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 implements LinkTarget {
  34         /** @var HashBagOStuff */
  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         /** @var int The page length, 0 for special pages */
 134         protected $mLength = -1;
 135
 136         /** @var null Is the article at this title a redirect? */
 137         public $mRedirect = null;
 138
 139         /** @var array Associative array of user ID -> timestamp/false */
 140         private $mNotificationTimestamp = array();
 141
 142         /** @var bool Whether a page has any subpages */
 143         private $mHasSubpages;
 144
 145         /** @var bool The (string) language code of the page's language and content code. */
 146         private $mPageLanguage = false;
 147
 148         /** @var string The page language code from the database */
 149         private $mDbPageLanguage = null;
 150
 151         /** @var TitleValue A corresponding TitleValue object */
 152         private $mTitleValue = null;
 153
 154         /** @var bool Would deleting this page be a big deletion? */
 155         private $mIsBigDeletion = null;
 156         // @}
 157
 158         /**
 159          * B/C kludge: provide a TitleParser for use by Title.
 160          * Ideally, Title would have no methods that need this.
 161          * Avoid usage of this singleton by using TitleValue
 162          * and the associated services when possible.
 163          *
 164          * @return TitleParser
 165          */
 166         private static function getTitleParser() {
 167                 global $wgContLang, $wgLocalInterwikis;
 168
 169                 static $titleCodec = null;
 170                 static $titleCodecFingerprint = null;
 171
 172                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 173                 // make sure we are using the right one. To detect changes over the course
 174                 // of a request, we remember a fingerprint of the config used to create the
 175                 // codec singleton, and re-create it if the fingerprint doesn't match.
 176                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 177
 178                 if ( $fingerprint !== $titleCodecFingerprint ) {
 179                         $titleCodec = null;
 180                 }
 181
 182                 if ( !$titleCodec ) {
 183                         $titleCodec = new MediaWikiTitleCodec(
 184                                 $wgContLang,
 185                                 GenderCache::singleton(),
 186                                 $wgLocalInterwikis
 187                         );
 188                         $titleCodecFingerprint = $fingerprint;
 189                 }
 190
 191                 return $titleCodec;
 192         }
 193
 194         /**
 195          * B/C kludge: provide a TitleParser for use by Title.
 196          * Ideally, Title would have no methods that need this.
 197          * Avoid usage of this singleton by using TitleValue
 198          * and the associated services when possible.
 199          *
 200          * @return TitleFormatter
 201          */
 202         private static function getTitleFormatter() {
 203                 // NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 204                 //      which implements TitleFormatter.
 205                 return self::getTitleParser();
 206         }
 207
 208         function __construct() {
 209         }
 210
 211         /**
 212          * Create a new Title from a prefixed DB key
 213          *
 214          * @param string $key The database key, which has underscores
 215          *      instead of spaces, possibly including namespace and
 216          *      interwiki prefixes
 217          * @return Title|null Title, or null on an error
 218          */
 219         public static function newFromDBkey( $key ) {
 220                 $t = new Title();
 221                 $t->mDbkeyform = $key;
 222
 223                 try {
 224                         $t->secureAndSplit();
 225                         return $t;
 226                 } catch ( MalformedTitleException $ex ) {
 227                         return null;
 228                 }
 229         }
 230
 231         /**
 232          * Create a new Title from a TitleValue
 233          *
 234          * @param TitleValue $titleValue Assumed to be safe.
 235          *
 236          * @return Title
 237          */
 238         public static function newFromTitleValue( TitleValue $titleValue ) {
 239                 return self::newFromLinkTarget( $titleValue );
 240         }
 241
 242         /**
 243          * Create a new Title from a LinkTarget
 244          *
 245          * @param LinkTarget $linkTarget Assumed to be safe.
 246          *
 247          * @return Title
 248          */
 249         public static function newFromLinkTarget( LinkTarget $linkTarget ) {
 250                 return self::makeTitle(
 251                         $linkTarget->getNamespace(),
 252                         $linkTarget->getText(),
 253                         $linkTarget->getFragment() );
 254         }
 255
 256         /**
 257          * Create a new Title from text, such as what one would find in a link. De-
 258          * codes any HTML entities in the text.
 259          *
 260          * @param string|null $text The link text; spaces, prefixes, and an
 261          *   initial ':' indicating the main namespace are accepted.
 262          * @param int $defaultNamespace The namespace to use if none is specified
 263          *   by a prefix.  If you want to force a specific namespace even if
 264          *   $text might begin with a namespace prefix, use makeTitle() or
 265          *   makeTitleSafe().
 266          * @throws InvalidArgumentException
 267          * @return Title|null Title or null on an error.
 268          */
 269         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 270                 if ( is_object( $text ) ) {
 271                         throw new InvalidArgumentException( '$text must be a string.' );
 272                 }
 273                 if ( $text !== null && !is_string( $text ) ) {
 274                         wfDebugLog( 'T76305', wfGetAllCallers( 5 ) );
 275                         return null;
 276                 }
 277                 if ( $text === null ) {
 278                         return null;
 279                 }
 280
 281                 try {
 282                         return Title::newFromTextThrow( $text, $defaultNamespace );
 283                 } catch ( MalformedTitleException $ex ) {
 284                         return null;
 285                 }
 286         }
 287
 288         /**
 289          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 290          * rather than returning null.
 291          *
 292          * The exception subclasses encode detailed information about why the title is invalid.
 293          *
 294          * @see Title::newFromText
 295          *
 296          * @since 1.25
 297          * @param string $text Title text to check
 298          * @param int $defaultNamespace
 299          * @throws MalformedTitleException If the title is invalid
 300          * @return Title
 301          */
 302         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 303                 if ( is_object( $text ) ) {
 304                         throw new MWException( '$text must be a string, given an object' );
 305                 }
 306
 307                 $titleCache = self::getTitleCache();
 308
 309                 // Wiki pages often contain multiple links to the same page.
 310                 // Title normalization and parsing can become expensive on pages with many
 311                 // links, so we can save a little time by caching them.
 312                 // In theory these are value objects and won't get changed...
 313                 if ( $defaultNamespace == NS_MAIN ) {
 314                         $t = $titleCache->get( $text );
 315                         if ( $t ) {
 316                                 return $t;
 317                         }
 318                 }
 319
 320                 // Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 321                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 322
 323                 $t = new Title();
 324                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 325                 $t->mDefaultNamespace = intval( $defaultNamespace );
 326
 327                 $t->secureAndSplit();
 328                 if ( $defaultNamespace == NS_MAIN ) {
 329                         $titleCache->set( $text, $t );
 330                 }
 331                 return $t;
 332         }
 333
 334         /**
 335          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 336          *
 337          * Example of wrong and broken code:
 338          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 339          *
 340          * Example of right code:
 341          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 342          *
 343          * Create a new Title from URL-encoded text. Ensures that
 344          * the given title's length does not exceed the maximum.
 345          *
 346          * @param string $url The title, as might be taken from a URL
 347          * @return Title|null The new object, or null on an error
 348          */
 349         public static function newFromURL( $url ) {
 350                 $t = new Title();
 351
 352                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 353                 # but some URLs used it as a space replacement and they still come
 354                 # from some external search tools.
 355                 if ( strpos( self::legalChars(), '+' ) === false ) {
 356                         $url = strtr( $url, '+', ' ' );
 357                 }
 358
 359                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 360
 361                 try {
 362                         $t->secureAndSplit();
 363                         return $t;
 364                 } catch ( MalformedTitleException $ex ) {
 365                         return null;
 366                 }
 367         }
 368
 369         /**
 370          * @return HashBagOStuff
 371          */
 372         private static function getTitleCache() {
 373                 if ( self::$titleCache == null ) {
 374                         self::$titleCache = new HashBagOStuff( array( 'maxKeys' => self::CACHE_MAX ) );
 375                 }
 376                 return self::$titleCache;
 377         }
 378
 379         /**
 380          * Returns a list of fields that are to be selected for initializing Title
 381          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 382          * whether to include page_content_model.
 383          *
 384          * @return array
 385          */
 386         protected static function getSelectFields() {
 387                 global $wgContentHandlerUseDB;
 388
 389                 $fields = array(
 390                         'page_namespace', 'page_title', 'page_id',
 391                         'page_len', 'page_is_redirect', 'page_latest',
 392                 );
 393
 394                 if ( $wgContentHandlerUseDB ) {
 395                         $fields[] = 'page_content_model';
 396                 }
 397
 398                 return $fields;
 399         }
 400
 401         /**
 402          * Create a new Title from an article ID
 403          *
 404          * @param int $id The page_id corresponding to the Title to create
 405          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 406          * @return Title|null The new object, or null on an error
 407          */
 408         public static function newFromID( $id, $flags = 0 ) {
 409                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 410                 $row = $db->selectRow(
 411                         'page',
 412                         self::getSelectFields(),
 413                         array( 'page_id' => $id ),
 414                         __METHOD__
 415                 );
 416                 if ( $row !== false ) {
 417                         $title = Title::newFromRow( $row );
 418                 } else {
 419                         $title = null;
 420                 }
 421                 return $title;
 422         }
 423
 424         /**
 425          * Make an array of titles from an array of IDs
 426          *
 427          * @param int[] $ids Array of IDs
 428          * @return Title[] Array of Titles
 429          */
 430         public static function newFromIDs( $ids ) {
 431                 if ( !count( $ids ) ) {
 432                         return array();
 433                 }
 434                 $dbr = wfGetDB( DB_SLAVE );
 435
 436                 $res = $dbr->select(
 437                         'page',
 438                         self::getSelectFields(),
 439                         array( 'page_id' => $ids ),
 440                         __METHOD__
 441                 );
 442
 443                 $titles = array();
 444                 foreach ( $res as $row ) {
 445                         $titles[] = Title::newFromRow( $row );
 446                 }
 447                 return $titles;
 448         }
 449
 450         /**
 451          * Make a Title object from a DB row
 452          *
 453          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 454          * @return Title Corresponding Title
 455          */
 456         public static function newFromRow( $row ) {
 457                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 458                 $t->loadFromRow( $row );
 459                 return $t;
 460         }
 461
 462         /**
 463          * Load Title object fields from a DB row.
 464          * If false is given, the title will be treated as non-existing.
 465          *
 466          * @param stdClass|bool $row Database row
 467          */
 468         public function loadFromRow( $row ) {
 469                 if ( $row ) { // page found
 470                         if ( isset( $row->page_id ) ) {
 471                                 $this->mArticleID = (int)$row->page_id;
 472                         }
 473                         if ( isset( $row->page_len ) ) {
 474                                 $this->mLength = (int)$row->page_len;
 475                         }
 476                         if ( isset( $row->page_is_redirect ) ) {
 477                                 $this->mRedirect = (bool)$row->page_is_redirect;
 478                         }
 479                         if ( isset( $row->page_latest ) ) {
 480                                 $this->mLatestID = (int)$row->page_latest;
 481                         }
 482                         if ( isset( $row->page_content_model ) ) {
 483                                 $this->mContentModel = strval( $row->page_content_model );
 484                         } else {
 485                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 486                         }
 487                         if ( isset( $row->page_lang ) ) {
 488                                 $this->mDbPageLanguage = (string)$row->page_lang;
 489                         }
 490                         if ( isset( $row->page_restrictions ) ) {
 491                                 $this->mOldRestrictions = $row->page_restrictions;
 492                         }
 493                 } else { // page not found
 494                         $this->mArticleID = 0;
 495                         $this->mLength = 0;
 496                         $this->mRedirect = false;
 497                         $this->mLatestID = 0;
 498                         $this->mContentModel = false; # initialized lazily in getContentModel()
 499                 }
 500         }
 501
 502         /**
 503          * Create a new Title from a namespace index and a DB key.
 504          * It's assumed that $ns and $title are *valid*, for instance when
 505          * they came directly from the database or a special page name.
 506          * For convenience, spaces are converted to underscores so that
 507          * eg user_text fields can be used directly.
 508          *
 509          * @param int $ns The namespace of the article
 510          * @param string $title The unprefixed database key form
 511          * @param string $fragment The link fragment (after the "#")
 512          * @param string $interwiki The interwiki prefix
 513          * @return Title The new object
 514          */
 515         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 516                 $t = new Title();
 517                 $t->mInterwiki = $interwiki;
 518                 $t->mFragment = $fragment;
 519                 $t->mNamespace = $ns = intval( $ns );
 520                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 521                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 522                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 523                 $t->mTextform = strtr( $title, '_', ' ' );
 524                 $t->mContentModel = false; # initialized lazily in getContentModel()
 525                 return $t;
 526         }
 527
 528         /**
 529          * Create a new Title from a namespace index and a DB key.
 530          * The parameters will be checked for validity, which is a bit slower
 531          * than makeTitle() but safer for user-provided data.
 532          *
 533          * @param int $ns The namespace of the article
 534          * @param string $title Database key form
 535          * @param string $fragment The link fragment (after the "#")
 536          * @param string $interwiki Interwiki prefix
 537          * @return Title|null The new object, or null on an error
 538          */
 539         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 540                 if ( !MWNamespace::exists( $ns ) ) {
 541                         return null;
 542                 }
 543
 544                 $t = new Title();
 545                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 546
 547                 try {
 548                         $t->secureAndSplit();
 549                         return $t;
 550                 } catch ( MalformedTitleException $ex ) {
 551                         return null;
 552                 }
 553         }
 554
 555         /**
 556          * Create a new Title for the Main Page
 557          *
 558          * @return Title The new object
 559          */
 560         public static function newMainPage() {
 561                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 562                 // Don't give fatal errors if the message is broken
 563                 if ( !$title ) {
 564                         $title = Title::newFromText( 'Main Page' );
 565                 }
 566                 return $title;
 567         }
 568
 569         /**
 570          * Extract a redirect destination from a string and return the
 571          * Title, or null if the text doesn't contain a valid redirect
 572          * This will only return the very next target, useful for
 573          * the redirect table and other checks that don't need full recursion
 574          *
 575          * @param string $text Text with possible redirect
 576          * @return Title The corresponding Title
 577          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 578          */
 579         public static function newFromRedirect( $text ) {
 580                 ContentHandler::deprecated( __METHOD__, '1.21' );
 581
 582                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 583                 return $content->getRedirectTarget();
 584         }
 585
 586         /**
 587          * Extract a redirect destination from a string and return the
 588          * Title, or null if the text doesn't contain a valid redirect
 589          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 590          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 591          *
 592          * @param string $text Text with possible redirect
 593          * @return Title
 594          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 595          */
 596         public static function newFromRedirectRecurse( $text ) {
 597                 ContentHandler::deprecated( __METHOD__, '1.21' );
 598
 599                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 600                 return $content->getUltimateRedirectTarget();
 601         }
 602
 603         /**
 604          * Extract a redirect destination from a string and return an
 605          * array of Titles, or null if the text doesn't contain a valid redirect
 606          * The last element in the array is the final destination after all redirects
 607          * have been resolved (up to $wgMaxRedirects times)
 608          *
 609          * @param string $text Text with possible redirect
 610          * @return Title[] Array of Titles, with the destination last
 611          * @deprecated since 1.21, use Content::getRedirectChain instead.
 612          */
 613         public static function newFromRedirectArray( $text ) {
 614                 ContentHandler::deprecated( __METHOD__, '1.21' );
 615
 616                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 617                 return $content->getRedirectChain();
 618         }
 619
 620         /**
 621          * Get the prefixed DB key associated with an ID
 622          *
 623          * @param int $id The page_id of the article
 624          * @return Title|null An object representing the article, or null if no such article was found
 625          */
 626         public static function nameOf( $id ) {
 627                 $dbr = wfGetDB( DB_SLAVE );
 628
 629                 $s = $dbr->selectRow(
 630                         'page',
 631                         array( 'page_namespace', 'page_title' ),
 632                         array( 'page_id' => $id ),
 633                         __METHOD__
 634                 );
 635                 if ( $s === false ) {
 636                         return null;
 637                 }
 638
 639                 $n = self::makeName( $s->page_namespace, $s->page_title );
 640                 return $n;
 641         }
 642
 643         /**
 644          * Get a regex character class describing the legal characters in a link
 645          *
 646          * @return string The list of characters, not delimited
 647          */
 648         public static function legalChars() {
 649                 global $wgLegalTitleChars;
 650                 return $wgLegalTitleChars;
 651         }
 652
 653         /**
 654          * Returns a simple regex that will match on characters and sequences invalid in titles.
 655          * Note that this doesn't pick up many things that could be wrong with titles, but that
 656          * replacing this regex with something valid will make many titles valid.
 657          *
 658          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 659          *
 660          * @return string Regex string
 661          */
 662         static function getTitleInvalidRegex() {
 663                 wfDeprecated( __METHOD__, '1.25' );
 664                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 665         }
 666
 667         /**
 668          * Utility method for converting a character sequence from bytes to Unicode.
 669          *
 670          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 671          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 672          *
 673          * @param string $byteClass
 674          * @return string
 675          */
 676         public static function convertByteClassToUnicodeClass( $byteClass ) {
 677                 $length = strlen( $byteClass );
 678                 // Input token queue
 679                 $x0 = $x1 = $x2 = '';
 680                 // Decoded queue
 681                 $d0 = $d1 = $d2 = '';
 682                 // Decoded integer codepoints
 683                 $ord0 = $ord1 = $ord2 = 0;
 684                 // Re-encoded queue
 685                 $r0 = $r1 = $r2 = '';
 686                 // Output
 687                 $out = '';
 688                 // Flags
 689                 $allowUnicode = false;
 690                 for ( $pos = 0; $pos < $length; $pos++ ) {
 691                         // Shift the queues down
 692                         $x2 = $x1;
 693                         $x1 = $x0;
 694                         $d2 = $d1;
 695                         $d1 = $d0;
 696                         $ord2 = $ord1;
 697                         $ord1 = $ord0;
 698                         $r2 = $r1;
 699                         $r1 = $r0;
 700                         // Load the current input token and decoded values
 701                         $inChar = $byteClass[$pos];
 702                         if ( $inChar == '\\' ) {
 703                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 704                                         $x0 = $inChar . $m[0];
 705                                         $d0 = chr( hexdec( $m[1] ) );
 706                                         $pos += strlen( $m[0] );
 707                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 708                                         $x0 = $inChar . $m[0];
 709                                         $d0 = chr( octdec( $m[0] ) );
 710                                         $pos += strlen( $m[0] );
 711                                 } elseif ( $pos + 1 >= $length ) {
 712                                         $x0 = $d0 = '\\';
 713                                 } else {
 714                                         $d0 = $byteClass[$pos + 1];
 715                                         $x0 = $inChar . $d0;
 716                                         $pos += 1;
 717                                 }
 718                         } else {
 719                                 $x0 = $d0 = $inChar;
 720                         }
 721                         $ord0 = ord( $d0 );
 722                         // Load the current re-encoded value
 723                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 724                                 $r0 = sprintf( '\x%02x', $ord0 );
 725                         } elseif ( $ord0 >= 0x80 ) {
 726                                 // Allow unicode if a single high-bit character appears
 727                                 $r0 = sprintf( '\x%02x', $ord0 );
 728                                 $allowUnicode = true;
 729                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 730                                 $r0 = '\\' . $d0;
 731                         } else {
 732                                 $r0 = $d0;
 733                         }
 734                         // Do the output
 735                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 736                                 // Range
 737                                 if ( $ord2 > $ord0 ) {
 738                                         // Empty range
 739                                 } elseif ( $ord0 >= 0x80 ) {
 740                                         // Unicode range
 741                                         $allowUnicode = true;
 742                                         if ( $ord2 < 0x80 ) {
 743                                                 // Keep the non-unicode section of the range
 744                                                 $out .= "$r2-\\x7F";
 745                                         }
 746                                 } else {
 747                                         // Normal range
 748                                         $out .= "$r2-$r0";
 749                                 }
 750                                 // Reset state to the initial value
 751                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 752                         } elseif ( $ord2 < 0x80 ) {
 753                                 // ASCII character
 754                                 $out .= $r2;
 755                         }
 756                 }
 757                 if ( $ord1 < 0x80 ) {
 758                         $out .= $r1;
 759                 }
 760                 if ( $ord0 < 0x80 ) {
 761                         $out .= $r0;
 762                 }
 763                 if ( $allowUnicode ) {
 764                         $out .= '\u0080-\uFFFF';
 765                 }
 766                 return $out;
 767         }
 768
 769         /**
 770          * Make a prefixed DB key from a DB key and a namespace index
 771          *
 772          * @param int $ns Numerical representation of the namespace
 773          * @param string $title The DB key form the title
 774          * @param string $fragment The link fragment (after the "#")
 775          * @param string $interwiki The interwiki prefix
 776          * @param bool $canonicalNamespace If true, use the canonical name for
 777          *   $ns instead of the localized version.
 778          * @return string The prefixed form of the title
 779          */
 780         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 781                 $canonicalNamespace = false
 782         ) {
 783                 global $wgContLang;
 784
 785                 if ( $canonicalNamespace ) {
 786                         $namespace = MWNamespace::getCanonicalName( $ns );
 787                 } else {
 788                         $namespace = $wgContLang->getNsText( $ns );
 789                 }
 790                 $name = $namespace == '' ? $title : "$namespace:$title";
 791                 if ( strval( $interwiki ) != '' ) {
 792                         $name = "$interwiki:$name";
 793                 }
 794                 if ( strval( $fragment ) != '' ) {
 795                         $name .= '#' . $fragment;
 796                 }
 797                 return $name;
 798         }
 799
 800         /**
 801          * Escape a text fragment, say from a link, for a URL
 802          *
 803          * @param string $fragment Containing a URL or link fragment (after the "#")
 804          * @return string Escaped string
 805          */
 806         static function escapeFragmentForURL( $fragment ) {
 807                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 808                 # fragments appear not to work in IE (at least up to 7) or in at least
 809                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 810                 # to care if they aren't encoded.
 811                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 812         }
 813
 814         /**
 815          * Callback for usort() to do title sorts by (namespace, title)
 816          *
 817          * @param Title $a
 818          * @param Title $b
 819          *
 820          * @return int Result of string comparison, or namespace comparison
 821          */
 822         public static function compare( $a, $b ) {
 823                 if ( $a->getNamespace() == $b->getNamespace() ) {
 824                         return strcmp( $a->getText(), $b->getText() );
 825                 } else {
 826                         return $a->getNamespace() - $b->getNamespace();
 827                 }
 828         }
 829
 830         /**
 831          * Determine whether the object refers to a page within
 832          * this project (either this wiki or a wiki with a local
 833          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 834          *
 835          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 836          */
 837         public function isLocal() {
 838                 if ( $this->isExternal() ) {
 839                         $iw = Interwiki::fetch( $this->mInterwiki );
 840                         if ( $iw ) {
 841                                 return $iw->isLocal();
 842                         }
 843                 }
 844                 return true;
 845         }
 846
 847         /**
 848          * Is this Title interwiki?
 849          *
 850          * @return bool
 851          */
 852         public function isExternal() {
 853                 return $this->mInterwiki !== '';
 854         }
 855
 856         /**
 857          * Get the interwiki prefix
 858          *
 859          * Use Title::isExternal to check if a interwiki is set
 860          *
 861          * @return string Interwiki prefix
 862          */
 863         public function getInterwiki() {
 864                 return $this->mInterwiki;
 865         }
 866
 867         /**
 868          * Was this a local interwiki link?
 869          *
 870          * @return bool
 871          */
 872         public function wasLocalInterwiki() {
 873                 return $this->mLocalInterwiki;
 874         }
 875
 876         /**
 877          * Determine whether the object refers to a page within
 878          * this project and is transcludable.
 879          *
 880          * @return bool True if this is transcludable
 881          */
 882         public function isTrans() {
 883                 if ( !$this->isExternal() ) {
 884                         return false;
 885                 }
 886
 887                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 888         }
 889
 890         /**
 891          * Returns the DB name of the distant wiki which owns the object.
 892          *
 893          * @return string The DB name
 894          */
 895         public function getTransWikiID() {
 896                 if ( !$this->isExternal() ) {
 897                         return false;
 898                 }
 899
 900                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 901         }
 902
 903         /**
 904          * Get a TitleValue object representing this Title.
 905          *
 906          * @note Not all valid Titles have a corresponding valid TitleValue
 907          * (e.g. TitleValues cannot represent page-local links that have a
 908          * fragment but no title text).
 909          *
 910          * @return TitleValue|null
 911          */
 912         public function getTitleValue() {
 913                 if ( $this->mTitleValue === null ) {
 914                         try {
 915                                 $this->mTitleValue = new TitleValue(
 916                                         $this->getNamespace(),
 917                                         $this->getDBkey(),
 918                                         $this->getFragment() );
 919                         } catch ( InvalidArgumentException $ex ) {
 920                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 921                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 922                         }
 923                 }
 924
 925                 return $this->mTitleValue;
 926         }
 927
 928         /**
 929          * Get the text form (spaces not underscores) of the main part
 930          *
 931          * @return string Main part of the title
 932          */
 933         public function getText() {
 934                 return $this->mTextform;
 935         }
 936
 937         /**
 938          * Get the URL-encoded form of the main part
 939          *
 940          * @return string Main part of the title, URL-encoded
 941          */
 942         public function getPartialURL() {
 943                 return $this->mUrlform;
 944         }
 945
 946         /**
 947          * Get the main part with underscores
 948          *
 949          * @return string Main part of the title, with underscores
 950          */
 951         public function getDBkey() {
 952                 return $this->mDbkeyform;
 953         }
 954
 955         /**
 956          * Get the DB key with the initial letter case as specified by the user
 957          *
 958          * @return string DB key
 959          */
 960         function getUserCaseDBKey() {
 961                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 962                         return $this->mUserCaseDBKey;
 963                 } else {
 964                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 965                         return $this->mDbkeyform;
 966                 }
 967         }
 968
 969         /**
 970          * Get the namespace index, i.e. one of the NS_xxxx constants.
 971          *
 972          * @return int Namespace index
 973          */
 974         public function getNamespace() {
 975                 return $this->mNamespace;
 976         }
 977
 978         /**
 979          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 980          *
 981          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 982          * @return string Content model id
 983          */
 984         public function getContentModel( $flags = 0 ) {
 985                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 986                         $linkCache = LinkCache::singleton();
 987                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 988                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 989                 }
 990
 991                 if ( !$this->mContentModel ) {
 992                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 993                 }
 994
 995                 return $this->mContentModel;
 996         }
 997
 998         /**
 999          * Convenience method for checking a title's content model name
1000          *
1001          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
1002          * @return bool True if $this->getContentModel() == $id
1003          */
1004         public function hasContentModel( $id ) {
1005                 return $this->getContentModel() == $id;
1006         }
1007
1008         /**
1009          * Get the namespace text
1010          *
1011          * @return string Namespace text
1012          */
1013         public function getNsText() {
1014                 if ( $this->isExternal() ) {
1015                         // This probably shouldn't even happen,
1016                         // but for interwiki transclusion it sometimes does.
1017                         // Use the canonical namespaces if possible to try to
1018                         // resolve a foreign namespace.
1019                         if ( MWNamespace::exists( $this->mNamespace ) ) {
1020                                 return MWNamespace::getCanonicalName( $this->mNamespace );
1021                         }
1022                 }
1023
1024                 try {
1025                         $formatter = self::getTitleFormatter();
1026                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
1027                 } catch ( InvalidArgumentException $ex ) {
1028                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1029                         return false;
1030                 }
1031         }
1032
1033         /**
1034          * Get the namespace text of the subject (rather than talk) page
1035          *
1036          * @return string Namespace text
1037          */
1038         public function getSubjectNsText() {
1039                 global $wgContLang;
1040                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1041         }
1042
1043         /**
1044          * Get the namespace text of the talk page
1045          *
1046          * @return string Namespace text
1047          */
1048         public function getTalkNsText() {
1049                 global $wgContLang;
1050                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1051         }
1052
1053         /**
1054          * Could this title have a corresponding talk page?
1055          *
1056          * @return bool
1057          */
1058         public function canTalk() {
1059                 return MWNamespace::canTalk( $this->mNamespace );
1060         }
1061
1062         /**
1063          * Is this in a namespace that allows actual pages?
1064          *
1065          * @return bool
1066          */
1067         public function canExist() {
1068                 return $this->mNamespace >= NS_MAIN;
1069         }
1070
1071         /**
1072          * Can this title be added to a user's watchlist?
1073          *
1074          * @return bool
1075          */
1076         public function isWatchable() {
1077                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1078         }
1079
1080         /**
1081          * Returns true if this is a special page.
1082          *
1083          * @return bool
1084          */
1085         public function isSpecialPage() {
1086                 return $this->getNamespace() == NS_SPECIAL;
1087         }
1088
1089         /**
1090          * Returns true if this title resolves to the named special page
1091          *
1092          * @param string $name The special page name
1093          * @return bool
1094          */
1095         public function isSpecial( $name ) {
1096                 if ( $this->isSpecialPage() ) {
1097                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1098                         if ( $name == $thisName ) {
1099                                 return true;
1100                         }
1101                 }
1102                 return false;
1103         }
1104
1105         /**
1106          * If the Title refers to a special page alias which is not the local default, resolve
1107          * the alias, and localise the name as necessary.  Otherwise, return $this
1108          *
1109          * @return Title
1110          */
1111         public function fixSpecialName() {
1112                 if ( $this->isSpecialPage() ) {
1113                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1114                         if ( $canonicalName ) {
1115                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1116                                 if ( $localName != $this->mDbkeyform ) {
1117                                         return Title::makeTitle( NS_SPECIAL, $localName );
1118                                 }
1119                         }
1120                 }
1121                 return $this;
1122         }
1123
1124         /**
1125          * Returns true if the title is inside the specified namespace.
1126          *
1127          * Please make use of this instead of comparing to getNamespace()
1128          * This function is much more resistant to changes we may make
1129          * to namespaces than code that makes direct comparisons.
1130          * @param int $ns The namespace
1131          * @return bool
1132          * @since 1.19
1133          */
1134         public function inNamespace( $ns ) {
1135                 return MWNamespace::equals( $this->getNamespace(), $ns );
1136         }
1137
1138         /**
1139          * Returns true if the title is inside one of the specified namespaces.
1140          *
1141          * @param int $namespaces,... The namespaces to check for
1142          * @return bool
1143          * @since 1.19
1144          */
1145         public function inNamespaces( /* ... */ ) {
1146                 $namespaces = func_get_args();
1147                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1148                         $namespaces = $namespaces[0];
1149                 }
1150
1151                 foreach ( $namespaces as $ns ) {
1152                         if ( $this->inNamespace( $ns ) ) {
1153                                 return true;
1154                         }
1155                 }
1156
1157                 return false;
1158         }
1159
1160         /**
1161          * Returns true if the title has the same subject namespace as the
1162          * namespace specified.
1163          * For example this method will take NS_USER and return true if namespace
1164          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1165          * as their subject namespace.
1166          *
1167          * This is MUCH simpler than individually testing for equivalence
1168          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1169          * @since 1.19
1170          * @param int $ns
1171          * @return bool
1172          */
1173         public function hasSubjectNamespace( $ns ) {
1174                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1175         }
1176
1177         /**
1178          * Is this Title in a namespace which contains content?
1179          * In other words, is this a content page, for the purposes of calculating
1180          * statistics, etc?
1181          *
1182          * @return bool
1183          */
1184         public function isContentPage() {
1185                 return MWNamespace::isContent( $this->getNamespace() );
1186         }
1187
1188         /**
1189          * Would anybody with sufficient privileges be able to move this page?
1190          * Some pages just aren't movable.
1191          *
1192          * @return bool
1193          */
1194         public function isMovable() {
1195                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1196                         // Interwiki title or immovable namespace. Hooks don't get to override here
1197                         return false;
1198                 }
1199
1200                 $result = true;
1201                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1202                 return $result;
1203         }
1204
1205         /**
1206          * Is this the mainpage?
1207          * @note Title::newFromText seems to be sufficiently optimized by the title
1208          * cache that we don't need to over-optimize by doing direct comparisons and
1209          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1210          * ends up reporting something differently than $title->isMainPage();
1211          *
1212          * @since 1.18
1213          * @return bool
1214          */
1215         public function isMainPage() {
1216                 return $this->equals( Title::newMainPage() );
1217         }
1218
1219         /**
1220          * Is this a subpage?
1221          *
1222          * @return bool
1223          */
1224         public function isSubpage() {
1225                 return MWNamespace::hasSubpages( $this->mNamespace )
1226                         ? strpos( $this->getText(), '/' ) !== false
1227                         : false;
1228         }
1229
1230         /**
1231          * Is this a conversion table for the LanguageConverter?
1232          *
1233          * @return bool
1234          */
1235         public function isConversionTable() {
1236                 // @todo ConversionTable should become a separate content model.
1237
1238                 return $this->getNamespace() == NS_MEDIAWIKI &&
1239                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1240         }
1241
1242         /**
1243          * Does that page contain wikitext, or it is JS, CSS or whatever?
1244          *
1245          * @return bool
1246          */
1247         public function isWikitextPage() {
1248                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1249         }
1250
1251         /**
1252          * Could this page contain custom CSS or JavaScript for the global UI.
1253          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1254          * or CONTENT_MODEL_JAVASCRIPT.
1255          *
1256          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1257          * for that!
1258          *
1259          * Note that this method should not return true for pages that contain and
1260          * show "inactive" CSS or JS.
1261          *
1262          * @return bool
1263          */
1264         public function isCssOrJsPage() {
1265                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1266                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1267                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1268
1269                 # @note This hook is also called in ContentHandler::getDefaultModel.
1270                 #   It's called here again to make sure hook functions can force this
1271                 #   method to return true even outside the MediaWiki namespace.
1272
1273                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1274
1275                 return $isCssOrJsPage;
1276         }
1277
1278         /**
1279          * Is this a .css or .js subpage of a user page?
1280          * @return bool
1281          */
1282         public function isCssJsSubpage() {
1283                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1284                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1285                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1286         }
1287
1288         /**
1289          * Trim down a .css or .js subpage title to get the corresponding skin name
1290          *
1291          * @return string Containing skin name from .css or .js subpage title
1292          */
1293         public function getSkinFromCssJsSubpage() {
1294                 $subpage = explode( '/', $this->mTextform );
1295                 $subpage = $subpage[count( $subpage ) - 1];
1296                 $lastdot = strrpos( $subpage, '.' );
1297                 if ( $lastdot === false ) {
1298                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1299                 }
1300                 return substr( $subpage, 0, $lastdot );
1301         }
1302
1303         /**
1304          * Is this a .css subpage of a user page?
1305          *
1306          * @return bool
1307          */
1308         public function isCssSubpage() {
1309                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1310                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1311         }
1312
1313         /**
1314          * Is this a .js subpage of a user page?
1315          *
1316          * @return bool
1317          */
1318         public function isJsSubpage() {
1319                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1320                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1321         }
1322
1323         /**
1324          * Is this a talk page of some sort?
1325          *
1326          * @return bool
1327          */
1328         public function isTalkPage() {
1329                 return MWNamespace::isTalk( $this->getNamespace() );
1330         }
1331
1332         /**
1333          * Get a Title object associated with the talk page of this article
1334          *
1335          * @return Title The object for the talk page
1336          */
1337         public function getTalkPage() {
1338                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1339         }
1340
1341         /**
1342          * Get a title object associated with the subject page of this
1343          * talk page
1344          *
1345          * @return Title The object for the subject page
1346          */
1347         public function getSubjectPage() {
1348                 // Is this the same title?
1349                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1350                 if ( $this->getNamespace() == $subjectNS ) {
1351                         return $this;
1352                 }
1353                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1354         }
1355
1356         /**
1357          * Get the other title for this page, if this is a subject page
1358          * get the talk page, if it is a subject page get the talk page
1359          *
1360          * @since 1.25
1361          * @throws MWException
1362          * @return Title
1363          */
1364         public function getOtherPage() {
1365                 if ( $this->isSpecialPage() ) {
1366                         throw new MWException( 'Special pages cannot have other pages' );
1367                 }
1368                 if ( $this->isTalkPage() ) {
1369                         return $this->getSubjectPage();
1370                 } else {
1371                         return $this->getTalkPage();
1372                 }
1373         }
1374
1375         /**
1376          * Get the default namespace index, for when there is no namespace
1377          *
1378          * @return int Default namespace index
1379          */
1380         public function getDefaultNamespace() {
1381                 return $this->mDefaultNamespace;
1382         }
1383
1384         /**
1385          * Get the Title fragment (i.e.\ the bit after the #) in text form
1386          *
1387          * Use Title::hasFragment to check for a fragment
1388          *
1389          * @return string Title fragment
1390          */
1391         public function getFragment() {
1392                 return $this->mFragment;
1393         }
1394
1395         /**
1396          * Check if a Title fragment is set
1397          *
1398          * @return bool
1399          * @since 1.23
1400          */
1401         public function hasFragment() {
1402                 return $this->mFragment !== '';
1403         }
1404
1405         /**
1406          * Get the fragment in URL form, including the "#" character if there is one
1407          * @return string Fragment in URL form
1408          */
1409         public function getFragmentForURL() {
1410                 if ( !$this->hasFragment() ) {
1411                         return '';
1412                 } else {
1413                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1414                 }
1415         }
1416
1417         /**
1418          * Set the fragment for this title. Removes the first character from the
1419          * specified fragment before setting, so it assumes you're passing it with
1420          * an initial "#".
1421          *
1422          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1423          * Still in active use privately.
1424          *
1425          * @private
1426          * @param string $fragment Text
1427          */
1428         public function setFragment( $fragment ) {
1429                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1430         }
1431
1432         /**
1433          * Prefix some arbitrary text with the namespace or interwiki prefix
1434          * of this object
1435          *
1436          * @param string $name The text
1437          * @return string The prefixed text
1438          */
1439         private function prefix( $name ) {
1440                 $p = '';
1441                 if ( $this->isExternal() ) {
1442                         $p = $this->mInterwiki . ':';
1443                 }
1444
1445                 if ( 0 != $this->mNamespace ) {
1446                         $p .= $this->getNsText() . ':';
1447                 }
1448                 return $p . $name;
1449         }
1450
1451         /**
1452          * Get the prefixed database key form
1453          *
1454          * @return string The prefixed title, with underscores and
1455          *  any interwiki and namespace prefixes
1456          */
1457         public function getPrefixedDBkey() {
1458                 $s = $this->prefix( $this->mDbkeyform );
1459                 $s = strtr( $s, ' ', '_' );
1460                 return $s;
1461         }
1462
1463         /**
1464          * Get the prefixed title with spaces.
1465          * This is the form usually used for display
1466          *
1467          * @return string The prefixed title, with spaces
1468          */
1469         public function getPrefixedText() {
1470                 if ( $this->mPrefixedText === null ) {
1471                         $s = $this->prefix( $this->mTextform );
1472                         $s = strtr( $s, '_', ' ' );
1473                         $this->mPrefixedText = $s;
1474                 }
1475                 return $this->mPrefixedText;
1476         }
1477
1478         /**
1479          * Return a string representation of this title
1480          *
1481          * @return string Representation of this title
1482          */
1483         public function __toString() {
1484                 return $this->getPrefixedText();
1485         }
1486
1487         /**
1488          * Get the prefixed title with spaces, plus any fragment
1489          * (part beginning with '#')
1490          *
1491          * @return string The prefixed title, with spaces and the fragment, including '#'
1492          */
1493         public function getFullText() {
1494                 $text = $this->getPrefixedText();
1495                 if ( $this->hasFragment() ) {
1496                         $text .= '#' . $this->getFragment();
1497                 }
1498                 return $text;
1499         }
1500
1501         /**
1502          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1503          *
1504          * @par Example:
1505          * @code
1506          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1507          * # returns: 'Foo'
1508          * @endcode
1509          *
1510          * @return string Root name
1511          * @since 1.20
1512          */
1513         public function getRootText() {
1514                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1515                         return $this->getText();
1516                 }
1517
1518                 return strtok( $this->getText(), '/' );
1519         }
1520
1521         /**
1522          * Get the root page name title, i.e. the leftmost part before any slashes
1523          *
1524          * @par Example:
1525          * @code
1526          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1527          * # returns: Title{User:Foo}
1528          * @endcode
1529          *
1530          * @return Title Root title
1531          * @since 1.20
1532          */
1533         public function getRootTitle() {
1534                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1535         }
1536
1537         /**
1538          * Get the base page name without a namespace, i.e. the part before the subpage name
1539          *
1540          * @par Example:
1541          * @code
1542          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1543          * # returns: 'Foo/Bar'
1544          * @endcode
1545          *
1546          * @return string Base name
1547          */
1548         public function getBaseText() {
1549                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1550                         return $this->getText();
1551                 }
1552
1553                 $parts = explode( '/', $this->getText() );
1554                 # Don't discard the real title if there's no subpage involved
1555                 if ( count( $parts ) > 1 ) {
1556                         unset( $parts[count( $parts ) - 1] );
1557                 }
1558                 return implode( '/', $parts );
1559         }
1560
1561         /**
1562          * Get the base page name title, i.e. the part before the subpage name
1563          *
1564          * @par Example:
1565          * @code
1566          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1567          * # returns: Title{User:Foo/Bar}
1568          * @endcode
1569          *
1570          * @return Title Base title
1571          * @since 1.20
1572          */
1573         public function getBaseTitle() {
1574                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1575         }
1576
1577         /**
1578          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1579          *
1580          * @par Example:
1581          * @code
1582          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1583          * # returns: "Baz"
1584          * @endcode
1585          *
1586          * @return string Subpage name
1587          */
1588         public function getSubpageText() {
1589                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1590                         return $this->mTextform;
1591                 }
1592                 $parts = explode( '/', $this->mTextform );
1593                 return $parts[count( $parts ) - 1];
1594         }
1595
1596         /**
1597          * Get the title for a subpage of the current page
1598          *
1599          * @par Example:
1600          * @code
1601          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1602          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1603          * @endcode
1604          *
1605          * @param string $text The subpage name to add to the title
1606          * @return Title Subpage title
1607          * @since 1.20
1608          */
1609         public function getSubpage( $text ) {
1610                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1611         }
1612
1613         /**
1614          * Get a URL-encoded form of the subpage text
1615          *
1616          * @return string URL-encoded subpage name
1617          */
1618         public function getSubpageUrlForm() {
1619                 $text = $this->getSubpageText();
1620                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1621                 return $text;
1622         }
1623
1624         /**
1625          * Get a URL-encoded title (not an actual URL) including interwiki
1626          *
1627          * @return string The URL-encoded form
1628          */
1629         public function getPrefixedURL() {
1630                 $s = $this->prefix( $this->mDbkeyform );
1631                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1632                 return $s;
1633         }
1634
1635         /**
1636          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1637          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1638          * second argument named variant. This was deprecated in favor
1639          * of passing an array of option with a "variant" key
1640          * Once $query2 is removed for good, this helper can be dropped
1641          * and the wfArrayToCgi moved to getLocalURL();
1642          *
1643          * @since 1.19 (r105919)
1644          * @param array|string $query
1645          * @param bool $query2
1646          * @return string
1647          */
1648         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1649                 if ( $query2 !== false ) {
1650                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1651                                 "method called with a second parameter is deprecated. Add your " .
1652                                 "parameter to an array passed as the first parameter.", "1.19" );
1653                 }
1654                 if ( is_array( $query ) ) {
1655                         $query = wfArrayToCgi( $query );
1656                 }
1657                 if ( $query2 ) {
1658                         if ( is_string( $query2 ) ) {
1659                                 // $query2 is a string, we will consider this to be
1660                                 // a deprecated $variant argument and add it to the query
1661                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1662                         } else {
1663                                 $query2 = wfArrayToCgi( $query2 );
1664                         }
1665                         // If we have $query content add a & to it first
1666                         if ( $query ) {
1667                                 $query .= '&';
1668                         }
1669                         // Now append the queries together
1670                         $query .= $query2;
1671                 }
1672                 return $query;
1673         }
1674
1675         /**
1676          * Get a real URL referring to this title, with interwiki link and
1677          * fragment
1678          *
1679          * @see self::getLocalURL for the arguments.
1680          * @see wfExpandUrl
1681          * @param array|string $query
1682          * @param bool $query2
1683          * @param string $proto Protocol type to use in URL
1684          * @return string The URL
1685          */
1686         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1687                 $query = self::fixUrlQueryArgs( $query, $query2 );
1688
1689                 # Hand off all the decisions on urls to getLocalURL
1690                 $url = $this->getLocalURL( $query );
1691
1692                 # Expand the url to make it a full url. Note that getLocalURL has the
1693                 # potential to output full urls for a variety of reasons, so we use
1694                 # wfExpandUrl instead of simply prepending $wgServer
1695                 $url = wfExpandUrl( $url, $proto );
1696
1697                 # Finally, add the fragment.
1698                 $url .= $this->getFragmentForURL();
1699
1700                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1701                 return $url;
1702         }
1703
1704         /**
1705          * Get a URL with no fragment or server name (relative URL) from a Title object.
1706          * If this page is generated with action=render, however,
1707          * $wgServer is prepended to make an absolute URL.
1708          *
1709          * @see self::getFullURL to always get an absolute URL.
1710          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1711          *  valid to link, locally, to the current Title.
1712          * @see self::newFromText to produce a Title object.
1713          *
1714          * @param string|array $query An optional query string,
1715          *   not used for interwiki links. Can be specified as an associative array as well,
1716          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1717          *   Some query patterns will trigger various shorturl path replacements.
1718          * @param array $query2 An optional secondary query array. This one MUST
1719          *   be an array. If a string is passed it will be interpreted as a deprecated
1720          *   variant argument and urlencoded into a variant= argument.
1721          *   This second query argument will be added to the $query
1722          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1723          *   pair in the first parameter array instead.
1724          *
1725          * @return string String of the URL.
1726          */
1727         public function getLocalURL( $query = '', $query2 = false ) {
1728                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1729
1730                 $query = self::fixUrlQueryArgs( $query, $query2 );
1731
1732                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1733                 if ( $interwiki ) {
1734                         $namespace = $this->getNsText();
1735                         if ( $namespace != '' ) {
1736                                 # Can this actually happen? Interwikis shouldn't be parsed.
1737                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1738                                 $namespace .= ':';
1739                         }
1740                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1741                         $url = wfAppendQuery( $url, $query );
1742                 } else {
1743                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1744                         if ( $query == '' ) {
1745                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1746                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1747                         } else {
1748                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1749                                 $url = false;
1750                                 $matches = array();
1751
1752                                 if ( !empty( $wgActionPaths )
1753                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1754                                 ) {
1755                                         $action = urldecode( $matches[2] );
1756                                         if ( isset( $wgActionPaths[$action] ) ) {
1757                                                 $query = $matches[1];
1758                                                 if ( isset( $matches[4] ) ) {
1759                                                         $query .= $matches[4];
1760                                                 }
1761                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1762                                                 if ( $query != '' ) {
1763                                                         $url = wfAppendQuery( $url, $query );
1764                                                 }
1765                                         }
1766                                 }
1767
1768                                 if ( $url === false
1769                                         && $wgVariantArticlePath
1770                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1771                                         && $this->getPageLanguage()->hasVariants()
1772                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1773                                 ) {
1774                                         $variant = urldecode( $matches[1] );
1775                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1776                                                 // Only do the variant replacement if the given variant is a valid
1777                                                 // variant for the page's language.
1778                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1779                                                 $url = str_replace( '$1', $dbkey, $url );
1780                                         }
1781                                 }
1782
1783                                 if ( $url === false ) {
1784                                         if ( $query == '-' ) {
1785                                                 $query = '';
1786                                         }
1787                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1788                                 }
1789                         }
1790
1791                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1792
1793                         // @todo FIXME: This causes breakage in various places when we
1794                         // actually expected a local URL and end up with dupe prefixes.
1795                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1796                                 $url = $wgServer . $url;
1797                         }
1798                 }
1799                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1800                 return $url;
1801         }
1802
1803         /**
1804          * Get a URL that's the simplest URL that will be valid to link, locally,
1805          * to the current Title.  It includes the fragment, but does not include
1806          * the server unless action=render is used (or the link is external).  If
1807          * there's a fragment but the prefixed text is empty, we just return a link
1808          * to the fragment.
1809          *
1810          * The result obviously should not be URL-escaped, but does need to be
1811          * HTML-escaped if it's being output in HTML.
1812          *
1813          * @param array $query
1814          * @param bool $query2
1815          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1816          * @see self::getLocalURL for the arguments.
1817          * @return string The URL
1818          */
1819         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1820                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1821                         $ret = $this->getFullURL( $query, $query2, $proto );
1822                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1823                         $ret = $this->getFragmentForURL();
1824                 } else {
1825                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1826                 }
1827                 return $ret;
1828         }
1829
1830         /**
1831          * Get the URL form for an internal link.
1832          * - Used in various CDN-related code, in case we have a different
1833          * internal hostname for the server from the exposed one.
1834          *
1835          * This uses $wgInternalServer to qualify the path, or $wgServer
1836          * if $wgInternalServer is not set. If the server variable used is
1837          * protocol-relative, the URL will be expanded to http://
1838          *
1839          * @see self::getLocalURL for the arguments.
1840          * @return string The URL
1841          */
1842         public function getInternalURL( $query = '', $query2 = false ) {
1843                 global $wgInternalServer, $wgServer;
1844                 $query = self::fixUrlQueryArgs( $query, $query2 );
1845                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1846                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1847                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1848                 return $url;
1849         }
1850
1851         /**
1852          * Get the URL for a canonical link, for use in things like IRC and
1853          * e-mail notifications. Uses $wgCanonicalServer and the
1854          * GetCanonicalURL hook.
1855          *
1856          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1857          *
1858          * @see self::getLocalURL for the arguments.
1859          * @return string The URL
1860          * @since 1.18
1861          */
1862         public function getCanonicalURL( $query = '', $query2 = false ) {
1863                 $query = self::fixUrlQueryArgs( $query, $query2 );
1864                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1865                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1866                 return $url;
1867         }
1868
1869         /**
1870          * Get the edit URL for this Title
1871          *
1872          * @return string The URL, or a null string if this is an interwiki link
1873          */
1874         public function getEditURL() {
1875                 if ( $this->isExternal() ) {
1876                         return '';
1877                 }
1878                 $s = $this->getLocalURL( 'action=edit' );
1879
1880                 return $s;
1881         }
1882
1883         /**
1884          * Can $user perform $action on this page?
1885          * This skips potentially expensive cascading permission checks
1886          * as well as avoids expensive error formatting
1887          *
1888          * Suitable for use for nonessential UI controls in common cases, but
1889          * _not_ for functional access control.
1890          *
1891          * May provide false positives, but should never provide a false negative.
1892          *
1893          * @param string $action Action that permission needs to be checked for
1894          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1895          * @return bool
1896          */
1897         public function quickUserCan( $action, $user = null ) {
1898                 return $this->userCan( $action, $user, false );
1899         }
1900
1901         /**
1902          * Can $user perform $action on this page?
1903          *
1904          * @param string $action Action that permission needs to be checked for
1905          * @param User $user User to check (since 1.19); $wgUser will be used if not
1906          *   provided.
1907          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1908          * @return bool
1909          */
1910         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1911                 if ( !$user instanceof User ) {
1912                         global $wgUser;
1913                         $user = $wgUser;
1914                 }
1915
1916                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1917         }
1918
1919         /**
1920          * Can $user perform $action on this page?
1921          *
1922          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1923          *
1924          * @param string $action Action that permission needs to be checked for
1925          * @param User $user User to check
1926          * @param string $rigor One of (quick,full,secure)
1927          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1928          *   - full   : does cheap and expensive checks possibly from a slave
1929          *   - secure : does cheap and expensive checks, using the master as needed
1930          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1931          *   whose corresponding errors may be ignored.
1932          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1933          */
1934         public function getUserPermissionsErrors(
1935                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1936         ) {
1937                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1938
1939                 // Remove the errors being ignored.
1940                 foreach ( $errors as $index => $error ) {
1941                         $errKey = is_array( $error ) ? $error[0] : $error;
1942
1943                         if ( in_array( $errKey, $ignoreErrors ) ) {
1944                                 unset( $errors[$index] );
1945                         }
1946                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
1947                                 unset( $errors[$index] );
1948                         }
1949                 }
1950
1951                 return $errors;
1952         }
1953
1954         /**
1955          * Permissions checks that fail most often, and which are easiest to test.
1956          *
1957          * @param string $action The action to check
1958          * @param User $user User to check
1959          * @param array $errors List of current errors
1960          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1961          * @param bool $short Short circuit on first error
1962          *
1963          * @return array List of errors
1964          */
1965         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1966                 if ( !Hooks::run( 'TitleQuickPermissions',
1967                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1968                 ) {
1969                         return $errors;
1970                 }
1971
1972                 if ( $action == 'create' ) {
1973                         if (
1974                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1975                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1976                         ) {
1977                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1978                         }
1979                 } elseif ( $action == 'move' ) {
1980                         if ( !$user->isAllowed( 'move-rootuserpages' )
1981                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1982                                 // Show user page-specific message only if the user can move other pages
1983                                 $errors[] = array( 'cant-move-user-page' );
1984                         }
1985
1986                         // Check if user is allowed to move files if it's a file
1987                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1988                                 $errors[] = array( 'movenotallowedfile' );
1989                         }
1990
1991                         // Check if user is allowed to move category pages if it's a category page
1992                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1993                                 $errors[] = array( 'cant-move-category-page' );
1994                         }
1995
1996                         if ( !$user->isAllowed( 'move' ) ) {
1997                                 // User can't move anything
1998                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1999                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2000                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2001                                         // custom message if logged-in users without any special rights can move
2002                                         $errors[] = array( 'movenologintext' );
2003                                 } else {
2004                                         $errors[] = array( 'movenotallowed' );
2005                                 }
2006                         }
2007                 } elseif ( $action == 'move-target' ) {
2008                         if ( !$user->isAllowed( 'move' ) ) {
2009                                 // User can't move anything
2010                                 $errors[] = array( 'movenotallowed' );
2011                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2012                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2013                                 // Show user page-specific message only if the user can move other pages
2014                                 $errors[] = array( 'cant-move-to-user-page' );
2015                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2016                                         && $this->mNamespace == NS_CATEGORY ) {
2017                                 // Show category page-specific message only if the user can move other pages
2018                                 $errors[] = array( 'cant-move-to-category-page' );
2019                         }
2020                 } elseif ( !$user->isAllowed( $action ) ) {
2021                         $errors[] = $this->missingPermissionError( $action, $short );
2022                 }
2023
2024                 return $errors;
2025         }
2026
2027         /**
2028          * Add the resulting error code to the errors array
2029          *
2030          * @param array $errors List of current errors
2031          * @param array $result Result of errors
2032          *
2033          * @return array List of errors
2034          */
2035         private function resultToError( $errors, $result ) {
2036                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2037                         // A single array representing an error
2038                         $errors[] = $result;
2039                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2040                         // A nested array representing multiple errors
2041                         $errors = array_merge( $errors, $result );
2042                 } elseif ( $result !== '' && is_string( $result ) ) {
2043                         // A string representing a message-id
2044                         $errors[] = array( $result );
2045                 } elseif ( $result instanceof MessageSpecifier ) {
2046                         // A message specifier representing an error
2047                         $errors[] = array( $result );
2048                 } elseif ( $result === false ) {
2049                         // a generic "We don't want them to do that"
2050                         $errors[] = array( 'badaccess-group0' );
2051                 }
2052                 return $errors;
2053         }
2054
2055         /**
2056          * Check various permission hooks
2057          *
2058          * @param string $action The action to check
2059          * @param User $user User to check
2060          * @param array $errors List of current errors
2061          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2062          * @param bool $short Short circuit on first error
2063          *
2064          * @return array List of errors
2065          */
2066         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2067                 // Use getUserPermissionsErrors instead
2068                 $result = '';
2069                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2070                         return $result ? array() : array( array( 'badaccess-group0' ) );
2071                 }
2072                 // Check getUserPermissionsErrors hook
2073                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2074                         $errors = $this->resultToError( $errors, $result );
2075                 }
2076                 // Check getUserPermissionsErrorsExpensive hook
2077                 if (
2078                         $rigor !== 'quick'
2079                         && !( $short && count( $errors ) > 0 )
2080                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2081                 ) {
2082                         $errors = $this->resultToError( $errors, $result );
2083                 }
2084
2085                 return $errors;
2086         }
2087
2088         /**
2089          * Check permissions on special pages & namespaces
2090          *
2091          * @param string $action The action to check
2092          * @param User $user User to check
2093          * @param array $errors List of current errors
2094          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2095          * @param bool $short Short circuit on first error
2096          *
2097          * @return array List of errors
2098          */
2099         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2100                 # Only 'createaccount' can be performed on special pages,
2101                 # which don't actually exist in the DB.
2102                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2103                         $errors[] = array( 'ns-specialprotected' );
2104                 }
2105
2106                 # Check $wgNamespaceProtection for restricted namespaces
2107                 if ( $this->isNamespaceProtected( $user ) ) {
2108                         $ns = $this->mNamespace == NS_MAIN ?
2109                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2110                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2111                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2112                 }
2113
2114                 return $errors;
2115         }
2116
2117         /**
2118          * Check CSS/JS sub-page permissions
2119          *
2120          * @param string $action The action to check
2121          * @param User $user User to check
2122          * @param array $errors List of current errors
2123          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2124          * @param bool $short Short circuit on first error
2125          *
2126          * @return array List of errors
2127          */
2128         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2129                 # Protect css/js subpages of user pages
2130                 # XXX: this might be better using restrictions
2131                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2132                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2133                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2134                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2135                                         $errors[] = array( 'mycustomcssprotected', $action );
2136                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2137                                         $errors[] = array( 'mycustomjsprotected', $action );
2138                                 }
2139                         } else {
2140                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2141                                         $errors[] = array( 'customcssprotected', $action );
2142                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2143                                         $errors[] = array( 'customjsprotected', $action );
2144                                 }
2145                         }
2146                 }
2147
2148                 return $errors;
2149         }
2150
2151         /**
2152          * Check against page_restrictions table requirements on this
2153          * page. The user must possess all required rights for this
2154          * action.
2155          *
2156          * @param string $action The action to check
2157          * @param User $user User to check
2158          * @param array $errors List of current errors
2159          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2160          * @param bool $short Short circuit on first error
2161          *
2162          * @return array List of errors
2163          */
2164         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2165                 foreach ( $this->getRestrictions( $action ) as $right ) {
2166                         // Backwards compatibility, rewrite sysop -> editprotected
2167                         if ( $right == 'sysop' ) {
2168                                 $right = 'editprotected';
2169                         }
2170                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2171                         if ( $right == 'autoconfirmed' ) {
2172                                 $right = 'editsemiprotected';
2173                         }
2174                         if ( $right == '' ) {
2175                                 continue;
2176                         }
2177                         if ( !$user->isAllowed( $right ) ) {
2178                                 $errors[] = array( 'protectedpagetext', $right, $action );
2179                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2180                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2181                         }
2182                 }
2183
2184                 return $errors;
2185         }
2186
2187         /**
2188          * Check restrictions on cascading pages.
2189          *
2190          * @param string $action The action to check
2191          * @param User $user User to check
2192          * @param array $errors List of current errors
2193          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2194          * @param bool $short Short circuit on first error
2195          *
2196          * @return array List of errors
2197          */
2198         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2199                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2200                         # We /could/ use the protection level on the source page, but it's
2201                         # fairly ugly as we have to establish a precedence hierarchy for pages
2202                         # included by multiple cascade-protected pages. So just restrict
2203                         # it to people with 'protect' permission, as they could remove the
2204                         # protection anyway.
2205                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2206                         # Cascading protection depends on more than this page...
2207                         # Several cascading protected pages may include this page...
2208                         # Check each cascading level
2209                         # This is only for protection restrictions, not for all actions
2210                         if ( isset( $restrictions[$action] ) ) {
2211                                 foreach ( $restrictions[$action] as $right ) {
2212                                         // Backwards compatibility, rewrite sysop -> editprotected
2213                                         if ( $right == 'sysop' ) {
2214                                                 $right = 'editprotected';
2215                                         }
2216                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2217                                         if ( $right == 'autoconfirmed' ) {
2218                                                 $right = 'editsemiprotected';
2219                                         }
2220                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2221                                                 $pages = '';
2222                                                 foreach ( $cascadingSources as $page ) {
2223                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2224                                                 }
2225                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2226                                         }
2227                                 }
2228                         }
2229                 }
2230
2231                 return $errors;
2232         }
2233
2234         /**
2235          * Check action permissions not already checked in checkQuickPermissions
2236          *
2237          * @param string $action The action to check
2238          * @param User $user User to check
2239          * @param array $errors List of current errors
2240          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2241          * @param bool $short Short circuit on first error
2242          *
2243          * @return array List of errors
2244          */
2245         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2246                 global $wgDeleteRevisionsLimit, $wgLang;
2247
2248                 if ( $action == 'protect' ) {
2249                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2250                                 // If they can't edit, they shouldn't protect.
2251                                 $errors[] = array( 'protect-cantedit' );
2252                         }
2253                 } elseif ( $action == 'create' ) {
2254                         $title_protection = $this->getTitleProtection();
2255                         if ( $title_protection ) {
2256                                 if ( $title_protection['permission'] == ''
2257                                         || !$user->isAllowed( $title_protection['permission'] )
2258                                 ) {
2259                                         $errors[] = array(
2260                                                 'titleprotected',
2261                                                 User::whoIs( $title_protection['user'] ),
2262                                                 $title_protection['reason']
2263                                         );
2264                                 }
2265                         }
2266                 } elseif ( $action == 'move' ) {
2267                         // Check for immobile pages
2268                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2269                                 // Specific message for this case
2270                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2271                         } elseif ( !$this->isMovable() ) {
2272                                 // Less specific message for rarer cases
2273                                 $errors[] = array( 'immobile-source-page' );
2274                         }
2275                 } elseif ( $action == 'move-target' ) {
2276                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2277                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2278                         } elseif ( !$this->isMovable() ) {
2279                                 $errors[] = array( 'immobile-target-page' );
2280                         }
2281                 } elseif ( $action == 'delete' ) {
2282                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2283                         if ( !$tempErrors ) {
2284                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2285                                         $user, $tempErrors, $rigor, true );
2286                         }
2287                         if ( $tempErrors ) {
2288                                 // If protection keeps them from editing, they shouldn't be able to delete.
2289                                 $errors[] = array( 'deleteprotected' );
2290                         }
2291                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2292                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2293                         ) {
2294                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2295                         }
2296                 }
2297                 return $errors;
2298         }
2299
2300         /**
2301          * Check that the user isn't blocked from editing.
2302          *
2303          * @param string $action The action to check
2304          * @param User $user User to check
2305          * @param array $errors List of current errors
2306          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2307          * @param bool $short Short circuit on first error
2308          *
2309          * @return array List of errors
2310          */
2311         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2312                 // Account creation blocks handled at userlogin.
2313                 // Unblocking handled in SpecialUnblock
2314                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2315                         return $errors;
2316                 }
2317
2318                 global $wgEmailConfirmToEdit;
2319
2320                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2321                         $errors[] = array( 'confirmedittext' );
2322                 }
2323
2324                 $useSlave = ( $rigor !== 'secure' );
2325                 if ( ( $action == 'edit' || $action == 'create' )
2326                         && !$user->isBlockedFrom( $this, $useSlave )
2327                 ) {
2328                         // Don't block the user from editing their own talk page unless they've been
2329                         // explicitly blocked from that too.
2330                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2331                         // @todo FIXME: Pass the relevant context into this function.
2332                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2333                 }
2334
2335                 return $errors;
2336         }
2337
2338         /**
2339          * Check that the user is allowed to read this page.
2340          *
2341          * @param string $action The action to check
2342          * @param User $user User to check
2343          * @param array $errors List of current errors
2344          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2345          * @param bool $short Short circuit on first error
2346          *
2347          * @return array List of errors
2348          */
2349         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2350                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2351
2352                 $whitelisted = false;
2353                 if ( User::isEveryoneAllowed( 'read' ) ) {
2354                         # Shortcut for public wikis, allows skipping quite a bit of code
2355                         $whitelisted = true;
2356                 } elseif ( $user->isAllowed( 'read' ) ) {
2357                         # If the user is allowed to read pages, he is allowed to read all pages
2358                         $whitelisted = true;
2359                 } elseif ( $this->isSpecial( 'Userlogin' )
2360                         || $this->isSpecial( 'ChangePassword' )
2361                         || $this->isSpecial( 'PasswordReset' )
2362                 ) {
2363                         # Always grant access to the login page.
2364                         # Even anons need to be able to log in.
2365                         $whitelisted = true;
2366                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2367                         # Time to check the whitelist
2368                         # Only do these checks is there's something to check against
2369                         $name = $this->getPrefixedText();
2370                         $dbName = $this->getPrefixedDBkey();
2371
2372                         // Check for explicit whitelisting with and without underscores
2373                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2374                                 $whitelisted = true;
2375                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2376                                 # Old settings might have the title prefixed with
2377                                 # a colon for main-namespace pages
2378                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2379                                         $whitelisted = true;
2380                                 }
2381                         } elseif ( $this->isSpecialPage() ) {
2382                                 # If it's a special page, ditch the subpage bit and check again
2383                                 $name = $this->getDBkey();
2384                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2385                                 if ( $name ) {
2386                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2387                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2388                                                 $whitelisted = true;
2389                                         }
2390                                 }
2391                         }
2392                 }
2393
2394                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2395                         $name = $this->getPrefixedText();
2396                         // Check for regex whitelisting
2397                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2398                                 if ( preg_match( $listItem, $name ) ) {
2399                                         $whitelisted = true;
2400                                         break;
2401                                 }
2402                         }
2403                 }
2404
2405                 if ( !$whitelisted ) {
2406                         # If the title is not whitelisted, give extensions a chance to do so...
2407                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2408                         if ( !$whitelisted ) {
2409                                 $errors[] = $this->missingPermissionError( $action, $short );
2410                         }
2411                 }
2412
2413                 return $errors;
2414         }
2415
2416         /**
2417          * Get a description array when the user doesn't have the right to perform
2418          * $action (i.e. when User::isAllowed() returns false)
2419          *
2420          * @param string $action The action to check
2421          * @param bool $short Short circuit on first error
2422          * @return array List of errors
2423          */
2424         private function missingPermissionError( $action, $short ) {
2425                 // We avoid expensive display logic for quickUserCan's and such
2426                 if ( $short ) {
2427                         return array( 'badaccess-group0' );
2428                 }
2429
2430                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2431                         User::getGroupsWithPermission( $action ) );
2432
2433                 if ( count( $groups ) ) {
2434                         global $wgLang;
2435                         return array(
2436                                 'badaccess-groups',
2437                                 $wgLang->commaList( $groups ),
2438                                 count( $groups )
2439                         );
2440                 } else {
2441                         return array( 'badaccess-group0' );
2442                 }
2443         }
2444
2445         /**
2446          * Can $user perform $action on this page? This is an internal function,
2447          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2448          * checks on wfReadOnly() and blocks)
2449          *
2450          * @param string $action Action that permission needs to be checked for
2451          * @param User $user User to check
2452          * @param string $rigor One of (quick,full,secure)
2453          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2454          *   - full   : does cheap and expensive checks possibly from a slave
2455          *   - secure : does cheap and expensive checks, using the master as needed
2456          * @param bool $short Set this to true to stop after the first permission error.
2457          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2458          */
2459         protected function getUserPermissionsErrorsInternal(
2460                 $action, $user, $rigor = 'secure', $short = false
2461         ) {
2462                 if ( $rigor === true ) {
2463                         $rigor = 'secure'; // b/c
2464                 } elseif ( $rigor === false ) {
2465                         $rigor = 'quick'; // b/c
2466                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2467                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2468                 }
2469
2470                 # Read has special handling
2471                 if ( $action == 'read' ) {
2472                         $checks = array(
2473                                 'checkPermissionHooks',
2474                                 'checkReadPermissions',
2475                         );
2476                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2477                 # here as it will lead to duplicate error messages. This is okay to do
2478                 # since anywhere that checks for create will also check for edit, and
2479                 # those checks are called for edit.
2480                 } elseif ( $action == 'create' ) {
2481                         $checks = array(
2482                                 'checkQuickPermissions',
2483                                 'checkPermissionHooks',
2484                                 'checkPageRestrictions',
2485                                 'checkCascadingSourcesRestrictions',
2486                                 'checkActionPermissions',
2487                                 'checkUserBlock'
2488                         );
2489                 } else {
2490                         $checks = array(
2491                                 'checkQuickPermissions',
2492                                 'checkPermissionHooks',
2493                                 'checkSpecialsAndNSPermissions',
2494                                 'checkCSSandJSPermissions',
2495                                 'checkPageRestrictions',
2496                                 'checkCascadingSourcesRestrictions',
2497                                 'checkActionPermissions',
2498                                 'checkUserBlock'
2499                         );
2500                 }
2501
2502                 $errors = array();
2503                 while ( count( $checks ) > 0 &&
2504                                 !( $short && count( $errors ) > 0 ) ) {
2505                         $method = array_shift( $checks );
2506                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2507                 }
2508
2509                 return $errors;
2510         }
2511
2512         /**
2513          * Get a filtered list of all restriction types supported by this wiki.
2514          * @param bool $exists True to get all restriction types that apply to
2515          * titles that do exist, False for all restriction types that apply to
2516          * titles that do not exist
2517          * @return array
2518          */
2519         public static function getFilteredRestrictionTypes( $exists = true ) {
2520                 global $wgRestrictionTypes;
2521                 $types = $wgRestrictionTypes;
2522                 if ( $exists ) {
2523                         # Remove the create restriction for existing titles
2524                         $types = array_diff( $types, array( 'create' ) );
2525                 } else {
2526                         # Only the create and upload restrictions apply to non-existing titles
2527                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2528                 }
2529                 return $types;
2530         }
2531
2532         /**
2533          * Returns restriction types for the current Title
2534          *
2535          * @return array Applicable restriction types
2536          */
2537         public function getRestrictionTypes() {
2538                 if ( $this->isSpecialPage() ) {
2539                         return array();
2540                 }
2541
2542                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2543
2544                 if ( $this->getNamespace() != NS_FILE ) {
2545                         # Remove the upload restriction for non-file titles
2546                         $types = array_diff( $types, array( 'upload' ) );
2547                 }
2548
2549                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2550
2551                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2552                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2553
2554                 return $types;
2555         }
2556
2557         /**
2558          * Is this title subject to title protection?
2559          * Title protection is the one applied against creation of such title.
2560          *
2561          * @return array|bool An associative array representing any existent title
2562          *   protection, or false if there's none.
2563          */
2564         public function getTitleProtection() {
2565                 // Can't protect pages in special namespaces
2566                 if ( $this->getNamespace() < 0 ) {
2567                         return false;
2568                 }
2569
2570                 // Can't protect pages that exist.
2571                 if ( $this->exists() ) {
2572                         return false;
2573                 }
2574
2575                 if ( $this->mTitleProtection === null ) {
2576                         $dbr = wfGetDB( DB_SLAVE );
2577                         $res = $dbr->select(
2578                                 'protected_titles',
2579                                 array(
2580                                         'user' => 'pt_user',
2581                                         'reason' => 'pt_reason',
2582                                         'expiry' => 'pt_expiry',
2583                                         'permission' => 'pt_create_perm'
2584                                 ),
2585                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2586                                 __METHOD__
2587                         );
2588
2589                         // fetchRow returns false if there are no rows.
2590                         $row = $dbr->fetchRow( $res );
2591                         if ( $row ) {
2592                                 if ( $row['permission'] == 'sysop' ) {
2593                                         $row['permission'] = 'editprotected'; // B/C
2594                                 }
2595                                 if ( $row['permission'] == 'autoconfirmed' ) {
2596                                         $row['permission'] = 'editsemiprotected'; // B/C
2597                                 }
2598                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2599                         }
2600                         $this->mTitleProtection = $row;
2601                 }
2602                 return $this->mTitleProtection;
2603         }
2604
2605         /**
2606          * Remove any title protection due to page existing
2607          */
2608         public function deleteTitleProtection() {
2609                 $dbw = wfGetDB( DB_MASTER );
2610
2611                 $dbw->delete(
2612                         'protected_titles',
2613                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2614                         __METHOD__
2615                 );
2616                 $this->mTitleProtection = false;
2617         }
2618
2619         /**
2620          * Is this page "semi-protected" - the *only* protection levels are listed
2621          * in $wgSemiprotectedRestrictionLevels?
2622          *
2623          * @param string $action Action to check (default: edit)
2624          * @return bool
2625          */
2626         public function isSemiProtected( $action = 'edit' ) {
2627                 global $wgSemiprotectedRestrictionLevels;
2628
2629                 $restrictions = $this->getRestrictions( $action );
2630                 $semi = $wgSemiprotectedRestrictionLevels;
2631                 if ( !$restrictions || !$semi ) {
2632                         // Not protected, or all protection is full protection
2633                         return false;
2634                 }
2635
2636                 // Remap autoconfirmed to editsemiprotected for BC
2637                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2638                         $semi[$key] = 'editsemiprotected';
2639                 }
2640                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2641                         $restrictions[$key] = 'editsemiprotected';
2642                 }
2643
2644                 return !array_diff( $restrictions, $semi );
2645         }
2646
2647         /**
2648          * Does the title correspond to a protected article?
2649          *
2650          * @param string $action The action the page is protected from,
2651          * by default checks all actions.
2652          * @return bool
2653          */
2654         public function isProtected( $action = '' ) {
2655                 global $wgRestrictionLevels;
2656
2657                 $restrictionTypes = $this->getRestrictionTypes();
2658
2659                 # Special pages have inherent protection
2660                 if ( $this->isSpecialPage() ) {
2661                         return true;
2662                 }
2663
2664                 # Check regular protection levels
2665                 foreach ( $restrictionTypes as $type ) {
2666                         if ( $action == $type || $action == '' ) {
2667                                 $r = $this->getRestrictions( $type );
2668                                 foreach ( $wgRestrictionLevels as $level ) {
2669                                         if ( in_array( $level, $r ) && $level != '' ) {
2670                                                 return true;
2671                                         }
2672                                 }
2673                         }
2674                 }
2675
2676                 return false;
2677         }
2678
2679         /**
2680          * Determines if $user is unable to edit this page because it has been protected
2681          * by $wgNamespaceProtection.
2682          *
2683          * @param User $user User object to check permissions
2684          * @return bool
2685          */
2686         public function isNamespaceProtected( User $user ) {
2687                 global $wgNamespaceProtection;
2688
2689                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2690                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2691                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2692                                         return true;
2693                                 }
2694                         }
2695                 }
2696                 return false;
2697         }
2698
2699         /**
2700          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2701          *
2702          * @return bool If the page is subject to cascading restrictions.
2703          */
2704         public function isCascadeProtected() {
2705                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2706                 return ( $sources > 0 );
2707         }
2708
2709         /**
2710          * Determines whether cascading protection sources have already been loaded from
2711          * the database.
2712          *
2713          * @param bool $getPages True to check if the pages are loaded, or false to check
2714          * if the status is loaded.
2715          * @return bool Whether or not the specified information has been loaded
2716          * @since 1.23
2717          */
2718         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2719                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2720         }
2721
2722         /**
2723          * Cascading protection: Get the source of any cascading restrictions on this page.
2724          *
2725          * @param bool $getPages Whether or not to retrieve the actual pages
2726          *        that the restrictions have come from and the actual restrictions
2727          *        themselves.
2728          * @return array Two elements: First is an array of Title objects of the
2729          *        pages from which cascading restrictions have come, false for
2730          *        none, or true if such restrictions exist but $getPages was not
2731          *        set. Second is an array like that returned by
2732          *        Title::getAllRestrictions(), or an empty array if $getPages is
2733          *        false.
2734          */
2735         public function getCascadeProtectionSources( $getPages = true ) {
2736                 $pagerestrictions = array();
2737
2738                 if ( $this->mCascadeSources !== null && $getPages ) {
2739                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2740                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2741                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2742                 }
2743
2744                 $dbr = wfGetDB( DB_SLAVE );
2745
2746                 if ( $this->getNamespace() == NS_FILE ) {
2747                         $tables = array( 'imagelinks', 'page_restrictions' );
2748                         $where_clauses = array(
2749                                 'il_to' => $this->getDBkey(),
2750                                 'il_from=pr_page',
2751                                 'pr_cascade' => 1
2752                         );
2753                 } else {
2754                         $tables = array( 'templatelinks', 'page_restrictions' );
2755                         $where_clauses = array(
2756                                 'tl_namespace' => $this->getNamespace(),
2757                                 'tl_title' => $this->getDBkey(),
2758                                 'tl_from=pr_page',
2759                                 'pr_cascade' => 1
2760                         );
2761                 }
2762
2763                 if ( $getPages ) {
2764                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2765                                 'pr_expiry', 'pr_type', 'pr_level' );
2766                         $where_clauses[] = 'page_id=pr_page';
2767                         $tables[] = 'page';
2768                 } else {
2769                         $cols = array( 'pr_expiry' );
2770                 }
2771
2772                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2773
2774                 $sources = $getPages ? array() : false;
2775                 $now = wfTimestampNow();
2776
2777                 foreach ( $res as $row ) {
2778                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2779                         if ( $expiry > $now ) {
2780                                 if ( $getPages ) {
2781                                         $page_id = $row->pr_page;
2782                                         $page_ns = $row->page_namespace;
2783                                         $page_title = $row->page_title;
2784                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2785                                         # Add groups needed for each restriction type if its not already there
2786                                         # Make sure this restriction type still exists
2787
2788                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2789                                                 $pagerestrictions[$row->pr_type] = array();
2790                                         }
2791
2792                                         if (
2793                                                 isset( $pagerestrictions[$row->pr_type] )
2794                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2795                                         ) {
2796                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2797                                         }
2798                                 } else {
2799                                         $sources = true;
2800                                 }
2801                         }
2802                 }
2803
2804                 if ( $getPages ) {
2805                         $this->mCascadeSources = $sources;
2806                         $this->mCascadingRestrictions = $pagerestrictions;
2807                 } else {
2808                         $this->mHasCascadingRestrictions = $sources;
2809                 }
2810
2811                 return array( $sources, $pagerestrictions );
2812         }
2813
2814         /**
2815          * Accessor for mRestrictionsLoaded
2816          *
2817          * @return bool Whether or not the page's restrictions have already been
2818          * loaded from the database
2819          * @since 1.23
2820          */
2821         public function areRestrictionsLoaded() {
2822                 return $this->mRestrictionsLoaded;
2823         }
2824
2825         /**
2826          * Accessor/initialisation for mRestrictions
2827          *
2828          * @param string $action Action that permission needs to be checked for
2829          * @return array Restriction levels needed to take the action. All levels are
2830          *     required. Note that restriction levels are normally user rights, but 'sysop'
2831          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2832          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2833          */
2834         public function getRestrictions( $action ) {
2835                 if ( !$this->mRestrictionsLoaded ) {
2836                         $this->loadRestrictions();
2837                 }
2838                 return isset( $this->mRestrictions[$action] )
2839                                 ? $this->mRestrictions[$action]
2840                                 : array();
2841         }
2842
2843         /**
2844          * Accessor/initialisation for mRestrictions
2845          *
2846          * @return array Keys are actions, values are arrays as returned by
2847          *     Title::getRestrictions()
2848          * @since 1.23
2849          */
2850         public function getAllRestrictions() {
2851                 if ( !$this->mRestrictionsLoaded ) {
2852                         $this->loadRestrictions();
2853                 }
2854                 return $this->mRestrictions;
2855         }
2856
2857         /**
2858          * Get the expiry time for the restriction against a given action
2859          *
2860          * @param string $action
2861          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2862          *     or not protected at all, or false if the action is not recognised.
2863          */
2864         public function getRestrictionExpiry( $action ) {
2865                 if ( !$this->mRestrictionsLoaded ) {
2866                         $this->loadRestrictions();
2867                 }
2868                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2869         }
2870
2871         /**
2872          * Returns cascading restrictions for the current article
2873          *
2874          * @return bool
2875          */
2876         function areRestrictionsCascading() {
2877                 if ( !$this->mRestrictionsLoaded ) {
2878                         $this->loadRestrictions();
2879                 }
2880
2881                 return $this->mCascadeRestriction;
2882         }
2883
2884         /**
2885          * Loads a string into mRestrictions array
2886          *
2887          * @param ResultWrapper $res Resource restrictions as an SQL result.
2888          * @param string $oldFashionedRestrictions Comma-separated list of page
2889          *        restrictions from page table (pre 1.10)
2890          */
2891         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2892                 $rows = array();
2893
2894                 foreach ( $res as $row ) {
2895                         $rows[] = $row;
2896                 }
2897
2898                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2899         }
2900
2901         /**
2902          * Compiles list of active page restrictions from both page table (pre 1.10)
2903          * and page_restrictions table for this existing page.
2904          * Public for usage by LiquidThreads.
2905          *
2906          * @param array $rows Array of db result objects
2907          * @param string $oldFashionedRestrictions Comma-separated list of page
2908          *   restrictions from page table (pre 1.10)
2909          */
2910         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2911                 $dbr = wfGetDB( DB_SLAVE );
2912
2913                 $restrictionTypes = $this->getRestrictionTypes();
2914
2915                 foreach ( $restrictionTypes as $type ) {
2916                         $this->mRestrictions[$type] = array();
2917                         $this->mRestrictionsExpiry[$type] = 'infinity';
2918                 }
2919
2920                 $this->mCascadeRestriction = false;
2921
2922                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2923                 if ( $oldFashionedRestrictions !== null ) {
2924                         $this->mOldRestrictions = $oldFashionedRestrictions;
2925                 }
2926
2927                 if ( $this->mOldRestrictions === false ) {
2928                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2929                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2930                 }
2931
2932                 if ( $this->mOldRestrictions != '' ) {
2933                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2934                                 $temp = explode( '=', trim( $restrict ) );
2935                                 if ( count( $temp ) == 1 ) {
2936                                         // old old format should be treated as edit/move restriction
2937                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2938                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2939                                 } else {
2940                                         $restriction = trim( $temp[1] );
2941                                         if ( $restriction != '' ) { // some old entries are empty
2942                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2943                                         }
2944                                 }
2945                         }
2946                 }
2947
2948                 if ( count( $rows ) ) {
2949                         # Current system - load second to make them override.
2950                         $now = wfTimestampNow();
2951
2952                         # Cycle through all the restrictions.
2953                         foreach ( $rows as $row ) {
2954
2955                                 // Don't take care of restrictions types that aren't allowed
2956                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2957                                         continue;
2958                                 }
2959
2960                                 // This code should be refactored, now that it's being used more generally,
2961                                 // But I don't really see any harm in leaving it in Block for now -werdna
2962                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2963
2964                                 // Only apply the restrictions if they haven't expired!
2965                                 if ( !$expiry || $expiry > $now ) {
2966                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2967                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2968
2969                                         $this->mCascadeRestriction |= $row->pr_cascade;
2970                                 }
2971                         }
2972                 }
2973
2974                 $this->mRestrictionsLoaded = true;
2975         }
2976
2977         /**
2978          * Load restrictions from the page_restrictions table
2979          *
2980          * @param string $oldFashionedRestrictions Comma-separated list of page
2981          *   restrictions from page table (pre 1.10)
2982          */
2983         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2984                 if ( !$this->mRestrictionsLoaded ) {
2985                         $dbr = wfGetDB( DB_SLAVE );
2986                         if ( $this->exists() ) {
2987                                 $res = $dbr->select(
2988                                         'page_restrictions',
2989                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2990                                         array( 'pr_page' => $this->getArticleID() ),
2991                                         __METHOD__
2992                                 );
2993
2994                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2995                         } else {
2996                                 $title_protection = $this->getTitleProtection();
2997
2998                                 if ( $title_protection ) {
2999                                         $now = wfTimestampNow();
3000                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
3001
3002                                         if ( !$expiry || $expiry > $now ) {
3003                                                 // Apply the restrictions
3004                                                 $this->mRestrictionsExpiry['create'] = $expiry;
3005                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
3006                                         } else { // Get rid of the old restrictions
3007                                                 $this->mTitleProtection = false;
3008                                         }
3009                                 } else {
3010                                         $this->mRestrictionsExpiry['create'] = 'infinity';
3011                                 }
3012                                 $this->mRestrictionsLoaded = true;
3013                         }
3014                 }
3015         }
3016
3017         /**
3018          * Flush the protection cache in this object and force reload from the database.
3019          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3020          */
3021         public function flushRestrictions() {
3022                 $this->mRestrictionsLoaded = false;
3023                 $this->mTitleProtection = null;
3024         }
3025
3026         /**
3027          * Purge expired restrictions from the page_restrictions table
3028          */
3029         static function purgeExpiredRestrictions() {
3030                 if ( wfReadOnly() ) {
3031                         return;
3032                 }
3033
3034                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3035                         wfGetDB( DB_MASTER ),
3036                         __METHOD__,
3037                         function ( IDatabase $dbw, $fname ) {
3038                                 $dbw->delete(
3039                                         'page_restrictions',
3040                                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3041                                         $fname
3042                                 );
3043                                 $dbw->delete(
3044                                         'protected_titles',
3045                                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3046                                         $fname
3047                                 );
3048                         }
3049                 ) );
3050         }
3051
3052         /**
3053          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3054          *
3055          * @return bool
3056          */
3057         public function hasSubpages() {
3058                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3059                         # Duh
3060                         return false;
3061                 }
3062
3063                 # We dynamically add a member variable for the purpose of this method
3064                 # alone to cache the result.  There's no point in having it hanging
3065                 # around uninitialized in every Title object; therefore we only add it
3066                 # if needed and don't declare it statically.
3067                 if ( $this->mHasSubpages === null ) {
3068                         $this->mHasSubpages = false;
3069                         $subpages = $this->getSubpages( 1 );
3070                         if ( $subpages instanceof TitleArray ) {
3071                                 $this->mHasSubpages = (bool)$subpages->count();
3072                         }
3073                 }
3074
3075                 return $this->mHasSubpages;
3076         }
3077
3078         /**
3079          * Get all subpages of this page.
3080          *
3081          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3082          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3083          *  doesn't allow subpages
3084          */
3085         public function getSubpages( $limit = -1 ) {
3086                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3087                         return array();
3088                 }
3089
3090                 $dbr = wfGetDB( DB_SLAVE );
3091                 $conds['page_namespace'] = $this->getNamespace();
3092                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3093                 $options = array();
3094                 if ( $limit > -1 ) {
3095                         $options['LIMIT'] = $limit;
3096                 }
3097                 $this->mSubpages = TitleArray::newFromResult(
3098                         $dbr->select( 'page',
3099                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3100                                 $conds,
3101                                 __METHOD__,
3102                                 $options
3103                         )
3104                 );
3105                 return $this->mSubpages;
3106         }
3107
3108         /**
3109          * Is there a version of this page in the deletion archive?
3110          *
3111          * @return int The number of archived revisions
3112          */
3113         public function isDeleted() {
3114                 if ( $this->getNamespace() < 0 ) {
3115                         $n = 0;
3116                 } else {
3117                         $dbr = wfGetDB( DB_SLAVE );
3118
3119                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3120                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3121                                 __METHOD__
3122                         );
3123                         if ( $this->getNamespace() == NS_FILE ) {
3124                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3125                                         array( 'fa_name' => $this->getDBkey() ),
3126                                         __METHOD__
3127                                 );
3128                         }
3129                 }
3130                 return (int)$n;
3131         }
3132
3133         /**
3134          * Is there a version of this page in the deletion archive?
3135          *
3136          * @return bool
3137          */
3138         public function isDeletedQuick() {
3139                 if ( $this->getNamespace() < 0 ) {
3140                         return false;
3141                 }
3142                 $dbr = wfGetDB( DB_SLAVE );
3143                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3144                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3145                         __METHOD__
3146                 );
3147                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3148                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3149                                 array( 'fa_name' => $this->getDBkey() ),
3150                                 __METHOD__
3151                         );
3152                 }
3153                 return $deleted;
3154         }
3155
3156         /**
3157          * Get the article ID for this Title from the link cache,
3158          * adding it if necessary
3159          *
3160          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3161          *  for update
3162          * @return int The ID
3163          */
3164         public function getArticleID( $flags = 0 ) {
3165                 if ( $this->getNamespace() < 0 ) {
3166                         $this->mArticleID = 0;
3167                         return $this->mArticleID;
3168                 }
3169                 $linkCache = LinkCache::singleton();
3170                 if ( $flags & self::GAID_FOR_UPDATE ) {
3171                         $oldUpdate = $linkCache->forUpdate( true );
3172                         $linkCache->clearLink( $this );
3173                         $this->mArticleID = $linkCache->addLinkObj( $this );
3174                         $linkCache->forUpdate( $oldUpdate );
3175                 } else {
3176                         if ( -1 == $this->mArticleID ) {
3177                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3178                         }
3179                 }
3180                 return $this->mArticleID;
3181         }
3182
3183         /**
3184          * Is this an article that is a redirect page?
3185          * Uses link cache, adding it if necessary
3186          *
3187          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3188          * @return bool
3189          */
3190         public function isRedirect( $flags = 0 ) {
3191                 if ( !is_null( $this->mRedirect ) ) {
3192                         return $this->mRedirect;
3193                 }
3194                 if ( !$this->getArticleID( $flags ) ) {
3195                         $this->mRedirect = false;
3196                         return $this->mRedirect;
3197                 }
3198
3199                 $linkCache = LinkCache::singleton();
3200                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3201                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3202                 if ( $cached === null ) {
3203                         # Trust LinkCache's state over our own
3204                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3205                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3206                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3207                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3208                         # LinkCache to refresh its data from the master.
3209                         $this->mRedirect = false;
3210                         return $this->mRedirect;
3211                 }
3212
3213                 $this->mRedirect = (bool)$cached;
3214
3215                 return $this->mRedirect;
3216         }
3217
3218         /**
3219          * What is the length of this page?
3220          * Uses link cache, adding it if necessary
3221          *
3222          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3223          * @return int
3224          */
3225         public function getLength( $flags = 0 ) {
3226                 if ( $this->mLength != -1 ) {
3227                         return $this->mLength;
3228                 }
3229                 if ( !$this->getArticleID( $flags ) ) {
3230                         $this->mLength = 0;
3231                         return $this->mLength;
3232                 }
3233                 $linkCache = LinkCache::singleton();
3234                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3235                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3236                 if ( $cached === null ) {
3237                         # Trust LinkCache's state over our own, as for isRedirect()
3238                         $this->mLength = 0;
3239                         return $this->mLength;
3240                 }
3241
3242                 $this->mLength = intval( $cached );
3243
3244                 return $this->mLength;
3245         }
3246
3247         /**
3248          * What is the page_latest field for this page?
3249          *
3250          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3251          * @return int Int or 0 if the page doesn't exist
3252          */
3253         public function getLatestRevID( $flags = 0 ) {
3254                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3255                         return intval( $this->mLatestID );
3256                 }
3257                 if ( !$this->getArticleID( $flags ) ) {
3258                         $this->mLatestID = 0;
3259                         return $this->mLatestID;
3260                 }
3261                 $linkCache = LinkCache::singleton();
3262                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3263                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3264                 if ( $cached === null ) {
3265                         # Trust LinkCache's state over our own, as for isRedirect()
3266                         $this->mLatestID = 0;
3267                         return $this->mLatestID;
3268                 }
3269
3270                 $this->mLatestID = intval( $cached );
3271
3272                 return $this->mLatestID;
3273         }
3274
3275         /**
3276          * This clears some fields in this object, and clears any associated
3277          * keys in the "bad links" section of the link cache.
3278          *
3279          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3280          * loading of the new page_id. It's also called from
3281          * WikiPage::doDeleteArticleReal()
3282          *
3283          * @param int $newid The new Article ID
3284          */
3285         public function resetArticleID( $newid ) {
3286                 $linkCache = LinkCache::singleton();
3287                 $linkCache->clearLink( $this );
3288
3289                 if ( $newid === false ) {
3290                         $this->mArticleID = -1;
3291                 } else {
3292                         $this->mArticleID = intval( $newid );
3293                 }
3294                 $this->mRestrictionsLoaded = false;
3295                 $this->mRestrictions = array();
3296                 $this->mOldRestrictions = false;
3297                 $this->mRedirect = null;
3298                 $this->mLength = -1;
3299                 $this->mLatestID = false;
3300                 $this->mContentModel = false;
3301                 $this->mEstimateRevisions = null;
3302                 $this->mPageLanguage = false;
3303                 $this->mDbPageLanguage = null;
3304                 $this->mIsBigDeletion = null;
3305         }
3306
3307         public static function clearCaches() {
3308                 $linkCache = LinkCache::singleton();
3309                 $linkCache->clear();
3310
3311                 $titleCache = self::getTitleCache();
3312                 $titleCache->clear();
3313         }
3314
3315         /**
3316          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3317          *
3318          * @param string $text Containing title to capitalize
3319          * @param int $ns Namespace index, defaults to NS_MAIN
3320          * @return string Containing capitalized title
3321          */
3322         public static function capitalize( $text, $ns = NS_MAIN ) {
3323                 global $wgContLang;
3324
3325                 if ( MWNamespace::isCapitalized( $ns ) ) {
3326                         return $wgContLang->ucfirst( $text );
3327                 } else {
3328                         return $text;
3329                 }
3330         }
3331
3332         /**
3333          * Secure and split - main initialisation function for this object
3334          *
3335          * Assumes that mDbkeyform has been set, and is urldecoded
3336          * and uses underscores, but not otherwise munged.  This function
3337          * removes illegal characters, splits off the interwiki and
3338          * namespace prefixes, sets the other forms, and canonicalizes
3339          * everything.
3340          *
3341          * @throws MalformedTitleException On invalid titles
3342          * @return bool True on success
3343          */
3344         private function secureAndSplit() {
3345                 # Initialisation
3346                 $this->mInterwiki = '';
3347                 $this->mFragment = '';
3348                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3349
3350                 $dbkey = $this->mDbkeyform;
3351
3352                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3353                 //        the parsing code with Title, while avoiding massive refactoring.
3354                 // @todo: get rid of secureAndSplit, refactor parsing code.
3355                 $titleParser = self::getTitleParser();
3356                 // MalformedTitleException can be thrown here
3357                 $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3358
3359                 # Fill fields
3360                 $this->setFragment( '#' . $parts['fragment'] );
3361                 $this->mInterwiki = $parts['interwiki'];
3362                 $this->mLocalInterwiki = $parts['local_interwiki'];
3363                 $this->mNamespace = $parts['namespace'];
3364                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3365
3366                 $this->mDbkeyform = $parts['dbkey'];
3367                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3368                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3369
3370                 # We already know that some pages won't be in the database!
3371                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3372                         $this->mArticleID = 0;
3373                 }
3374
3375                 return true;
3376         }
3377
3378         /**
3379          * Get an array of Title objects linking to this Title
3380          * Also stores the IDs in the link cache.
3381          *
3382          * WARNING: do not use this function on arbitrary user-supplied titles!
3383          * On heavily-used templates it will max out the memory.
3384          *
3385          * @param array $options May be FOR UPDATE
3386          * @param string $table Table name
3387          * @param string $prefix Fields prefix
3388          * @return Title[] Array of Title objects linking here
3389          */
3390         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3391                 if ( count( $options ) > 0 ) {
3392                         $db = wfGetDB( DB_MASTER );
3393                 } else {
3394                         $db = wfGetDB( DB_SLAVE );
3395                 }
3396
3397                 $res = $db->select(
3398                         array( 'page', $table ),
3399                         self::getSelectFields(),
3400                         array(
3401                                 "{$prefix}_from=page_id",
3402                                 "{$prefix}_namespace" => $this->getNamespace(),
3403                                 "{$prefix}_title" => $this->getDBkey() ),
3404                         __METHOD__,
3405                         $options
3406                 );
3407
3408                 $retVal = array();
3409                 if ( $res->numRows() ) {
3410                         $linkCache = LinkCache::singleton();
3411                         foreach ( $res as $row ) {
3412                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3413                                 if ( $titleObj ) {
3414                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3415                                         $retVal[] = $titleObj;
3416                                 }
3417                         }
3418                 }
3419                 return $retVal;
3420         }
3421
3422         /**
3423          * Get an array of Title objects using this Title as a template
3424          * Also stores the IDs in the link cache.
3425          *
3426          * WARNING: do not use this function on arbitrary user-supplied titles!
3427          * On heavily-used templates it will max out the memory.
3428          *
3429          * @param array $options May be FOR UPDATE
3430          * @return Title[] Array of Title the Title objects linking here
3431          */
3432         public function getTemplateLinksTo( $options = array() ) {
3433                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3434         }
3435
3436         /**
3437          * Get an array of Title objects linked from this Title
3438          * Also stores the IDs in the link cache.
3439          *
3440          * WARNING: do not use this function on arbitrary user-supplied titles!
3441          * On heavily-used templates it will max out the memory.
3442          *
3443          * @param array $options May be FOR UPDATE
3444          * @param string $table Table name
3445          * @param string $prefix Fields prefix
3446          * @return array Array of Title objects linking here
3447          */
3448         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3449                 $id = $this->getArticleID();
3450
3451                 # If the page doesn't exist; there can't be any link from this page
3452                 if ( !$id ) {
3453                         return array();
3454                 }
3455
3456                 if ( count( $options ) > 0 ) {
3457                         $db = wfGetDB( DB_MASTER );
3458                 } else {
3459                         $db = wfGetDB( DB_SLAVE );
3460                 }
3461
3462                 $blNamespace = "{$prefix}_namespace";
3463                 $blTitle = "{$prefix}_title";
3464
3465                 $res = $db->select(
3466                         array( $table, 'page' ),
3467                         array_merge(
3468                                 array( $blNamespace, $blTitle ),
3469                                 WikiPage::selectFields()
3470                         ),
3471                         array( "{$prefix}_from" => $id ),
3472                         __METHOD__,
3473                         $options,
3474                         array( 'page' => array(
3475                                 'LEFT JOIN',
3476                                 array( "page_namespace=$blNamespace", "page_title=$blTitle" )
3477                         ) )
3478                 );
3479
3480                 $retVal = array();
3481                 $linkCache = LinkCache::singleton();
3482                 foreach ( $res as $row ) {
3483                         if ( $row->page_id ) {
3484                                 $titleObj = Title::newFromRow( $row );
3485                         } else {
3486                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3487                                 $linkCache->addBadLinkObj( $titleObj );
3488                         }
3489                         $retVal[] = $titleObj;
3490                 }
3491
3492                 return $retVal;
3493         }
3494
3495         /**
3496          * Get an array of Title objects used on this Title as a template
3497          * Also stores the IDs in the link cache.
3498          *
3499          * WARNING: do not use this function on arbitrary user-supplied titles!
3500          * On heavily-used templates it will max out the memory.
3501          *
3502          * @param array $options May be FOR UPDATE
3503          * @return Title[] Array of Title the Title objects used here
3504          */
3505         public function getTemplateLinksFrom( $options = array() ) {
3506                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3507         }
3508
3509         /**
3510          * Get an array of Title objects referring to non-existent articles linked
3511          * from this page.
3512          *
3513          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3514          *   should use redirect table in this case).
3515          * @return Title[] Array of Title the Title objects
3516          */
3517         public function getBrokenLinksFrom() {
3518                 if ( $this->getArticleID() == 0 ) {
3519                         # All links from article ID 0 are false positives
3520                         return array();
3521                 }
3522
3523                 $dbr = wfGetDB( DB_SLAVE );
3524                 $res = $dbr->select(
3525                         array( 'page', 'pagelinks' ),
3526                         array( 'pl_namespace', 'pl_title' ),
3527                         array(
3528                                 'pl_from' => $this->getArticleID(),
3529                                 'page_namespace IS NULL'
3530                         ),
3531                         __METHOD__, array(),
3532                         array(
3533                                 'page' => array(
3534                                         'LEFT JOIN',
3535                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3536                                 )
3537                         )
3538                 );
3539
3540                 $retVal = array();
3541                 foreach ( $res as $row ) {
3542                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3543                 }
3544                 return $retVal;
3545         }
3546
3547         /**
3548          * Get a list of URLs to purge from the CDN cache when this
3549          * page changes
3550          *
3551          * @return string[] Array of String the URLs
3552          */
3553         public function getCdnUrls() {
3554                 $urls = array(
3555                         $this->getInternalURL(),
3556                         $this->getInternalURL( 'action=history' )
3557                 );
3558
3559                 $pageLang = $this->getPageLanguage();
3560                 if ( $pageLang->hasVariants() ) {
3561                         $variants = $pageLang->getVariants();
3562                         foreach ( $variants as $vCode ) {
3563                                 $urls[] = $this->getInternalURL( $vCode );
3564                         }
3565                 }
3566
3567                 // If we are looking at a css/js user subpage, purge the action=raw.
3568                 if ( $this->isJsSubpage() ) {
3569                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3570                 } elseif ( $this->isCssSubpage() ) {
3571                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3572                 }
3573
3574                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3575                 return $urls;
3576         }
3577
3578         /**
3579          * @deprecated since 1.27 use getCdnUrls()
3580          */
3581         public function getSquidURLs() {
3582                 return $this->getCdnUrls();
3583         }
3584
3585         /**
3586          * Purge all applicable CDN URLs
3587          */
3588         public function purgeSquid() {
3589                 DeferredUpdates::addUpdate(
3590                         new CdnCacheUpdate( $this->getCdnUrls() ),
3591                         DeferredUpdates::PRESEND
3592                 );
3593         }
3594
3595         /**
3596          * Move this page without authentication
3597          *
3598          * @deprecated since 1.25 use MovePage class instead
3599          * @param Title $nt The new page Title
3600          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3601          */
3602         public function moveNoAuth( &$nt ) {
3603                 wfDeprecated( __METHOD__, '1.25' );
3604                 return $this->moveTo( $nt, false );
3605         }
3606
3607         /**
3608          * Check whether a given move operation would be valid.
3609          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3610          *
3611          * @deprecated since 1.25, use MovePage's methods instead
3612          * @param Title $nt The new title
3613          * @param bool $auth Whether to check user permissions (uses $wgUser)
3614          * @param string $reason Is the log summary of the move, used for spam checking
3615          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3616          */
3617         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3618                 global $wgUser;
3619
3620                 if ( !( $nt instanceof Title ) ) {
3621                         // Normally we'd add this to $errors, but we'll get
3622                         // lots of syntax errors if $nt is not an object
3623                         return array( array( 'badtitletext' ) );
3624                 }
3625
3626                 $mp = new MovePage( $this, $nt );
3627                 $errors = $mp->isValidMove()->getErrorsArray();
3628                 if ( $auth ) {
3629                         $errors = wfMergeErrorArrays(
3630                                 $errors,
3631                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3632                         );
3633                 }
3634
3635                 return $errors ?: true;
3636         }
3637
3638         /**
3639          * Check if the requested move target is a valid file move target
3640          * @todo move this to MovePage
3641          * @param Title $nt Target title
3642          * @return array List of errors
3643          */
3644         protected function validateFileMoveOperation( $nt ) {
3645                 global $wgUser;
3646
3647                 $errors = array();
3648
3649                 $destFile = wfLocalFile( $nt );
3650                 $destFile->load( File::READ_LATEST );
3651                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3652                         && !$destFile->exists() && wfFindFile( $nt )
3653                 ) {
3654                         $errors[] = array( 'file-exists-sharedrepo' );
3655                 }
3656
3657                 return $errors;
3658         }
3659
3660         /**
3661          * Move a title to a new location
3662          *
3663          * @deprecated since 1.25, use the MovePage class instead
3664          * @param Title $nt The new title
3665          * @param bool $auth Indicates whether $wgUser's permissions
3666          *  should be checked
3667          * @param string $reason The reason for the move
3668          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3669          *  Ignored if the user doesn't have the suppressredirect right.
3670          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3671          */
3672         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3673                 global $wgUser;
3674                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3675                 if ( is_array( $err ) ) {
3676                         // Auto-block user's IP if the account was "hard" blocked
3677                         $wgUser->spreadAnyEditBlock();
3678                         return $err;
3679                 }
3680                 // Check suppressredirect permission
3681                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3682                         $createRedirect = true;
3683                 }
3684
3685                 $mp = new MovePage( $this, $nt );
3686                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3687                 if ( $status->isOK() ) {
3688                         return true;
3689                 } else {
3690                         return $status->getErrorsArray();
3691                 }
3692         }
3693
3694         /**
3695          * Move this page's subpages to be subpages of $nt
3696          *
3697          * @param Title $nt Move target
3698          * @param bool $auth Whether $wgUser's permissions should be checked
3699          * @param string $reason The reason for the move
3700          * @param bool $createRedirect Whether to create redirects from the old subpages to
3701          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3702          * @return array Array with old page titles as keys, and strings (new page titles) or
3703          *     arrays (errors) as values, or an error array with numeric indices if no pages
3704          *     were moved
3705          */
3706         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3707                 global $wgMaximumMovedPages;
3708                 // Check permissions
3709                 if ( !$this->userCan( 'move-subpages' ) ) {
3710                         return array( 'cant-move-subpages' );
3711                 }
3712                 // Do the source and target namespaces support subpages?
3713                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3714                         return array( 'namespace-nosubpages',
3715                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3716                 }
3717                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3718                         return array( 'namespace-nosubpages',
3719                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3720                 }
3721
3722                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3723                 $retval = array();
3724                 $count = 0;
3725                 foreach ( $subpages as $oldSubpage ) {
3726                         $count++;
3727                         if ( $count > $wgMaximumMovedPages ) {
3728                                 $retval[$oldSubpage->getPrefixedText()] =
3729                                                 array( 'movepage-max-pages',
3730                                                         $wgMaximumMovedPages );
3731                                 break;
3732                         }
3733
3734                         // We don't know whether this function was called before
3735                         // or after moving the root page, so check both
3736                         // $this and $nt
3737                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3738                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3739                         ) {
3740                                 // When moving a page to a subpage of itself,
3741                                 // don't move it twice
3742                                 continue;
3743                         }
3744                         $newPageName = preg_replace(
3745                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3746                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3747                                         $oldSubpage->getDBkey() );
3748                         if ( $oldSubpage->isTalkPage() ) {
3749                                 $newNs = $nt->getTalkPage()->getNamespace();
3750                         } else {
3751                                 $newNs = $nt->getSubjectPage()->getNamespace();
3752                         }
3753                         # Bug 14385: we need makeTitleSafe because the new page names may
3754                         # be longer than 255 characters.
3755                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3756
3757                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3758                         if ( $success === true ) {
3759                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3760                         } else {
3761                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3762                         }
3763                 }
3764                 return $retval;
3765         }
3766
3767         /**
3768          * Checks if this page is just a one-rev redirect.
3769          * Adds lock, so don't use just for light purposes.
3770          *
3771          * @return bool
3772          */
3773         public function isSingleRevRedirect() {
3774                 global $wgContentHandlerUseDB;
3775
3776                 $dbw = wfGetDB( DB_MASTER );
3777
3778                 # Is it a redirect?
3779                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3780                 if ( $wgContentHandlerUseDB ) {
3781                         $fields[] = 'page_content_model';
3782                 }
3783
3784                 $row = $dbw->selectRow( 'page',
3785                         $fields,
3786                         $this->pageCond(),
3787                         __METHOD__,
3788                         array( 'FOR UPDATE' )
3789                 );
3790                 # Cache some fields we may want
3791                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3792                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3793                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3794                 $this->mContentModel = $row && isset( $row->page_content_model )
3795                         ? strval( $row->page_content_model )
3796                         : false;
3797
3798                 if ( !$this->mRedirect ) {
3799                         return false;
3800                 }
3801                 # Does the article have a history?
3802                 $row = $dbw->selectField( array( 'page', 'revision' ),
3803                         'rev_id',
3804                         array( 'page_namespace' => $this->getNamespace(),
3805                                 'page_title' => $this->getDBkey(),
3806                                 'page_id=rev_page',
3807                                 'page_latest != rev_id'
3808                         ),
3809                         __METHOD__,
3810                         array( 'FOR UPDATE' )
3811                 );
3812                 # Return true if there was no history
3813                 return ( $row === false );
3814         }
3815
3816         /**
3817          * Checks if $this can be moved to a given Title
3818          * - Selects for update, so don't call it unless you mean business
3819          *
3820          * @deprecated since 1.25, use MovePage's methods instead
3821          * @param Title $nt The new title to check
3822          * @return bool
3823          */
3824         public function isValidMoveTarget( $nt ) {
3825                 # Is it an existing file?
3826                 if ( $nt->getNamespace() == NS_FILE ) {
3827                         $file = wfLocalFile( $nt );
3828                         $file->load( File::READ_LATEST );
3829                         if ( $file->exists() ) {
3830                                 wfDebug( __METHOD__ . ": file exists\n" );
3831                                 return false;
3832                         }
3833                 }
3834                 # Is it a redirect with no history?
3835                 if ( !$nt->isSingleRevRedirect() ) {
3836                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3837                         return false;
3838                 }
3839                 # Get the article text
3840                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3841                 if ( !is_object( $rev ) ) {
3842                         return false;
3843                 }
3844                 $content = $rev->getContent();
3845                 # Does the redirect point to the source?
3846                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3847                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3848
3849                 if ( $redirTitle ) {
3850                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3851                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3852                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3853                                 return false;
3854                         } else {
3855                                 return true;
3856                         }
3857                 } else {
3858                         # Fail safe (not a redirect after all. strange.)
3859                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3860                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3861                         return false;
3862                 }
3863         }
3864
3865         /**
3866          * Get categories to which this Title belongs and return an array of
3867          * categories' names.
3868          *
3869          * @return array Array of parents in the form:
3870          *        $parent => $currentarticle
3871          */
3872         public function getParentCategories() {
3873                 global $wgContLang;
3874
3875                 $data = array();
3876
3877                 $titleKey = $this->getArticleID();
3878
3879                 if ( $titleKey === 0 ) {
3880                         return $data;
3881                 }
3882
3883                 $dbr = wfGetDB( DB_SLAVE );
3884
3885                 $res = $dbr->select(
3886                         'categorylinks',
3887                         'cl_to',
3888                         array( 'cl_from' => $titleKey ),
3889                         __METHOD__
3890                 );
3891
3892                 if ( $res->numRows() > 0 ) {
3893                         foreach ( $res as $row ) {
3894                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3895                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3896                         }
3897                 }
3898                 return $data;
3899         }
3900
3901         /**
3902          * Get a tree of parent categories
3903          *
3904          * @param array $children Array with the children in the keys, to check for circular refs
3905          * @return array Tree of parent categories
3906          */
3907         public function getParentCategoryTree( $children = array() ) {
3908                 $stack = array();
3909                 $parents = $this->getParentCategories();
3910
3911                 if ( $parents ) {
3912                         foreach ( $parents as $parent => $current ) {
3913                                 if ( array_key_exists( $parent, $children ) ) {
3914                                         # Circular reference
3915                                         $stack[$parent] = array();
3916                                 } else {
3917                                         $nt = Title::newFromText( $parent );
3918                                         if ( $nt ) {
3919                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3920                                         }
3921                                 }
3922                         }
3923                 }
3924
3925                 return $stack;
3926         }
3927
3928         /**
3929          * Get an associative array for selecting this title from
3930          * the "page" table
3931          *
3932          * @return array Array suitable for the $where parameter of DB::select()
3933          */
3934         public function pageCond() {
3935                 if ( $this->mArticleID > 0 ) {
3936                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3937                         return array( 'page_id' => $this->mArticleID );
3938                 } else {
3939                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3940                 }
3941         }
3942
3943         /**
3944          * Get the revision ID of the previous revision
3945          *
3946          * @param int $revId Revision ID. Get the revision that was before this one.
3947          * @param int $flags Title::GAID_FOR_UPDATE
3948          * @return int|bool Old revision ID, or false if none exists
3949          */
3950         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3951                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3952                 $revId = $db->selectField( 'revision', 'rev_id',
3953                         array(
3954                                 'rev_page' => $this->getArticleID( $flags ),
3955                                 'rev_id < ' . intval( $revId )
3956                         ),
3957                         __METHOD__,
3958                         array( 'ORDER BY' => 'rev_id DESC' )
3959                 );
3960
3961                 if ( $revId === false ) {
3962                         return false;
3963                 } else {
3964                         return intval( $revId );
3965                 }
3966         }
3967
3968         /**
3969          * Get the revision ID of the next revision
3970          *
3971          * @param int $revId Revision ID. Get the revision that was after this one.
3972          * @param int $flags Title::GAID_FOR_UPDATE
3973          * @return int|bool Next revision ID, or false if none exists
3974          */
3975         public function getNextRevisionID( $revId, $flags = 0 ) {
3976                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3977                 $revId = $db->selectField( 'revision', 'rev_id',
3978                         array(
3979                                 'rev_page' => $this->getArticleID( $flags ),
3980                                 'rev_id > ' . intval( $revId )
3981                         ),
3982                         __METHOD__,
3983                         array( 'ORDER BY' => 'rev_id' )
3984                 );
3985
3986                 if ( $revId === false ) {
3987                         return false;
3988                 } else {
3989                         return intval( $revId );
3990                 }
3991         }
3992
3993         /**
3994          * Get the first revision of the page
3995          *
3996          * @param int $flags Title::GAID_FOR_UPDATE
3997          * @return Revision|null If page doesn't exist
3998          */
3999         public function getFirstRevision( $flags = 0 ) {
4000                 $pageId = $this->getArticleID( $flags );
4001                 if ( $pageId ) {
4002                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4003                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4004                                 array( 'rev_page' => $pageId ),
4005                                 __METHOD__,
4006                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4007                         );
4008                         if ( $row ) {
4009                                 return new Revision( $row );
4010                         }
4011                 }
4012                 return null;
4013         }
4014
4015         /**
4016          * Get the oldest revision timestamp of this page
4017          *
4018          * @param int $flags Title::GAID_FOR_UPDATE
4019          * @return string MW timestamp
4020          */
4021         public function getEarliestRevTime( $flags = 0 ) {
4022                 $rev = $this->getFirstRevision( $flags );
4023                 return $rev ? $rev->getTimestamp() : null;
4024         }
4025
4026         /**
4027          * Check if this is a new page
4028          *
4029          * @return bool
4030          */
4031         public function isNewPage() {
4032                 $dbr = wfGetDB( DB_SLAVE );
4033                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4034         }
4035
4036         /**
4037          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4038          *
4039          * @return bool
4040          */
4041         public function isBigDeletion() {
4042                 global $wgDeleteRevisionsLimit;
4043
4044                 if ( !$wgDeleteRevisionsLimit ) {
4045                         return false;
4046                 }
4047
4048                 if ( $this->mIsBigDeletion === null ) {
4049                         $dbr = wfGetDB( DB_SLAVE );
4050
4051                         $revCount = $dbr->selectRowCount(
4052                                 'revision',
4053                                 '1',
4054                                 array( 'rev_page' => $this->getArticleID() ),
4055                                 __METHOD__,
4056                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4057                         );
4058
4059                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4060                 }
4061
4062                 return $this->mIsBigDeletion;
4063         }
4064
4065         /**
4066          * Get the approximate revision count of this page.
4067          *
4068          * @return int
4069          */
4070         public function estimateRevisionCount() {
4071                 if ( !$this->exists() ) {
4072                         return 0;
4073                 }
4074
4075                 if ( $this->mEstimateRevisions === null ) {
4076                         $dbr = wfGetDB( DB_SLAVE );
4077                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4078                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4079                 }
4080
4081                 return $this->mEstimateRevisions;
4082         }
4083
4084         /**
4085          * Get the number of revisions between the given revision.
4086          * Used for diffs and other things that really need it.
4087          *
4088          * @param int|Revision $old Old revision or rev ID (first before range)
4089          * @param int|Revision $new New revision or rev ID (first after range)
4090          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4091          * @return int Number of revisions between these revisions.
4092          */
4093         public function countRevisionsBetween( $old, $new, $max = null ) {
4094                 if ( !( $old instanceof Revision ) ) {
4095                         $old = Revision::newFromTitle( $this, (int)$old );
4096                 }
4097                 if ( !( $new instanceof Revision ) ) {
4098                         $new = Revision::newFromTitle( $this, (int)$new );
4099                 }
4100                 if ( !$old || !$new ) {
4101                         return 0; // nothing to compare
4102                 }
4103                 $dbr = wfGetDB( DB_SLAVE );
4104                 $conds = array(
4105                         'rev_page' => $this->getArticleID(),
4106                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4107                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4108                 );
4109                 if ( $max !== null ) {
4110                         return $dbr->selectRowCount( 'revision', '1',
4111                                 $conds,
4112                                 __METHOD__,
4113                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4114                         );
4115                 } else {
4116                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4117                 }
4118         }
4119
4120         /**
4121          * Get the authors between the given revisions or revision IDs.
4122          * Used for diffs and other things that really need it.
4123          *
4124          * @since 1.23
4125          *
4126          * @param int|Revision $old Old revision or rev ID (first before range by default)
4127          * @param int|Revision $new New revision or rev ID (first after range by default)
4128          * @param int $limit Maximum number of authors
4129          * @param string|array $options (Optional): Single option, or an array of options:
4130          *     'include_old' Include $old in the range; $new is excluded.
4131          *     'include_new' Include $new in the range; $old is excluded.
4132          *     'include_both' Include both $old and $new in the range.
4133          *     Unknown option values are ignored.
4134          * @return array|null Names of revision authors in the range; null if not both revisions exist
4135          */
4136         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4137                 if ( !( $old instanceof Revision ) ) {
4138                         $old = Revision::newFromTitle( $this, (int)$old );
4139                 }
4140                 if ( !( $new instanceof Revision ) ) {
4141                         $new = Revision::newFromTitle( $this, (int)$new );
4142                 }
4143                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4144                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4145                 // in the sanity check below?
4146                 if ( !$old || !$new ) {
4147                         return null; // nothing to compare
4148                 }
4149                 $authors = array();
4150                 $old_cmp = '>';
4151                 $new_cmp = '<';
4152                 $options = (array)$options;
4153                 if ( in_array( 'include_old', $options ) ) {
4154                         $old_cmp = '>=';
4155                 }
4156                 if ( in_array( 'include_new', $options ) ) {
4157                         $new_cmp = '<=';
4158                 }
4159                 if ( in_array( 'include_both', $options ) ) {
4160                         $old_cmp = '>=';
4161                         $new_cmp = '<=';
4162                 }
4163                 // No DB query needed if $old and $new are the same or successive revisions:
4164                 if ( $old->getId() === $new->getId() ) {
4165                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4166                                 array() :
4167                                 array( $old->getUserText( Revision::RAW ) );
4168                 } elseif ( $old->getId() === $new->getParentId() ) {
4169                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4170                                 $authors[] = $old->getUserText( Revision::RAW );
4171                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4172                                         $authors[] = $new->getUserText( Revision::RAW );
4173                                 }
4174                         } elseif ( $old_cmp === '>=' ) {
4175                                 $authors[] = $old->getUserText( Revision::RAW );
4176                         } elseif ( $new_cmp === '<=' ) {
4177                                 $authors[] = $new->getUserText( Revision::RAW );
4178                         }
4179                         return $authors;
4180                 }
4181                 $dbr = wfGetDB( DB_SLAVE );
4182                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4183                         array(
4184                                 'rev_page' => $this->getArticleID(),
4185                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4186                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4187                         ), __METHOD__,
4188                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4189                 );
4190                 foreach ( $res as $row ) {
4191                         $authors[] = $row->rev_user_text;
4192                 }
4193                 return $authors;
4194         }
4195
4196         /**
4197          * Get the number of authors between the given revisions or revision IDs.
4198          * Used for diffs and other things that really need it.
4199          *
4200          * @param int|Revision $old Old revision or rev ID (first before range by default)
4201          * @param int|Revision $new New revision or rev ID (first after range by default)
4202          * @param int $limit Maximum number of authors
4203          * @param string|array $options (Optional): Single option, or an array of options:
4204          *     'include_old' Include $old in the range; $new is excluded.
4205          *     'include_new' Include $new in the range; $old is excluded.
4206          *     'include_both' Include both $old and $new in the range.
4207          *     Unknown option values are ignored.
4208          * @return int Number of revision authors in the range; zero if not both revisions exist
4209          */
4210         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4211                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4212                 return $authors ? count( $authors ) : 0;
4213         }
4214
4215         /**
4216          * Compare with another title.
4217          *
4218          * @param Title $title
4219          * @return bool
4220          */
4221         public function equals( Title $title ) {
4222                 // Note: === is necessary for proper matching of number-like titles.
4223                 return $this->getInterwiki() === $title->getInterwiki()
4224                         && $this->getNamespace() == $title->getNamespace()
4225                         && $this->getDBkey() === $title->getDBkey();
4226         }
4227
4228         /**
4229          * Check if this title is a subpage of another title
4230          *
4231          * @param Title $title
4232          * @return bool
4233          */
4234         public function isSubpageOf( Title $title ) {
4235                 return $this->getInterwiki() === $title->getInterwiki()
4236                         && $this->getNamespace() == $title->getNamespace()
4237                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4238         }
4239
4240         /**
4241          * Check if page exists.  For historical reasons, this function simply
4242          * checks for the existence of the title in the page table, and will
4243          * thus return false for interwiki links, special pages and the like.
4244          * If you want to know if a title can be meaningfully viewed, you should
4245          * probably call the isKnown() method instead.
4246          *
4247          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4248          *   from master/for update
4249          * @return bool
4250          */
4251         public function exists( $flags = 0 ) {
4252                 $exists = $this->getArticleID( $flags ) != 0;
4253                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4254                 return $exists;
4255         }
4256
4257         /**
4258          * Should links to this title be shown as potentially viewable (i.e. as
4259          * "bluelinks"), even if there's no record by this title in the page
4260          * table?
4261          *
4262          * This function is semi-deprecated for public use, as well as somewhat
4263          * misleadingly named.  You probably just want to call isKnown(), which
4264          * calls this function internally.
4265          *
4266          * (ISSUE: Most of these checks are cheap, but the file existence check
4267          * can potentially be quite expensive.  Including it here fixes a lot of
4268          * existing code, but we might want to add an optional parameter to skip
4269          * it and any other expensive checks.)
4270          *
4271          * @return bool
4272          */
4273         public function isAlwaysKnown() {
4274                 $isKnown = null;
4275
4276                 /**
4277                  * Allows overriding default behavior for determining if a page exists.
4278                  * If $isKnown is kept as null, regular checks happen. If it's
4279                  * a boolean, this value is returned by the isKnown method.
4280                  *
4281                  * @since 1.20
4282                  *
4283                  * @param Title $title
4284                  * @param bool|null $isKnown
4285                  */
4286                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4287
4288                 if ( !is_null( $isKnown ) ) {
4289                         return $isKnown;
4290                 }
4291
4292                 if ( $this->isExternal() ) {
4293                         return true;  // any interwiki link might be viewable, for all we know
4294                 }
4295
4296                 switch ( $this->mNamespace ) {
4297                         case NS_MEDIA:
4298                         case NS_FILE:
4299                                 // file exists, possibly in a foreign repo
4300                                 return (bool)wfFindFile( $this );
4301                         case NS_SPECIAL:
4302                                 // valid special page
4303                                 return SpecialPageFactory::exists( $this->getDBkey() );
4304                         case NS_MAIN:
4305                                 // selflink, possibly with fragment
4306                                 return $this->mDbkeyform == '';
4307                         case NS_MEDIAWIKI:
4308                                 // known system message
4309                                 return $this->hasSourceText() !== false;
4310                         default:
4311                                 return false;
4312                 }
4313         }
4314
4315         /**
4316          * Does this title refer to a page that can (or might) be meaningfully
4317          * viewed?  In particular, this function may be used to determine if
4318          * links to the title should be rendered as "bluelinks" (as opposed to
4319          * "redlinks" to non-existent pages).
4320          * Adding something else to this function will cause inconsistency
4321          * since LinkHolderArray calls isAlwaysKnown() and does its own
4322          * page existence check.
4323          *
4324          * @return bool
4325          */
4326         public function isKnown() {
4327                 return $this->isAlwaysKnown() || $this->exists();
4328         }
4329
4330         /**
4331          * Does this page have source text?
4332          *
4333          * @return bool
4334          */
4335         public function hasSourceText() {
4336                 if ( $this->exists() ) {
4337                         return true;
4338                 }
4339
4340                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4341                         // If the page doesn't exist but is a known system message, default
4342                         // message content will be displayed, same for language subpages-
4343                         // Use always content language to avoid loading hundreds of languages
4344                         // to get the link color.
4345                         global $wgContLang;
4346                         list( $name, ) = MessageCache::singleton()->figureMessage(
4347                                 $wgContLang->lcfirst( $this->getText() )
4348                         );
4349                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4350                         return $message->exists();
4351                 }
4352
4353                 return false;
4354         }
4355
4356         /**
4357          * Get the default message text or false if the message doesn't exist
4358          *
4359          * @return string|bool
4360          */
4361         public function getDefaultMessageText() {
4362                 global $wgContLang;
4363
4364                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4365                         return false;
4366                 }
4367
4368                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4369                         $wgContLang->lcfirst( $this->getText() )
4370                 );
4371                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4372
4373                 if ( $message->exists() ) {
4374                         return $message->plain();
4375                 } else {
4376                         return false;
4377                 }
4378         }
4379
4380         /**
4381          * Updates page_touched for this page; called from LinksUpdate.php
4382          *
4383          * @param string $purgeTime [optional] TS_MW timestamp
4384          * @return bool True if the update succeeded
4385          */
4386         public function invalidateCache( $purgeTime = null ) {
4387                 if ( wfReadOnly() ) {
4388                         return false;
4389                 }
4390
4391                 if ( $this->mArticleID === 0 ) {
4392                         return true; // avoid gap locking if we know it's not there
4393                 }
4394
4395                 $method = __METHOD__;
4396                 $dbw = wfGetDB( DB_MASTER );
4397                 $conds = $this->pageCond();
4398                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4399                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4400
4401                         $dbw->update(
4402                                 'page',
4403                                 array( 'page_touched' => $dbTimestamp ),
4404                                 $conds + array( 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ),
4405                                 $method
4406                         );
4407                 } );
4408
4409                 return true;
4410         }
4411
4412         /**
4413          * Update page_touched timestamps and send CDN purge messages for
4414          * pages linking to this title. May be sent to the job queue depending
4415          * on the number of links. Typically called on create and delete.
4416          */
4417         public function touchLinks() {
4418                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4419                 if ( $this->getNamespace() == NS_CATEGORY ) {
4420                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4421                 }
4422         }
4423
4424         /**
4425          * Get the last touched timestamp
4426          *
4427          * @param IDatabase $db Optional db
4428          * @return string Last-touched timestamp
4429          */
4430         public function getTouched( $db = null ) {
4431                 if ( $db === null ) {
4432                         $db = wfGetDB( DB_SLAVE );
4433                 }
4434                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4435                 return $touched;
4436         }
4437
4438         /**
4439          * Get the timestamp when this page was updated since the user last saw it.
4440          *
4441          * @param User $user
4442          * @return string|null
4443          */
4444         public function getNotificationTimestamp( $user = null ) {
4445                 global $wgUser;
4446
4447                 // Assume current user if none given
4448                 if ( !$user ) {
4449                         $user = $wgUser;
4450                 }
4451                 // Check cache first
4452                 $uid = $user->getId();
4453                 if ( !$uid ) {
4454                         return false;
4455                 }
4456                 // avoid isset here, as it'll return false for null entries
4457                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4458                         return $this->mNotificationTimestamp[$uid];
4459                 }
4460                 // Don't cache too much!
4461                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4462                         $this->mNotificationTimestamp = array();
4463                 }
4464
4465                 $watchedItem = WatchedItem::fromUserTitle( $user, $this );
4466                 $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4467
4468                 return $this->mNotificationTimestamp[$uid];
4469         }
4470
4471         /**
4472          * Generate strings used for xml 'id' names in monobook tabs
4473          *
4474          * @param string $prepend Defaults to 'nstab-'
4475          * @return string XML 'id' name
4476          */
4477         public function getNamespaceKey( $prepend = 'nstab-' ) {
4478                 global $wgContLang;
4479                 // Gets the subject namespace if this title
4480                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4481                 // Checks if canonical namespace name exists for namespace
4482                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4483                         // Uses canonical namespace name
4484                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4485                 } else {
4486                         // Uses text of namespace
4487                         $namespaceKey = $this->getSubjectNsText();
4488                 }
4489                 // Makes namespace key lowercase
4490                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4491                 // Uses main
4492                 if ( $namespaceKey == '' ) {
4493                         $namespaceKey = 'main';
4494                 }
4495                 // Changes file to image for backwards compatibility
4496                 if ( $namespaceKey == 'file' ) {
4497                         $namespaceKey = 'image';
4498                 }
4499                 return $prepend . $namespaceKey;
4500         }
4501
4502         /**
4503          * Get all extant redirects to this Title
4504          *
4505          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4506          * @return Title[] Array of Title redirects to this title
4507          */
4508         public function getRedirectsHere( $ns = null ) {
4509                 $redirs = array();
4510
4511                 $dbr = wfGetDB( DB_SLAVE );
4512                 $where = array(
4513                         'rd_namespace' => $this->getNamespace(),
4514                         'rd_title' => $this->getDBkey(),
4515                         'rd_from = page_id'
4516                 );
4517                 if ( $this->isExternal() ) {
4518                         $where['rd_interwiki'] = $this->getInterwiki();
4519                 } else {
4520                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4521                 }
4522                 if ( !is_null( $ns ) ) {
4523                         $where['page_namespace'] = $ns;
4524                 }
4525
4526                 $res = $dbr->select(
4527                         array( 'redirect', 'page' ),
4528                         array( 'page_namespace', 'page_title' ),
4529                         $where,
4530                         __METHOD__
4531                 );
4532
4533                 foreach ( $res as $row ) {
4534                         $redirs[] = self::newFromRow( $row );
4535                 }
4536                 return $redirs;
4537         }
4538
4539         /**
4540          * Check if this Title is a valid redirect target
4541          *
4542          * @return bool
4543          */
4544         public function isValidRedirectTarget() {
4545                 global $wgInvalidRedirectTargets;
4546
4547                 if ( $this->isSpecialPage() ) {
4548                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4549                         if ( $this->isSpecial( 'Userlogout' ) ) {
4550                                 return false;
4551                         }
4552
4553                         foreach ( $wgInvalidRedirectTargets as $target ) {
4554                                 if ( $this->isSpecial( $target ) ) {
4555                                         return false;
4556                                 }
4557                         }
4558                 }
4559
4560                 return true;
4561         }
4562
4563         /**
4564          * Get a backlink cache object
4565          *
4566          * @return BacklinkCache
4567          */
4568         public function getBacklinkCache() {
4569                 return BacklinkCache::get( $this );
4570         }
4571
4572         /**
4573          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4574          *
4575          * @return bool
4576          */
4577         public function canUseNoindex() {
4578                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4579
4580                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4581                         ? $wgContentNamespaces
4582                         : $wgExemptFromUserRobotsControl;
4583
4584                 return !in_array( $this->mNamespace, $bannedNamespaces );
4585
4586         }
4587
4588         /**
4589          * Returns the raw sort key to be used for categories, with the specified
4590          * prefix.  This will be fed to Collation::getSortKey() to get a
4591          * binary sortkey that can be used for actual sorting.
4592          *
4593          * @param string $prefix The prefix to be used, specified using
4594          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4595          *   prefix.
4596          * @return string
4597          */
4598         public function getCategorySortkey( $prefix = '' ) {
4599                 $unprefixed = $this->getText();
4600
4601                 // Anything that uses this hook should only depend
4602                 // on the Title object passed in, and should probably
4603                 // tell the users to run updateCollations.php --force
4604                 // in order to re-sort existing category relations.
4605                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4606                 if ( $prefix !== '' ) {
4607                         # Separate with a line feed, so the unprefixed part is only used as
4608                         # a tiebreaker when two pages have the exact same prefix.
4609                         # In UCA, tab is the only character that can sort above LF
4610                         # so we strip both of them from the original prefix.
4611                         $prefix = strtr( $prefix, "\n\t", '  ' );
4612                         return "$prefix\n$unprefixed";
4613                 }
4614                 return $unprefixed;
4615         }
4616
4617         /**
4618          * Get the language in which the content of this page is written in
4619          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4620          * e.g. $wgLang (such as special pages, which are in the user language).
4621          *
4622          * @since 1.18
4623          * @return Language
4624          */
4625         public function getPageLanguage() {
4626                 global $wgLang, $wgLanguageCode;
4627                 if ( $this->isSpecialPage() ) {
4628                         // special pages are in the user language
4629                         return $wgLang;
4630                 }
4631
4632                 // Checking if DB language is set
4633                 if ( $this->mDbPageLanguage ) {
4634                         return wfGetLangObj( $this->mDbPageLanguage );
4635                 }
4636
4637                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4638                         // Note that this may depend on user settings, so the cache should
4639                         // be only per-request.
4640                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4641                         // content to determine the page language!
4642                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4643                         // tests.
4644                         $contentHandler = ContentHandler::getForTitle( $this );
4645                         $langObj = $contentHandler->getPageLanguage( $this );
4646                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4647                 } else {
4648                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4649                 }
4650
4651                 return $langObj;
4652         }
4653
4654         /**
4655          * Get the language in which the content of this page is written when
4656          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4657          * e.g. $wgLang (such as special pages, which are in the user language).
4658          *
4659          * @since 1.20
4660          * @return Language
4661          */
4662         public function getPageViewLanguage() {
4663                 global $wgLang;
4664
4665                 if ( $this->isSpecialPage() ) {
4666                         // If the user chooses a variant, the content is actually
4667                         // in a language whose code is the variant code.
4668                         $variant = $wgLang->getPreferredVariant();
4669                         if ( $wgLang->getCode() !== $variant ) {
4670                                 return Language::factory( $variant );
4671                         }
4672
4673                         return $wgLang;
4674                 }
4675
4676                 // @note Can't be cached persistently, depends on user settings.
4677                 // @note ContentHandler::getPageViewLanguage() may need to load the
4678                 //   content to determine the page language!
4679                 $contentHandler = ContentHandler::getForTitle( $this );
4680                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4681                 return $pageLang;
4682         }
4683
4684         /**
4685          * Get a list of rendered edit notices for this page.
4686          *
4687          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4688          * they will already be wrapped in paragraphs.
4689          *
4690          * @since 1.21
4691          * @param int $oldid Revision ID that's being edited
4692          * @return array
4693          */
4694         public function getEditNotices( $oldid = 0 ) {
4695                 $notices = array();
4696
4697                 // Optional notice for the entire namespace
4698                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4699                 $msg = wfMessage( $editnotice_ns );
4700                 if ( $msg->exists() ) {
4701                         $html = $msg->parseAsBlock();
4702                         // Edit notices may have complex logic, but output nothing (T91715)
4703                         if ( trim( $html ) !== '' ) {
4704                                 $notices[$editnotice_ns] = Html::rawElement(
4705                                         'div',
4706                                         array( 'class' => array(
4707                                                 'mw-editnotice',
4708                                                 'mw-editnotice-namespace',
4709                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4710                                         ) ),
4711                                         $html
4712                                 );
4713                         }
4714                 }
4715
4716                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4717                         // Optional notice for page itself and any parent page
4718                         $parts = explode( '/', $this->getDBkey() );
4719                         $editnotice_base = $editnotice_ns;
4720                         while ( count( $parts ) > 0 ) {
4721                                 $editnotice_base .= '-' . array_shift( $parts );
4722                                 $msg = wfMessage( $editnotice_base );
4723                                 if ( $msg->exists() ) {
4724                                         $html = $msg->parseAsBlock();
4725                                         if ( trim( $html ) !== '' ) {
4726                                                 $notices[$editnotice_base] = Html::rawElement(
4727                                                         'div',
4728                                                         array( 'class' => array(
4729                                                                 'mw-editnotice',
4730                                                                 'mw-editnotice-base',
4731                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4732                                                         ) ),
4733                                                         $html
4734                                                 );
4735                                         }
4736                                 }
4737                         }
4738                 } else {
4739                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4740                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4741                         $msg = wfMessage( $editnoticeText );
4742                         if ( $msg->exists() ) {
4743                                 $html = $msg->parseAsBlock();
4744                                 if ( trim( $html ) !== '' ) {
4745                                         $notices[$editnoticeText] = Html::rawElement(
4746                                                 'div',
4747                                                 array( 'class' => array(
4748                                                         'mw-editnotice',
4749                                                         'mw-editnotice-page',
4750                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4751                                                 ) ),
4752                                                 $html
4753                                         );
4754                                 }
4755                         }
4756                 }
4757
4758                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4759                 return $notices;
4760         }
4761
4762         /**
4763          * @return array
4764          */
4765         public function __sleep() {
4766                 return array(
4767                         'mNamespace',
4768                         'mDbkeyform',
4769                         'mFragment',
4770                         'mInterwiki',
4771                         'mLocalInterwiki',
4772                         'mUserCaseDBKey',
4773                         'mDefaultNamespace',
4774                 );
4775         }
4776
4777         public function __wakeup() {
4778                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4779                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4780                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4781         }
4782
4783 }