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( __METHOD__ . ': $text must be a string. This will throw an InvalidArgumentException in future.', 2 );
 270                 }
 271
 272                 try {
 273                         return Title::newFromTextThrow( $text, $defaultNamespace );
 274                 } catch ( MalformedTitleException $ex ) {
 275                         return null;
 276                 }
 277         }
 278
 279         /**
 280          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 281          * rather than returning null.
 282          *
 283          * The exception subclasses encode detailed information about why the title is invalid.
 284          *
 285          * @see Title::newFromText
 286          *
 287          * @since 1.25
 288          * @param string $text Title text to check
 289          * @param int $defaultNamespace
 290          * @throws MalformedTitleException If the title is invalid
 291          * @return Title
 292          */
 293         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 294                 if ( is_object( $text ) ) {
 295                         throw new MWException( 'Title::newFromTextThrow given an object' );
 296                 }
 297
 298                 $cache = self::getTitleCache();
 299
 300                 /**
 301                  * Wiki pages often contain multiple links to the same page.
 302                  * Title normalization and parsing can become expensive on
 303                  * pages with many links, so we can save a little time by
 304                  * caching them.
 305                  *
 306                  * In theory these are value objects and won't get changed...
 307                  */
 308                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 309                         return $cache->get( $text );
 310                 }
 311
 312                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 313                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 314
 315                 $t = new Title();
 316                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 317                 $t->mDefaultNamespace = intval( $defaultNamespace );
 318
 319                 $t->secureAndSplit();
 320                 if ( $defaultNamespace == NS_MAIN ) {
 321                         $cache->set( $text, $t );
 322                 }
 323                 return $t;
 324         }
 325
 326         /**
 327          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 328          *
 329          * Example of wrong and broken code:
 330          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 331          *
 332          * Example of right code:
 333          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 334          *
 335          * Create a new Title from URL-encoded text. Ensures that
 336          * the given title's length does not exceed the maximum.
 337          *
 338          * @param string $url The title, as might be taken from a URL
 339          * @return Title|null The new object, or null on an error
 340          */
 341         public static function newFromURL( $url ) {
 342                 $t = new Title();
 343
 344                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 345                 # but some URLs used it as a space replacement and they still come
 346                 # from some external search tools.
 347                 if ( strpos( self::legalChars(), '+' ) === false ) {
 348                         $url = strtr( $url, '+', ' ' );
 349                 }
 350
 351                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 352
 353                 try {
 354                         $t->secureAndSplit();
 355                         return $t;
 356                 } catch ( MalformedTitleException $ex ) {
 357                         return null;
 358                 }
 359         }
 360
 361         /**
 362          * @return MapCacheLRU
 363          */
 364         private static function getTitleCache() {
 365                 if ( self::$titleCache == null ) {
 366                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 367                 }
 368                 return self::$titleCache;
 369         }
 370
 371         /**
 372          * Returns a list of fields that are to be selected for initializing Title
 373          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 374          * whether to include page_content_model.
 375          *
 376          * @return array
 377          */
 378         protected static function getSelectFields() {
 379                 global $wgContentHandlerUseDB;
 380
 381                 $fields = array(
 382                         'page_namespace', 'page_title', 'page_id',
 383                         'page_len', 'page_is_redirect', 'page_latest',
 384                 );
 385
 386                 if ( $wgContentHandlerUseDB ) {
 387                         $fields[] = 'page_content_model';
 388                 }
 389
 390                 return $fields;
 391         }
 392
 393         /**
 394          * Create a new Title from an article ID
 395          *
 396          * @param int $id The page_id corresponding to the Title to create
 397          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 398          * @return Title|null The new object, or null on an error
 399          */
 400         public static function newFromID( $id, $flags = 0 ) {
 401                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 402                 $row = $db->selectRow(
 403                         'page',
 404                         self::getSelectFields(),
 405                         array( 'page_id' => $id ),
 406                         __METHOD__
 407                 );
 408                 if ( $row !== false ) {
 409                         $title = Title::newFromRow( $row );
 410                 } else {
 411                         $title = null;
 412                 }
 413                 return $title;
 414         }
 415
 416         /**
 417          * Make an array of titles from an array of IDs
 418          *
 419          * @param int[] $ids Array of IDs
 420          * @return Title[] Array of Titles
 421          */
 422         public static function newFromIDs( $ids ) {
 423                 if ( !count( $ids ) ) {
 424                         return array();
 425                 }
 426                 $dbr = wfGetDB( DB_SLAVE );
 427
 428                 $res = $dbr->select(
 429                         'page',
 430                         self::getSelectFields(),
 431                         array( 'page_id' => $ids ),
 432                         __METHOD__
 433                 );
 434
 435                 $titles = array();
 436                 foreach ( $res as $row ) {
 437                         $titles[] = Title::newFromRow( $row );
 438                 }
 439                 return $titles;
 440         }
 441
 442         /**
 443          * Make a Title object from a DB row
 444          *
 445          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 446          * @return Title Corresponding Title
 447          */
 448         public static function newFromRow( $row ) {
 449                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 450                 $t->loadFromRow( $row );
 451                 return $t;
 452         }
 453
 454         /**
 455          * Load Title object fields from a DB row.
 456          * If false is given, the title will be treated as non-existing.
 457          *
 458          * @param stdClass|bool $row Database row
 459          */
 460         public function loadFromRow( $row ) {
 461                 if ( $row ) { // page found
 462                         if ( isset( $row->page_id ) ) {
 463                                 $this->mArticleID = (int)$row->page_id;
 464                         }
 465                         if ( isset( $row->page_len ) ) {
 466                                 $this->mLength = (int)$row->page_len;
 467                         }
 468                         if ( isset( $row->page_is_redirect ) ) {
 469                                 $this->mRedirect = (bool)$row->page_is_redirect;
 470                         }
 471                         if ( isset( $row->page_latest ) ) {
 472                                 $this->mLatestID = (int)$row->page_latest;
 473                         }
 474                         if ( isset( $row->page_content_model ) ) {
 475                                 $this->mContentModel = strval( $row->page_content_model );
 476                         } else {
 477                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 478                         }
 479                         if ( isset( $row->page_lang ) ) {
 480                                 $this->mDbPageLanguage = (string)$row->page_lang;
 481                         }
 482                         if ( isset( $row->page_restrictions ) ) {
 483                                 $this->mOldRestrictions = $row->page_restrictions;
 484                         }
 485                 } else { // page not found
 486                         $this->mArticleID = 0;
 487                         $this->mLength = 0;
 488                         $this->mRedirect = false;
 489                         $this->mLatestID = 0;
 490                         $this->mContentModel = false; # initialized lazily in getContentModel()
 491                 }
 492         }
 493
 494         /**
 495          * Create a new Title from a namespace index and a DB key.
 496          * It's assumed that $ns and $title are *valid*, for instance when
 497          * they came directly from the database or a special page name.
 498          * For convenience, spaces are converted to underscores so that
 499          * eg user_text fields can be used directly.
 500          *
 501          * @param int $ns The namespace of the article
 502          * @param string $title The unprefixed database key form
 503          * @param string $fragment The link fragment (after the "#")
 504          * @param string $interwiki The interwiki prefix
 505          * @return Title The new object
 506          */
 507         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 508                 $t = new Title();
 509                 $t->mInterwiki = $interwiki;
 510                 $t->mFragment = $fragment;
 511                 $t->mNamespace = $ns = intval( $ns );
 512                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 513                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 514                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 515                 $t->mTextform = strtr( $title, '_', ' ' );
 516                 $t->mContentModel = false; # initialized lazily in getContentModel()
 517                 return $t;
 518         }
 519
 520         /**
 521          * Create a new Title from a namespace index and a DB key.
 522          * The parameters will be checked for validity, which is a bit slower
 523          * than makeTitle() but safer for user-provided data.
 524          *
 525          * @param int $ns The namespace of the article
 526          * @param string $title Database key form
 527          * @param string $fragment The link fragment (after the "#")
 528          * @param string $interwiki Interwiki prefix
 529          * @return Title The new object, or null on an error
 530          */
 531         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 532                 if ( !MWNamespace::exists( $ns ) ) {
 533                         return null;
 534                 }
 535
 536                 $t = new Title();
 537                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 538
 539                 try {
 540                         $t->secureAndSplit();
 541                         return $t;
 542                 } catch ( MalformedTitleException $ex ) {
 543                         return null;
 544                 }
 545         }
 546
 547         /**
 548          * Create a new Title for the Main Page
 549          *
 550          * @return Title The new object
 551          */
 552         public static function newMainPage() {
 553                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 554                 // Don't give fatal errors if the message is broken
 555                 if ( !$title ) {
 556                         $title = Title::newFromText( 'Main Page' );
 557                 }
 558                 return $title;
 559         }
 560
 561         /**
 562          * Extract a redirect destination from a string and return the
 563          * Title, or null if the text doesn't contain a valid redirect
 564          * This will only return the very next target, useful for
 565          * the redirect table and other checks that don't need full recursion
 566          *
 567          * @param string $text Text with possible redirect
 568          * @return Title The corresponding Title
 569          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 570          */
 571         public static function newFromRedirect( $text ) {
 572                 ContentHandler::deprecated( __METHOD__, '1.21' );
 573
 574                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 575                 return $content->getRedirectTarget();
 576         }
 577
 578         /**
 579          * Extract a redirect destination from a string and return the
 580          * Title, or null if the text doesn't contain a valid redirect
 581          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 582          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 583          *
 584          * @param string $text Text with possible redirect
 585          * @return Title
 586          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 587          */
 588         public static function newFromRedirectRecurse( $text ) {
 589                 ContentHandler::deprecated( __METHOD__, '1.21' );
 590
 591                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 592                 return $content->getUltimateRedirectTarget();
 593         }
 594
 595         /**
 596          * Extract a redirect destination from a string and return an
 597          * array of Titles, or null if the text doesn't contain a valid redirect
 598          * The last element in the array is the final destination after all redirects
 599          * have been resolved (up to $wgMaxRedirects times)
 600          *
 601          * @param string $text Text with possible redirect
 602          * @return Title[] Array of Titles, with the destination last
 603          * @deprecated since 1.21, use Content::getRedirectChain instead.
 604          */
 605         public static function newFromRedirectArray( $text ) {
 606                 ContentHandler::deprecated( __METHOD__, '1.21' );
 607
 608                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 609                 return $content->getRedirectChain();
 610         }
 611
 612         /**
 613          * Get the prefixed DB key associated with an ID
 614          *
 615          * @param int $id The page_id of the article
 616          * @return Title|null An object representing the article, or null if no such article was found
 617          */
 618         public static function nameOf( $id ) {
 619                 $dbr = wfGetDB( DB_SLAVE );
 620
 621                 $s = $dbr->selectRow(
 622                         'page',
 623                         array( 'page_namespace', 'page_title' ),
 624                         array( 'page_id' => $id ),
 625                         __METHOD__
 626                 );
 627                 if ( $s === false ) {
 628                         return null;
 629                 }
 630
 631                 $n = self::makeName( $s->page_namespace, $s->page_title );
 632                 return $n;
 633         }
 634
 635         /**
 636          * Get a regex character class describing the legal characters in a link
 637          *
 638          * @return string The list of characters, not delimited
 639          */
 640         public static function legalChars() {
 641                 global $wgLegalTitleChars;
 642                 return $wgLegalTitleChars;
 643         }
 644
 645         /**
 646          * Returns a simple regex that will match on characters and sequences invalid in titles.
 647          * Note that this doesn't pick up many things that could be wrong with titles, but that
 648          * replacing this regex with something valid will make many titles valid.
 649          *
 650          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 651          *
 652          * @return string Regex string
 653          */
 654         static function getTitleInvalidRegex() {
 655                 wfDeprecated( __METHOD__, '1.25' );
 656                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 657         }
 658
 659         /**
 660          * Utility method for converting a character sequence from bytes to Unicode.
 661          *
 662          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 663          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 664          *
 665          * @param string $byteClass
 666          * @return string
 667          */
 668         public static function convertByteClassToUnicodeClass( $byteClass ) {
 669                 $length = strlen( $byteClass );
 670                 // Input token queue
 671                 $x0 = $x1 = $x2 = '';
 672                 // Decoded queue
 673                 $d0 = $d1 = $d2 = '';
 674                 // Decoded integer codepoints
 675                 $ord0 = $ord1 = $ord2 = 0;
 676                 // Re-encoded queue
 677                 $r0 = $r1 = $r2 = '';
 678                 // Output
 679                 $out = '';
 680                 // Flags
 681                 $allowUnicode = false;
 682                 for ( $pos = 0; $pos < $length; $pos++ ) {
 683                         // Shift the queues down
 684                         $x2 = $x1;
 685                         $x1 = $x0;
 686                         $d2 = $d1;
 687                         $d1 = $d0;
 688                         $ord2 = $ord1;
 689                         $ord1 = $ord0;
 690                         $r2 = $r1;
 691                         $r1 = $r0;
 692                         // Load the current input token and decoded values
 693                         $inChar = $byteClass[$pos];
 694                         if ( $inChar == '\\' ) {
 695                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 696                                         $x0 = $inChar . $m[0];
 697                                         $d0 = chr( hexdec( $m[1] ) );
 698                                         $pos += strlen( $m[0] );
 699                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 700                                         $x0 = $inChar . $m[0];
 701                                         $d0 = chr( octdec( $m[0] ) );
 702                                         $pos += strlen( $m[0] );
 703                                 } elseif ( $pos + 1 >= $length ) {
 704                                         $x0 = $d0 = '\\';
 705                                 } else {
 706                                         $d0 = $byteClass[$pos + 1];
 707                                         $x0 = $inChar . $d0;
 708                                         $pos += 1;
 709                                 }
 710                         } else {
 711                                 $x0 = $d0 = $inChar;
 712                         }
 713                         $ord0 = ord( $d0 );
 714                         // Load the current re-encoded value
 715                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 716                                 $r0 = sprintf( '\x%02x', $ord0 );
 717                         } elseif ( $ord0 >= 0x80 ) {
 718                                 // Allow unicode if a single high-bit character appears
 719                                 $r0 = sprintf( '\x%02x', $ord0 );
 720                                 $allowUnicode = true;
 721                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 722                                 $r0 = '\\' . $d0;
 723                         } else {
 724                                 $r0 = $d0;
 725                         }
 726                         // Do the output
 727                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 728                                 // Range
 729                                 if ( $ord2 > $ord0 ) {
 730                                         // Empty range
 731                                 } elseif ( $ord0 >= 0x80 ) {
 732                                         // Unicode range
 733                                         $allowUnicode = true;
 734                                         if ( $ord2 < 0x80 ) {
 735                                                 // Keep the non-unicode section of the range
 736                                                 $out .= "$r2-\\x7F";
 737                                         }
 738                                 } else {
 739                                         // Normal range
 740                                         $out .= "$r2-$r0";
 741                                 }
 742                                 // Reset state to the initial value
 743                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 744                         } elseif ( $ord2 < 0x80 ) {
 745                                 // ASCII character
 746                                 $out .= $r2;
 747                         }
 748                 }
 749                 if ( $ord1 < 0x80 ) {
 750                         $out .= $r1;
 751                 }
 752                 if ( $ord0 < 0x80 ) {
 753                         $out .= $r0;
 754                 }
 755                 if ( $allowUnicode ) {
 756                         $out .= '\u0080-\uFFFF';
 757                 }
 758                 return $out;
 759         }
 760
 761         /**
 762          * Make a prefixed DB key from a DB key and a namespace index
 763          *
 764          * @param int $ns Numerical representation of the namespace
 765          * @param string $title The DB key form the title
 766          * @param string $fragment The link fragment (after the "#")
 767          * @param string $interwiki The interwiki prefix
 768          * @param bool $canoncialNamespace If true, use the canonical name for
 769          *   $ns instead of the localized version.
 770          * @return string The prefixed form of the title
 771          */
 772         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 773                 $canoncialNamespace = false
 774         ) {
 775                 global $wgContLang;
 776
 777                 if ( $canoncialNamespace ) {
 778                         $namespace = MWNamespace::getCanonicalName( $ns );
 779                 } else {
 780                         $namespace = $wgContLang->getNsText( $ns );
 781                 }
 782                 $name = $namespace == '' ? $title : "$namespace:$title";
 783                 if ( strval( $interwiki ) != '' ) {
 784                         $name = "$interwiki:$name";
 785                 }
 786                 if ( strval( $fragment ) != '' ) {
 787                         $name .= '#' . $fragment;
 788                 }
 789                 return $name;
 790         }
 791
 792         /**
 793          * Escape a text fragment, say from a link, for a URL
 794          *
 795          * @param string $fragment Containing a URL or link fragment (after the "#")
 796          * @return string Escaped string
 797          */
 798         static function escapeFragmentForURL( $fragment ) {
 799                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 800                 # fragments appear not to work in IE (at least up to 7) or in at least
 801                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 802                 # to care if they aren't encoded.
 803                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 804         }
 805
 806         /**
 807          * Callback for usort() to do title sorts by (namespace, title)
 808          *
 809          * @param Title $a
 810          * @param Title $b
 811          *
 812          * @return int Result of string comparison, or namespace comparison
 813          */
 814         public static function compare( $a, $b ) {
 815                 if ( $a->getNamespace() == $b->getNamespace() ) {
 816                         return strcmp( $a->getText(), $b->getText() );
 817                 } else {
 818                         return $a->getNamespace() - $b->getNamespace();
 819                 }
 820         }
 821
 822         /**
 823          * Determine whether the object refers to a page within
 824          * this project (either this wiki or a wiki with a local
 825          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 826          *
 827          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 828          */
 829         public function isLocal() {
 830                 if ( $this->isExternal() ) {
 831                         $iw = Interwiki::fetch( $this->mInterwiki );
 832                         if ( $iw ) {
 833                                 return $iw->isLocal();
 834                         }
 835                 }
 836                 return true;
 837         }
 838
 839         /**
 840          * Is this Title interwiki?
 841          *
 842          * @return bool
 843          */
 844         public function isExternal() {
 845                 return $this->mInterwiki !== '';
 846         }
 847
 848         /**
 849          * Get the interwiki prefix
 850          *
 851          * Use Title::isExternal to check if a interwiki is set
 852          *
 853          * @return string Interwiki prefix
 854          */
 855         public function getInterwiki() {
 856                 return $this->mInterwiki;
 857         }
 858
 859         /**
 860          * Was this a local interwiki link?
 861          *
 862          * @return bool
 863          */
 864         public function wasLocalInterwiki() {
 865                 return $this->mLocalInterwiki;
 866         }
 867
 868         /**
 869          * Determine whether the object refers to a page within
 870          * this project and is transcludable.
 871          *
 872          * @return bool True if this is transcludable
 873          */
 874         public function isTrans() {
 875                 if ( !$this->isExternal() ) {
 876                         return false;
 877                 }
 878
 879                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 880         }
 881
 882         /**
 883          * Returns the DB name of the distant wiki which owns the object.
 884          *
 885          * @return string The DB name
 886          */
 887         public function getTransWikiID() {
 888                 if ( !$this->isExternal() ) {
 889                         return false;
 890                 }
 891
 892                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 893         }
 894
 895         /**
 896          * Get a TitleValue object representing this Title.
 897          *
 898          * @note Not all valid Titles have a corresponding valid TitleValue
 899          * (e.g. TitleValues cannot represent page-local links that have a
 900          * fragment but no title text).
 901          *
 902          * @return TitleValue|null
 903          */
 904         public function getTitleValue() {
 905                 if ( $this->mTitleValue === null ) {
 906                         try {
 907                                 $this->mTitleValue = new TitleValue(
 908                                         $this->getNamespace(),
 909                                         $this->getDBkey(),
 910                                         $this->getFragment() );
 911                         } catch ( InvalidArgumentException $ex ) {
 912                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 913                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 914                         }
 915                 }
 916
 917                 return $this->mTitleValue;
 918         }
 919
 920         /**
 921          * Get the text form (spaces not underscores) of the main part
 922          *
 923          * @return string Main part of the title
 924          */
 925         public function getText() {
 926                 return $this->mTextform;
 927         }
 928
 929         /**
 930          * Get the URL-encoded form of the main part
 931          *
 932          * @return string Main part of the title, URL-encoded
 933          */
 934         public function getPartialURL() {
 935                 return $this->mUrlform;
 936         }
 937
 938         /**
 939          * Get the main part with underscores
 940          *
 941          * @return string Main part of the title, with underscores
 942          */
 943         public function getDBkey() {
 944                 return $this->mDbkeyform;
 945         }
 946
 947         /**
 948          * Get the DB key with the initial letter case as specified by the user
 949          *
 950          * @return string DB key
 951          */
 952         function getUserCaseDBKey() {
 953                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 954                         return $this->mUserCaseDBKey;
 955                 } else {
 956                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 957                         return $this->mDbkeyform;
 958                 }
 959         }
 960
 961         /**
 962          * Get the namespace index, i.e. one of the NS_xxxx constants.
 963          *
 964          * @return int Namespace index
 965          */
 966         public function getNamespace() {
 967                 return $this->mNamespace;
 968         }
 969
 970         /**
 971          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 972          *
 973          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 974          * @return string Content model id
 975          */
 976         public function getContentModel( $flags = 0 ) {
 977                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 978                         $linkCache = LinkCache::singleton();
 979                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 980                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 981                 }
 982
 983                 if ( !$this->mContentModel ) {
 984                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 985                 }
 986
 987                 return $this->mContentModel;
 988         }
 989
 990         /**
 991          * Convenience method for checking a title's content model name
 992          *
 993          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 994          * @return bool True if $this->getContentModel() == $id
 995          */
 996         public function hasContentModel( $id ) {
 997                 return $this->getContentModel() == $id;
 998         }
 999
1000         /**
1001          * Get the namespace text
1002          *
1003          * @return string Namespace text
1004          */
1005         public function getNsText() {
1006                 if ( $this->isExternal() ) {
1007                         // This probably shouldn't even happen. ohh man, oh yuck.
1008                         // But for interwiki transclusion it sometimes does.
1009                         // Shit. Shit shit shit.
1010                         //
1011                         // Use the canonical namespaces if possible to try to
1012                         // resolve a foreign namespace.
1013                         if ( MWNamespace::exists( $this->mNamespace ) ) {
1014                                 return MWNamespace::getCanonicalName( $this->mNamespace );
1015                         }
1016                 }
1017
1018                 try {
1019                         $formatter = self::getTitleFormatter();
1020                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
1021                 } catch ( InvalidArgumentException $ex ) {
1022                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1023                         return false;
1024                 }
1025         }
1026
1027         /**
1028          * Get the namespace text of the subject (rather than talk) page
1029          *
1030          * @return string Namespace text
1031          */
1032         public function getSubjectNsText() {
1033                 global $wgContLang;
1034                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1035         }
1036
1037         /**
1038          * Get the namespace text of the talk page
1039          *
1040          * @return string Namespace text
1041          */
1042         public function getTalkNsText() {
1043                 global $wgContLang;
1044                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1045         }
1046
1047         /**
1048          * Could this title have a corresponding talk page?
1049          *
1050          * @return bool
1051          */
1052         public function canTalk() {
1053                 return MWNamespace::canTalk( $this->mNamespace );
1054         }
1055
1056         /**
1057          * Is this in a namespace that allows actual pages?
1058          *
1059          * @return bool
1060          */
1061         public function canExist() {
1062                 return $this->mNamespace >= NS_MAIN;
1063         }
1064
1065         /**
1066          * Can this title be added to a user's watchlist?
1067          *
1068          * @return bool
1069          */
1070         public function isWatchable() {
1071                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1072         }
1073
1074         /**
1075          * Returns true if this is a special page.
1076          *
1077          * @return bool
1078          */
1079         public function isSpecialPage() {
1080                 return $this->getNamespace() == NS_SPECIAL;
1081         }
1082
1083         /**
1084          * Returns true if this title resolves to the named special page
1085          *
1086          * @param string $name The special page name
1087          * @return bool
1088          */
1089         public function isSpecial( $name ) {
1090                 if ( $this->isSpecialPage() ) {
1091                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1092                         if ( $name == $thisName ) {
1093                                 return true;
1094                         }
1095                 }
1096                 return false;
1097         }
1098
1099         /**
1100          * If the Title refers to a special page alias which is not the local default, resolve
1101          * the alias, and localise the name as necessary.  Otherwise, return $this
1102          *
1103          * @return Title
1104          */
1105         public function fixSpecialName() {
1106                 if ( $this->isSpecialPage() ) {
1107                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1108                         if ( $canonicalName ) {
1109                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1110                                 if ( $localName != $this->mDbkeyform ) {
1111                                         return Title::makeTitle( NS_SPECIAL, $localName );
1112                                 }
1113                         }
1114                 }
1115                 return $this;
1116         }
1117
1118         /**
1119          * Returns true if the title is inside the specified namespace.
1120          *
1121          * Please make use of this instead of comparing to getNamespace()
1122          * This function is much more resistant to changes we may make
1123          * to namespaces than code that makes direct comparisons.
1124          * @param int $ns The namespace
1125          * @return bool
1126          * @since 1.19
1127          */
1128         public function inNamespace( $ns ) {
1129                 return MWNamespace::equals( $this->getNamespace(), $ns );
1130         }
1131
1132         /**
1133          * Returns true if the title is inside one of the specified namespaces.
1134          *
1135          * @param int $namespaces,... The namespaces to check for
1136          * @return bool
1137          * @since 1.19
1138          */
1139         public function inNamespaces( /* ... */ ) {
1140                 $namespaces = func_get_args();
1141                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1142                         $namespaces = $namespaces[0];
1143                 }
1144
1145                 foreach ( $namespaces as $ns ) {
1146                         if ( $this->inNamespace( $ns ) ) {
1147                                 return true;
1148                         }
1149                 }
1150
1151                 return false;
1152         }
1153
1154         /**
1155          * Returns true if the title has the same subject namespace as the
1156          * namespace specified.
1157          * For example this method will take NS_USER and return true if namespace
1158          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1159          * as their subject namespace.
1160          *
1161          * This is MUCH simpler than individually testing for equivalence
1162          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1163          * @since 1.19
1164          * @param int $ns
1165          * @return bool
1166          */
1167         public function hasSubjectNamespace( $ns ) {
1168                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1169         }
1170
1171         /**
1172          * Is this Title in a namespace which contains content?
1173          * In other words, is this a content page, for the purposes of calculating
1174          * statistics, etc?
1175          *
1176          * @return bool
1177          */
1178         public function isContentPage() {
1179                 return MWNamespace::isContent( $this->getNamespace() );
1180         }
1181
1182         /**
1183          * Would anybody with sufficient privileges be able to move this page?
1184          * Some pages just aren't movable.
1185          *
1186          * @return bool
1187          */
1188         public function isMovable() {
1189                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1190                         // Interwiki title or immovable namespace. Hooks don't get to override here
1191                         return false;
1192                 }
1193
1194                 $result = true;
1195                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1196                 return $result;
1197         }
1198
1199         /**
1200          * Is this the mainpage?
1201          * @note Title::newFromText seems to be sufficiently optimized by the title
1202          * cache that we don't need to over-optimize by doing direct comparisons and
1203          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1204          * ends up reporting something differently than $title->isMainPage();
1205          *
1206          * @since 1.18
1207          * @return bool
1208          */
1209         public function isMainPage() {
1210                 return $this->equals( Title::newMainPage() );
1211         }
1212
1213         /**
1214          * Is this a subpage?
1215          *
1216          * @return bool
1217          */
1218         public function isSubpage() {
1219                 return MWNamespace::hasSubpages( $this->mNamespace )
1220                         ? strpos( $this->getText(), '/' ) !== false
1221                         : false;
1222         }
1223
1224         /**
1225          * Is this a conversion table for the LanguageConverter?
1226          *
1227          * @return bool
1228          */
1229         public function isConversionTable() {
1230                 // @todo ConversionTable should become a separate content model.
1231
1232                 return $this->getNamespace() == NS_MEDIAWIKI &&
1233                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1234         }
1235
1236         /**
1237          * Does that page contain wikitext, or it is JS, CSS or whatever?
1238          *
1239          * @return bool
1240          */
1241         public function isWikitextPage() {
1242                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1243         }
1244
1245         /**
1246          * Could this page contain custom CSS or JavaScript for the global UI.
1247          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1248          * or CONTENT_MODEL_JAVASCRIPT.
1249          *
1250          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1251          * for that!
1252          *
1253          * Note that this method should not return true for pages that contain and
1254          * show "inactive" CSS or JS.
1255          *
1256          * @return bool
1257          */
1258         public function isCssOrJsPage() {
1259                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1260                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1261                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1262
1263                 # @note This hook is also called in ContentHandler::getDefaultModel.
1264                 #   It's called here again to make sure hook functions can force this
1265                 #   method to return true even outside the MediaWiki namespace.
1266
1267                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1268
1269                 return $isCssOrJsPage;
1270         }
1271
1272         /**
1273          * Is this a .css or .js subpage of a user page?
1274          * @return bool
1275          */
1276         public function isCssJsSubpage() {
1277                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1278                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1279                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1280         }
1281
1282         /**
1283          * Trim down a .css or .js subpage title to get the corresponding skin name
1284          *
1285          * @return string Containing skin name from .css or .js subpage title
1286          */
1287         public function getSkinFromCssJsSubpage() {
1288                 $subpage = explode( '/', $this->mTextform );
1289                 $subpage = $subpage[count( $subpage ) - 1];
1290                 $lastdot = strrpos( $subpage, '.' );
1291                 if ( $lastdot === false ) {
1292                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1293                 }
1294                 return substr( $subpage, 0, $lastdot );
1295         }
1296
1297         /**
1298          * Is this a .css subpage of a user page?
1299          *
1300          * @return bool
1301          */
1302         public function isCssSubpage() {
1303                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1304                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1305         }
1306
1307         /**
1308          * Is this a .js subpage of a user page?
1309          *
1310          * @return bool
1311          */
1312         public function isJsSubpage() {
1313                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1314                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1315         }
1316
1317         /**
1318          * Is this a talk page of some sort?
1319          *
1320          * @return bool
1321          */
1322         public function isTalkPage() {
1323                 return MWNamespace::isTalk( $this->getNamespace() );
1324         }
1325
1326         /**
1327          * Get a Title object associated with the talk page of this article
1328          *
1329          * @return Title The object for the talk page
1330          */
1331         public function getTalkPage() {
1332                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1333         }
1334
1335         /**
1336          * Get a title object associated with the subject page of this
1337          * talk page
1338          *
1339          * @return Title The object for the subject page
1340          */
1341         public function getSubjectPage() {
1342                 // Is this the same title?
1343                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1344                 if ( $this->getNamespace() == $subjectNS ) {
1345                         return $this;
1346                 }
1347                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1348         }
1349
1350         /**
1351          * Get the other title for this page, if this is a subject page
1352          * get the talk page, if it is a subject page get the talk page
1353          *
1354          * @since 1.25
1355          * @throws MWException
1356          * @return Title
1357          */
1358         public function getOtherPage() {
1359                 if ( $this->isSpecialPage() ) {
1360                         throw new MWException( 'Special pages cannot have other pages' );
1361                 }
1362                 if ( $this->isTalkPage() ) {
1363                         return $this->getSubjectPage();
1364                 } else {
1365                         return $this->getTalkPage();
1366                 }
1367         }
1368
1369         /**
1370          * Get the default namespace index, for when there is no namespace
1371          *
1372          * @return int Default namespace index
1373          */
1374         public function getDefaultNamespace() {
1375                 return $this->mDefaultNamespace;
1376         }
1377
1378         /**
1379          * Get the Title fragment (i.e.\ the bit after the #) in text form
1380          *
1381          * Use Title::hasFragment to check for a fragment
1382          *
1383          * @return string Title fragment
1384          */
1385         public function getFragment() {
1386                 return $this->mFragment;
1387         }
1388
1389         /**
1390          * Check if a Title fragment is set
1391          *
1392          * @return bool
1393          * @since 1.23
1394          */
1395         public function hasFragment() {
1396                 return $this->mFragment !== '';
1397         }
1398
1399         /**
1400          * Get the fragment in URL form, including the "#" character if there is one
1401          * @return string Fragment in URL form
1402          */
1403         public function getFragmentForURL() {
1404                 if ( !$this->hasFragment() ) {
1405                         return '';
1406                 } else {
1407                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1408                 }
1409         }
1410
1411         /**
1412          * Set the fragment for this title. Removes the first character from the
1413          * specified fragment before setting, so it assumes you're passing it with
1414          * an initial "#".
1415          *
1416          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1417          * Still in active use privately.
1418          *
1419          * @param string $fragment Text
1420          */
1421         public function setFragment( $fragment ) {
1422                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1423         }
1424
1425         /**
1426          * Prefix some arbitrary text with the namespace or interwiki prefix
1427          * of this object
1428          *
1429          * @param string $name The text
1430          * @return string The prefixed text
1431          */
1432         private function prefix( $name ) {
1433                 $p = '';
1434                 if ( $this->isExternal() ) {
1435                         $p = $this->mInterwiki . ':';
1436                 }
1437
1438                 if ( 0 != $this->mNamespace ) {
1439                         $p .= $this->getNsText() . ':';
1440                 }
1441                 return $p . $name;
1442         }
1443
1444         /**
1445          * Get the prefixed database key form
1446          *
1447          * @return string The prefixed title, with underscores and
1448          *  any interwiki and namespace prefixes
1449          */
1450         public function getPrefixedDBkey() {
1451                 $s = $this->prefix( $this->mDbkeyform );
1452                 $s = strtr( $s, ' ', '_' );
1453                 return $s;
1454         }
1455
1456         /**
1457          * Get the prefixed title with spaces.
1458          * This is the form usually used for display
1459          *
1460          * @return string The prefixed title, with spaces
1461          */
1462         public function getPrefixedText() {
1463                 if ( $this->mPrefixedText === null ) {
1464                         $s = $this->prefix( $this->mTextform );
1465                         $s = strtr( $s, '_', ' ' );
1466                         $this->mPrefixedText = $s;
1467                 }
1468                 return $this->mPrefixedText;
1469         }
1470
1471         /**
1472          * Return a string representation of this title
1473          *
1474          * @return string Representation of this title
1475          */
1476         public function __toString() {
1477                 return $this->getPrefixedText();
1478         }
1479
1480         /**
1481          * Get the prefixed title with spaces, plus any fragment
1482          * (part beginning with '#')
1483          *
1484          * @return string The prefixed title, with spaces and the fragment, including '#'
1485          */
1486         public function getFullText() {
1487                 $text = $this->getPrefixedText();
1488                 if ( $this->hasFragment() ) {
1489                         $text .= '#' . $this->getFragment();
1490                 }
1491                 return $text;
1492         }
1493
1494         /**
1495          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1496          *
1497          * @par Example:
1498          * @code
1499          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1500          * # returns: 'Foo'
1501          * @endcode
1502          *
1503          * @return string Root name
1504          * @since 1.20
1505          */
1506         public function getRootText() {
1507                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1508                         return $this->getText();
1509                 }
1510
1511                 return strtok( $this->getText(), '/' );
1512         }
1513
1514         /**
1515          * Get the root page name title, i.e. the leftmost part before any slashes
1516          *
1517          * @par Example:
1518          * @code
1519          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1520          * # returns: Title{User:Foo}
1521          * @endcode
1522          *
1523          * @return Title Root title
1524          * @since 1.20
1525          */
1526         public function getRootTitle() {
1527                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1528         }
1529
1530         /**
1531          * Get the base page name without a namespace, i.e. the part before the subpage name
1532          *
1533          * @par Example:
1534          * @code
1535          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1536          * # returns: 'Foo/Bar'
1537          * @endcode
1538          *
1539          * @return string Base name
1540          */
1541         public function getBaseText() {
1542                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1543                         return $this->getText();
1544                 }
1545
1546                 $parts = explode( '/', $this->getText() );
1547                 # Don't discard the real title if there's no subpage involved
1548                 if ( count( $parts ) > 1 ) {
1549                         unset( $parts[count( $parts ) - 1] );
1550                 }
1551                 return implode( '/', $parts );
1552         }
1553
1554         /**
1555          * Get the base page name title, i.e. the part before the subpage name
1556          *
1557          * @par Example:
1558          * @code
1559          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1560          * # returns: Title{User:Foo/Bar}
1561          * @endcode
1562          *
1563          * @return Title Base title
1564          * @since 1.20
1565          */
1566         public function getBaseTitle() {
1567                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1568         }
1569
1570         /**
1571          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1572          *
1573          * @par Example:
1574          * @code
1575          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1576          * # returns: "Baz"
1577          * @endcode
1578          *
1579          * @return string Subpage name
1580          */
1581         public function getSubpageText() {
1582                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1583                         return $this->mTextform;
1584                 }
1585                 $parts = explode( '/', $this->mTextform );
1586                 return $parts[count( $parts ) - 1];
1587         }
1588
1589         /**
1590          * Get the title for a subpage of the current page
1591          *
1592          * @par Example:
1593          * @code
1594          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1595          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1596          * @endcode
1597          *
1598          * @param string $text The subpage name to add to the title
1599          * @return Title Subpage title
1600          * @since 1.20
1601          */
1602         public function getSubpage( $text ) {
1603                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1604         }
1605
1606         /**
1607          * Get a URL-encoded form of the subpage text
1608          *
1609          * @return string URL-encoded subpage name
1610          */
1611         public function getSubpageUrlForm() {
1612                 $text = $this->getSubpageText();
1613                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1614                 return $text;
1615         }
1616
1617         /**
1618          * Get a URL-encoded title (not an actual URL) including interwiki
1619          *
1620          * @return string The URL-encoded form
1621          */
1622         public function getPrefixedURL() {
1623                 $s = $this->prefix( $this->mDbkeyform );
1624                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1625                 return $s;
1626         }
1627
1628         /**
1629          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1630          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1631          * second argument named variant. This was deprecated in favor
1632          * of passing an array of option with a "variant" key
1633          * Once $query2 is removed for good, this helper can be dropped
1634          * and the wfArrayToCgi moved to getLocalURL();
1635          *
1636          * @since 1.19 (r105919)
1637          * @param array|string $query
1638          * @param bool $query2
1639          * @return string
1640          */
1641         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1642                 if ( $query2 !== false ) {
1643                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1644                                 "method called with a second parameter is deprecated. Add your " .
1645                                 "parameter to an array passed as the first parameter.", "1.19" );
1646                 }
1647                 if ( is_array( $query ) ) {
1648                         $query = wfArrayToCgi( $query );
1649                 }
1650                 if ( $query2 ) {
1651                         if ( is_string( $query2 ) ) {
1652                                 // $query2 is a string, we will consider this to be
1653                                 // a deprecated $variant argument and add it to the query
1654                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1655                         } else {
1656                                 $query2 = wfArrayToCgi( $query2 );
1657                         }
1658                         // If we have $query content add a & to it first
1659                         if ( $query ) {
1660                                 $query .= '&';
1661                         }
1662                         // Now append the queries together
1663                         $query .= $query2;
1664                 }
1665                 return $query;
1666         }
1667
1668         /**
1669          * Get a real URL referring to this title, with interwiki link and
1670          * fragment
1671          *
1672          * @see self::getLocalURL for the arguments.
1673          * @see wfExpandUrl
1674          * @param array|string $query
1675          * @param bool $query2
1676          * @param string $proto Protocol type to use in URL
1677          * @return string The URL
1678          */
1679         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1680                 $query = self::fixUrlQueryArgs( $query, $query2 );
1681
1682                 # Hand off all the decisions on urls to getLocalURL
1683                 $url = $this->getLocalURL( $query );
1684
1685                 # Expand the url to make it a full url. Note that getLocalURL has the
1686                 # potential to output full urls for a variety of reasons, so we use
1687                 # wfExpandUrl instead of simply prepending $wgServer
1688                 $url = wfExpandUrl( $url, $proto );
1689
1690                 # Finally, add the fragment.
1691                 $url .= $this->getFragmentForURL();
1692
1693                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1694                 return $url;
1695         }
1696
1697         /**
1698          * Get a URL with no fragment or server name (relative URL) from a Title object.
1699          * If this page is generated with action=render, however,
1700          * $wgServer is prepended to make an absolute URL.
1701          *
1702          * @see self::getFullURL to always get an absolute URL.
1703          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1704          *  valid to link, locally, to the current Title.
1705          * @see self::newFromText to produce a Title object.
1706          *
1707          * @param string|array $query An optional query string,
1708          *   not used for interwiki links. Can be specified as an associative array as well,
1709          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1710          *   Some query patterns will trigger various shorturl path replacements.
1711          * @param array $query2 An optional secondary query array. This one MUST
1712          *   be an array. If a string is passed it will be interpreted as a deprecated
1713          *   variant argument and urlencoded into a variant= argument.
1714          *   This second query argument will be added to the $query
1715          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1716          *   pair in the first parameter array instead.
1717          *
1718          * @return string String of the URL.
1719          */
1720         public function getLocalURL( $query = '', $query2 = false ) {
1721                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1722
1723                 $query = self::fixUrlQueryArgs( $query, $query2 );
1724
1725                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1726                 if ( $interwiki ) {
1727                         $namespace = $this->getNsText();
1728                         if ( $namespace != '' ) {
1729                                 # Can this actually happen? Interwikis shouldn't be parsed.
1730                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1731                                 $namespace .= ':';
1732                         }
1733                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1734                         $url = wfAppendQuery( $url, $query );
1735                 } else {
1736                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1737                         if ( $query == '' ) {
1738                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1739                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1740                         } else {
1741                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1742                                 $url = false;
1743                                 $matches = array();
1744
1745                                 if ( !empty( $wgActionPaths )
1746                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1747                                 ) {
1748                                         $action = urldecode( $matches[2] );
1749                                         if ( isset( $wgActionPaths[$action] ) ) {
1750                                                 $query = $matches[1];
1751                                                 if ( isset( $matches[4] ) ) {
1752                                                         $query .= $matches[4];
1753                                                 }
1754                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1755                                                 if ( $query != '' ) {
1756                                                         $url = wfAppendQuery( $url, $query );
1757                                                 }
1758                                         }
1759                                 }
1760
1761                                 if ( $url === false
1762                                         && $wgVariantArticlePath
1763                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1764                                         && $this->getPageLanguage()->hasVariants()
1765                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1766                                 ) {
1767                                         $variant = urldecode( $matches[1] );
1768                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1769                                                 // Only do the variant replacement if the given variant is a valid
1770                                                 // variant for the page's language.
1771                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1772                                                 $url = str_replace( '$1', $dbkey, $url );
1773                                         }
1774                                 }
1775
1776                                 if ( $url === false ) {
1777                                         if ( $query == '-' ) {
1778                                                 $query = '';
1779                                         }
1780                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1781                                 }
1782                         }
1783
1784                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1785
1786                         // @todo FIXME: This causes breakage in various places when we
1787                         // actually expected a local URL and end up with dupe prefixes.
1788                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1789                                 $url = $wgServer . $url;
1790                         }
1791                 }
1792                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1793                 return $url;
1794         }
1795
1796         /**
1797          * Get a URL that's the simplest URL that will be valid to link, locally,
1798          * to the current Title.  It includes the fragment, but does not include
1799          * the server unless action=render is used (or the link is external).  If
1800          * there's a fragment but the prefixed text is empty, we just return a link
1801          * to the fragment.
1802          *
1803          * The result obviously should not be URL-escaped, but does need to be
1804          * HTML-escaped if it's being output in HTML.
1805          *
1806          * @param array $query
1807          * @param bool $query2
1808          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1809          * @see self::getLocalURL for the arguments.
1810          * @return string The URL
1811          */
1812         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1813                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1814                         $ret = $this->getFullURL( $query, $query2, $proto );
1815                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1816                         $ret = $this->getFragmentForURL();
1817                 } else {
1818                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1819                 }
1820                 return $ret;
1821         }
1822
1823         /**
1824          * Get the URL form for an internal link.
1825          * - Used in various Squid-related code, in case we have a different
1826          * internal hostname for the server from the exposed one.
1827          *
1828          * This uses $wgInternalServer to qualify the path, or $wgServer
1829          * if $wgInternalServer is not set. If the server variable used is
1830          * protocol-relative, the URL will be expanded to http://
1831          *
1832          * @see self::getLocalURL for the arguments.
1833          * @return string The URL
1834          */
1835         public function getInternalURL( $query = '', $query2 = false ) {
1836                 global $wgInternalServer, $wgServer;
1837                 $query = self::fixUrlQueryArgs( $query, $query2 );
1838                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1839                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1840                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1841                 return $url;
1842         }
1843
1844         /**
1845          * Get the URL for a canonical link, for use in things like IRC and
1846          * e-mail notifications. Uses $wgCanonicalServer and the
1847          * GetCanonicalURL hook.
1848          *
1849          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1850          *
1851          * @see self::getLocalURL for the arguments.
1852          * @return string The URL
1853          * @since 1.18
1854          */
1855         public function getCanonicalURL( $query = '', $query2 = false ) {
1856                 $query = self::fixUrlQueryArgs( $query, $query2 );
1857                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1858                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1859                 return $url;
1860         }
1861
1862         /**
1863          * Get the edit URL for this Title
1864          *
1865          * @return string The URL, or a null string if this is an interwiki link
1866          */
1867         public function getEditURL() {
1868                 if ( $this->isExternal() ) {
1869                         return '';
1870                 }
1871                 $s = $this->getLocalURL( 'action=edit' );
1872
1873                 return $s;
1874         }
1875
1876         /**
1877          * Is $wgUser watching this page?
1878          *
1879          * @deprecated since 1.20; use User::isWatched() instead.
1880          * @return bool
1881          */
1882         public function userIsWatching() {
1883                 global $wgUser;
1884
1885                 if ( is_null( $this->mWatched ) ) {
1886                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1887                                 $this->mWatched = false;
1888                         } else {
1889                                 $this->mWatched = $wgUser->isWatched( $this );
1890                         }
1891                 }
1892                 return $this->mWatched;
1893         }
1894
1895         /**
1896          * Can $user perform $action on this page?
1897          * This skips potentially expensive cascading permission checks
1898          * as well as avoids expensive error formatting
1899          *
1900          * Suitable for use for nonessential UI controls in common cases, but
1901          * _not_ for functional access control.
1902          *
1903          * May provide false positives, but should never provide a false negative.
1904          *
1905          * @param string $action Action that permission needs to be checked for
1906          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1907          * @return bool
1908          */
1909         public function quickUserCan( $action, $user = null ) {
1910                 return $this->userCan( $action, $user, false );
1911         }
1912
1913         /**
1914          * Can $user perform $action on this page?
1915          *
1916          * @param string $action Action that permission needs to be checked for
1917          * @param User $user User to check (since 1.19); $wgUser will be used if not
1918          *   provided.
1919          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1920          * @return bool
1921          */
1922         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1923                 if ( !$user instanceof User ) {
1924                         global $wgUser;
1925                         $user = $wgUser;
1926                 }
1927
1928                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1929         }
1930
1931         /**
1932          * Can $user perform $action on this page?
1933          *
1934          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1935          *
1936          * @param string $action Action that permission needs to be checked for
1937          * @param User $user User to check
1938          * @param string $rigor One of (quick,full,secure)
1939          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1940          *   - full   : does cheap and expensive checks possibly from a slave
1941          *   - secure : does cheap and expensive checks, using the master as needed
1942          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1943          *   whose corresponding errors may be ignored.
1944          * @return array Array of arguments to wfMessage to explain permissions problems.
1945          */
1946         public function getUserPermissionsErrors(
1947                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1948         ) {
1949                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1950
1951                 // Remove the errors being ignored.
1952                 foreach ( $errors as $index => $error ) {
1953                         $error_key = is_array( $error ) ? $error[0] : $error;
1954
1955                         if ( in_array( $error_key, $ignoreErrors ) ) {
1956                                 unset( $errors[$index] );
1957                         }
1958                 }
1959
1960                 return $errors;
1961         }
1962
1963         /**
1964          * Permissions checks that fail most often, and which are easiest to test.
1965          *
1966          * @param string $action The action to check
1967          * @param User $user User to check
1968          * @param array $errors List of current errors
1969          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1970          * @param bool $short Short circuit on first error
1971          *
1972          * @return array List of errors
1973          */
1974         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1975                 if ( !Hooks::run( 'TitleQuickPermissions',
1976                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1977                 ) {
1978                         return $errors;
1979                 }
1980
1981                 if ( $action == 'create' ) {
1982                         if (
1983                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1984                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1985                         ) {
1986                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1987                         }
1988                 } elseif ( $action == 'move' ) {
1989                         if ( !$user->isAllowed( 'move-rootuserpages' )
1990                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1991                                 // Show user page-specific message only if the user can move other pages
1992                                 $errors[] = array( 'cant-move-user-page' );
1993                         }
1994
1995                         // Check if user is allowed to move files if it's a file
1996                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1997                                 $errors[] = array( 'movenotallowedfile' );
1998                         }
1999
2000                         // Check if user is allowed to move category pages if it's a category page
2001                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
2002                                 $errors[] = array( 'cant-move-category-page' );
2003                         }
2004
2005                         if ( !$user->isAllowed( 'move' ) ) {
2006                                 // User can't move anything
2007                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
2008                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2009                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2010                                         // custom message if logged-in users without any special rights can move
2011                                         $errors[] = array( 'movenologintext' );
2012                                 } else {
2013                                         $errors[] = array( 'movenotallowed' );
2014                                 }
2015                         }
2016                 } elseif ( $action == 'move-target' ) {
2017                         if ( !$user->isAllowed( 'move' ) ) {
2018                                 // User can't move anything
2019                                 $errors[] = array( 'movenotallowed' );
2020                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2021                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2022                                 // Show user page-specific message only if the user can move other pages
2023                                 $errors[] = array( 'cant-move-to-user-page' );
2024                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2025                                         && $this->mNamespace == NS_CATEGORY ) {
2026                                 // Show category page-specific message only if the user can move other pages
2027                                 $errors[] = array( 'cant-move-to-category-page' );
2028                         }
2029                 } elseif ( !$user->isAllowed( $action ) ) {
2030                         $errors[] = $this->missingPermissionError( $action, $short );
2031                 }
2032
2033                 return $errors;
2034         }
2035
2036         /**
2037          * Add the resulting error code to the errors array
2038          *
2039          * @param array $errors List of current errors
2040          * @param array $result Result of errors
2041          *
2042          * @return array List of errors
2043          */
2044         private function resultToError( $errors, $result ) {
2045                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2046                         // A single array representing an error
2047                         $errors[] = $result;
2048                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2049                         // A nested array representing multiple errors
2050                         $errors = array_merge( $errors, $result );
2051                 } elseif ( $result !== '' && is_string( $result ) ) {
2052                         // A string representing a message-id
2053                         $errors[] = array( $result );
2054                 } elseif ( $result === false ) {
2055                         // a generic "We don't want them to do that"
2056                         $errors[] = array( 'badaccess-group0' );
2057                 }
2058                 return $errors;
2059         }
2060
2061         /**
2062          * Check various permission hooks
2063          *
2064          * @param string $action The action to check
2065          * @param User $user User to check
2066          * @param array $errors List of current errors
2067          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2068          * @param bool $short Short circuit on first error
2069          *
2070          * @return array List of errors
2071          */
2072         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2073                 // Use getUserPermissionsErrors instead
2074                 $result = '';
2075                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2076                         return $result ? array() : array( array( 'badaccess-group0' ) );
2077                 }
2078                 // Check getUserPermissionsErrors hook
2079                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2080                         $errors = $this->resultToError( $errors, $result );
2081                 }
2082                 // Check getUserPermissionsErrorsExpensive hook
2083                 if (
2084                         $rigor !== 'quick'
2085                         && !( $short && count( $errors ) > 0 )
2086                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2087                 ) {
2088                         $errors = $this->resultToError( $errors, $result );
2089                 }
2090
2091                 return $errors;
2092         }
2093
2094         /**
2095          * Check permissions on special pages & namespaces
2096          *
2097          * @param string $action The action to check
2098          * @param User $user User to check
2099          * @param array $errors List of current errors
2100          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2101          * @param bool $short Short circuit on first error
2102          *
2103          * @return array List of errors
2104          */
2105         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2106                 # Only 'createaccount' can be performed on special pages,
2107                 # which don't actually exist in the DB.
2108                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2109                         $errors[] = array( 'ns-specialprotected' );
2110                 }
2111
2112                 # Check $wgNamespaceProtection for restricted namespaces
2113                 if ( $this->isNamespaceProtected( $user ) ) {
2114                         $ns = $this->mNamespace == NS_MAIN ?
2115                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2116                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2117                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2118                 }
2119
2120                 return $errors;
2121         }
2122
2123         /**
2124          * Check CSS/JS sub-page permissions
2125          *
2126          * @param string $action The action to check
2127          * @param User $user User to check
2128          * @param array $errors List of current errors
2129          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2130          * @param bool $short Short circuit on first error
2131          *
2132          * @return array List of errors
2133          */
2134         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2135                 # Protect css/js subpages of user pages
2136                 # XXX: this might be better using restrictions
2137                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2138                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2139                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2140                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2141                                         $errors[] = array( 'mycustomcssprotected', $action );
2142                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2143                                         $errors[] = array( 'mycustomjsprotected', $action );
2144                                 }
2145                         } else {
2146                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2147                                         $errors[] = array( 'customcssprotected', $action );
2148                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2149                                         $errors[] = array( 'customjsprotected', $action );
2150                                 }
2151                         }
2152                 }
2153
2154                 return $errors;
2155         }
2156
2157         /**
2158          * Check against page_restrictions table requirements on this
2159          * page. The user must possess all required rights for this
2160          * action.
2161          *
2162          * @param string $action The action to check
2163          * @param User $user User to check
2164          * @param array $errors List of current errors
2165          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2166          * @param bool $short Short circuit on first error
2167          *
2168          * @return array List of errors
2169          */
2170         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2171                 foreach ( $this->getRestrictions( $action ) as $right ) {
2172                         // Backwards compatibility, rewrite sysop -> editprotected
2173                         if ( $right == 'sysop' ) {
2174                                 $right = 'editprotected';
2175                         }
2176                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2177                         if ( $right == 'autoconfirmed' ) {
2178                                 $right = 'editsemiprotected';
2179                         }
2180                         if ( $right == '' ) {
2181                                 continue;
2182                         }
2183                         if ( !$user->isAllowed( $right ) ) {
2184                                 $errors[] = array( 'protectedpagetext', $right, $action );
2185                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2186                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2187                         }
2188                 }
2189
2190                 return $errors;
2191         }
2192
2193         /**
2194          * Check restrictions on cascading pages.
2195          *
2196          * @param string $action The action to check
2197          * @param User $user User to check
2198          * @param array $errors List of current errors
2199          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2200          * @param bool $short Short circuit on first error
2201          *
2202          * @return array List of errors
2203          */
2204         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2205                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2206                         # We /could/ use the protection level on the source page, but it's
2207                         # fairly ugly as we have to establish a precedence hierarchy for pages
2208                         # included by multiple cascade-protected pages. So just restrict
2209                         # it to people with 'protect' permission, as they could remove the
2210                         # protection anyway.
2211                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2212                         # Cascading protection depends on more than this page...
2213                         # Several cascading protected pages may include this page...
2214                         # Check each cascading level
2215                         # This is only for protection restrictions, not for all actions
2216                         if ( isset( $restrictions[$action] ) ) {
2217                                 foreach ( $restrictions[$action] as $right ) {
2218                                         // Backwards compatibility, rewrite sysop -> editprotected
2219                                         if ( $right == 'sysop' ) {
2220                                                 $right = 'editprotected';
2221                                         }
2222                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2223                                         if ( $right == 'autoconfirmed' ) {
2224                                                 $right = 'editsemiprotected';
2225                                         }
2226                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2227                                                 $pages = '';
2228                                                 foreach ( $cascadingSources as $page ) {
2229                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2230                                                 }
2231                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2232                                         }
2233                                 }
2234                         }
2235                 }
2236
2237                 return $errors;
2238         }
2239
2240         /**
2241          * Check action permissions not already checked in checkQuickPermissions
2242          *
2243          * @param string $action The action to check
2244          * @param User $user User to check
2245          * @param array $errors List of current errors
2246          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2247          * @param bool $short Short circuit on first error
2248          *
2249          * @return array List of errors
2250          */
2251         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2252                 global $wgDeleteRevisionsLimit, $wgLang;
2253
2254                 if ( $action == 'protect' ) {
2255                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2256                                 // If they can't edit, they shouldn't protect.
2257                                 $errors[] = array( 'protect-cantedit' );
2258                         }
2259                 } elseif ( $action == 'create' ) {
2260                         $title_protection = $this->getTitleProtection();
2261                         if ( $title_protection ) {
2262                                 if ( $title_protection['permission'] == ''
2263                                         || !$user->isAllowed( $title_protection['permission'] )
2264                                 ) {
2265                                         $errors[] = array(
2266                                                 'titleprotected',
2267                                                 User::whoIs( $title_protection['user'] ),
2268                                                 $title_protection['reason']
2269                                         );
2270                                 }
2271                         }
2272                 } elseif ( $action == 'move' ) {
2273                         // Check for immobile pages
2274                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2275                                 // Specific message for this case
2276                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2277                         } elseif ( !$this->isMovable() ) {
2278                                 // Less specific message for rarer cases
2279                                 $errors[] = array( 'immobile-source-page' );
2280                         }
2281                 } elseif ( $action == 'move-target' ) {
2282                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2283                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2284                         } elseif ( !$this->isMovable() ) {
2285                                 $errors[] = array( 'immobile-target-page' );
2286                         }
2287                 } elseif ( $action == 'delete' ) {
2288                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2289                         if ( !$tempErrors ) {
2290                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2291                                         $user, $tempErrors, $rigor, true );
2292                         }
2293                         if ( $tempErrors ) {
2294                                 // If protection keeps them from editing, they shouldn't be able to delete.
2295                                 $errors[] = array( 'deleteprotected' );
2296                         }
2297                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2298                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2299                         ) {
2300                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2301                         }
2302                 }
2303                 return $errors;
2304         }
2305
2306         /**
2307          * Check that the user isn't blocked from editing.
2308          *
2309          * @param string $action The action to check
2310          * @param User $user User to check
2311          * @param array $errors List of current errors
2312          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2313          * @param bool $short Short circuit on first error
2314          *
2315          * @return array List of errors
2316          */
2317         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2318                 // Account creation blocks handled at userlogin.
2319                 // Unblocking handled in SpecialUnblock
2320                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2321                         return $errors;
2322                 }
2323
2324                 global $wgEmailConfirmToEdit;
2325
2326                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2327                         $errors[] = array( 'confirmedittext' );
2328                 }
2329
2330                 $useSlave = ( $rigor !== 'secure' );
2331                 if ( ( $action == 'edit' || $action == 'create' )
2332                         && !$user->isBlockedFrom( $this, $useSlave )
2333                 ) {
2334                         // Don't block the user from editing their own talk page unless they've been
2335                         // explicitly blocked from that too.
2336                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2337                         // @todo FIXME: Pass the relevant context into this function.
2338                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2339                 }
2340
2341                 return $errors;
2342         }
2343
2344         /**
2345          * Check that the user is allowed to read this page.
2346          *
2347          * @param string $action The action to check
2348          * @param User $user User to check
2349          * @param array $errors List of current errors
2350          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2351          * @param bool $short Short circuit on first error
2352          *
2353          * @return array List of errors
2354          */
2355         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2356                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2357
2358                 $whitelisted = false;
2359                 if ( User::isEveryoneAllowed( 'read' ) ) {
2360                         # Shortcut for public wikis, allows skipping quite a bit of code
2361                         $whitelisted = true;
2362                 } elseif ( $user->isAllowed( 'read' ) ) {
2363                         # If the user is allowed to read pages, he is allowed to read all pages
2364                         $whitelisted = true;
2365                 } elseif ( $this->isSpecial( 'Userlogin' )
2366                         || $this->isSpecial( 'ChangePassword' )
2367                         || $this->isSpecial( 'PasswordReset' )
2368                 ) {
2369                         # Always grant access to the login page.
2370                         # Even anons need to be able to log in.
2371                         $whitelisted = true;
2372                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2373                         # Time to check the whitelist
2374                         # Only do these checks is there's something to check against
2375                         $name = $this->getPrefixedText();
2376                         $dbName = $this->getPrefixedDBkey();
2377
2378                         // Check for explicit whitelisting with and without underscores
2379                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2380                                 $whitelisted = true;
2381                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2382                                 # Old settings might have the title prefixed with
2383                                 # a colon for main-namespace pages
2384                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2385                                         $whitelisted = true;
2386                                 }
2387                         } elseif ( $this->isSpecialPage() ) {
2388                                 # If it's a special page, ditch the subpage bit and check again
2389                                 $name = $this->getDBkey();
2390                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2391                                 if ( $name ) {
2392                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2393                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2394                                                 $whitelisted = true;
2395                                         }
2396                                 }
2397                         }
2398                 }
2399
2400                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2401                         $name = $this->getPrefixedText();
2402                         // Check for regex whitelisting
2403                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2404                                 if ( preg_match( $listItem, $name ) ) {
2405                                         $whitelisted = true;
2406                                         break;
2407                                 }
2408                         }
2409                 }
2410
2411                 if ( !$whitelisted ) {
2412                         # If the title is not whitelisted, give extensions a chance to do so...
2413                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2414                         if ( !$whitelisted ) {
2415                                 $errors[] = $this->missingPermissionError( $action, $short );
2416                         }
2417                 }
2418
2419                 return $errors;
2420         }
2421
2422         /**
2423          * Get a description array when the user doesn't have the right to perform
2424          * $action (i.e. when User::isAllowed() returns false)
2425          *
2426          * @param string $action The action to check
2427          * @param bool $short Short circuit on first error
2428          * @return array List of errors
2429          */
2430         private function missingPermissionError( $action, $short ) {
2431                 // We avoid expensive display logic for quickUserCan's and such
2432                 if ( $short ) {
2433                         return array( 'badaccess-group0' );
2434                 }
2435
2436                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2437                         User::getGroupsWithPermission( $action ) );
2438
2439                 if ( count( $groups ) ) {
2440                         global $wgLang;
2441                         return array(
2442                                 'badaccess-groups',
2443                                 $wgLang->commaList( $groups ),
2444                                 count( $groups )
2445                         );
2446                 } else {
2447                         return array( 'badaccess-group0' );
2448                 }
2449         }
2450
2451         /**
2452          * Can $user perform $action on this page? This is an internal function,
2453          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2454          * checks on wfReadOnly() and blocks)
2455          *
2456          * @param string $action Action that permission needs to be checked for
2457          * @param User $user User to check
2458          * @param string $rigor One of (quick,full,secure)
2459          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2460          *   - full   : does cheap and expensive checks possibly from a slave
2461          *   - secure : does cheap and expensive checks, using the master as needed
2462          * @param bool $short Set this to true to stop after the first permission error.
2463          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2464          */
2465         protected function getUserPermissionsErrorsInternal(
2466                 $action, $user, $rigor = 'secure', $short = false
2467         ) {
2468                 if ( $rigor === true ) {
2469                         $rigor = 'secure'; // b/c
2470                 } elseif ( $rigor === false ) {
2471                         $rigor = 'quick'; // b/c
2472                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2473                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2474                 }
2475
2476                 # Read has special handling
2477                 if ( $action == 'read' ) {
2478                         $checks = array(
2479                                 'checkPermissionHooks',
2480                                 'checkReadPermissions',
2481                         );
2482                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2483                 # here as it will lead to duplicate error messages. This is okay to do
2484                 # since anywhere that checks for create will also check for edit, and
2485                 # those checks are called for edit.
2486                 } elseif ( $action == 'create' ) {
2487                         $checks = array(
2488                                 'checkQuickPermissions',
2489                                 'checkPermissionHooks',
2490                                 'checkPageRestrictions',
2491                                 'checkCascadingSourcesRestrictions',
2492                                 'checkActionPermissions',
2493                                 'checkUserBlock'
2494                         );
2495                 } else {
2496                         $checks = array(
2497                                 'checkQuickPermissions',
2498                                 'checkPermissionHooks',
2499                                 'checkSpecialsAndNSPermissions',
2500                                 'checkCSSandJSPermissions',
2501                                 'checkPageRestrictions',
2502                                 'checkCascadingSourcesRestrictions',
2503                                 'checkActionPermissions',
2504                                 'checkUserBlock'
2505                         );
2506                 }
2507
2508                 $errors = array();
2509                 while ( count( $checks ) > 0 &&
2510                                 !( $short && count( $errors ) > 0 ) ) {
2511                         $method = array_shift( $checks );
2512                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2513                 }
2514
2515                 return $errors;
2516         }
2517
2518         /**
2519          * Get a filtered list of all restriction types supported by this wiki.
2520          * @param bool $exists True to get all restriction types that apply to
2521          * titles that do exist, False for all restriction types that apply to
2522          * titles that do not exist
2523          * @return array
2524          */
2525         public static function getFilteredRestrictionTypes( $exists = true ) {
2526                 global $wgRestrictionTypes;
2527                 $types = $wgRestrictionTypes;
2528                 if ( $exists ) {
2529                         # Remove the create restriction for existing titles
2530                         $types = array_diff( $types, array( 'create' ) );
2531                 } else {
2532                         # Only the create and upload restrictions apply to non-existing titles
2533                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2534                 }
2535                 return $types;
2536         }
2537
2538         /**
2539          * Returns restriction types for the current Title
2540          *
2541          * @return array Applicable restriction types
2542          */
2543         public function getRestrictionTypes() {
2544                 if ( $this->isSpecialPage() ) {
2545                         return array();
2546                 }
2547
2548                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2549
2550                 if ( $this->getNamespace() != NS_FILE ) {
2551                         # Remove the upload restriction for non-file titles
2552                         $types = array_diff( $types, array( 'upload' ) );
2553                 }
2554
2555                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2556
2557                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2558                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2559
2560                 return $types;
2561         }
2562
2563         /**
2564          * Is this title subject to title protection?
2565          * Title protection is the one applied against creation of such title.
2566          *
2567          * @return array|bool An associative array representing any existent title
2568          *   protection, or false if there's none.
2569          */
2570         public function getTitleProtection() {
2571                 // Can't protect pages in special namespaces
2572                 if ( $this->getNamespace() < 0 ) {
2573                         return false;
2574                 }
2575
2576                 // Can't protect pages that exist.
2577                 if ( $this->exists() ) {
2578                         return false;
2579                 }
2580
2581                 if ( $this->mTitleProtection === null ) {
2582                         $dbr = wfGetDB( DB_SLAVE );
2583                         $res = $dbr->select(
2584                                 'protected_titles',
2585                                 array(
2586                                         'user' => 'pt_user',
2587                                         'reason' => 'pt_reason',
2588                                         'expiry' => 'pt_expiry',
2589                                         'permission' => 'pt_create_perm'
2590                                 ),
2591                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2592                                 __METHOD__
2593                         );
2594
2595                         // fetchRow returns false if there are no rows.
2596                         $row = $dbr->fetchRow( $res );
2597                         if ( $row ) {
2598                                 if ( $row['permission'] == 'sysop' ) {
2599                                         $row['permission'] = 'editprotected'; // B/C
2600                                 }
2601                                 if ( $row['permission'] == 'autoconfirmed' ) {
2602                                         $row['permission'] = 'editsemiprotected'; // B/C
2603                                 }
2604                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2605                         }
2606                         $this->mTitleProtection = $row;
2607                 }
2608                 return $this->mTitleProtection;
2609         }
2610
2611         /**
2612          * Remove any title protection due to page existing
2613          */
2614         public function deleteTitleProtection() {
2615                 $dbw = wfGetDB( DB_MASTER );
2616
2617                 $dbw->delete(
2618                         'protected_titles',
2619                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2620                         __METHOD__
2621                 );
2622                 $this->mTitleProtection = false;
2623         }
2624
2625         /**
2626          * Is this page "semi-protected" - the *only* protection levels are listed
2627          * in $wgSemiprotectedRestrictionLevels?
2628          *
2629          * @param string $action Action to check (default: edit)
2630          * @return bool
2631          */
2632         public function isSemiProtected( $action = 'edit' ) {
2633                 global $wgSemiprotectedRestrictionLevels;
2634
2635                 $restrictions = $this->getRestrictions( $action );
2636                 $semi = $wgSemiprotectedRestrictionLevels;
2637                 if ( !$restrictions || !$semi ) {
2638                         // Not protected, or all protection is full protection
2639                         return false;
2640                 }
2641
2642                 // Remap autoconfirmed to editsemiprotected for BC
2643                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2644                         $semi[$key] = 'editsemiprotected';
2645                 }
2646                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2647                         $restrictions[$key] = 'editsemiprotected';
2648                 }
2649
2650                 return !array_diff( $restrictions, $semi );
2651         }
2652
2653         /**
2654          * Does the title correspond to a protected article?
2655          *
2656          * @param string $action The action the page is protected from,
2657          * by default checks all actions.
2658          * @return bool
2659          */
2660         public function isProtected( $action = '' ) {
2661                 global $wgRestrictionLevels;
2662
2663                 $restrictionTypes = $this->getRestrictionTypes();
2664
2665                 # Special pages have inherent protection
2666                 if ( $this->isSpecialPage() ) {
2667                         return true;
2668                 }
2669
2670                 # Check regular protection levels
2671                 foreach ( $restrictionTypes as $type ) {
2672                         if ( $action == $type || $action == '' ) {
2673                                 $r = $this->getRestrictions( $type );
2674                                 foreach ( $wgRestrictionLevels as $level ) {
2675                                         if ( in_array( $level, $r ) && $level != '' ) {
2676                                                 return true;
2677                                         }
2678                                 }
2679                         }
2680                 }
2681
2682                 return false;
2683         }
2684
2685         /**
2686          * Determines if $user is unable to edit this page because it has been protected
2687          * by $wgNamespaceProtection.
2688          *
2689          * @param User $user User object to check permissions
2690          * @return bool
2691          */
2692         public function isNamespaceProtected( User $user ) {
2693                 global $wgNamespaceProtection;
2694
2695                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2696                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2697                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2698                                         return true;
2699                                 }
2700                         }
2701                 }
2702                 return false;
2703         }
2704
2705         /**
2706          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2707          *
2708          * @return bool If the page is subject to cascading restrictions.
2709          */
2710         public function isCascadeProtected() {
2711                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2712                 return ( $sources > 0 );
2713         }
2714
2715         /**
2716          * Determines whether cascading protection sources have already been loaded from
2717          * the database.
2718          *
2719          * @param bool $getPages True to check if the pages are loaded, or false to check
2720          * if the status is loaded.
2721          * @return bool Whether or not the specified information has been loaded
2722          * @since 1.23
2723          */
2724         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2725                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2726         }
2727
2728         /**
2729          * Cascading protection: Get the source of any cascading restrictions on this page.
2730          *
2731          * @param bool $getPages Whether or not to retrieve the actual pages
2732          *        that the restrictions have come from and the actual restrictions
2733          *        themselves.
2734          * @return array Two elements: First is an array of Title objects of the
2735          *        pages from which cascading restrictions have come, false for
2736          *        none, or true if such restrictions exist but $getPages was not
2737          *        set. Second is an array like that returned by
2738          *        Title::getAllRestrictions(), or an empty array if $getPages is
2739          *        false.
2740          */
2741         public function getCascadeProtectionSources( $getPages = true ) {
2742                 $pagerestrictions = array();
2743
2744                 if ( $this->mCascadeSources !== null && $getPages ) {
2745                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2746                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2747                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2748                 }
2749
2750                 $dbr = wfGetDB( DB_SLAVE );
2751
2752                 if ( $this->getNamespace() == NS_FILE ) {
2753                         $tables = array( 'imagelinks', 'page_restrictions' );
2754                         $where_clauses = array(
2755                                 'il_to' => $this->getDBkey(),
2756                                 'il_from=pr_page',
2757                                 'pr_cascade' => 1
2758                         );
2759                 } else {
2760                         $tables = array( 'templatelinks', 'page_restrictions' );
2761                         $where_clauses = array(
2762                                 'tl_namespace' => $this->getNamespace(),
2763                                 'tl_title' => $this->getDBkey(),
2764                                 'tl_from=pr_page',
2765                                 'pr_cascade' => 1
2766                         );
2767                 }
2768
2769                 if ( $getPages ) {
2770                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2771                                 'pr_expiry', 'pr_type', 'pr_level' );
2772                         $where_clauses[] = 'page_id=pr_page';
2773                         $tables[] = 'page';
2774                 } else {
2775                         $cols = array( 'pr_expiry' );
2776                 }
2777
2778                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2779
2780                 $sources = $getPages ? array() : false;
2781                 $now = wfTimestampNow();
2782
2783                 foreach ( $res as $row ) {
2784                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2785                         if ( $expiry > $now ) {
2786                                 if ( $getPages ) {
2787                                         $page_id = $row->pr_page;
2788                                         $page_ns = $row->page_namespace;
2789                                         $page_title = $row->page_title;
2790                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2791                                         # Add groups needed for each restriction type if its not already there
2792                                         # Make sure this restriction type still exists
2793
2794                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2795                                                 $pagerestrictions[$row->pr_type] = array();
2796                                         }
2797
2798                                         if (
2799                                                 isset( $pagerestrictions[$row->pr_type] )
2800                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2801                                         ) {
2802                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2803                                         }
2804                                 } else {
2805                                         $sources = true;
2806                                 }
2807                         }
2808                 }
2809
2810                 if ( $getPages ) {
2811                         $this->mCascadeSources = $sources;
2812                         $this->mCascadingRestrictions = $pagerestrictions;
2813                 } else {
2814                         $this->mHasCascadingRestrictions = $sources;
2815                 }
2816
2817                 return array( $sources, $pagerestrictions );
2818         }
2819
2820         /**
2821          * Accessor for mRestrictionsLoaded
2822          *
2823          * @return bool Whether or not the page's restrictions have already been
2824          * loaded from the database
2825          * @since 1.23
2826          */
2827         public function areRestrictionsLoaded() {
2828                 return $this->mRestrictionsLoaded;
2829         }
2830
2831         /**
2832          * Accessor/initialisation for mRestrictions
2833          *
2834          * @param string $action Action that permission needs to be checked for
2835          * @return array Restriction levels needed to take the action. All levels are
2836          *     required. Note that restriction levels are normally user rights, but 'sysop'
2837          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2838          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2839          */
2840         public function getRestrictions( $action ) {
2841                 if ( !$this->mRestrictionsLoaded ) {
2842                         $this->loadRestrictions();
2843                 }
2844                 return isset( $this->mRestrictions[$action] )
2845                                 ? $this->mRestrictions[$action]
2846                                 : array();
2847         }
2848
2849         /**
2850          * Accessor/initialisation for mRestrictions
2851          *
2852          * @return array Keys are actions, values are arrays as returned by
2853          *     Title::getRestrictions()
2854          * @since 1.23
2855          */
2856         public function getAllRestrictions() {
2857                 if ( !$this->mRestrictionsLoaded ) {
2858                         $this->loadRestrictions();
2859                 }
2860                 return $this->mRestrictions;
2861         }
2862
2863         /**
2864          * Get the expiry time for the restriction against a given action
2865          *
2866          * @param string $action
2867          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2868          *     or not protected at all, or false if the action is not recognised.
2869          */
2870         public function getRestrictionExpiry( $action ) {
2871                 if ( !$this->mRestrictionsLoaded ) {
2872                         $this->loadRestrictions();
2873                 }
2874                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2875         }
2876
2877         /**
2878          * Returns cascading restrictions for the current article
2879          *
2880          * @return bool
2881          */
2882         function areRestrictionsCascading() {
2883                 if ( !$this->mRestrictionsLoaded ) {
2884                         $this->loadRestrictions();
2885                 }
2886
2887                 return $this->mCascadeRestriction;
2888         }
2889
2890         /**
2891          * Loads a string into mRestrictions array
2892          *
2893          * @param ResultWrapper $res Resource restrictions as an SQL result.
2894          * @param string $oldFashionedRestrictions Comma-separated list of page
2895          *        restrictions from page table (pre 1.10)
2896          */
2897         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2898                 $rows = array();
2899
2900                 foreach ( $res as $row ) {
2901                         $rows[] = $row;
2902                 }
2903
2904                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2905         }
2906
2907         /**
2908          * Compiles list of active page restrictions from both page table (pre 1.10)
2909          * and page_restrictions table for this existing page.
2910          * Public for usage by LiquidThreads.
2911          *
2912          * @param array $rows Array of db result objects
2913          * @param string $oldFashionedRestrictions Comma-separated list of page
2914          *   restrictions from page table (pre 1.10)
2915          */
2916         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2917                 $dbr = wfGetDB( DB_SLAVE );
2918
2919                 $restrictionTypes = $this->getRestrictionTypes();
2920
2921                 foreach ( $restrictionTypes as $type ) {
2922                         $this->mRestrictions[$type] = array();
2923                         $this->mRestrictionsExpiry[$type] = 'infinity';
2924                 }
2925
2926                 $this->mCascadeRestriction = false;
2927
2928                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2929                 if ( $oldFashionedRestrictions !== null ) {
2930                         $this->mOldRestrictions = $oldFashionedRestrictions;
2931                 }
2932
2933                 if ( $this->mOldRestrictions === false ) {
2934                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2935                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2936                 }
2937
2938                 if ( $this->mOldRestrictions != '' ) {
2939                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2940                                 $temp = explode( '=', trim( $restrict ) );
2941                                 if ( count( $temp ) == 1 ) {
2942                                         // old old format should be treated as edit/move restriction
2943                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2944                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2945                                 } else {
2946                                         $restriction = trim( $temp[1] );
2947                                         if ( $restriction != '' ) { //some old entries are empty
2948                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2949                                         }
2950                                 }
2951                         }
2952                 }
2953
2954                 if ( count( $rows ) ) {
2955                         # Current system - load second to make them override.
2956                         $now = wfTimestampNow();
2957
2958                         # Cycle through all the restrictions.
2959                         foreach ( $rows as $row ) {
2960
2961                                 // Don't take care of restrictions types that aren't allowed
2962                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2963                                         continue;
2964                                 }
2965
2966                                 // This code should be refactored, now that it's being used more generally,
2967                                 // But I don't really see any harm in leaving it in Block for now -werdna
2968                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2969
2970                                 // Only apply the restrictions if they haven't expired!
2971                                 if ( !$expiry || $expiry > $now ) {
2972                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2973                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2974
2975                                         $this->mCascadeRestriction |= $row->pr_cascade;
2976                                 }
2977                         }
2978                 }
2979
2980                 $this->mRestrictionsLoaded = true;
2981         }
2982
2983         /**
2984          * Load restrictions from the page_restrictions table
2985          *
2986          * @param string $oldFashionedRestrictions Comma-separated list of page
2987          *   restrictions from page table (pre 1.10)
2988          */
2989         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2990                 if ( !$this->mRestrictionsLoaded ) {
2991                         $dbr = wfGetDB( DB_SLAVE );
2992                         if ( $this->exists() ) {
2993                                 $res = $dbr->select(
2994                                         'page_restrictions',
2995                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2996                                         array( 'pr_page' => $this->getArticleID() ),
2997                                         __METHOD__
2998                                 );
2999
3000                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
3001                         } else {
3002                                 $title_protection = $this->getTitleProtection();
3003
3004                                 if ( $title_protection ) {
3005                                         $now = wfTimestampNow();
3006                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
3007
3008                                         if ( !$expiry || $expiry > $now ) {
3009                                                 // Apply the restrictions
3010                                                 $this->mRestrictionsExpiry['create'] = $expiry;
3011                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
3012                                         } else { // Get rid of the old restrictions
3013                                                 $this->mTitleProtection = false;
3014                                         }
3015                                 } else {
3016                                         $this->mRestrictionsExpiry['create'] = 'infinity';
3017                                 }
3018                                 $this->mRestrictionsLoaded = true;
3019                         }
3020                 }
3021         }
3022
3023         /**
3024          * Flush the protection cache in this object and force reload from the database.
3025          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3026          */
3027         public function flushRestrictions() {
3028                 $this->mRestrictionsLoaded = false;
3029                 $this->mTitleProtection = null;
3030         }
3031
3032         /**
3033          * Purge expired restrictions from the page_restrictions table
3034          */
3035         static function purgeExpiredRestrictions() {
3036                 if ( wfReadOnly() ) {
3037                         return;
3038                 }
3039
3040                 $method = __METHOD__;
3041                 $dbw = wfGetDB( DB_MASTER );
3042                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3043                         $dbw->delete(
3044                                 'page_restrictions',
3045                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3046                                 $method
3047                         );
3048                         $dbw->delete(
3049                                 'protected_titles',
3050                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3051                                 $method
3052                         );
3053                 } );
3054         }
3055
3056         /**
3057          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3058          *
3059          * @return bool
3060          */
3061         public function hasSubpages() {
3062                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3063                         # Duh
3064                         return false;
3065                 }
3066
3067                 # We dynamically add a member variable for the purpose of this method
3068                 # alone to cache the result.  There's no point in having it hanging
3069                 # around uninitialized in every Title object; therefore we only add it
3070                 # if needed and don't declare it statically.
3071                 if ( $this->mHasSubpages === null ) {
3072                         $this->mHasSubpages = false;
3073                         $subpages = $this->getSubpages( 1 );
3074                         if ( $subpages instanceof TitleArray ) {
3075                                 $this->mHasSubpages = (bool)$subpages->count();
3076                         }
3077                 }
3078
3079                 return $this->mHasSubpages;
3080         }
3081
3082         /**
3083          * Get all subpages of this page.
3084          *
3085          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3086          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3087          *  doesn't allow subpages
3088          */
3089         public function getSubpages( $limit = -1 ) {
3090                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3091                         return array();
3092                 }
3093
3094                 $dbr = wfGetDB( DB_SLAVE );
3095                 $conds['page_namespace'] = $this->getNamespace();
3096                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3097                 $options = array();
3098                 if ( $limit > -1 ) {
3099                         $options['LIMIT'] = $limit;
3100                 }
3101                 $this->mSubpages = TitleArray::newFromResult(
3102                         $dbr->select( 'page',
3103                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3104                                 $conds,
3105                                 __METHOD__,
3106                                 $options
3107                         )
3108                 );
3109                 return $this->mSubpages;
3110         }
3111
3112         /**
3113          * Is there a version of this page in the deletion archive?
3114          *
3115          * @return int The number of archived revisions
3116          */
3117         public function isDeleted() {
3118                 if ( $this->getNamespace() < 0 ) {
3119                         $n = 0;
3120                 } else {
3121                         $dbr = wfGetDB( DB_SLAVE );
3122
3123                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3124                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3125                                 __METHOD__
3126                         );
3127                         if ( $this->getNamespace() == NS_FILE ) {
3128                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3129                                         array( 'fa_name' => $this->getDBkey() ),
3130                                         __METHOD__
3131                                 );
3132                         }
3133                 }
3134                 return (int)$n;
3135         }
3136
3137         /**
3138          * Is there a version of this page in the deletion archive?
3139          *
3140          * @return bool
3141          */
3142         public function isDeletedQuick() {
3143                 if ( $this->getNamespace() < 0 ) {
3144                         return false;
3145                 }
3146                 $dbr = wfGetDB( DB_SLAVE );
3147                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3148                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3149                         __METHOD__
3150                 );
3151                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3152                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3153                                 array( 'fa_name' => $this->getDBkey() ),
3154                                 __METHOD__
3155                         );
3156                 }
3157                 return $deleted;
3158         }
3159
3160         /**
3161          * Get the article ID for this Title from the link cache,
3162          * adding it if necessary
3163          *
3164          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3165          *  for update
3166          * @return int The ID
3167          */
3168         public function getArticleID( $flags = 0 ) {
3169                 if ( $this->getNamespace() < 0 ) {
3170                         $this->mArticleID = 0;
3171                         return $this->mArticleID;
3172                 }
3173                 $linkCache = LinkCache::singleton();
3174                 if ( $flags & self::GAID_FOR_UPDATE ) {
3175                         $oldUpdate = $linkCache->forUpdate( true );
3176                         $linkCache->clearLink( $this );
3177                         $this->mArticleID = $linkCache->addLinkObj( $this );
3178                         $linkCache->forUpdate( $oldUpdate );
3179                 } else {
3180                         if ( -1 == $this->mArticleID ) {
3181                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3182                         }
3183                 }
3184                 return $this->mArticleID;
3185         }
3186
3187         /**
3188          * Is this an article that is a redirect page?
3189          * Uses link cache, adding it if necessary
3190          *
3191          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3192          * @return bool
3193          */
3194         public function isRedirect( $flags = 0 ) {
3195                 if ( !is_null( $this->mRedirect ) ) {
3196                         return $this->mRedirect;
3197                 }
3198                 if ( !$this->getArticleID( $flags ) ) {
3199                         $this->mRedirect = false;
3200                         return $this->mRedirect;
3201                 }
3202
3203                 $linkCache = LinkCache::singleton();
3204                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3205                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3206                 if ( $cached === null ) {
3207                         # Trust LinkCache's state over our own
3208                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3209                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3210                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3211                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3212                         # LinkCache to refresh its data from the master.
3213                         $this->mRedirect = false;
3214                         return $this->mRedirect;
3215                 }
3216
3217                 $this->mRedirect = (bool)$cached;
3218
3219                 return $this->mRedirect;
3220         }
3221
3222         /**
3223          * What is the length of this page?
3224          * Uses link cache, adding it if necessary
3225          *
3226          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3227          * @return int
3228          */
3229         public function getLength( $flags = 0 ) {
3230                 if ( $this->mLength != -1 ) {
3231                         return $this->mLength;
3232                 }
3233                 if ( !$this->getArticleID( $flags ) ) {
3234                         $this->mLength = 0;
3235                         return $this->mLength;
3236                 }
3237                 $linkCache = LinkCache::singleton();
3238                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3239                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3240                 if ( $cached === null ) {
3241                         # Trust LinkCache's state over our own, as for isRedirect()
3242                         $this->mLength = 0;
3243                         return $this->mLength;
3244                 }
3245
3246                 $this->mLength = intval( $cached );
3247
3248                 return $this->mLength;
3249         }
3250
3251         /**
3252          * What is the page_latest field for this page?
3253          *
3254          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3255          * @return int Int or 0 if the page doesn't exist
3256          */
3257         public function getLatestRevID( $flags = 0 ) {
3258                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3259                         return intval( $this->mLatestID );
3260                 }
3261                 if ( !$this->getArticleID( $flags ) ) {
3262                         $this->mLatestID = 0;
3263                         return $this->mLatestID;
3264                 }
3265                 $linkCache = LinkCache::singleton();
3266                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3267                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3268                 if ( $cached === null ) {
3269                         # Trust LinkCache's state over our own, as for isRedirect()
3270                         $this->mLatestID = 0;
3271                         return $this->mLatestID;
3272                 }
3273
3274                 $this->mLatestID = intval( $cached );
3275
3276                 return $this->mLatestID;
3277         }
3278
3279         /**
3280          * This clears some fields in this object, and clears any associated
3281          * keys in the "bad links" section of the link cache.
3282          *
3283          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3284          * loading of the new page_id. It's also called from
3285          * WikiPage::doDeleteArticleReal()
3286          *
3287          * @param int $newid The new Article ID
3288          */
3289         public function resetArticleID( $newid ) {
3290                 $linkCache = LinkCache::singleton();
3291                 $linkCache->clearLink( $this );
3292
3293                 if ( $newid === false ) {
3294                         $this->mArticleID = -1;
3295                 } else {
3296                         $this->mArticleID = intval( $newid );
3297                 }
3298                 $this->mRestrictionsLoaded = false;
3299                 $this->mRestrictions = array();
3300                 $this->mOldRestrictions = false;
3301                 $this->mRedirect = null;
3302                 $this->mLength = -1;
3303                 $this->mLatestID = false;
3304                 $this->mContentModel = false;
3305                 $this->mEstimateRevisions = null;
3306                 $this->mPageLanguage = false;
3307                 $this->mDbPageLanguage = null;
3308                 $this->mIsBigDeletion = null;
3309         }
3310
3311         public static function clearCaches() {
3312                 $linkCache = LinkCache::singleton();
3313                 $linkCache->clear();
3314
3315                 $titleCache = self::getTitleCache();
3316                 $titleCache->clear();
3317         }
3318
3319         /**
3320          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3321          *
3322          * @param string $text Containing title to capitalize
3323          * @param int $ns Namespace index, defaults to NS_MAIN
3324          * @return string Containing capitalized title
3325          */
3326         public static function capitalize( $text, $ns = NS_MAIN ) {
3327                 global $wgContLang;
3328
3329                 if ( MWNamespace::isCapitalized( $ns ) ) {
3330                         return $wgContLang->ucfirst( $text );
3331                 } else {
3332                         return $text;
3333                 }
3334         }
3335
3336         /**
3337          * Secure and split - main initialisation function for this object
3338          *
3339          * Assumes that mDbkeyform has been set, and is urldecoded
3340          * and uses underscores, but not otherwise munged.  This function
3341          * removes illegal characters, splits off the interwiki and
3342          * namespace prefixes, sets the other forms, and canonicalizes
3343          * everything.
3344          *
3345          * @throws MalformedTitleException On invalid titles
3346          * @return bool True on success
3347          */
3348         private function secureAndSplit() {
3349                 # Initialisation
3350                 $this->mInterwiki = '';
3351                 $this->mFragment = '';
3352                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3353
3354                 $dbkey = $this->mDbkeyform;
3355
3356                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3357                 //        the parsing code with Title, while avoiding massive refactoring.
3358                 // @todo: get rid of secureAndSplit, refactor parsing code.
3359                 $titleParser = self::getTitleParser();
3360                 // MalformedTitleException can be thrown here
3361                 $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3362
3363                 # Fill fields
3364                 $this->setFragment( '#' . $parts['fragment'] );
3365                 $this->mInterwiki = $parts['interwiki'];
3366                 $this->mLocalInterwiki = $parts['local_interwiki'];
3367                 $this->mNamespace = $parts['namespace'];
3368                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3369
3370                 $this->mDbkeyform = $parts['dbkey'];
3371                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3372                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3373
3374                 # We already know that some pages won't be in the database!
3375                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3376                         $this->mArticleID = 0;
3377                 }
3378
3379                 return true;
3380         }
3381
3382         /**
3383          * Get an array of Title objects linking to this Title
3384          * Also stores the IDs in the link cache.
3385          *
3386          * WARNING: do not use this function on arbitrary user-supplied titles!
3387          * On heavily-used templates it will max out the memory.
3388          *
3389          * @param array $options May be FOR UPDATE
3390          * @param string $table Table name
3391          * @param string $prefix Fields prefix
3392          * @return Title[] Array of Title objects linking here
3393          */
3394         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3395                 if ( count( $options ) > 0 ) {
3396                         $db = wfGetDB( DB_MASTER );
3397                 } else {
3398                         $db = wfGetDB( DB_SLAVE );
3399                 }
3400
3401                 $res = $db->select(
3402                         array( 'page', $table ),
3403                         self::getSelectFields(),
3404                         array(
3405                                 "{$prefix}_from=page_id",
3406                                 "{$prefix}_namespace" => $this->getNamespace(),
3407                                 "{$prefix}_title" => $this->getDBkey() ),
3408                         __METHOD__,
3409                         $options
3410                 );
3411
3412                 $retVal = array();
3413                 if ( $res->numRows() ) {
3414                         $linkCache = LinkCache::singleton();
3415                         foreach ( $res as $row ) {
3416                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3417                                 if ( $titleObj ) {
3418                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3419                                         $retVal[] = $titleObj;
3420                                 }
3421                         }
3422                 }
3423                 return $retVal;
3424         }
3425
3426         /**
3427          * Get an array of Title objects using this Title as a template
3428          * Also stores the IDs in the link cache.
3429          *
3430          * WARNING: do not use this function on arbitrary user-supplied titles!
3431          * On heavily-used templates it will max out the memory.
3432          *
3433          * @param array $options May be FOR UPDATE
3434          * @return Title[] Array of Title the Title objects linking here
3435          */
3436         public function getTemplateLinksTo( $options = array() ) {
3437                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3438         }
3439
3440         /**
3441          * Get an array of Title objects linked from this Title
3442          * Also stores the IDs in the link cache.
3443          *
3444          * WARNING: do not use this function on arbitrary user-supplied titles!
3445          * On heavily-used templates it will max out the memory.
3446          *
3447          * @param array $options May be FOR UPDATE
3448          * @param string $table Table name
3449          * @param string $prefix Fields prefix
3450          * @return array Array of Title objects linking here
3451          */
3452         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3453                 $id = $this->getArticleID();
3454
3455                 # If the page doesn't exist; there can't be any link from this page
3456                 if ( !$id ) {
3457                         return array();
3458                 }
3459
3460                 if ( count( $options ) > 0 ) {
3461                         $db = wfGetDB( DB_MASTER );
3462                 } else {
3463                         $db = wfGetDB( DB_SLAVE );
3464                 }
3465
3466                 $blNamespace = "{$prefix}_namespace";
3467                 $blTitle = "{$prefix}_title";
3468
3469                 $res = $db->select(
3470                         array( $table, 'page' ),
3471                         array_merge(
3472                                 array( $blNamespace, $blTitle ),
3473                                 WikiPage::selectFields()
3474                         ),
3475                         array( "{$prefix}_from" => $id ),
3476                         __METHOD__,
3477                         $options,
3478                         array( 'page' => array(
3479                                 'LEFT JOIN',
3480                                 array( "page_namespace=$blNamespace", "page_title=$blTitle" )
3481                         ) )
3482                 );
3483
3484                 $retVal = array();
3485                 $linkCache = LinkCache::singleton();
3486                 foreach ( $res as $row ) {
3487                         if ( $row->page_id ) {
3488                                 $titleObj = Title::newFromRow( $row );
3489                         } else {
3490                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3491                                 $linkCache->addBadLinkObj( $titleObj );
3492                         }
3493                         $retVal[] = $titleObj;
3494                 }
3495
3496                 return $retVal;
3497         }
3498
3499         /**
3500          * Get an array of Title objects used on this Title as a template
3501          * Also stores the IDs in the link cache.
3502          *
3503          * WARNING: do not use this function on arbitrary user-supplied titles!
3504          * On heavily-used templates it will max out the memory.
3505          *
3506          * @param array $options May be FOR UPDATE
3507          * @return Title[] Array of Title the Title objects used here
3508          */
3509         public function getTemplateLinksFrom( $options = array() ) {
3510                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3511         }
3512
3513         /**
3514          * Get an array of Title objects referring to non-existent articles linked
3515          * from this page.
3516          *
3517          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3518          *   should use redirect table in this case).
3519          * @return Title[] Array of Title the Title objects
3520          */
3521         public function getBrokenLinksFrom() {
3522                 if ( $this->getArticleID() == 0 ) {
3523                         # All links from article ID 0 are false positives
3524                         return array();
3525                 }
3526
3527                 $dbr = wfGetDB( DB_SLAVE );
3528                 $res = $dbr->select(
3529                         array( 'page', 'pagelinks' ),
3530                         array( 'pl_namespace', 'pl_title' ),
3531                         array(
3532                                 'pl_from' => $this->getArticleID(),
3533                                 'page_namespace IS NULL'
3534                         ),
3535                         __METHOD__, array(),
3536                         array(
3537                                 'page' => array(
3538                                         'LEFT JOIN',
3539                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3540                                 )
3541                         )
3542                 );
3543
3544                 $retVal = array();
3545                 foreach ( $res as $row ) {
3546                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3547                 }
3548                 return $retVal;
3549         }
3550
3551         /**
3552          * Get a list of URLs to purge from the Squid cache when this
3553          * page changes
3554          *
3555          * @return string[] Array of String the URLs
3556          */
3557         public function getSquidURLs() {
3558                 $urls = array(
3559                         $this->getInternalURL(),
3560                         $this->getInternalURL( 'action=history' )
3561                 );
3562
3563                 $pageLang = $this->getPageLanguage();
3564                 if ( $pageLang->hasVariants() ) {
3565                         $variants = $pageLang->getVariants();
3566                         foreach ( $variants as $vCode ) {
3567                                 $urls[] = $this->getInternalURL( '', $vCode );
3568                         }
3569                 }
3570
3571                 // If we are looking at a css/js user subpage, purge the action=raw.
3572                 if ( $this->isJsSubpage() ) {
3573                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3574                 } elseif ( $this->isCssSubpage() ) {
3575                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3576                 }
3577
3578                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3579                 return $urls;
3580         }
3581
3582         /**
3583          * Purge all applicable Squid URLs
3584          */
3585         public function purgeSquid() {
3586                 global $wgUseSquid;
3587                 if ( $wgUseSquid ) {
3588                         $urls = $this->getSquidURLs();
3589                         $u = new SquidUpdate( $urls );
3590                         $u->doUpdate();
3591                 }
3592         }
3593
3594         /**
3595          * Move this page without authentication
3596          *
3597          * @deprecated since 1.25 use MovePage class instead
3598          * @param Title $nt The new page Title
3599          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3600          */
3601         public function moveNoAuth( &$nt ) {
3602                 wfDeprecated( __METHOD__, '1.25' );
3603                 return $this->moveTo( $nt, false );
3604         }
3605
3606         /**
3607          * Check whether a given move operation would be valid.
3608          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3609          *
3610          * @deprecated since 1.25, use MovePage's methods instead
3611          * @param Title $nt The new title
3612          * @param bool $auth Whether to check user permissions (uses $wgUser)
3613          * @param string $reason Is the log summary of the move, used for spam checking
3614          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3615          */
3616         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3617                 global $wgUser;
3618
3619                 if ( !( $nt instanceof Title ) ) {
3620                         // Normally we'd add this to $errors, but we'll get
3621                         // lots of syntax errors if $nt is not an object
3622                         return array( array( 'badtitletext' ) );
3623                 }
3624
3625                 $mp = new MovePage( $this, $nt );
3626                 $errors = $mp->isValidMove()->getErrorsArray();
3627                 if ( $auth ) {
3628                         $errors = wfMergeErrorArrays(
3629                                 $errors,
3630                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3631                         );
3632                 }
3633
3634                 return $errors ?: true;
3635         }
3636
3637         /**
3638          * Check if the requested move target is a valid file move target
3639          * @todo move this to MovePage
3640          * @param Title $nt Target title
3641          * @return array List of errors
3642          */
3643         protected function validateFileMoveOperation( $nt ) {
3644                 global $wgUser;
3645
3646                 $errors = array();
3647
3648                 $destFile = wfLocalFile( $nt );
3649                 $destFile->load( File::READ_LATEST );
3650                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3651                         && !$destFile->exists() && wfFindFile( $nt )
3652                 ) {
3653                         $errors[] = array( 'file-exists-sharedrepo' );
3654                 }
3655
3656                 return $errors;
3657         }
3658
3659         /**
3660          * Move a title to a new location
3661          *
3662          * @deprecated since 1.25, use the MovePage class instead
3663          * @param Title $nt The new title
3664          * @param bool $auth Indicates whether $wgUser's permissions
3665          *  should be checked
3666          * @param string $reason The reason for the move
3667          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3668          *  Ignored if the user doesn't have the suppressredirect right.
3669          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3670          */
3671         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3672                 global $wgUser;
3673                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3674                 if ( is_array( $err ) ) {
3675                         // Auto-block user's IP if the account was "hard" blocked
3676                         $wgUser->spreadAnyEditBlock();
3677                         return $err;
3678                 }
3679                 // Check suppressredirect permission
3680                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3681                         $createRedirect = true;
3682                 }
3683
3684                 $mp = new MovePage( $this, $nt );
3685                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3686                 if ( $status->isOK() ) {
3687                         return true;
3688                 } else {
3689                         return $status->getErrorsArray();
3690                 }
3691         }
3692
3693         /**
3694          * Move this page's subpages to be subpages of $nt
3695          *
3696          * @param Title $nt Move target
3697          * @param bool $auth Whether $wgUser's permissions should be checked
3698          * @param string $reason The reason for the move
3699          * @param bool $createRedirect Whether to create redirects from the old subpages to
3700          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3701          * @return array Array with old page titles as keys, and strings (new page titles) or
3702          *     arrays (errors) as values, or an error array with numeric indices if no pages
3703          *     were moved
3704          */
3705         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3706                 global $wgMaximumMovedPages;
3707                 // Check permissions
3708                 if ( !$this->userCan( 'move-subpages' ) ) {
3709                         return array( 'cant-move-subpages' );
3710                 }
3711                 // Do the source and target namespaces support subpages?
3712                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3713                         return array( 'namespace-nosubpages',
3714                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3715                 }
3716                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3717                         return array( 'namespace-nosubpages',
3718                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3719                 }
3720
3721                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3722                 $retval = array();
3723                 $count = 0;
3724                 foreach ( $subpages as $oldSubpage ) {
3725                         $count++;
3726                         if ( $count > $wgMaximumMovedPages ) {
3727                                 $retval[$oldSubpage->getPrefixedText()] =
3728                                                 array( 'movepage-max-pages',
3729                                                         $wgMaximumMovedPages );
3730                                 break;
3731                         }
3732
3733                         // We don't know whether this function was called before
3734                         // or after moving the root page, so check both
3735                         // $this and $nt
3736                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3737                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3738                         ) {
3739                                 // When moving a page to a subpage of itself,
3740                                 // don't move it twice
3741                                 continue;
3742                         }
3743                         $newPageName = preg_replace(
3744                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3745                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3746                                         $oldSubpage->getDBkey() );
3747                         if ( $oldSubpage->isTalkPage() ) {
3748                                 $newNs = $nt->getTalkPage()->getNamespace();
3749                         } else {
3750                                 $newNs = $nt->getSubjectPage()->getNamespace();
3751                         }
3752                         # Bug 14385: we need makeTitleSafe because the new page names may
3753                         # be longer than 255 characters.
3754                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3755
3756                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3757                         if ( $success === true ) {
3758                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3759                         } else {
3760                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3761                         }
3762                 }
3763                 return $retval;
3764         }
3765
3766         /**
3767          * Checks if this page is just a one-rev redirect.
3768          * Adds lock, so don't use just for light purposes.
3769          *
3770          * @return bool
3771          */
3772         public function isSingleRevRedirect() {
3773                 global $wgContentHandlerUseDB;
3774
3775                 $dbw = wfGetDB( DB_MASTER );
3776
3777                 # Is it a redirect?
3778                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3779                 if ( $wgContentHandlerUseDB ) {
3780                         $fields[] = 'page_content_model';
3781                 }
3782
3783                 $row = $dbw->selectRow( 'page',
3784                         $fields,
3785                         $this->pageCond(),
3786                         __METHOD__,
3787                         array( 'FOR UPDATE' )
3788                 );
3789                 # Cache some fields we may want
3790                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3791                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3792                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3793                 $this->mContentModel = $row && isset( $row->page_content_model )
3794                         ? strval( $row->page_content_model )
3795                         : false;
3796
3797                 if ( !$this->mRedirect ) {
3798                         return false;
3799                 }
3800                 # Does the article have a history?
3801                 $row = $dbw->selectField( array( 'page', 'revision' ),
3802                         'rev_id',
3803                         array( 'page_namespace' => $this->getNamespace(),
3804                                 'page_title' => $this->getDBkey(),
3805                                 'page_id=rev_page',
3806                                 'page_latest != rev_id'
3807                         ),
3808                         __METHOD__,
3809                         array( 'FOR UPDATE' )
3810                 );
3811                 # Return true if there was no history
3812                 return ( $row === false );
3813         }
3814
3815         /**
3816          * Checks if $this can be moved to a given Title
3817          * - Selects for update, so don't call it unless you mean business
3818          *
3819          * @deprecated since 1.25, use MovePage's methods instead
3820          * @param Title $nt The new title to check
3821          * @return bool
3822          */
3823         public function isValidMoveTarget( $nt ) {
3824                 # Is it an existing file?
3825                 if ( $nt->getNamespace() == NS_FILE ) {
3826                         $file = wfLocalFile( $nt );
3827                         $file->load( File::READ_LATEST );
3828                         if ( $file->exists() ) {
3829                                 wfDebug( __METHOD__ . ": file exists\n" );
3830                                 return false;
3831                         }
3832                 }
3833                 # Is it a redirect with no history?
3834                 if ( !$nt->isSingleRevRedirect() ) {
3835                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3836                         return false;
3837                 }
3838                 # Get the article text
3839                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3840                 if ( !is_object( $rev ) ) {
3841                         return false;
3842                 }
3843                 $content = $rev->getContent();
3844                 # Does the redirect point to the source?
3845                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3846                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3847
3848                 if ( $redirTitle ) {
3849                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3850                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3851                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3852                                 return false;
3853                         } else {
3854                                 return true;
3855                         }
3856                 } else {
3857                         # Fail safe (not a redirect after all. strange.)
3858                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3859                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3860                         return false;
3861                 }
3862         }
3863
3864         /**
3865          * Get categories to which this Title belongs and return an array of
3866          * categories' names.
3867          *
3868          * @return array Array of parents in the form:
3869          *        $parent => $currentarticle
3870          */
3871         public function getParentCategories() {
3872                 global $wgContLang;
3873
3874                 $data = array();
3875
3876                 $titleKey = $this->getArticleID();
3877
3878                 if ( $titleKey === 0 ) {
3879                         return $data;
3880                 }
3881
3882                 $dbr = wfGetDB( DB_SLAVE );
3883
3884                 $res = $dbr->select(
3885                         'categorylinks',
3886                         'cl_to',
3887                         array( 'cl_from' => $titleKey ),
3888                         __METHOD__
3889                 );
3890
3891                 if ( $res->numRows() > 0 ) {
3892                         foreach ( $res as $row ) {
3893                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3894                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3895                         }
3896                 }
3897                 return $data;
3898         }
3899
3900         /**
3901          * Get a tree of parent categories
3902          *
3903          * @param array $children Array with the children in the keys, to check for circular refs
3904          * @return array Tree of parent categories
3905          */
3906         public function getParentCategoryTree( $children = array() ) {
3907                 $stack = array();
3908                 $parents = $this->getParentCategories();
3909
3910                 if ( $parents ) {
3911                         foreach ( $parents as $parent => $current ) {
3912                                 if ( array_key_exists( $parent, $children ) ) {
3913                                         # Circular reference
3914                                         $stack[$parent] = array();
3915                                 } else {
3916                                         $nt = Title::newFromText( $parent );
3917                                         if ( $nt ) {
3918                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3919                                         }
3920                                 }
3921                         }
3922                 }
3923
3924                 return $stack;
3925         }
3926
3927         /**
3928          * Get an associative array for selecting this title from
3929          * the "page" table
3930          *
3931          * @return array Array suitable for the $where parameter of DB::select()
3932          */
3933         public function pageCond() {
3934                 if ( $this->mArticleID > 0 ) {
3935                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3936                         return array( 'page_id' => $this->mArticleID );
3937                 } else {
3938                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3939                 }
3940         }
3941
3942         /**
3943          * Get the revision ID of the previous revision
3944          *
3945          * @param int $revId Revision ID. Get the revision that was before this one.
3946          * @param int $flags Title::GAID_FOR_UPDATE
3947          * @return int|bool Old revision ID, or false if none exists
3948          */
3949         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3950                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3951                 $revId = $db->selectField( 'revision', 'rev_id',
3952                         array(
3953                                 'rev_page' => $this->getArticleID( $flags ),
3954                                 'rev_id < ' . intval( $revId )
3955                         ),
3956                         __METHOD__,
3957                         array( 'ORDER BY' => 'rev_id DESC' )
3958                 );
3959
3960                 if ( $revId === false ) {
3961                         return false;
3962                 } else {
3963                         return intval( $revId );
3964                 }
3965         }
3966
3967         /**
3968          * Get the revision ID of the next revision
3969          *
3970          * @param int $revId Revision ID. Get the revision that was after this one.
3971          * @param int $flags Title::GAID_FOR_UPDATE
3972          * @return int|bool Next revision ID, or false if none exists
3973          */
3974         public function getNextRevisionID( $revId, $flags = 0 ) {
3975                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3976                 $revId = $db->selectField( 'revision', 'rev_id',
3977                         array(
3978                                 'rev_page' => $this->getArticleID( $flags ),
3979                                 'rev_id > ' . intval( $revId )
3980                         ),
3981                         __METHOD__,
3982                         array( 'ORDER BY' => 'rev_id' )
3983                 );
3984
3985                 if ( $revId === false ) {
3986                         return false;
3987                 } else {
3988                         return intval( $revId );
3989                 }
3990         }
3991
3992         /**
3993          * Get the first revision of the page
3994          *
3995          * @param int $flags Title::GAID_FOR_UPDATE
3996          * @return Revision|null If page doesn't exist
3997          */
3998         public function getFirstRevision( $flags = 0 ) {
3999                 $pageId = $this->getArticleID( $flags );
4000                 if ( $pageId ) {
4001                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4002                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4003                                 array( 'rev_page' => $pageId ),
4004                                 __METHOD__,
4005                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4006                         );
4007                         if ( $row ) {
4008                                 return new Revision( $row );
4009                         }
4010                 }
4011                 return null;
4012         }
4013
4014         /**
4015          * Get the oldest revision timestamp of this page
4016          *
4017          * @param int $flags Title::GAID_FOR_UPDATE
4018          * @return string MW timestamp
4019          */
4020         public function getEarliestRevTime( $flags = 0 ) {
4021                 $rev = $this->getFirstRevision( $flags );
4022                 return $rev ? $rev->getTimestamp() : null;
4023         }
4024
4025         /**
4026          * Check if this is a new page
4027          *
4028          * @return bool
4029          */
4030         public function isNewPage() {
4031                 $dbr = wfGetDB( DB_SLAVE );
4032                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4033         }
4034
4035         /**
4036          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4037          *
4038          * @return bool
4039          */
4040         public function isBigDeletion() {
4041                 global $wgDeleteRevisionsLimit;
4042
4043                 if ( !$wgDeleteRevisionsLimit ) {
4044                         return false;
4045                 }
4046
4047                 if ( $this->mIsBigDeletion === null ) {
4048                         $dbr = wfGetDB( DB_SLAVE );
4049
4050                         $revCount = $dbr->selectRowCount(
4051                                 'revision',
4052                                 '1',
4053                                 array( 'rev_page' => $this->getArticleID() ),
4054                                 __METHOD__,
4055                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4056                         );
4057
4058                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4059                 }
4060
4061                 return $this->mIsBigDeletion;
4062         }
4063
4064         /**
4065          * Get the approximate revision count of this page.
4066          *
4067          * @return int
4068          */
4069         public function estimateRevisionCount() {
4070                 if ( !$this->exists() ) {
4071                         return 0;
4072                 }
4073
4074                 if ( $this->mEstimateRevisions === null ) {
4075                         $dbr = wfGetDB( DB_SLAVE );
4076                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4077                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4078                 }
4079
4080                 return $this->mEstimateRevisions;
4081         }
4082
4083         /**
4084          * Get the number of revisions between the given revision.
4085          * Used for diffs and other things that really need it.
4086          *
4087          * @param int|Revision $old Old revision or rev ID (first before range)
4088          * @param int|Revision $new New revision or rev ID (first after range)
4089          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4090          * @return int Number of revisions between these revisions.
4091          */
4092         public function countRevisionsBetween( $old, $new, $max = null ) {
4093                 if ( !( $old instanceof Revision ) ) {
4094                         $old = Revision::newFromTitle( $this, (int)$old );
4095                 }
4096                 if ( !( $new instanceof Revision ) ) {
4097                         $new = Revision::newFromTitle( $this, (int)$new );
4098                 }
4099                 if ( !$old || !$new ) {
4100                         return 0; // nothing to compare
4101                 }
4102                 $dbr = wfGetDB( DB_SLAVE );
4103                 $conds = array(
4104                         'rev_page' => $this->getArticleID(),
4105                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4106                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4107                 );
4108                 if ( $max !== null ) {
4109                         return $dbr->selectRowCount( 'revision', '1',
4110                                 $conds,
4111                                 __METHOD__,
4112                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4113                         );
4114                 } else {
4115                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4116                 }
4117         }
4118
4119         /**
4120          * Get the authors between the given revisions or revision IDs.
4121          * Used for diffs and other things that really need it.
4122          *
4123          * @since 1.23
4124          *
4125          * @param int|Revision $old Old revision or rev ID (first before range by default)
4126          * @param int|Revision $new New revision or rev ID (first after range by default)
4127          * @param int $limit Maximum number of authors
4128          * @param string|array $options (Optional): Single option, or an array of options:
4129          *     'include_old' Include $old in the range; $new is excluded.
4130          *     'include_new' Include $new in the range; $old is excluded.
4131          *     'include_both' Include both $old and $new in the range.
4132          *     Unknown option values are ignored.
4133          * @return array|null Names of revision authors in the range; null if not both revisions exist
4134          */
4135         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4136                 if ( !( $old instanceof Revision ) ) {
4137                         $old = Revision::newFromTitle( $this, (int)$old );
4138                 }
4139                 if ( !( $new instanceof Revision ) ) {
4140                         $new = Revision::newFromTitle( $this, (int)$new );
4141                 }
4142                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4143                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4144                 // in the sanity check below?
4145                 if ( !$old || !$new ) {
4146                         return null; // nothing to compare
4147                 }
4148                 $authors = array();
4149                 $old_cmp = '>';
4150                 $new_cmp = '<';
4151                 $options = (array)$options;
4152                 if ( in_array( 'include_old', $options ) ) {
4153                         $old_cmp = '>=';
4154                 }
4155                 if ( in_array( 'include_new', $options ) ) {
4156                         $new_cmp = '<=';
4157                 }
4158                 if ( in_array( 'include_both', $options ) ) {
4159                         $old_cmp = '>=';
4160                         $new_cmp = '<=';
4161                 }
4162                 // No DB query needed if $old and $new are the same or successive revisions:
4163                 if ( $old->getId() === $new->getId() ) {
4164                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4165                                 array() :
4166                                 array( $old->getUserText( Revision::RAW ) );
4167                 } elseif ( $old->getId() === $new->getParentId() ) {
4168                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4169                                 $authors[] = $old->getUserText( Revision::RAW );
4170                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4171                                         $authors[] = $new->getUserText( Revision::RAW );
4172                                 }
4173                         } elseif ( $old_cmp === '>=' ) {
4174                                 $authors[] = $old->getUserText( Revision::RAW );
4175                         } elseif ( $new_cmp === '<=' ) {
4176                                 $authors[] = $new->getUserText( Revision::RAW );
4177                         }
4178                         return $authors;
4179                 }
4180                 $dbr = wfGetDB( DB_SLAVE );
4181                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4182                         array(
4183                                 'rev_page' => $this->getArticleID(),
4184                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4185                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4186                         ), __METHOD__,
4187                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4188                 );
4189                 foreach ( $res as $row ) {
4190                         $authors[] = $row->rev_user_text;
4191                 }
4192                 return $authors;
4193         }
4194
4195         /**
4196          * Get the number of authors between the given revisions or revision IDs.
4197          * Used for diffs and other things that really need it.
4198          *
4199          * @param int|Revision $old Old revision or rev ID (first before range by default)
4200          * @param int|Revision $new New revision or rev ID (first after range by default)
4201          * @param int $limit Maximum number of authors
4202          * @param string|array $options (Optional): Single option, or an array of options:
4203          *     'include_old' Include $old in the range; $new is excluded.
4204          *     'include_new' Include $new in the range; $old is excluded.
4205          *     'include_both' Include both $old and $new in the range.
4206          *     Unknown option values are ignored.
4207          * @return int Number of revision authors in the range; zero if not both revisions exist
4208          */
4209         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4210                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4211                 return $authors ? count( $authors ) : 0;
4212         }
4213
4214         /**
4215          * Compare with another title.
4216          *
4217          * @param Title $title
4218          * @return bool
4219          */
4220         public function equals( Title $title ) {
4221                 // Note: === is necessary for proper matching of number-like titles.
4222                 return $this->getInterwiki() === $title->getInterwiki()
4223                         && $this->getNamespace() == $title->getNamespace()
4224                         && $this->getDBkey() === $title->getDBkey();
4225         }
4226
4227         /**
4228          * Check if this title is a subpage of another title
4229          *
4230          * @param Title $title
4231          * @return bool
4232          */
4233         public function isSubpageOf( Title $title ) {
4234                 return $this->getInterwiki() === $title->getInterwiki()
4235                         && $this->getNamespace() == $title->getNamespace()
4236                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4237         }
4238
4239         /**
4240          * Check if page exists.  For historical reasons, this function simply
4241          * checks for the existence of the title in the page table, and will
4242          * thus return false for interwiki links, special pages and the like.
4243          * If you want to know if a title can be meaningfully viewed, you should
4244          * probably call the isKnown() method instead.
4245          *
4246          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4247          *   from master/for update
4248          * @return bool
4249          */
4250         public function exists( $flags = 0 ) {
4251                 $exists = $this->getArticleID( $flags ) != 0;
4252                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4253                 return $exists;
4254         }
4255
4256         /**
4257          * Should links to this title be shown as potentially viewable (i.e. as
4258          * "bluelinks"), even if there's no record by this title in the page
4259          * table?
4260          *
4261          * This function is semi-deprecated for public use, as well as somewhat
4262          * misleadingly named.  You probably just want to call isKnown(), which
4263          * calls this function internally.
4264          *
4265          * (ISSUE: Most of these checks are cheap, but the file existence check
4266          * can potentially be quite expensive.  Including it here fixes a lot of
4267          * existing code, but we might want to add an optional parameter to skip
4268          * it and any other expensive checks.)
4269          *
4270          * @return bool
4271          */
4272         public function isAlwaysKnown() {
4273                 $isKnown = null;
4274
4275                 /**
4276                  * Allows overriding default behavior for determining if a page exists.
4277                  * If $isKnown is kept as null, regular checks happen. If it's
4278                  * a boolean, this value is returned by the isKnown method.
4279                  *
4280                  * @since 1.20
4281                  *
4282                  * @param Title $title
4283                  * @param bool|null $isKnown
4284                  */
4285                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4286
4287                 if ( !is_null( $isKnown ) ) {
4288                         return $isKnown;
4289                 }
4290
4291                 if ( $this->isExternal() ) {
4292                         return true;  // any interwiki link might be viewable, for all we know
4293                 }
4294
4295                 switch ( $this->mNamespace ) {
4296                         case NS_MEDIA:
4297                         case NS_FILE:
4298                                 // file exists, possibly in a foreign repo
4299                                 return (bool)wfFindFile( $this );
4300                         case NS_SPECIAL:
4301                                 // valid special page
4302                                 return SpecialPageFactory::exists( $this->getDBkey() );
4303                         case NS_MAIN:
4304                                 // selflink, possibly with fragment
4305                                 return $this->mDbkeyform == '';
4306                         case NS_MEDIAWIKI:
4307                                 // known system message
4308                                 return $this->hasSourceText() !== false;
4309                         default:
4310                                 return false;
4311                 }
4312         }
4313
4314         /**
4315          * Does this title refer to a page that can (or might) be meaningfully
4316          * viewed?  In particular, this function may be used to determine if
4317          * links to the title should be rendered as "bluelinks" (as opposed to
4318          * "redlinks" to non-existent pages).
4319          * Adding something else to this function will cause inconsistency
4320          * since LinkHolderArray calls isAlwaysKnown() and does its own
4321          * page existence check.
4322          *
4323          * @return bool
4324          */
4325         public function isKnown() {
4326                 return $this->isAlwaysKnown() || $this->exists();
4327         }
4328
4329         /**
4330          * Does this page have source text?
4331          *
4332          * @return bool
4333          */
4334         public function hasSourceText() {
4335                 if ( $this->exists() ) {
4336                         return true;
4337                 }
4338
4339                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4340                         // If the page doesn't exist but is a known system message, default
4341                         // message content will be displayed, same for language subpages-
4342                         // Use always content language to avoid loading hundreds of languages
4343                         // to get the link color.
4344                         global $wgContLang;
4345                         list( $name, ) = MessageCache::singleton()->figureMessage(
4346                                 $wgContLang->lcfirst( $this->getText() )
4347                         );
4348                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4349                         return $message->exists();
4350                 }
4351
4352                 return false;
4353         }
4354
4355         /**
4356          * Get the default message text or false if the message doesn't exist
4357          *
4358          * @return string|bool
4359          */
4360         public function getDefaultMessageText() {
4361                 global $wgContLang;
4362
4363                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4364                         return false;
4365                 }
4366
4367                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4368                         $wgContLang->lcfirst( $this->getText() )
4369                 );
4370                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4371
4372                 if ( $message->exists() ) {
4373                         return $message->plain();
4374                 } else {
4375                         return false;
4376                 }
4377         }
4378
4379         /**
4380          * Updates page_touched for this page; called from LinksUpdate.php
4381          *
4382          * @param integer $purgeTime TS_MW timestamp [optional]
4383          * @return bool True if the update succeeded
4384          */
4385         public function invalidateCache( $purgeTime = null ) {
4386                 if ( wfReadOnly() ) {
4387                         return false;
4388                 }
4389
4390                 if ( $this->mArticleID === 0 ) {
4391                         return true; // avoid gap locking if we know it's not there
4392                 }
4393
4394                 $method = __METHOD__;
4395                 $dbw = wfGetDB( DB_MASTER );
4396                 $conds = $this->pageCond();
4397                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4398                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4399
4400                         $dbw->update(
4401                                 'page',
4402                                 array( 'page_touched' => $dbTimestamp ),
4403                                 $conds + array( 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ),
4404                                 $method
4405                         );
4406                 } );
4407
4408                 return true;
4409         }
4410
4411         /**
4412          * Update page_touched timestamps and send squid purge messages for
4413          * pages linking to this title. May be sent to the job queue depending
4414          * on the number of links. Typically called on create and delete.
4415          */
4416         public function touchLinks() {
4417                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4418                 $u->doUpdate();
4419
4420                 if ( $this->getNamespace() == NS_CATEGORY ) {
4421                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4422                         $u->doUpdate();
4423                 }
4424         }
4425
4426         /**
4427          * Get the last touched timestamp
4428          *
4429          * @param DatabaseBase $db Optional db
4430          * @return string Last-touched timestamp
4431          */
4432         public function getTouched( $db = null ) {
4433                 if ( $db === null ) {
4434                         $db = wfGetDB( DB_SLAVE );
4435                 }
4436                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4437                 return $touched;
4438         }
4439
4440         /**
4441          * Get the timestamp when this page was updated since the user last saw it.
4442          *
4443          * @param User $user
4444          * @return string|null
4445          */
4446         public function getNotificationTimestamp( $user = null ) {
4447                 global $wgUser;
4448
4449                 // Assume current user if none given
4450                 if ( !$user ) {
4451                         $user = $wgUser;
4452                 }
4453                 // Check cache first
4454                 $uid = $user->getId();
4455                 if ( !$uid ) {
4456                         return false;
4457                 }
4458                 // avoid isset here, as it'll return false for null entries
4459                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4460                         return $this->mNotificationTimestamp[$uid];
4461                 }
4462                 // Don't cache too much!
4463                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4464                         $this->mNotificationTimestamp = array();
4465                 }
4466
4467                 $watchedItem = WatchedItem::fromUserTitle( $user, $this );
4468                 $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4469
4470                 return $this->mNotificationTimestamp[$uid];
4471         }
4472
4473         /**
4474          * Generate strings used for xml 'id' names in monobook tabs
4475          *
4476          * @param string $prepend Defaults to 'nstab-'
4477          * @return string XML 'id' name
4478          */
4479         public function getNamespaceKey( $prepend = 'nstab-' ) {
4480                 global $wgContLang;
4481                 // Gets the subject namespace if this title
4482                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4483                 // Checks if canonical namespace name exists for namespace
4484                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4485                         // Uses canonical namespace name
4486                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4487                 } else {
4488                         // Uses text of namespace
4489                         $namespaceKey = $this->getSubjectNsText();
4490                 }
4491                 // Makes namespace key lowercase
4492                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4493                 // Uses main
4494                 if ( $namespaceKey == '' ) {
4495                         $namespaceKey = 'main';
4496                 }
4497                 // Changes file to image for backwards compatibility
4498                 if ( $namespaceKey == 'file' ) {
4499                         $namespaceKey = 'image';
4500                 }
4501                 return $prepend . $namespaceKey;
4502         }
4503
4504         /**
4505          * Get all extant redirects to this Title
4506          *
4507          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4508          * @return Title[] Array of Title redirects to this title
4509          */
4510         public function getRedirectsHere( $ns = null ) {
4511                 $redirs = array();
4512
4513                 $dbr = wfGetDB( DB_SLAVE );
4514                 $where = array(
4515                         'rd_namespace' => $this->getNamespace(),
4516                         'rd_title' => $this->getDBkey(),
4517                         'rd_from = page_id'
4518                 );
4519                 if ( $this->isExternal() ) {
4520                         $where['rd_interwiki'] = $this->getInterwiki();
4521                 } else {
4522                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4523                 }
4524                 if ( !is_null( $ns ) ) {
4525                         $where['page_namespace'] = $ns;
4526                 }
4527
4528                 $res = $dbr->select(
4529                         array( 'redirect', 'page' ),
4530                         array( 'page_namespace', 'page_title' ),
4531                         $where,
4532                         __METHOD__
4533                 );
4534
4535                 foreach ( $res as $row ) {
4536                         $redirs[] = self::newFromRow( $row );
4537                 }
4538                 return $redirs;
4539         }
4540
4541         /**
4542          * Check if this Title is a valid redirect target
4543          *
4544          * @return bool
4545          */
4546         public function isValidRedirectTarget() {
4547                 global $wgInvalidRedirectTargets;
4548
4549                 if ( $this->isSpecialPage() ) {
4550                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4551                         if ( $this->isSpecial( 'Userlogout' ) ) {
4552                                 return false;
4553                         }
4554
4555                         foreach ( $wgInvalidRedirectTargets as $target ) {
4556                                 if ( $this->isSpecial( $target ) ) {
4557                                         return false;
4558                                 }
4559                         }
4560                 }
4561
4562                 return true;
4563         }
4564
4565         /**
4566          * Get a backlink cache object
4567          *
4568          * @return BacklinkCache
4569          */
4570         public function getBacklinkCache() {
4571                 return BacklinkCache::get( $this );
4572         }
4573
4574         /**
4575          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4576          *
4577          * @return bool
4578          */
4579         public function canUseNoindex() {
4580                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4581
4582                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4583                         ? $wgContentNamespaces
4584                         : $wgExemptFromUserRobotsControl;
4585
4586                 return !in_array( $this->mNamespace, $bannedNamespaces );
4587
4588         }
4589
4590         /**
4591          * Returns the raw sort key to be used for categories, with the specified
4592          * prefix.  This will be fed to Collation::getSortKey() to get a
4593          * binary sortkey that can be used for actual sorting.
4594          *
4595          * @param string $prefix The prefix to be used, specified using
4596          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4597          *   prefix.
4598          * @return string
4599          */
4600         public function getCategorySortkey( $prefix = '' ) {
4601                 $unprefixed = $this->getText();
4602
4603                 // Anything that uses this hook should only depend
4604                 // on the Title object passed in, and should probably
4605                 // tell the users to run updateCollations.php --force
4606                 // in order to re-sort existing category relations.
4607                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4608                 if ( $prefix !== '' ) {
4609                         # Separate with a line feed, so the unprefixed part is only used as
4610                         # a tiebreaker when two pages have the exact same prefix.
4611                         # In UCA, tab is the only character that can sort above LF
4612                         # so we strip both of them from the original prefix.
4613                         $prefix = strtr( $prefix, "\n\t", '  ' );
4614                         return "$prefix\n$unprefixed";
4615                 }
4616                 return $unprefixed;
4617         }
4618
4619         /**
4620          * Get the language in which the content of this page is written in
4621          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4622          * e.g. $wgLang (such as special pages, which are in the user language).
4623          *
4624          * @since 1.18
4625          * @return Language
4626          */
4627         public function getPageLanguage() {
4628                 global $wgLang, $wgLanguageCode;
4629                 if ( $this->isSpecialPage() ) {
4630                         // special pages are in the user language
4631                         return $wgLang;
4632                 }
4633
4634                 // Checking if DB language is set
4635                 if ( $this->mDbPageLanguage ) {
4636                         return wfGetLangObj( $this->mDbPageLanguage );
4637                 }
4638
4639                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4640                         // Note that this may depend on user settings, so the cache should
4641                         // be only per-request.
4642                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4643                         // content to determine the page language!
4644                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4645                         // tests.
4646                         $contentHandler = ContentHandler::getForTitle( $this );
4647                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4648                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4649                 } else {
4650                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4651                 }
4652
4653                 return $langObj;
4654         }
4655
4656         /**
4657          * Get the language in which the content of this page is written when
4658          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4659          * e.g. $wgLang (such as special pages, which are in the user language).
4660          *
4661          * @since 1.20
4662          * @return Language
4663          */
4664         public function getPageViewLanguage() {
4665                 global $wgLang;
4666
4667                 if ( $this->isSpecialPage() ) {
4668                         // If the user chooses a variant, the content is actually
4669                         // in a language whose code is the variant code.
4670                         $variant = $wgLang->getPreferredVariant();
4671                         if ( $wgLang->getCode() !== $variant ) {
4672                                 return Language::factory( $variant );
4673                         }
4674
4675                         return $wgLang;
4676                 }
4677
4678                 // @note Can't be cached persistently, depends on user settings.
4679                 // @note ContentHandler::getPageViewLanguage() may need to load the
4680                 //   content to determine the page language!
4681                 $contentHandler = ContentHandler::getForTitle( $this );
4682                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4683                 return $pageLang;
4684         }
4685
4686         /**
4687          * Get a list of rendered edit notices for this page.
4688          *
4689          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4690          * they will already be wrapped in paragraphs.
4691          *
4692          * @since 1.21
4693          * @param int $oldid Revision ID that's being edited
4694          * @return array
4695          */
4696         public function getEditNotices( $oldid = 0 ) {
4697                 $notices = array();
4698
4699                 // Optional notice for the entire namespace
4700                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4701                 $msg = wfMessage( $editnotice_ns );
4702                 if ( $msg->exists() ) {
4703                         $html = $msg->parseAsBlock();
4704                         // Edit notices may have complex logic, but output nothing (T91715)
4705                         if ( trim( $html ) !== '' ) {
4706                                 $notices[$editnotice_ns] = Html::rawElement(
4707                                         'div',
4708                                         array( 'class' => array(
4709                                                 'mw-editnotice',
4710                                                 'mw-editnotice-namespace',
4711                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4712                                         ) ),
4713                                         $html
4714                                 );
4715                         }
4716                 }
4717
4718                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4719                         // Optional notice for page itself and any parent page
4720                         $parts = explode( '/', $this->getDBkey() );
4721                         $editnotice_base = $editnotice_ns;
4722                         while ( count( $parts ) > 0 ) {
4723                                 $editnotice_base .= '-' . array_shift( $parts );
4724                                 $msg = wfMessage( $editnotice_base );
4725                                 if ( $msg->exists() ) {
4726                                         $html = $msg->parseAsBlock();
4727                                         if ( trim( $html ) !== '' ) {
4728                                                 $notices[$editnotice_base] = Html::rawElement(
4729                                                         'div',
4730                                                         array( 'class' => array(
4731                                                                 'mw-editnotice',
4732                                                                 'mw-editnotice-base',
4733                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4734                                                         ) ),
4735                                                         $html
4736                                                 );
4737                                         }
4738                                 }
4739                         }
4740                 } else {
4741                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4742                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4743                         $msg = wfMessage( $editnoticeText );
4744                         if ( $msg->exists() ) {
4745                                 $html = $msg->parseAsBlock();
4746                                 if ( trim( $html ) !== '' ) {
4747                                         $notices[$editnoticeText] = Html::rawElement(
4748                                                 'div',
4749                                                 array( 'class' => array(
4750                                                         'mw-editnotice',
4751                                                         'mw-editnotice-page',
4752                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4753                                                 ) ),
4754                                                 $html
4755                                         );
4756                                 }
4757                         }
4758                 }
4759
4760                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4761                 return $notices;
4762         }
4763
4764         /**
4765          * @return array
4766          */
4767         public function __sleep() {
4768                 return array(
4769                         'mNamespace',
4770                         'mDbkeyform',
4771                         'mFragment',
4772                         'mInterwiki',
4773                         'mLocalInterwiki',
4774                         'mUserCaseDBKey',
4775                         'mDefaultNamespace',
4776                 );
4777         }
4778
4779         public function __wakeup() {
4780                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4781                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4782                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4783         }
4784
4785 }