ( is_array( $query ) ) {
1652                         $query = wfArrayToCgi( $query );
1653                 }
1654                 if ( $query2 ) {
1655                         if ( is_string( $query2 ) ) {
1656                                 // $query2 is a string, we will consider this to be
1657                                 // a deprecated $variant argument and add it to the query
1658                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1659                         } else {
1660                                 $query2 = wfArrayToCgi( $query2 );
1661                         }
1662                         // If we have $query content add a & to it first
1663                         if ( $query ) {
1664                                 $query .= '&';
1665                         }
1666                         // Now append the queries together
1667                         $query .= $query2;
1668                 }
1669                 return $query;
1670         }
1671
1672         /**
1673          * Get a real URL referring to this title, with interwiki link and
1674          * fragment
1675          *
1676          * @see self::getLocalURL for the arguments.
1677          * @see wfExpandUrl
1678          * @param array|string $query
1679          * @param bool $query2
1680          * @param string $proto Protocol type to use in URL
1681          * @return string The URL
1682          */
1683         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1684                 $query = self::fixUrlQueryArgs( $query, $query2 );
1685
1686                 # Hand off all the decisions on urls to getLocalURL
1687                 $url = $this->getLocalURL( $query );
1688
1689                 # Expand the url to make it a full url. Note that getLocalURL has the
1690                 # potential to output full urls for a variety of reasons, so we use
1691                 # wfExpandUrl instead of simply prepending $wgServer
1692                 $url = wfExpandUrl( $url, $proto );
1693
1694                 # Finally, add the fragment.
1695                 $url .= $this->getFragmentForURL();
1696
1697                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1698                 return $url;
1699         }
1700
1701         /**
1702          * Get a URL with no fragment or server name (relative URL) from a Title object.
1703          * If this page is generated with action=render, however,
1704          * $wgServer is prepended to make an absolute URL.
1705          *
1706          * @see self::getFullURL to always get an absolute URL.
1707          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1708          *  valid to link, locally, to the current Title.
1709          * @see self::newFromText to produce a Title object.
1710          *
1711          * @param string|array $query An optional query string,
1712          *   not used for interwiki links. Can be specified as an associative array as well,
1713          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1714          *   Some query patterns will trigger various shorturl path replacements.
1715          * @param array $query2 An optional secondary query array. This one MUST
1716          *   be an array. If a string is passed it will be interpreted as a deprecated
1717          *   variant argument and urlencoded into a variant= argument.
1718          *   This second query argument will be added to the $query
1719          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1720          *   pair in the first parameter array instead.
1721          *
1722          * @return string String of the URL.
1723          */
1724         public function getLocalURL( $query = '', $query2 = false ) {
1725                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1726
1727                 $query = self::fixUrlQueryArgs( $query, $query2 );
1728
1729                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1730                 if ( $interwiki ) {
1731                         $namespace = $this->getNsText();
1732                         if ( $namespace != '' ) {
1733                                 # Can this actually happen? Interwikis shouldn't be parsed.
1734                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1735                                 $namespace .= ':';
1736                         }
1737                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1738                         $url = wfAppendQuery( $url, $query );
1739                 } else {
1740                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1741                         if ( $query == '' ) {
1742                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1743                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1744                         } else {
1745                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1746                                 $url = false;
1747                                 $matches = array();
1748
1749                                 if ( !empty( $wgActionPaths )
1750                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1751                                 ) {
1752                                         $action = urldecode( $matches[2] );
1753                                         if ( isset( $wgActionPaths[$action] ) ) {
1754                                                 $query = $matches[1];
1755                                                 if ( isset( $matches[4] ) ) {
1756                                                         $query .= $matches[4];
1757                                                 }
1758                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1759                                                 if ( $query != '' ) {
1760                                                         $url = wfAppendQuery( $url, $query );
1761                                                 }
1762                                         }
1763                                 }
1764
1765                                 if ( $url === false
1766                                         && $wgVariantArticlePath
1767                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1768                                         && $this->getPageLanguage()->hasVariants()
1769                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1770                                 ) {
1771                                         $variant = urldecode( $matches[1] );
1772                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1773                                                 // Only do the variant replacement if the given variant is a valid
1774                                                 // variant for the page's language.
1775                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1776                                                 $url = str_replace( '$1', $dbkey, $url );
1777                                         }
1778                                 }
1779
1780                                 if ( $url === false ) {
1781                                         if ( $query == '-' ) {
1782                                                 $query = '';
1783                                         }
1784                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1785                                 }
1786                         }
1787
1788                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1789
1790                         // @todo FIXME: This causes breakage in various places when we
1791                         // actually expected a local URL and end up with dupe prefixes.
1792                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1793                                 $url = $wgServer . $url;
1794                         }
1795                 }
1796                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1797                 return $url;
1798         }
1799
1800         /**
1801          * Get a URL that's the simplest URL that will be valid to link, locally,
1802          * to the current Title.  It includes the fragment, but does not include
1803          * the server unless action=render is used (or the link is external).  If
1804          * there's a fragment but the prefixed text is empty, we just return a link
1805          * to the fragment.
1806          *
1807          * The result obviously should not be URL-escaped, but does need to be
1808          * HTML-escaped if it's being output in HTML.
1809          *
1810          * @param array $query
1811          * @param bool $query2
1812          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1813          * @see self::getLocalURL for the arguments.
1814          * @return string The URL
1815          */
1816         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1817                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1818                         $ret = $this->getFullURL( $query, $query2, $proto );
1819                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1820                         $ret = $this->getFragmentForURL();
1821                 } else {
1822                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1823                 }
1824                 return $ret;
1825         }
1826
1827         /**
1828          * Get the URL form for an internal link.
1829          * - Used in various Squid-related code, in case we have a different
1830          * internal hostname for the server from the exposed one.
1831          *
1832          * This uses $wgInternalServer to qualify the path, or $wgServer
1833          * if $wgInternalServer is not set. If the server variable used is
1834          * protocol-relative, the URL will be expanded to http://
1835          *
1836          * @see self::getLocalURL for the arguments.
1837          * @return string The URL
1838          */
1839         public function getInternalURL( $query = '', $query2 = false ) {
1840                 global $wgInternalServer, $wgServer;
1841                 $query = self::fixUrlQueryArgs( $query, $query2 );
1842                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1843                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1844                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1845                 return $url;
1846         }
1847
1848         /**
1849          * Get the URL for a canonical link, for use in things like IRC and
1850          * e-mail notifications. Uses $wgCanonicalServer and the
1851          * GetCanonicalURL hook.
1852          *
1853          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1854          *
1855          * @see self::getLocalURL for the arguments.
1856          * @return string The URL
1857          * @since 1.18
1858          */
1859         public function getCanonicalURL( $query = '', $query2 = false ) {
1860                 $query = self::fixUrlQueryArgs( $query, $query2 );
1861                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1862                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1863                 return $url;
1864         }
1865
1866         /**
1867          * Get the edit URL for this Title
1868          *
1869          * @return string The URL, or a null string if this is an interwiki link
1870          */
1871         public function getEditURL() {
1872                 if ( $this->isExternal() ) {
1873                         return '';
1874                 }
1875                 $s = $this->getLocalURL( 'action=edit' );
1876
1877                 return $s;
1878         }
1879
1880         /**
1881          * Is $wgUser watching this page?
1882          *
1883          * @deprecated since 1.20; use User::isWatched() instead.
1884          * @return bool
1885          */
1886         public function userIsWatching() {
1887                 global $wgUser;
1888
1889                 if ( is_null( $this->mWatched ) ) {
1890                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1891                                 $this->mWatched = false;
1892                         } else {
1893                                 $this->mWatched = $wgUser->isWatched( $this );
1894                         }
1895                 }
1896                 return $this->mWatched;
1897         }
1898
1899         /**
1900          * Can $user perform $action on this page?
1901          * This skips potentially expensive cascading permission checks
1902          * as well as avoids expensive error formatting
1903          *
1904          * Suitable for use for nonessential UI controls in common cases, but
1905          * _not_ for functional access control.
1906          *
1907          * May provide false positives, but should never provide a false negative.
1908          *
1909          * @param string $action Action that permission needs to be checked for
1910          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1911          * @return bool
1912          */
1913         public function quickUserCan( $action, $user = null ) {
1914                 return $this->userCan( $action, $user, false );
1915         }
1916
1917         /**
1918          * Can $user perform $action on this page?
1919          *
1920          * @param string $action Action that permission needs to be checked for
1921          * @param User $user User to check (since 1.19); $wgUser will be used if not
1922          *   provided.
1923          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1924          * @return bool
1925          */
1926         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1927                 if ( !$user instanceof User ) {
1928                         global $wgUser;
1929                         $user = $wgUser;
1930                 }
1931
1932                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1933         }
1934
1935         /**
1936          * Can $user perform $action on this page?
1937          *
1938          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1939          *
1940          * @param string $action Action that permission needs to be checked for
1941          * @param User $user User to check
1942          * @param string $rigor One of (quick,full,secure)
1943          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1944          *   - full   : does cheap and expensive checks possibly from a slave
1945          *   - secure : does cheap and expensive checks, using the master as needed
1946          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1947          *   whose corresponding errors may be ignored.
1948          * @return array Array of arguments to wfMessage to explain permissions problems.
1949          */
1950         public function getUserPermissionsErrors(
1951                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1952         ) {
1953                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1954
1955                 // Remove the errors being ignored.
1956                 foreach ( $errors as $index => $error ) {
1957                         $error_key = is_array( $error ) ? $error[0] : $error;
1958
1959                         if ( in_array( $error_key, $ignoreErrors ) ) {
1960                                 unset( $errors[$index] );
1961                         }
1962                 }
1963
1964                 return $errors;
1965         }
1966
1967         /**
1968          * Permissions checks that fail most often, and which are easiest to test.
1969          *
1970          * @param string $action The action to check
1971          * @param User $user User to check
1972          * @param array $errors List of current errors
1973          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1974          * @param bool $short Short circuit on first error
1975          *
1976          * @return array List of errors
1977          */
1978         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1979                 if ( !Hooks::run( 'TitleQuickPermissions',
1980                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1981                 ) {
1982                         return $errors;
1983                 }
1984
1985                 if ( $action == 'create' ) {
1986                         if (
1987                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1988                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1989                         ) {
1990                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1991                         }
1992                 } elseif ( $action == 'move' ) {
1993                         if ( !$user->isAllowed( 'move-rootuserpages' )
1994                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1995                                 // Show user page-specific message only if the user can move other pages
1996                                 $errors[] = array( 'cant-move-user-page' );
1997                         }
1998
1999                         // Check if user is allowed to move files if it's a file
2000                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
2001                                 $errors[] = array( 'movenotallowedfile' );
2002                         }
2003
2004                         // Check if user is allowed to move category pages if it's a category page
2005                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
2006                                 $errors[] = array( 'cant-move-category-page' );
2007                         }
2008
2009                         if ( !$user->isAllowed( 'move' ) ) {
2010                                 // User can't move anything
2011                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
2012                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2013                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2014                                         // custom message if logged-in users without any special rights can move
2015                                         $errors[] = array( 'movenologintext' );
2016                                 } else {
2017                                         $errors[] = array( 'movenotallowed' );
2018                                 }
2019                         }
2020                 } elseif ( $action == 'move-target' ) {
2021                         if ( !$user->isAllowed( 'move' ) ) {
2022                                 // User can't move anything
2023                                 $errors[] = array( 'movenotallowed' );
2024                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2025                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2026                                 // Show user page-specific message only if the user can move other pages
2027                                 $errors[] = array( 'cant-move-to-user-page' );
2028                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2029                                         && $this->mNamespace == NS_CATEGORY ) {
2030                                 // Show category page-specific message only if the user can move other pages
2031                                 $errors[] = array( 'cant-move-to-category-page' );
2032                         }
2033                 } elseif ( !$user->isAllowed( $action ) ) {
2034                         $errors[] = $this->missingPermissionError( $action, $short );
2035                 }
2036
2037                 return $errors;
2038         }
2039
2040         /**
2041          * Add the resulting error code to the errors array
2042          *
2043          * @param array $errors List of current errors
2044          * @param array $result Result of errors
2045          *
2046          * @return array List of errors
2047          */
2048         private function resultToError( $errors, $result ) {
2049                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2050                         // A single array representing an error
2051                         $errors[] = $result;
2052                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2053                         // A nested array representing multiple errors
2054                         $errors = array_merge( $errors, $result );
2055                 } elseif ( $result !== '' && is_string( $result ) ) {
2056                         // A string representing a message-id
2057                         $errors[] = array( $result );
2058                 } elseif ( $result === false ) {
2059                         // a generic "We don't want them to do that"
2060                         $errors[] = array( 'badaccess-group0' );
2061                 }
2062                 return $errors;
2063         }
2064
2065         /**
2066          * Check various permission hooks
2067          *
2068          * @param string $action The action to check
2069          * @param User $user User to check
2070          * @param array $errors List of current errors
2071          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2072          * @param bool $short Short circuit on first error
2073          *
2074          * @return array List of errors
2075          */
2076         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2077                 // Use getUserPermissionsErrors instead
2078                 $result = '';
2079                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2080                         return $result ? array() : array( array( 'badaccess-group0' ) );
2081                 }
2082                 // Check getUserPermissionsErrors hook
2083                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2084                         $errors = $this->resultToError( $errors, $result );
2085                 }
2086                 // Check getUserPermissionsErrorsExpensive hook
2087                 if (
2088                         $rigor !== 'quick'
2089                         && !( $short && count( $errors ) > 0 )
2090                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2091                 ) {
2092                         $errors = $this->resultToError( $errors, $result );
2093                 }
2094
2095                 return $errors;
2096         }
2097
2098         /**
2099          * Check permissions on special pages & namespaces
2100          *
2101          * @param string $action The action to check
2102          * @param User $user User to check
2103          * @param array $errors List of current errors
2104          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2105          * @param bool $short Short circuit on first error
2106          *
2107          * @return array List of errors
2108          */
2109         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2110                 # Only 'createaccount' can be performed on special pages,
2111                 # which don't actually exist in the DB.
2112                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2113                         $errors[] = array( 'ns-specialprotected' );
2114                 }
2115
2116                 # Check $wgNamespaceProtection for restricted namespaces
2117                 if ( $this->isNamespaceProtected( $user ) ) {
2118                         $ns = $this->mNamespace == NS_MAIN ?
2119                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2120                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2121                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2122                 }
2123
2124                 return $errors;
2125         }
2126
2127         /**
2128          * Check CSS/JS sub-page permissions
2129          *
2130          * @param string $action The action to check
2131          * @param User $user User to check
2132          * @param array $errors List of current errors
2133          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2134          * @param bool $short Short circuit on first error
2135          *
2136          * @return array List of errors
2137          */
2138         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2139                 # Protect css/js subpages of user pages
2140                 # XXX: this might be better using restrictions
2141                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2142                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2143                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2144                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2145                                         $errors[] = array( 'mycustomcssprotected', $action );
2146                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2147                                         $errors[] = array( 'mycustomjsprotected', $action );
2148                                 }
2149                         } else {
2150                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2151                                         $errors[] = array( 'customcssprotected', $action );
2152                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2153                                         $errors[] = array( 'customjsprotected', $action );
2154                                 }
2155                         }
2156                 }
2157
2158                 return $errors;
2159         }
2160
2161         /**
2162          * Check against page_restrictions table requirements on this
2163          * page. The user must possess all required rights for this
2164          * action.
2165          *
2166          * @param string $action The action to check
2167          * @param User $user User to check
2168          * @param array $errors List of current errors
2169          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2170          * @param bool $short Short circuit on first error
2171          *
2172          * @return array List of errors
2173          */
2174         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2175                 foreach ( $this->getRestrictions( $action ) as $right ) {
2176                         // Backwards compatibility, rewrite sysop -> editprotected
2177                         if ( $right == 'sysop' ) {
2178                                 $right = 'editprotected';
2179                         }
2180                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2181                         if ( $right == 'autoconfirmed' ) {
2182                                 $right = 'editsemiprotected';
2183                         }
2184                         if ( $right == '' ) {
2185                                 continue;
2186                         }
2187                         if ( !$user->isAllowed( $right ) ) {
2188                                 $errors[] = array( 'protectedpagetext', $right, $action );
2189                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2190                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2191                         }
2192                 }
2193
2194                 return $errors;
2195         }
2196
2197         /**
2198          * Check restrictions on cascading pages.
2199          *
2200          * @param string $action The action to check
2201          * @param User $user User to check
2202          * @param array $errors List of current errors
2203          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2204          * @param bool $short Short circuit on first error
2205          *
2206          * @return array List of errors
2207          */
2208         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2209                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2210                         # We /could/ use the protection level on the source page, but it's
2211                         # fairly ugly as we have to establish a precedence hierarchy for pages
2212                         # included by multiple cascade-protected pages. So just restrict
2213                         # it to people with 'protect' permission, as they could remove the
2214                         # protection anyway.
2215                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2216                         # Cascading protection depends on more than this page...
2217                         # Several cascading protected pages may include this page...
2218                         # Check each cascading level
2219                         # This is only for protection restrictions, not for all actions
2220                         if ( isset( $restrictions[$action] ) ) {
2221                                 foreach ( $restrictions[$action] as $right ) {
2222                                         // Backwards compatibility, rewrite sysop -> editprotected
2223                                         if ( $right == 'sysop' ) {
2224                                                 $right = 'editprotected';
2225                                         }
2226                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2227                                         if ( $right == 'autoconfirmed' ) {
2228                                                 $right = 'editsemiprotected';
2229                                         }
2230                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2231                                                 $pages = '';
2232                                                 foreach ( $cascadingSources as $page ) {
2233                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2234                                                 }
2235                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2236                                         }
2237                                 }
2238                         }
2239                 }
2240
2241                 return $errors;
2242         }
2243
2244         /**
2245          * Check action permissions not already checked in checkQuickPermissions
2246          *
2247          * @param string $action The action to check
2248          * @param User $user User to check
2249          * @param array $errors List of current errors
2250          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2251          * @param bool $short Short circuit on first error
2252          *
2253          * @return array List of errors
2254          */
2255         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2256                 global $wgDeleteRevisionsLimit, $wgLang;
2257
2258                 if ( $action == 'protect' ) {
2259                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2260                                 // If they can't edit, they shouldn't protect.
2261                                 $errors[] = array( 'protect-cantedit' );
2262                         }
2263                 } elseif ( $action == 'create' ) {
2264                         $title_protection = $this->getTitleProtection();
2265                         if ( $title_protection ) {
2266                                 if ( $title_protection['permission'] == ''
2267                                         || !$user->isAllowed( $title_protection['permission'] )
2268                                 ) {
2269                                         $errors[] = array(
2270                                                 'titleprotected',
2271                                                 User::whoIs( $title_protection['user'] ),
2272                                                 $title_protection['reason']
2273                                         );
2274                                 }
2275                         }
2276                 } elseif ( $action == 'move' ) {
2277                         // Check for immobile pages
2278                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2279                                 // Specific message for this case
2280                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2281                         } elseif ( !$this->isMovable() ) {
2282                                 // Less specific message for rarer cases
2283                                 $errors[] = array( 'immobile-source-page' );
2284                         }
2285                 } elseif ( $action == 'move-target' ) {
2286                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2287                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2288                         } elseif ( !$this->isMovable() ) {
2289                                 $errors[] = array( 'immobile-target-page' );
2290                         }
2291                 } elseif ( $action == 'delete' ) {
2292                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2293                         if ( !$tempErrors ) {
2294                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2295                                         $user, $tempErrors, $rigor, true );
2296                         }
2297                         if ( $tempErrors ) {
2298                                 // If protection keeps them from editing, they shouldn't be able to delete.
2299                                 $errors[] = array( 'deleteprotected' );
2300                         }
2301                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2302                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2303                         ) {
2304                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2305                         }
2306                 }
2307                 return $errors;
2308         }
2309
2310         /**
2311          * Check that the user isn't blocked from editing.
2312          *
2313          * @param string $action The action to check
2314          * @param User $user User to check
2315          * @param array $errors List of current errors
2316          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2317          * @param bool $short Short circuit on first error
2318          *
2319          * @return array List of errors
2320          */
2321         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2322                 // Account creation blocks handled at userlogin.
2323                 // Unblocking handled in SpecialUnblock
2324                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2325                         return $errors;
2326                 }
2327
2328                 global $wgEmailConfirmToEdit;
2329
2330                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2331                         $errors[] = array( 'confirmedittext' );
2332                 }
2333
2334                 $useSlave = ( $rigor !== 'secure' );
2335                 if ( ( $action == 'edit' || $action == 'create' )
2336                         && !$user->isBlockedFrom( $this, $useSlave )
2337                 ) {
2338                         // Don't block the user from editing their own talk page unless they've been
2339                         // explicitly blocked from that too.
2340                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2341                         // @todo FIXME: Pass the relevant context into this function.
2342                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2343                 }
2344
2345                 return $errors;
2346         }
2347
2348         /**
2349          * Check that the user is allowed to read this page.
2350          *
2351          * @param string $action The action to check
2352          * @param User $user User to check
2353          * @param array $errors List of current errors
2354          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2355          * @param bool $short Short circuit on first error
2356          *
2357          * @return array List of errors
2358          */
2359         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2360                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2361
2362                 $whitelisted = false;
2363                 if ( User::isEveryoneAllowed( 'read' ) ) {
2364                         # Shortcut for public wikis, allows skipping quite a bit of code
2365                         $whitelisted = true;
2366                 } elseif ( $user->isAllowed( 'read' ) ) {
2367                         # If the user is allowed to read pages, he is allowed to read all pages
2368                         $whitelisted = true;
2369                 } elseif ( $this->isSpecial( 'Userlogin' )
2370                         || $this->isSpecial( 'ChangePassword' )
2371                         || $this->isSpecial( 'PasswordReset' )
2372                 ) {
2373                         # Always grant access to the login page.
2374                         # Even anons need to be able to log in.
2375                         $whitelisted = true;
2376                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2377                         # Time to check the whitelist
2378                         # Only do these checks is there's something to check against
2379                         $name = $this->getPrefixedText();
2380                         $dbName = $this->getPrefixedDBkey();
2381
2382                         // Check for explicit whitelisting with and without underscores
2383                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2384                                 $whitelisted = true;
2385                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2386                                 # Old settings might have the title prefixed with
2387                                 # a colon for main-namespace pages
2388                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2389                                         $whitelisted = true;
2390                                 }
2391                         } elseif ( $this->isSpecialPage() ) {
2392                                 # If it's a special page, ditch the subpage bit and check again
2393                                 $name = $this->getDBkey();
2394                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2395                                 if ( $name ) {
2396                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2397                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2398                                                 $whitelisted = true;
2399                                         }
2400                                 }
2401                         }
2402                 }
2403
2404                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2405                         $name = $this->getPrefixedText();
2406                         // Check for regex whitelisting
2407                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2408                                 if ( preg_match( $listItem, $name ) ) {
2409                                         $whitelisted = true;
2410                                         break;
2411                                 }
2412                         }
2413                 }
2414
2415                 if ( !$whitelisted ) {
2416                         # If the title is not whitelisted, give extensions a chance to do so...
2417                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2418                         if ( !$whitelisted ) {
2419                                 $errors[] = $this->missingPermissionError( $action, $short );
2420                         }
2421                 }
2422
2423                 return $errors;
2424         }
2425
2426         /**
2427          * Get a description array when the user doesn't have the right to perform
2428          * $action (i.e. when User::isAllowed() returns false)
2429          *
2430          * @param string $action The action to check
2431          * @param bool $short Short circuit on first error
2432          * @return array List of errors
2433          */
2434         private function missingPermissionError( $action, $short ) {
2435                 // We avoid expensive display logic for quickUserCan's and such
2436                 if ( $short ) {
2437                         return array( 'badaccess-group0' );
2438                 }
2439
2440                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2441                         User::getGroupsWithPermission( $action ) );
2442
2443                 if ( count( $groups ) ) {
2444                         global $wgLang;
2445                         return array(
2446                                 'badaccess-groups',
2447                                 $wgLang->commaList( $groups ),
2448                                 count( $groups )
2449                         );
2450                 } else {
2451                         return array( 'badaccess-group0' );
2452                 }
2453         }
2454
2455         /**
2456          * Can $user perform $action on this page? This is an internal function,
2457          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2458          * checks on wfReadOnly() and blocks)
2459          *
2460          * @param string $action Action that permission needs to be checked for
2461          * @param User $user User to check
2462          * @param string $rigor One of (quick,full,secure)
2463          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2464          *   - full   : does cheap and expensive checks possibly from a slave
2465          *   - secure : does cheap and expensive checks, using the master as needed
2466          * @param bool $short Set this to true to stop after the first permission error.
2467          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2468          */
2469         protected function getUserPermissionsErrorsInternal(
2470                 $action, $user, $rigor = 'secure', $short = false
2471         ) {
2472                 if ( $rigor === true ) {
2473                         $rigor = 'secure'; // b/c
2474                 } elseif ( $rigor === false ) {
2475                         $rigor = 'quick'; // b/c
2476                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2477                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2478                 }
2479
2480                 # Read has special handling
2481                 if ( $action == 'read' ) {
2482                         $checks = array(
2483                                 'checkPermissionHooks',
2484                                 'checkReadPermissions',
2485                         );
2486                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2487                 # here as it will lead to duplicate error messages. This is okay to do
2488                 # since anywhere that checks for create will also check for edit, and
2489                 # those checks are called for edit.
2490                 } elseif ( $action == 'create' ) {
2491                         $checks = array(
2492                                 'checkQuickPermissions',
2493                                 'checkPermissionHooks',
2494                                 'checkPageRestrictions',
2495                                 'checkCascadingSourcesRestrictions',
2496                                 'checkActionPermissions',
2497                                 'checkUserBlock'
2498                         );
2499                 } else {
2500                         $checks = array(
2501                                 'checkQuickPermissions',
2502                                 'checkPermissionHooks',
2503                                 'checkSpecialsAndNSPermissions',
2504                                 'checkCSSandJSPermissions',
2505                                 'checkPageRestrictions',
2506                                 'checkCascadingSourcesRestrictions',
2507                                 'checkActionPermissions',
2508                                 'checkUserBlock'
2509                         );
2510                 }
2511
2512                 $errors = array();
2513                 while ( count( $checks ) > 0 &&
2514                                 !( $short && count( $errors ) > 0 ) ) {
2515                         $method = array_shift( $checks );
2516                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2517                 }
2518
2519                 return $errors;
2520         }
2521
2522         /**
2523          * Get a filtered list of all restriction types supported by this wiki.
2524          * @param bool $exists True to get all restriction types that apply to
2525          * titles that do exist, False for all restriction types that apply to
2526          * titles that do not exist
2527          * @return array
2528          */
2529         public static function getFilteredRestrictionTypes( $exists = true ) {
2530                 global $wgRestrictionTypes;
2531                 $types = $wgRestrictionTypes;
2532                 if ( $exists ) {
2533                         # Remove the create restriction for existing titles
2534                         $types = array_diff( $types, array( 'create' ) );
2535                 } else {
2536                         # Only the create and upload restrictions apply to non-existing titles
2537                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2538                 }
2539                 return $types;
2540         }
2541
2542         /**
2543          * Returns restriction types for the current Title
2544          *
2545          * @return array Applicable restriction types
2546          */
2547         public function getRestrictionTypes() {
2548                 if ( $this->isSpecialPage() ) {
2549                         return array();
2550                 }
2551
2552                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2553
2554                 if ( $this->getNamespace() != NS_FILE ) {
2555                         # Remove the upload restriction for non-file titles
2556                         $types = array_diff( $types, array( 'upload' ) );
2557                 }
2558
2559                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2560
2561                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2562                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2563
2564                 return $types;
2565         }
2566
2567         /**
2568          * Is this title subject to title protection?
2569          * Title protection is the one applied against creation of such title.
2570          *
2571          * @return array|bool An associative array representing any existent title
2572          *   protection, or false if there's none.
2573          */
2574         public function getTitleProtection() {
2575                 // Can't protect pages in special namespaces
2576                 if ( $this->getNamespace() < 0 ) {
2577                         return false;
2578                 }
2579
2580                 // Can't protect pages that exist.
2581                 if ( $this->exists() ) {
2582                         return false;
2583                 }
2584
2585                 if ( $this->mTitleProtection === null ) {
2586                         $dbr = wfGetDB( DB_SLAVE );
2587                         $res = $dbr->select(
2588                                 'protected_titles',
2589                                 array(
2590                                         'user' => 'pt_user',
2591                                         'reason' => 'pt_reason',
2592                                         'expiry' => 'pt_expiry',
2593                                         'permission' => 'pt_create_perm'
2594                                 ),
2595                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2596                                 __METHOD__
2597                         );
2598
2599                         // fetchRow returns false if there are no rows.
2600                         $row = $dbr->fetchRow( $res );
2601                         if ( $row ) {
2602                                 if ( $row['permission'] == 'sysop' ) {
2603                                         $row['permission'] = 'editprotected'; // B/C
2604                                 }
2605                                 if ( $row['permission'] == 'autoconfirmed' ) {
2606                                         $row['permission'] = 'editsemiprotected'; // B/C
2607                                 }
2608                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2609                         }
2610                         $this->mTitleProtection = $row;
2611                 }
2612                 return $this->mTitleProtection;
2613         }
2614
2615         /**
2616          * Remove any title protection due to page existing
2617          */
2618         public function deleteTitleProtection() {
2619                 $dbw = wfGetDB( DB_MASTER );
2620
2621                 $dbw->delete(
2622                         'protected_titles',
2623                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2624                         __METHOD__
2625                 );
2626                 $this->mTitleProtection = false;
2627         }
2628
2629         /**
2630          * Is this page "semi-protected" - the *only* protection levels are listed
2631          * in $wgSemiprotectedRestrictionLevels?
2632          *
2633          * @param string $action Action to check (default: edit)
2634          * @return bool
2635          */
2636         public function isSemiProtected( $action = 'edit' ) {
2637                 global $wgSemiprotectedRestrictionLevels;
2638
2639                 $restrictions = $this->getRestrictions( $action );
2640                 $semi = $wgSemiprotectedRestrictionLevels;
2641                 if ( !$restrictions || !$semi ) {
2642                         // Not protected, or all protection is full protection
2643                         return false;
2644                 }
2645
2646                 // Remap autoconfirmed to editsemiprotected for BC
2647                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2648                         $semi[$key] = 'editsemiprotected';
2649                 }
2650                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2651                         $restrictions[$key] = 'editsemiprotected';
2652                 }
2653
2654                 return !array_diff( $restrictions, $semi );
2655         }
2656
2657         /**
2658          * Does the title correspond to a protected article?
2659          *
2660          * @param string $action The action the page is protected from,
2661          * by default checks all actions.
2662          * @return bool
2663          */
2664         public function isProtected( $action = '' ) {
2665                 global $wgRestrictionLevels;
2666
2667                 $restrictionTypes = $this->getRestrictionTypes();
2668
2669                 # Special pages have inherent protection
2670                 if ( $this->isSpecialPage() ) {
2671                         return true;
2672                 }
2673
2674                 # Check regular protection levels
2675                 foreach ( $restrictionTypes as $type ) {
2676                         if ( $action == $type || $action == '' ) {
2677                                 $r = $this->getRestrictions( $type );
2678                                 foreach ( $wgRestrictionLevels as $level ) {
2679                                         if ( in_array( $level, $r ) && $level != '' ) {
2680                                                 return true;
2681                                         }
2682                                 }
2683                         }
2684                 }
2685
2686                 return false;
2687         }
2688
2689         /**
2690          * Determines if $user is unable to edit this page because it has been protected
2691          * by $wgNamespaceProtection.
2692          *
2693          * @param User $user User object to check permissions
2694          * @return bool
2695          */
2696         public function isNamespaceProtected( User $user ) {
2697                 global $wgNamespaceProtection;
2698
2699                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2700                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2701                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2702                                         return true;
2703                                 }
2704                         }
2705                 }
2706                 return false;
2707         }
2708
2709         /**
2710          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2711          *
2712          * @return bool If the page is subject to cascading restrictions.
2713          */
2714         public function isCascadeProtected() {
2715                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2716                 return ( $sources > 0 );
2717         }
2718
2719         /**
2720          * Determines whether cascading protection sources have already been loaded from
2721          * the database.
2722          *
2723          * @param bool $getPages True to check if the pages are loaded, or false to check
2724          * if the status is loaded.
2725          * @return bool Whether or not the specified information has been loaded
2726          * @since 1.23
2727          */
2728         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2729                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2730         }
2731
2732         /**
2733          * Cascading protection: Get the source of any cascading restrictions on this page.
2734          *
2735          * @param bool $getPages Whether or not to retrieve the actual pages
2736          *        that the restrictions have come from and the actual restrictions
2737          *        themselves.
2738          * @return array Two elements: First is an array of Title objects of the
2739          *        pages from which cascading restrictions have come, false for
2740          *        none, or true if such restrictions exist but $getPages was not
2741          *        set. Second is an array like that returned by
2742          *        Title::getAllRestrictions(), or an empty array if $getPages is
2743          *        false.
2744          */
2745         public function getCascadeProtectionSources( $getPages = true ) {
2746                 $pagerestrictions = array();
2747
2748                 if ( $this->mCascadeSources !== null && $getPages ) {
2749                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2750                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2751                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2752                 }
2753
2754                 $dbr = wfGetDB( DB_SLAVE );
2755
2756                 if ( $this->getNamespace() == NS_FILE ) {
2757                         $tables = array( 'imagelinks', 'page_restrictions' );
2758                         $where_clauses = array(
2759                                 'il_to' => $this->getDBkey(),
2760                                 'il_from=pr_page',
2761                                 'pr_cascade' => 1
2762                         );
2763                 } else {
2764                         $tables = array( 'templatelinks', 'page_restrictions' );
2765                         $where_clauses = array(
2766                                 'tl_namespace' => $this->getNamespace(),
2767                                 'tl_title' => $this->getDBkey(),
2768                                 'tl_from=pr_page',
2769                                 'pr_cascade' => 1
2770                         );
2771                 }
2772
2773                 if ( $getPages ) {
2774                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2775                                 'pr_expiry', 'pr_type', 'pr_level' );
2776                         $where_clauses[] = 'page_id=pr_page';
2777                         $tables[] = 'page';
2778                 } else {
2779                         $cols = array( 'pr_expiry' );
2780                 }
2781
2782                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2783
2784                 $sources = $getPages ? array() : false;
2785                 $now = wfTimestampNow();
2786
2787                 foreach ( $res as $row ) {
2788                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2789                         if ( $expiry > $now ) {
2790                                 if ( $getPages ) {
2791                                         $page_id = $row->pr_page;
2792                                         $page_ns = $row->page_namespace;
2793                                         $page_title = $row->page_title;
2794                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2795                                         # Add groups needed for each restriction type if its not already there
2796                                         # Make sure this restriction type still exists
2797
2798                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2799                                                 $pagerestrictions[$row->pr_type] = array();
2800                                         }
2801
2802                                         if (
2803                                                 isset( $pagerestrictions[$row->pr_type] )
2804                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2805                                         ) {
2806                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2807                                         }
2808                                 } else {
2809                                         $sources = true;
2810                                 }
2811                         }
2812                 }
2813
2814                 if ( $getPages ) {
2815                         $this->mCascadeSources = $sources;
2816                         $this->mCascadingRestrictions = $pagerestrictions;
2817                 } else {
2818                         $this->mHasCascadingRestrictions = $sources;
2819                 }
2820
2821                 return array( $sources, $pagerestrictions );
2822         }
2823
2824         /**
2825          * Accessor for mRestrictionsLoaded
2826          *
2827          * @return bool Whether or not the page's restrictions have already been
2828          * loaded from the database
2829          * @since 1.23
2830          */
2831         public function areRestrictionsLoaded() {
2832                 return $this->mRestrictionsLoaded;
2833         }
2834
2835         /**
2836          * Accessor/initialisation for mRestrictions
2837          *
2838          * @param string $action Action that permission needs to be checked for
2839          * @return array Restriction levels needed to take the action. All levels are
2840          *     required. Note that restriction levels are normally user rights, but 'sysop'
2841          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2842          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2843          */
2844         public function getRestrictions( $action ) {
2845                 if ( !$this->mRestrictionsLoaded ) {
2846                         $this->loadRestrictions();
2847                 }
2848                 return isset( $this->mRestrictions[$action] )
2849                                 ? $this->mRestrictions[$action]
2850                                 : array();
2851         }
2852
2853         /**
2854          * Accessor/initialisation for mRestrictions
2855          *
2856          * @return array Keys are actions, values are arrays as returned by
2857          *     Title::getRestrictions()
2858          * @since 1.23
2859          */
2860         public function getAllRestrictions() {
2861                 if ( !$this->mRestrictionsLoaded ) {
2862                         $this->loadRestrictions();
2863                 }
2864                 return $this->mRestrictions;
2865         }
2866
2867         /**
2868          * Get the expiry time for the restriction against a given action
2869          *
2870          * @param string $action
2871          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2872          *     or not protected at all, or false if the action is not recognised.
2873          */
2874         public function getRestrictionExpiry( $action ) {
2875                 if ( !$this->mRestrictionsLoaded ) {
2876                         $this->loadRestrictions();
2877                 }
2878                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2879         }
2880
2881         /**
2882          * Returns cascading restrictions for the current article
2883          *
2884          * @return bool
2885          */
2886         function areRestrictionsCascading() {
2887                 if ( !$this->mRestrictionsLoaded ) {
2888                         $this->loadRestrictions();
2889                 }
2890
2891                 return $this->mCascadeRestriction;
2892         }
2893
2894         /**
2895          * Loads a string into mRestrictions array
2896          *
2897          * @param ResultWrapper $res Resource restrictions as an SQL result.
2898          * @param string $oldFashionedRestrictions Comma-separated list of page
2899          *        restrictions from page table (pre 1.10)
2900          */
2901         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2902                 $rows = array();
2903
2904                 foreach ( $res as $row ) {
2905                         $rows[] = $row;
2906                 }
2907
2908                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2909         }
2910
2911         /**
2912          * Compiles list of active page restrictions from both page table (pre 1.10)
2913          * and page_restrictions table for this existing page.
2914          * Public for usage by LiquidThreads.
2915          *
2916          * @param array $rows Array of db result objects
2917          * @param string $oldFashionedRestrictions Comma-separated list of page
2918          *   restrictions from page table (pre 1.10)
2919          */
2920         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2921                 $dbr = wfGetDB( DB_SLAVE );
2922
2923                 $restrictionTypes = $this->getRestrictionTypes();
2924
2925                 foreach ( $restrictionTypes as $type ) {
2926                         $this->mRestrictions[$type] = array();
2927                         $this->mRestrictionsExpiry[$type] = 'infinity';
2928                 }
2929
2930                 $this->mCascadeRestriction = false;
2931
2932                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2933                 if ( $oldFashionedRestrictions !== null ) {
2934                         $this->mOldRestrictions = $oldFashionedRestrictions;
2935                 }
2936
2937                 if ( $this->mOldRestrictions === false ) {
2938                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2939                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2940                 }
2941
2942                 if ( $this->mOldRestrictions != '' ) {
2943                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2944                                 $temp = explode( '=', trim( $restrict ) );
2945                                 if ( count( $temp ) == 1 ) {
2946                                         // old old format should be treated as edit/move restriction
2947                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2948                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2949                                 } else {
2950                                         $restriction = trim( $temp[1] );
2951                                         if ( $restriction != '' ) { // some old entries are empty
2952                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2953                                         }
2954                                 }
2955                         }
2956                 }
2957
2958                 if ( count( $rows ) ) {
2959                         # Current system - load second to make them override.
2960                         $now = wfTimestampNow();
2961
2962                         # Cycle through all the restrictions.
2963                         foreach ( $rows as $row ) {
2964
2965                                 // Don't take care of restrictions types that aren't allowed
2966                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2967                                         continue;
2968                                 }
2969
2970                                 // This code should be refactored, now that it's being used more generally,
2971                                 // But I don't really see any harm in leaving it in Block for now -werdna
2972                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2973
2974                                 // Only apply the restrictions if they haven't expired!
2975                                 if ( !$expiry || $expiry > $now ) {
2976                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2977                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2978
2979                                         $this->mCascadeRestriction |= $row->pr_cascade;
2980                                 }
2981                         }
2982                 }
2983
2984                 $this->mRestrictionsLoaded = true;
2985         }
2986
2987         /**
2988          * Load restrictions from the page_restrictions table
2989          *
2990          * @param string $oldFashionedRestrictions Comma-separated list of page
2991          *   restrictions from page table (pre 1.10)
2992          */
2993         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2994                 if ( !$this->mRestrictionsLoaded ) {
2995                         $dbr = wfGetDB( DB_SLAVE );
2996                         if ( $this->exists() ) {
2997                                 $res = $dbr->select(
2998                                         'page_restrictions',
2999                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
3000                                         array( 'pr_page' => $this->getArticleID() ),
3001                                         __METHOD__
3002                                 );
3003
3004                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
3005                         } else {
3006                                 $title_protection = $this->getTitleProtection();
3007
3008                                 if ( $title_protection ) {
3009                                         $now = wfTimestampNow();
3010                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
3011
3012                                         if ( !$expiry || $expiry > $now ) {
3013                                                 // Apply the restrictions
3014                                                 $this->mRestrictionsExpiry['create'] = $expiry;
3015                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
3016                                         } else { // Get rid of the old restrictions
3017                                                 $this->mTitleProtection = false;
3018                                         }
3019                                 } else {
3020                                         $this->mRestrictionsExpiry['create'] = 'infinity';
3021                                 }
3022                                 $this->mRestrictionsLoaded = true;
3023                         }
3024                 }
3025         }
3026
3027         /**
3028          * Flush the protection cache in this object and force reload from the database.
3029          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3030          */
3031         public function flushRestrictions() {
3032                 $this->mRestrictionsLoaded = false;
3033                 $this->mTitleProtection = null;
3034         }
3035
3036         /**
3037          * Purge expired restrictions from the page_restrictions table
3038          */
3039         static function purgeExpiredRestrictions() {
3040                 if ( wfReadOnly() ) {
3041                         return;
3042                 }
3043
3044                 $method = __METHOD__;
3045                 $dbw = wfGetDB( DB_MASTER );
3046                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3047                         $dbw->delete(
3048                                 'page_restrictions',
3049                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3050                                 $method
3051                         );
3052                         $dbw->delete(
3053                                 'protected_titles',
3054                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3055                                 $method
3056                         );
3057                 } );
3058         }
3059
3060         /**
3061          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3062          *
3063          * @return bool
3064          */
3065         public function hasSubpages() {
3066                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3067                         # Duh
3068                         return false;
3069                 }
3070
3071                 # We dynamically add a member variable for the purpose of this method
3072                 # alone to cache the result.  There's no point in having it hanging
3073                 # around uninitialized in every Title object; therefore we only add it
3074                 # if needed and don't declare it statically.
3075                 if ( $this->mHasSubpages === null ) {
3076                         $this->mHasSubpages = false;
3077                         $subpages = $this->getSubpages( 1 );
3078                         if ( $subpages instanceof TitleArray ) {
3079                                 $this->mHasSubpages = (bool)$subpages->count();
3080                         }
3081                 }
3082
3083                 return $this->mHasSubpages;
3084         }
3085
3086         /**
3087          * Get all subpages of this page.
3088          *
3089          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3090          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3091          *  doesn't allow subpages
3092          */
3093         public function getSubpages( $limit = -1 ) {
3094                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3095                         return array();
3096                 }
3097
3098                 $dbr = wfGetDB( DB_SLAVE );
3099                 $conds['page_namespace'] = $this->getNamespace();
3100                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3101                 $options = array();
3102                 if ( $limit > -1 ) {
3103                         $options['LIMIT'] = $limit;
3104                 }
3105                 $this->mSubpages = TitleArray::newFromResult(
3106                         $dbr->select( 'page',
3107                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3108                                 $conds,
3109                                 __METHOD__,
3110                                 $options
3111                         )
3112                 );
3113                 return $this->mSubpages;
3114         }
3115
3116         /**
3117          * Is there a version of this page in the deletion archive?
3118          *
3119          * @return int The number of archived revisions
3120          */
3121         public function isDeleted() {
3122                 if ( $this->getNamespace() < 0 ) {
3123                         $n = 0;
3124                 } else {
3125                         $dbr = wfGetDB( DB_SLAVE );
3126
3127                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3128                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3129                                 __METHOD__
3130                         );
3131                         if ( $this->getNamespace() == NS_FILE ) {
3132                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3133                                         array( 'fa_name' => $this->getDBkey() ),
3134                                         __METHOD__
3135                                 );
3136                         }
3137                 }
3138                 return (int)$n;
3139         }
3140
3141         /**
3142          * Is there a version of this page in the deletion archive?
3143          *
3144          * @return bool
3145          */
3146         public function isDeletedQuick() {
3147                 if ( $this->getNamespace() < 0 ) {
3148                         return false;
3149                 }
3150                 $dbr = wfGetDB( DB_SLAVE );
3151                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3152                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3153                         __METHOD__
3154                 );
3155                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3156                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3157                                 array( 'fa_name' => $this->getDBkey() ),
3158                                 __METHOD__
3159                         );
3160                 }
3161                 return $deleted;
3162         }
3163
3164         /**
3165          * Get the article ID for this Title from the link cache,
3166          * adding it if necessary
3167          *
3168          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3169          *  for update
3170          * @return int The ID
3171          */
3172         public function getArticleID( $flags = 0 ) {
3173                 if ( $this->getNamespace() < 0 ) {
3174                         $this->mArticleID = 0;
3175                         return $this->mArticleID;
3176                 }
3177                 $linkCache = LinkCache::singleton();
3178                 if ( $flags & self::GAID_FOR_UPDATE ) {
3179                         $oldUpdate = $linkCache->forUpdate( true );
3180                         $linkCache->clearLink( $this );
3181                         $this->mArticleID = $linkCache->addLinkObj( $this );
3182                         $linkCache->forUpdate( $oldUpdate );
3183                 } else {
3184                         if ( -1 == $this->mArticleID ) {
3185                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3186                         }
3187                 }
3188                 return $this->mArticleID;
3189         }
3190
3191         /**
3192          * Is this an article that is a redirect page?
3193          * Uses link cache, adding it if necessary
3194          *
3195          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3196          * @return bool
3197          */
3198         public function isRedirect( $flags = 0 ) {
3199                 if ( !is_null( $this->mRedirect ) ) {
3200                         return $this->mRedirect;
3201                 }
3202                 if ( !$this->getArticleID( $flags ) ) {
3203                         $this->mRedirect = false;
3204                         return $this->mRedirect;
3205                 }
3206
3207                 $linkCache = LinkCache::singleton();
3208                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3209                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3210                 if ( $cached === null ) {
3211                         # Trust LinkCache's state over our own
3212                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3213                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3214                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3215                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3216                         # LinkCache to refresh its data from the master.
3217                         $this->mRedirect = false;
3218                         return $this->mRedirect;
3219                 }
3220
3221                 $this->mRedirect = (bool)$cached;
3222
3223                 return $this->mRedirect;
3224         }
3225
3226         /**
3227          * What is the length of this page?
3228          * Uses link cache, adding it if necessary
3229          *
3230          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3231          * @return int
3232          */
3233         public function getLength( $flags = 0 ) {
3234                 if ( $this->mLength != -1 ) {
3235                         return $this->mLength;
3236                 }
3237                 if ( !$this->getArticleID( $flags ) ) {
3238                         $this->mLength = 0;
3239                         return $this->mLength;
3240                 }
3241                 $linkCache = LinkCache::singleton();
3242                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3243                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3244                 if ( $cached === null ) {
3245                         # Trust LinkCache's state over our own, as for isRedirect()
3246                         $this->mLength = 0;
3247                         return $this->mLength;
3248                 }
3249
3250                 $this->mLength = intval( $cached );
3251
3252                 return $this->mLength;
3253         }
3254
3255         /**
3256          * What is the page_latest field for this page?
3257          *
3258          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3259          * @return int Int or 0 if the page doesn't exist
3260          */
3261         public function getLatestRevID( $flags = 0 ) {
3262                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3263                         return intval( $this->mLatestID );
3264                 }
3265                 if ( !$this->getArticleID( $flags ) ) {
3266                         $this->mLatestID = 0;
3267                         return $this->mLatestID;
3268                 }
3269                 $linkCache = LinkCache::singleton();
3270                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3271                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3272                 if ( $cached === null ) {
3273                         # Trust LinkCache's state over our own, as for isRedirect()
3274                         $this->mLatestID = 0;
3275                         return $this->mLatestID;
3276                 }
3277
3278                 $this->mLatestID = intval( $cached );
3279
3280                 return $this->mLatestID;
3281         }
3282
3283         /**
3284          * This clears some fields in this object, and clears any associated
3285          * keys in the "bad links" section of the link cache.
3286          *
3287          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3288          * loading of the new page_id. It's also called from
3289          * WikiPage::doDeleteArticleReal()
3290          *
3291          * @param int $newid The new Article ID
3292          */
3293         public function resetArticleID( $newid ) {
3294                 $linkCache = LinkCache::singleton();
3295                 $linkCache->clearLink( $this );
3296
3297                 if ( $newid === false ) {
3298                         $this->mArticleID = -1;
3299                 } else {
3300                         $this->mArticleID = intval( $newid );
3301                 }
3302                 $this->mRestrictionsLoaded = false;
3303                 $this->mRestrictions = array();
3304                 $this->mOldRestrictions = false;
3305                 $this->mRedirect = null;
3306                 $this->mLength = -1;
3307                 $this->mLatestID = false;
3308                 $this->mContentModel = false;
3309                 $this->mEstimateRevisions = null;
3310                 $this->mPageLanguage = false;
3311                 $this->mDbPageLanguage = null;
3312                 $this->mIsBigDeletion = null;
3313         }
3314
3315         public static function clearCaches() {
3316                 $linkCache = LinkCache::singleton();
3317                 $linkCache->clear();
3318
3319                 $titleCache = self::getTitleCache();
3320                 $titleCache->clear();
3321         }
3322
3323         /**
3324          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3325          *
3326          * @param string $text Containing title to capitalize
3327          * @param int $ns Namespace index, defaults to NS_MAIN
3328          * @return string Containing capitalized title
3329          */
3330         public static function capitalize( $text, $ns = NS_MAIN ) {
3331                 global $wgContLang;
3332
3333                 if ( MWNamespace::isCapitalized( $ns ) ) {
3334                         return $wgContLang->ucfirst( $text );
3335                 } else {
3336                         return $text;
3337                 }
3338         }
3339
3340         /**
3341          * Secure and split - main initialisation function for this object
3342          *
3343          * Assumes that mDbkeyform has been set, and is urldecoded
3344          * and uses underscores, but not otherwise munged.  This function
3345          * removes illegal characters, splits off the interwiki and
3346          * namespace prefixes, sets the other forms, and canonicalizes
3347          * everything.
3348          *
3349          * @throws MalformedTitleException On invalid titles
3350          * @return bool True on success
3351          */
3352         private function secureAndSplit() {
3353                 # Initialisation
3354                 $this->mInterwiki = '';
3355                 $this->mFragment = '';
3356                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3357
3358                 $dbkey = $this->mDbkeyform;
3359
3360                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3361                 //        the parsing code with Title, while avoiding massive refactoring.
3362                 // @todo: get rid of secureAndSplit, refactor parsing code.
3363                 $titleParser = self::getTitleParser();
3364                 // MalformedTitleException can be thrown here
3365                 $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3366
3367                 # Fill fields
3368                 $this->setFragment( '#' . $parts['fragment'] );
3369                 $this->mInterwiki = $parts['interwiki'];
3370                 $this->mLocalInterwiki = $parts['local_interwiki'];
3371                 $this->mNamespace = $parts['namespace'];
3372                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3373
3374                 $this->mDbkeyform = $parts['dbkey'];
3375                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3376                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3377
3378                 # We already know that some pages won't be in the database!
3379                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3380                         $this->mArticleID = 0;
3381                 }
3382
3383                 return true;
3384         }
3385
3386         /**
3387          * Get an array of Title objects linking to this Title
3388          * Also stores the IDs in the link cache.
3389          *
3390          * WARNING: do not use this function on arbitrary user-supplied titles!
3391          * On heavily-used templates it will max out the memory.
3392          *
3393          * @param array $options May be FOR UPDATE
3394          * @param string $table Table name
3395          * @param string $prefix Fields prefix
3396          * @return Title[] Array of Title objects linking here
3397          */
3398         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3399                 if ( count( $options ) > 0 ) {
3400                         $db = wfGetDB( DB_MASTER );
3401                 } else {
3402                         $db = wfGetDB( DB_SLAVE );
3403                 }
3404
3405                 $res = $db->select(
3406                         array( 'page', $table ),
3407                         self::getSelectFields(),
3408                         array(
3409                                 "{$prefix}_from=page_id",
3410                                 "{$prefix}_namespace" => $this->getNamespace(),
3411                                 "{$prefix}_title" => $this->getDBkey() ),
3412                         __METHOD__,
3413                         $options
3414                 );
3415
3416                 $retVal = array();
3417                 if ( $res->numRows() ) {
3418                         $linkCache = LinkCache::singleton();
3419                         foreach ( $res as $row ) {
3420                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3421                                 if ( $titleObj ) {
3422                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3423                                         $retVal[] = $titleObj;
3424                                 }
3425                         }
3426                 }
3427                 return $retVal;
3428         }
3429
3430         /**
3431          * Get an array of Title objects using this Title as a template
3432          * Also stores the IDs in the link cache.
3433          *
3434          * WARNING: do not use this function on arbitrary user-supplied titles!
3435          * On heavily-used templates it will max out the memory.
3436          *
3437          * @param array $options May be FOR UPDATE
3438          * @return Title[] Array of Title the Title objects linking here
3439          */
3440         public function getTemplateLinksTo( $options = array() ) {
3441                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3442         }
3443
3444         /**
3445          * Get an array of Title objects linked from this Title
3446          * Also stores the IDs in the link cache.
3447          *
3448          * WARNING: do not use this function on arbitrary user-supplied titles!
3449          * On heavily-used templates it will max out the memory.
3450          *
3451          * @param array $options May be FOR UPDATE
3452          * @param string $table Table name
3453          * @param string $prefix Fields prefix
3454          * @return array Array of Title objects linking here
3455          */
3456         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3457                 $id = $this->getArticleID();
3458
3459                 # If the page doesn't exist; there can't be any link from this page
3460                 if ( !$id ) {
3461                         return array();
3462                 }
3463
3464                 if ( count( $options ) > 0 ) {
3465                         $db = wfGetDB( DB_MASTER );
3466                 } else {
3467                         $db = wfGetDB( DB_SLAVE );
3468                 }
3469
3470                 $blNamespace = "{$prefix}_namespace";
3471                 $blTitle = "{$prefix}_title";
3472
3473                 $res = $db->select(
3474                         array( $table, 'page' ),
3475                         array_merge(
3476                                 array( $blNamespace, $blTitle ),
3477                                 WikiPage::selectFields()
3478                         ),
3479                         array( "{$prefix}_from" => $id ),
3480                         __METHOD__,
3481                         $options,
3482                         array( 'page' => array(
3483                                 'LEFT JOIN',
3484                                 array( "page_namespace=$blNamespace", "page_title=$blTitle" )
3485                         ) )
3486                 );
3487
3488                 $retVal = array();
3489                 $linkCache = LinkCache::singleton();
3490                 foreach ( $res as $row ) {
3491                         if ( $row->page_id ) {
3492                                 $titleObj = Title::newFromRow( $row );
3493                         } else {
3494                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3495                                 $linkCache->addBadLinkObj( $titleObj );
3496                         }
3497                         $retVal[] = $titleObj;
3498                 }
3499
3500                 return $retVal;
3501         }
3502
3503         /**
3504          * Get an array of Title objects used on this Title as a template
3505          * Also stores the IDs in the link cache.
3506          *
3507          * WARNING: do not use this function on arbitrary user-supplied titles!
3508          * On heavily-used templates it will max out the memory.
3509          *
3510          * @param array $options May be FOR UPDATE
3511          * @return Title[] Array of Title the Title objects used here
3512          */
3513         public function getTemplateLinksFrom( $options = array() ) {
3514                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3515         }
3516
3517         /**
3518          * Get an array of Title objects referring to non-existent articles linked
3519          * from this page.
3520          *
3521          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3522          *   should use redirect table in this case).
3523          * @return Title[] Array of Title the Title objects
3524          */
3525         public function getBrokenLinksFrom() {
3526                 if ( $this->getArticleID() == 0 ) {
3527                         # All links from article ID 0 are false positives
3528                         return array();
3529                 }
3530
3531                 $dbr = wfGetDB( DB_SLAVE );
3532                 $res = $dbr->select(
3533                         array( 'page', 'pagelinks' ),
3534                         array( 'pl_namespace', 'pl_title' ),
3535                         array(
3536                                 'pl_from' => $this->getArticleID(),
3537                                 'page_namespace IS NULL'
3538                         ),
3539                         __METHOD__, array(),
3540                         array(
3541                                 'page' => array(
3542                                         'LEFT JOIN',
3543                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3544                                 )
3545                         )
3546                 );
3547
3548                 $retVal = array();
3549                 foreach ( $res as $row ) {
3550                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3551                 }
3552                 return $retVal;
3553         }
3554
3555         /**
3556          * Get a list of URLs to purge from the Squid cache when this
3557          * page changes
3558          *
3559          * @return string[] Array of String the URLs
3560          */
3561         public function getSquidURLs() {
3562                 $urls = array(
3563                         $this->getInternalURL(),
3564                         $this->getInternalURL( 'action=history' )
3565                 );
3566
3567                 $pageLang = $this->getPageLanguage();
3568                 if ( $pageLang->hasVariants() ) {
3569                         $variants = $pageLang->getVariants();
3570                         foreach ( $variants as $vCode ) {
3571                                 $urls[] = $this->getInternalURL( '', $vCode );
3572                         }
3573                 }
3574
3575                 // If we are looking at a css/js user subpage, purge the action=raw.
3576                 if ( $this->isJsSubpage() ) {
3577                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3578                 } elseif ( $this->isCssSubpage() ) {
3579                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3580                 }
3581
3582                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3583                 return $urls;
3584         }
3585
3586         /**
3587          * Purge all applicable Squid URLs
3588          */
3589         public function purgeSquid() {
3590                 global $wgUseSquid;
3591                 if ( $wgUseSquid ) {
3592                         $urls = $this->getSquidURLs();
3593                         $u = new SquidUpdate( $urls );
3594                         $u->doUpdate();
3595                 }
3596         }
3597
3598         /**
3599          * Move this page without authentication
3600          *
3601          * @deprecated since 1.25 use MovePage class instead
3602          * @param Title $nt The new page Title
3603          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3604          */
3605         public function moveNoAuth( &$nt ) {
3606                 wfDeprecated( __METHOD__, '1.25' );
3607                 return $this->moveTo( $nt, false );
3608         }
3609
3610         /**
3611          * Check whether a given move operation would be valid.
3612          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3613          *
3614          * @deprecated since 1.25, use MovePage's methods instead
3615          * @param Title $nt The new title
3616          * @param bool $auth Whether to check user permissions (uses $wgUser)
3617          * @param string $reason Is the log summary of the move, used for spam checking
3618          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3619          */
3620         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3621                 global $wgUser;
3622
3623                 if ( !( $nt instanceof Title ) ) {
3624                         // Normally we'd add this to $errors, but we'll get
3625                         // lots of syntax errors if $nt is not an object
3626                         return array( array( 'badtitletext' ) );
3627                 }
3628
3629                 $mp = new MovePage( $this, $nt );
3630                 $errors = $mp->isValidMove()->getErrorsArray();
3631                 if ( $auth ) {
3632                         $errors = wfMergeErrorArrays(
3633                                 $errors,
3634                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3635                         );
3636                 }
3637
3638                 return $errors ?: true;
3639         }
3640
3641         /**
3642          * Check if the requested move target is a valid file move target
3643          * @todo move this to MovePage
3644          * @param Title $nt Target title
3645          * @return array List of errors
3646          */
3647         protected function validateFileMoveOperation( $nt ) {
3648                 global $wgUser;
3649
3650                 $errors = array();
3651
3652                 $destFile = wfLocalFile( $nt );
3653                 $destFile->load( File::READ_LATEST );
3654                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3655                         && !$destFile->exists() && wfFindFile( $nt )
3656                 ) {
3657                         $errors[] = array( 'file-exists-sharedrepo' );
3658                 }
3659
3660                 return $errors;
3661         }
3662
3663         /**
3664          * Move a title to a new location
3665          *
3666          * @deprecated since 1.25, use the MovePage class instead
3667          * @param Title $nt The new title
3668          * @param bool $auth Indicates whether $wgUser's permissions
3669          *  should be checked
3670          * @param string $reason The reason for the move
3671          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3672          *  Ignored if the user doesn't have the suppressredirect right.
3673          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3674          */
3675         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3676                 global $wgUser;
3677                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3678                 if ( is_array( $err ) ) {
3679                         // Auto-block user's IP if the account was "hard" blocked
3680                         $wgUser->spreadAnyEditBlock();
3681                         return $err;
3682                 }
3683                 // Check suppressredirect permission
3684                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3685                         $createRedirect = true;
3686                 }
3687
3688                 $mp = new MovePage( $this, $nt );
3689                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3690                 if ( $status->isOK() ) {
3691                         return true;
3692                 } else {
3693                         return $status->getErrorsArray();
3694                 }
3695         }
3696
3697         /**
3698          * Move this page's subpages to be subpages of $nt
3699          *
3700          * @param Title $nt Move target
3701          * @param bool $auth Whether $wgUser's permissions should be checked
3702          * @param string $reason The reason for the move
3703          * @param bool $createRedirect Whether to create redirects from the old subpages to
3704          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3705          * @return array Array with old page titles as keys, and strings (new page titles) or
3706          *     arrays (errors) as values, or an error array with numeric indices if no pages
3707          *     were moved
3708          */
3709         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3710                 global $wgMaximumMovedPages;
3711                 // Check permissions
3712                 if ( !$this->userCan( 'move-subpages' ) ) {
3713                         return array( 'cant-move-subpages' );
3714                 }
3715                 // Do the source and target namespaces support subpages?
3716                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3717                         return array( 'namespace-nosubpages',
3718                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3719                 }
3720                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3721                         return array( 'namespace-nosubpages',
3722                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3723                 }
3724
3725                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3726                 $retval = array();
3727                 $count = 0;
3728                 foreach ( $subpages as $oldSubpage ) {
3729                         $count++;
3730                         if ( $count > $wgMaximumMovedPages ) {
3731                                 $retval[$oldSubpage->getPrefixedText()] =
3732                                                 array( 'movepage-max-pages',
3733                                                         $wgMaximumMovedPages );
3734                                 break;
3735                         }
3736
3737                         // We don't know whether this function was called before
3738                         // or after moving the root page, so check both
3739                         // $this and $nt
3740                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3741                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3742                         ) {
3743                                 // When moving a page to a subpage of itself,
3744                                 // don't move it twice
3745                                 continue;
3746                         }
3747                         $newPageName = preg_replace(
3748                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3749                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3750                                         $oldSubpage->getDBkey() );
3751                         if ( $oldSubpage->isTalkPage() ) {
3752                                 $newNs = $nt->getTalkPage()->getNamespace();
3753                         } else {
3754                                 $newNs = $nt->getSubjectPage()->getNamespace();
3755                         }
3756                         # Bug 14385: we need makeTitleSafe because the new page names may
3757                         # be longer than 255 characters.
3758                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3759
3760                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3761                         if ( $success === true ) {
3762                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3763                         } else {
3764                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3765                         }
3766                 }
3767                 return $retval;
3768         }
3769
3770         /**
3771          * Checks if this page is just a one-rev redirect.
3772          * Adds lock, so don't use just for light purposes.
3773          *
3774          * @return bool
3775          */
3776         public function isSingleRevRedirect() {
3777                 global $wgContentHandlerUseDB;
3778
3779                 $dbw = wfGetDB( DB_MASTER );
3780
3781                 # Is it a redirect?
3782                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3783                 if ( $wgContentHandlerUseDB ) {
3784                         $fields[] = 'page_content_model';
3785                 }
3786
3787                 $row = $dbw->selectRow( 'page',
3788                         $fields,
3789                         $this->pageCond(),
3790                         __METHOD__,
3791                         array( 'FOR UPDATE' )
3792                 );
3793                 # Cache some fields we may want
3794                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3795                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3796                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3797                 $this->mContentModel = $row && isset( $row->page_content_model )
3798                         ? strval( $row->page_content_model )
3799                         : false;
3800
3801                 if ( !$this->mRedirect ) {
3802                         return false;
3803                 }
3804                 # Does the article have a history?
3805                 $row = $dbw->selectField( array( 'page', 'revision' ),
3806                         'rev_id',
3807                         array( 'page_namespace' => $this->getNamespace(),
3808                                 'page_title' => $this->getDBkey(),
3809                                 'page_id=rev_page',
3810                                 'page_latest != rev_id'
3811                         ),
3812                         __METHOD__,
3813                         array( 'FOR UPDATE' )
3814                 );
3815                 # Return true if there was no history
3816                 return ( $row === false );
3817         }
3818
3819         /**
3820          * Checks if $this can be moved to a given Title
3821          * - Selects for update, so don't call it unless you mean business
3822          *
3823          * @deprecated since 1.25, use MovePage's methods instead
3824          * @param Title $nt The new title to check
3825          * @return bool
3826          */
3827         public function isValidMoveTarget( $nt ) {
3828                 # Is it an existing file?
3829                 if ( $nt->getNamespace() == NS_FILE ) {
3830                         $file = wfLocalFile( $nt );
3831                         $file->load( File::READ_LATEST );
3832                         if ( $file->exists() ) {
3833                                 wfDebug( __METHOD__ . ": file exists\n" );
3834                                 return false;
3835                         }
3836                 }
3837                 # Is it a redirect with no history?
3838                 if ( !$nt->isSingleRevRedirect() ) {
3839                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3840                         return false;
3841                 }
3842                 # Get the article text
3843                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3844                 if ( !is_object( $rev ) ) {
3845                         return false;
3846                 }
3847                 $content = $rev->getContent();
3848                 # Does the redirect point to the source?
3849                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3850                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3851
3852                 if ( $redirTitle ) {
3853                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3854                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3855                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3856                                 return false;
3857                         } else {
3858                                 return true;
3859                         }
3860                 } else {
3861                         # Fail safe (not a redirect after all. strange.)
3862                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3863                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3864                         return false;
3865                 }
3866         }
3867
3868         /**
3869          * Get categories to which this Title belongs and return an array of
3870          * categories' names.
3871          *
3872          * @return array Array of parents in the form:
3873          *        $parent => $currentarticle
3874          */
3875         public function getParentCategories() {
3876                 global $wgContLang;
3877
3878                 $data = array();
3879
3880                 $titleKey = $this->getArticleID();
3881
3882                 if ( $titleKey === 0 ) {
3883                         return $data;
3884                 }
3885
3886                 $dbr = wfGetDB( DB_SLAVE );
3887
3888                 $res = $dbr->select(
3889                         'categorylinks',
3890                         'cl_to',
3891                         array( 'cl_from' => $titleKey ),
3892                         __METHOD__
3893                 );
3894
3895                 if ( $res->numRows() > 0 ) {
3896                         foreach ( $res as $row ) {
3897                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3898                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3899                         }
3900                 }
3901                 return $data;
3902         }
3903
3904         /**
3905          * Get a tree of parent categories
3906          *
3907          * @param array $children Array with the children in the keys, to check for circular refs
3908          * @return array Tree of parent categories
3909          */
3910         public function getParentCategoryTree( $children = array() ) {
3911                 $stack = array();
3912                 $parents = $this->getParentCategories();
3913
3914                 if ( $parents ) {
3915                         foreach ( $parents as $parent => $current ) {
3916                                 if ( array_key_exists( $parent, $children ) ) {
3917                                         # Circular reference
3918                                         $stack[$parent] = array();
3919                                 } else {
3920                                         $nt = Title::newFromText( $parent );
3921                                         if ( $nt ) {
3922                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3923                                         }
3924                                 }
3925                         }
3926                 }
3927
3928                 return $stack;
3929         }
3930
3931         /**
3932          * Get an associative array for selecting this title from
3933          * the "page" table
3934          *
3935          * @return array Array suitable for the $where parameter of DB::select()
3936          */
3937         public function pageCond() {
3938                 if ( $this->mArticleID > 0 ) {
3939                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3940                         return array( 'page_id' => $this->mArticleID );
3941                 } else {
3942                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3943                 }
3944         }
3945
3946         /**
3947          * Get the revision ID of the previous revision
3948          *
3949          * @param int $revId Revision ID. Get the revision that was before this one.
3950          * @param int $flags Title::GAID_FOR_UPDATE
3951          * @return int|bool Old revision ID, or false if none exists
3952          */
3953         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3954                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3955                 $revId = $db->selectField( 'revision', 'rev_id',
3956                         array(
3957                                 'rev_page' => $this->getArticleID( $flags ),
3958                                 'rev_id < ' . intval( $revId )
3959                         ),
3960                         __METHOD__,
3961                         array( 'ORDER BY' => 'rev_id DESC' )
3962                 );
3963
3964                 if ( $revId === false ) {
3965                         return false;
3966                 } else {
3967                         return intval( $revId );
3968                 }
3969         }
3970
3971         /**
3972          * Get the revision ID of the next revision
3973          *
3974          * @param int $revId Revision ID. Get the revision that was after this one.
3975          * @param int $flags Title::GAID_FOR_UPDATE
3976          * @return int|bool Next revision ID, or false if none exists
3977          */
3978         public function getNextRevisionID( $revId, $flags = 0 ) {
3979                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3980                 $revId = $db->selectField( 'revision', 'rev_id',
3981                         array(
3982                                 'rev_page' => $this->getArticleID( $flags ),
3983                                 'rev_id > ' . intval( $revId )
3984                         ),
3985                         __METHOD__,
3986                         array( 'ORDER BY' => 'rev_id' )
3987                 );
3988
3989                 if ( $revId === false ) {
3990                         return false;
3991                 } else {
3992                         return intval( $revId );
3993                 }
3994         }
3995
3996         /**
3997          * Get the first revision of the page
3998          *
3999          * @param int $flags Title::GAID_FOR_UPDATE
4000          * @return Revision|null If page doesn't exist
4001          */
4002         public function getFirstRevision( $flags = 0 ) {
4003                 $pageId = $this->getArticleID( $flags );
4004                 if ( $pageId ) {
4005                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4006                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4007                                 array( 'rev_page' => $pageId ),
4008                                 __METHOD__,
4009                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4010                         );
4011                         if ( $row ) {
4012                                 return new Revision( $row );
4013                         }
4014                 }
4015                 return null;
4016         }
4017
4018         /**
4019          * Get the oldest revision timestamp of this page
4020          *
4021          * @param int $flags Title::GAID_FOR_UPDATE
4022          * @return string MW timestamp
4023          */
4024         public function getEarliestRevTime( $flags = 0 ) {
4025                 $rev = $this->getFirstRevision( $flags );
4026                 return $rev ? $rev->getTimestamp() : null;
4027         }
4028
4029         /**
4030          * Check if this is a new page
4031          *
4032          * @return bool
4033          */
4034         public function isNewPage() {
4035                 $dbr = wfGetDB( DB_SLAVE );
4036                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4037         }
4038
4039         /**
4040          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4041          *
4042          * @return bool
4043          */
4044         public function isBigDeletion() {
4045                 global $wgDeleteRevisionsLimit;
4046
4047                 if ( !$wgDeleteRevisionsLimit ) {
4048                         return false;
4049                 }
4050
4051                 if ( $this->mIsBigDeletion === null ) {
4052                         $dbr = wfGetDB( DB_SLAVE );
4053
4054                         $revCount = $dbr->selectRowCount(
4055                                 'revision',
4056                                 '1',
4057                                 array( 'rev_page' => $this->getArticleID() ),
4058                                 __METHOD__,
4059                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4060                         );
4061
4062                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4063                 }
4064
4065                 return $this->mIsBigDeletion;
4066         }
4067
4068         /**
4069          * Get the approximate revision count of this page.
4070          *
4071          * @return int
4072          */
4073         public function estimateRevisionCount() {
4074                 if ( !$this->exists() ) {
4075                         return 0;
4076                 }
4077
4078                 if ( $this->mEstimateRevisions === null ) {
4079                         $dbr = wfGetDB( DB_SLAVE );
4080                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4081                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4082                 }
4083
4084                 return $this->mEstimateRevisions;
4085         }
4086
4087         /**
4088          * Get the number of revisions between the given revision.
4089          * Used for diffs and other things that really need it.
4090          *
4091          * @param int|Revision $old Old revision or rev ID (first before range)
4092          * @param int|Revision $new New revision or rev ID (first after range)
4093          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4094          * @return int Number of revisions between these revisions.
4095          */
4096         public function countRevisionsBetween( $old, $new, $max = null ) {
4097                 if ( !( $old instanceof Revision ) ) {
4098                         $old = Revision::newFromTitle( $this, (int)$old );
4099                 }
4100                 if ( !( $new instanceof Revision ) ) {
4101                         $new = Revision::newFromTitle( $this, (int)$new );
4102                 }
4103                 if ( !$old || !$new ) {
4104                         return 0; // nothing to compare
4105                 }
4106                 $dbr = wfGetDB( DB_SLAVE );
4107                 $conds = array(
4108                         'rev_page' => $this->getArticleID(),
4109                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4110                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4111                 );
4112                 if ( $max !== null ) {
4113                         return $dbr->selectRowCount( 'revision', '1',
4114                                 $conds,
4115                                 __METHOD__,
4116                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4117                         );
4118                 } else {
4119                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4120                 }
4121         }
4122
4123         /**
4124          * Get the authors between the given revisions or revision IDs.
4125          * Used for diffs and other things that really need it.
4126          *
4127          * @since 1.23
4128          *
4129          * @param int|Revision $old Old revision or rev ID (first before range by default)
4130          * @param int|Revision $new New revision or rev ID (first after range by default)
4131          * @param int $limit Maximum number of authors
4132          * @param string|array $options (Optional): Single option, or an array of options:
4133          *     'include_old' Include $old in the range; $new is excluded.
4134          *     'include_new' Include $new in the range; $old is excluded.
4135          *     'include_both' Include both $old and $new in the range.
4136          *     Unknown option values are ignored.
4137          * @return array|null Names of revision authors in the range; null if not both revisions exist
4138          */
4139         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4140                 if ( !( $old instanceof Revision ) ) {
4141                         $old = Revision::newFromTitle( $this, (int)$old );
4142                 }
4143                 if ( !( $new instanceof Revision ) ) {
4144                         $new = Revision::newFromTitle( $this, (int)$new );
4145                 }
4146                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4147                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4148                 // in the sanity check below?
4149                 if ( !$old || !$new ) {
4150                         return null; // nothing to compare
4151                 }
4152                 $authors = array();
4153                 $old_cmp = '>';
4154                 $new_cmp = '<';
4155                 $options = (array)$options;
4156                 if ( in_array( 'include_old', $options ) ) {
4157                         $old_cmp = '>=';
4158                 }
4159                 if ( in_array( 'include_new', $options ) ) {
4160                         $new_cmp = '<=';
4161                 }
4162                 if ( in_array( 'include_both', $options ) ) {
4163                         $old_cmp = '>=';
4164                         $new_cmp = '<=';
4165                 }
4166                 // No DB query needed if $old and $new are the same or successive revisions:
4167                 if ( $old->getId() === $new->getId() ) {
4168                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4169                                 array() :
4170                                 array( $old->getUserText( Revision::RAW ) );
4171                 } elseif ( $old->getId() === $new->getParentId() ) {
4172                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4173                                 $authors[] = $old->getUserText( Revision::RAW );
4174                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4175                                         $authors[] = $new->getUserText( Revision::RAW );
4176                                 }
4177                         } elseif ( $old_cmp === '>=' ) {
4178                                 $authors[] = $old->getUserText( Revision::RAW );
4179                         } elseif ( $new_cmp === '<=' ) {
4180                                 $authors[] = $new->getUserText( Revision::RAW );
4181                         }
4182                         return $authors;
4183                 }
4184                 $dbr = wfGetDB( DB_SLAVE );
4185                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4186                         array(
4187                                 'rev_page' => $this->getArticleID(),
4188                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4189                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4190                         ), __METHOD__,
4191                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4192                 );
4193                 foreach ( $res as $row ) {
4194                         $authors[] = $row->rev_user_text;
4195                 }
4196                 return $authors;
4197         }
4198
4199         /**
4200          * Get the number of authors between the given revisions or revision IDs.
4201          * Used for diffs and other things that really need it.
4202          *
4203          * @param int|Revision $old Old revision or rev ID (first before range by default)
4204          * @param int|Revision $new New revision or rev ID (first after range by default)
4205          * @param int $limit Maximum number of authors
4206          * @param string|array $options (Optional): Single option, or an array of options:
4207          *     'include_old' Include $old in the range; $new is excluded.
4208          *     'include_new' Include $new in the range; $old is excluded.
4209          *     'include_both' Include both $old and $new in the range.
4210          *     Unknown option values are ignored.
4211          * @return int Number of revision authors in the range; zero if not both revisions exist
4212          */
4213         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4214                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4215                 return $authors ? count( $authors ) : 0;
4216         }
4217
4218         /**
4219          * Compare with another title.
4220          *
4221          * @param Title $title
4222          * @return bool
4223          */
4224         public function equals( Title $title ) {
4225                 // Note: === is necessary for proper matching of number-like titles.
4226                 return $this->getInterwiki() === $title->getInterwiki()
4227                         && $this->getNamespace() == $title->getNamespace()
4228                         && $this->getDBkey() === $title->getDBkey();
4229         }
4230
4231         /**
4232          * Check if this title is a subpage of another title
4233          *
4234          * @param Title $title
4235          * @return bool
4236          */
4237         public function isSubpageOf( Title $title ) {
4238                 return $this->getInterwiki() === $title->getInterwiki()
4239                         && $this->getNamespace() == $title->getNamespace()
4240                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4241         }
4242
4243         /**
4244          * Check if page exists.  For historical reasons, this function simply
4245          * checks for the existence of the title in the page table, and will
4246          * thus return false for interwiki links, special pages and the like.
4247          * If you want to know if a title can be meaningfully viewed, you should
4248          * probably call the isKnown() method instead.
4249          *
4250          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4251          *   from master/for update
4252          * @return bool
4253          */
4254         public function exists( $flags = 0 ) {
4255                 $exists = $this->getArticleID( $flags ) != 0;
4256                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4257                 return $exists;
4258         }
4259
4260         /**
4261          * Should links to this title be shown as potentially viewable (i.e. as
4262          * "bluelinks"), even if there's no record by this title in the page
4263          * table?
4264          *
4265          * This function is semi-deprecated for public use, as well as somewhat
4266          * misleadingly named.  You probably just want to call isKnown(), which
4267          * calls this function internally.
4268          *
4269          * (ISSUE: Most of these checks are cheap, but the file existence check
4270          * can potentially be quite expensive.  Including it here fixes a lot of
4271          * existing code, but we might want to add an optional parameter to skip
4272          * it and any other expensive checks.)
4273          *
4274          * @return bool
4275          */
4276         public function isAlwaysKnown() {
4277                 $isKnown = null;
4278
4279                 /**
4280                  * Allows overriding default behavior for determining if a page exists.
4281                  * If $isKnown is kept as null, regular checks happen. If it's
4282                  * a boolean, this value is returned by the isKnown method.
4283                  *
4284                  * @since 1.20
4285                  *
4286                  * @param Title $title
4287                  * @param bool|null $isKnown
4288                  */
4289                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4290
4291                 if ( !is_null( $isKnown ) ) {
4292                         return $isKnown;
4293                 }
4294
4295                 if ( $this->isExternal() ) {
4296                         return true;  // any interwiki link might be viewable, for all we know
4297                 }
4298
4299                 switch ( $this->mNamespace ) {
4300                         case NS_MEDIA:
4301                         case NS_FILE:
4302                                 // file exists, possibly in a foreign repo
4303                                 return (bool)wfFindFile( $this );
4304                         case NS_SPECIAL:
4305                                 // valid special page
4306                                 return SpecialPageFactory::exists( $this->getDBkey() );
4307                         case NS_MAIN:
4308                                 // selflink, possibly with fragment
4309                                 return $this->mDbkeyform == '';
4310                         case NS_MEDIAWIKI:
4311                                 // known system message
4312                                 return $this->hasSourceText() !== false;
4313                         default:
4314                                 return false;
4315                 }
4316         }
4317
4318         /**
4319          * Does this title refer to a page that can (or might) be meaningfully
4320          * viewed?  In particular, this function may be used to determine if
4321          * links to the title should be rendered as "bluelinks" (as opposed to
4322          * "redlinks" to non-existent pages).
4323          * Adding something else to this function will cause inconsistency
4324          * since LinkHolderArray calls isAlwaysKnown() and does its own
4325          * page existence check.
4326          *
4327          * @return bool
4328          */
4329         public function isKnown() {
4330                 return $this->isAlwaysKnown() || $this->exists();
4331         }
4332
4333         /**
4334          * Does this page have source text?
4335          *
4336          * @return bool
4337          */
4338         public function hasSourceText() {
4339                 if ( $this->exists() ) {
4340                         return true;
4341                 }
4342
4343                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4344                         // If the page doesn't exist but is a known system message, default
4345                         // message content will be displayed, same for language subpages-
4346                         // Use always content language to avoid loading hundreds of languages
4347                         // to get the link color.
4348                         global $wgContLang;
4349                         list( $name, ) = MessageCache::singleton()->figureMessage(
4350                                 $wgContLang->lcfirst( $this->getText() )
4351                         );
4352                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4353                         return $message->exists();
4354                 }
4355
4356                 return false;
4357         }
4358
4359         /**
4360          * Get the default message text or false if the message doesn't exist
4361          *
4362          * @return string|bool
4363          */
4364         public function getDefaultMessageText() {
4365                 global $wgContLang;
4366
4367                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4368                         return false;
4369                 }
4370
4371                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4372                         $wgContLang->lcfirst( $this->getText() )
4373                 );
4374                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4375
4376                 if ( $message->exists() ) {
4377                         return $message->plain();
4378                 } else {
4379                         return false;
4380                 }
4381         }
4382
4383         /**
4384          * Updates page_touched for this page; called from LinksUpdate.php
4385          *
4386          * @param string $purgeTime [optional] TS_MW timestamp
4387          * @return bool True if the update succeeded
4388          */
4389         public function invalidateCache( $purgeTime = null ) {
4390                 if ( wfReadOnly() ) {
4391                         return false;
4392                 }
4393
4394                 if ( $this->mArticleID === 0 ) {
4395                         return true; // avoid gap locking if we know it's not there
4396                 }
4397
4398                 $method = __METHOD__;
4399                 $dbw = wfGetDB( DB_MASTER );
4400                 $conds = $this->pageCond();
4401                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4402                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4403
4404                         $dbw->update(
4405                                 'page',
4406                                 array( 'page_touched' => $dbTimestamp ),
4407                                 $conds + array( 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ),
4408                                 $method
4409                         );
4410                 } );
4411
4412                 return true;
4413         }
4414
4415         /**
4416          * Update page_touched timestamps and send squid purge messages for
4417          * pages linking to this title. May be sent to the job queue depending
4418          * on the number of links. Typically called on create and delete.
4419          */
4420         public function touchLinks() {
4421                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4422                 if ( $this->getNamespace() == NS_CATEGORY ) {
4423                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4424                 }
4425         }
4426
4427         /**
4428          * Get the last touched timestamp
4429          *
4430          * @param IDatabase $db Optional db
4431          * @return string Last-touched timestamp
4432          */
4433         public function getTouched( $db = null ) {
4434                 if ( $db === null ) {
4435                         $db = wfGetDB( DB_SLAVE );
4436                 }
4437                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4438                 return $touched;
4439         }
4440
4441         /**
4442          * Get the timestamp when this page was updated since the user last saw it.
4443          *
4444          * @param User $user
4445          * @return string|null
4446          */
4447         public function getNotificationTimestamp( $user = null ) {
4448                 global $wgUser;
4449
4450                 // Assume current user if none given
4451                 if ( !$user ) {
4452                         $user = $wgUser;
4453                 }
4454                 // Check cache first
4455                 $uid = $user->getId();
4456                 if ( !$uid ) {
4457                         return false;
4458                 }
4459                 // avoid isset here, as it'll return false for null entries
4460                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4461                         return $this->mNotificationTimestamp[$uid];
4462                 }
4463                 // Don't cache too much!
4464                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4465                         $this->mNotificationTimestamp = array();
4466                 }
4467
4468                 $watchedItem = WatchedItem::fromUserTitle( $user, $this );
4469                 $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4470
4471                 return $this->mNotificationTimestamp[$uid];
4472         }
4473
4474         /**
4475          * Generate strings used for xml 'id' names in monobook tabs
4476          *
4477          * @param string $prepend Defaults to 'nstab-'
4478          * @return string XML 'id' name
4479          */
4480         public function getNamespaceKey( $prepend = 'nstab-' ) {
4481                 global $wgContLang;
4482                 // Gets the subject namespace if this title
4483                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4484                 // Checks if canonical namespace name exists for namespace
4485                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4486                         // Uses canonical namespace name
4487                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4488                 } else {
4489                         // Uses text of namespace
4490                         $namespaceKey = $this->getSubjectNsText();
4491                 }
4492                 // Makes namespace key lowercase
4493                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4494                 // Uses main
4495                 if ( $namespaceKey == '' ) {
4496                         $namespaceKey = 'main';
4497                 }
4498                 // Changes file to image for backwards compatibility
4499                 if ( $namespaceKey == 'file' ) {
4500                         $namespaceKey = 'image';
4501                 }
4502                 return $prepend . $namespaceKey;
4503         }
4504
4505         /**
4506          * Get all extant redirects to this Title
4507          *
4508          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4509          * @return Title[] Array of Title redirects to this title
4510          */
4511         public function getRedirectsHere( $ns = null ) {
4512                 $redirs = array();
4513
4514                 $dbr = wfGetDB( DB_SLAVE );
4515                 $where = array(
4516                         'rd_namespace' => $this->getNamespace(),
4517                         'rd_title' => $this->getDBkey(),
4518                         'rd_from = page_id'
4519                 );
4520                 if ( $this->isExternal() ) {
4521                         $where['rd_interwiki'] = $this->getInterwiki();
4522                 } else {
4523                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4524                 }
4525                 if ( !is_null( $ns ) ) {
4526                         $where['page_namespace'] = $ns;
4527                 }
4528
4529                 $res = $dbr->select(
4530                         array( 'redirect', 'page' ),
4531                         array( 'page_namespace', 'page_title' ),
4532                         $where,
4533                         __METHOD__
4534                 );
4535
4536                 foreach ( $res as $row ) {
4537                         $redirs[] = self::newFromRow( $row );
4538                 }
4539                 return $redirs;
4540         }
4541
4542         /**
4543          * Check if this Title is a valid redirect target
4544          *
4545          * @return bool
4546          */
4547         public function isValidRedirectTarget() {
4548                 global $wgInvalidRedirectTargets;
4549
4550                 if ( $this->isSpecialPage() ) {
4551                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4552                         if ( $this->isSpecial( 'Userlogout' ) ) {
4553                                 return false;
4554                         }
4555
4556                         foreach ( $wgInvalidRedirectTargets as $target ) {
4557                                 if ( $this->isSpecial( $target ) ) {
4558                                         return false;
4559                                 }
4560                         }
4561                 }
4562
4563                 return true;
4564         }
4565
4566         /**
4567          * Get a backlink cache object
4568          *
4569          * @return BacklinkCache
4570          */
4571         public function getBacklinkCache() {
4572                 return BacklinkCache::get( $this );
4573         }
4574
4575         /**
4576          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4577          *
4578          * @return bool
4579          */
4580         public function canUseNoindex() {
4581                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4582
4583                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4584                         ? $wgContentNamespaces
4585                         : $wgExemptFromUserRobotsControl;
4586
4587                 return !in_array( $this->mNamespace, $bannedNamespaces );
4588
4589         }
4590
4591         /**
4592          * Returns the raw sort key to be used for categories, with the specified
4593          * prefix.  This will be fed to Collation::getSortKey() to get a
4594          * binary sortkey that can be used for actual sorting.
4595          *
4596          * @param string $prefix The prefix to be used, specified using
4597          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4598          *   prefix.
4599          * @return string
4600          */
4601         public function getCategorySortkey( $prefix = '' ) {
4602                 $unprefixed = $this->getText();
4603
4604                 // Anything that uses this hook should only depend
4605                 // on the Title object passed in, and should probably
4606                 // tell the users to run updateCollations.php --force
4607                 // in order to re-sort existing category relations.
4608                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4609                 if ( $prefix !== '' ) {
4610                         # Separate with a line feed, so the unprefixed part is only used as
4611                         # a tiebreaker when two pages have the exact same prefix.
4612                         # In UCA, tab is the only character that can sort above LF
4613                         # so we strip both of them from the original prefix.
4614                         $prefix = strtr( $prefix, "\n\t", '  ' );
4615                         return "$prefix\n$unprefixed";
4616                 }
4617                 return $unprefixed;
4618         }
4619
4620         /**
4621          * Get the language in which the content of this page is written in
4622          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4623          * e.g. $wgLang (such as special pages, which are in the user language).
4624          *
4625          * @since 1.18
4626          * @return Language
4627          */
4628         public function getPageLanguage() {
4629                 global $wgLang, $wgLanguageCode;
4630                 if ( $this->isSpecialPage() ) {
4631                         // special pages are in the user language
4632                         return $wgLang;
4633                 }
4634
4635                 // Checking if DB language is set
4636                 if ( $this->mDbPageLanguage ) {
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                 return $langObj;
4655         }
4656
4657         /**
4658          * Get the language in which the content of this page is written when
4659          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4660          * e.g. $wgLang (such as special pages, which are in the user language).
4661          *
4662          * @since 1.20
4663          * @return Language
4664          */
4665         public function getPageViewLanguage() {
4666                 global $wgLang;
4667
4668                 if ( $this->isSpecialPage() ) {
4669                         // If the user chooses a variant, the content is actually
4670                         // in a language whose code is the variant code.
4671                         $variant = $wgLang->getPreferredVariant();
4672                         if ( $wgLang->getCode() !== $variant ) {
4673                                 return Language::factory( $variant );
4674                         }
4675
4676                         return $wgLang;
4677                 }
4678
4679                 // @note Can't be cached persistently, depends on user settings.
4680                 // @note ContentHandler::getPageViewLanguage() may need to load the
4681                 //   content to determine the page language!
4682                 $contentHandler = ContentHandler::getForTitle( $this );
4683                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4684                 return $pageLang;
4685         }
4686
4687         /**
4688          * Get a list of rendered edit notices for this page.
4689          *
4690          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4691          * they will already be wrapped in paragraphs.
4692          *
4693          * @since 1.21
4694          * @param int $oldid Revision ID that's being edited
4695          * @return array
4696          */
4697         public function getEditNotices( $oldid = 0 ) {
4698                 $notices = array();
4699
4700                 // Optional notice for the entire namespace
4701                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4702                 $msg = wfMessage( $editnotice_ns );
4703                 if ( $msg->exists() ) {
4704                         $html = $msg->parseAsBlock();
4705                         // Edit notices may have complex logic, but output nothing (T91715)
4706                         if ( trim( $html ) !== '' ) {
4707                                 $notices[$editnotice_ns] = Html::rawElement(
4708                                         'div',
4709                                         array( 'class' => array(
4710                                                 'mw-editnotice',
4711                                                 'mw-editnotice-namespace',
4712                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4713                                         ) ),
4714                                         $html
4715                                 );
4716                         }
4717                 }
4718
4719                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4720                         // Optional notice for page itself and any parent page
4721                         $parts = explode( '/', $this->getDBkey() );
4722                         $editnotice_base = $editnotice_ns;
4723                         while ( count( $parts ) > 0 ) {
4724                                 $editnotice_base .= '-' . array_shift( $parts );
4725                                 $msg = wfMessage( $editnotice_base );
4726                                 if ( $msg->exists() ) {
4727                                         $html = $msg->parseAsBlock();
4728                                         if ( trim( $html ) !== '' ) {
4729                                                 $notices[$editnotice_base] = Html::rawElement(
4730                                                         'div',
4731                                                         array( 'class' => array(
4732                                                                 'mw-editnotice',
4733                                                                 'mw-editnotice-base',
4734                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4735                                                         ) ),
4736                                                         $html
4737                                                 );
4738                                         }
4739                                 }
4740                         }
4741                 } else {
4742                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4743                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4744                         $msg = wfMessage( $editnoticeText );
4745                         if ( $msg->exists() ) {
4746                                 $html = $msg->parseAsBlock();
4747                                 if ( trim( $html ) !== '' ) {
4748                                         $notices[$editnoticeText] = Html::rawElement(
4749                                                 'div',
4750                                                 array( 'class' => array(
4751                                                         'mw-editnotice',
4752                                                         'mw-editnotice-page',
4753                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4754                                                 ) ),
4755                                                 $html
4756                                         );
4757                                 }
4758                         }
4759                 }
4760
4761                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4762                 return $notices;
4763         }
4764
4765         /**
4766          * @return array
4767          */
4768         public function __sleep() {
4769                 return array(
4770                         'mNamespace',
4771                         'mDbkeyform',
4772                         'mFragment',
4773                         'mInterwiki',
4774                         'mLocalInterwiki',
4775                         'mUserCaseDBKey',
4776                         'mDefaultNamespace',
4777                 );
4778         }
4779
4780         public function __wakeup() {
4781                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4782                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4783                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4784         }
4785
4786 }