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 MediaWikiTitleCodec
 165          */
 166         private static function getMediaWikiTitleCodec() {
 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 getMediaWikiTitleCodec() returns a MediaWikiTitleCodec,
 204                 //      which implements TitleFormatter.
 205                 return self::getMediaWikiTitleCodec();
 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|int|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                 // DWIM: Integers can be passed in here when page titles are used as array keys.
 274                 if ( $text !== null && !is_string( $text ) && !is_int( $text ) ) {
 275                         wfDebugLog( 'T76305', wfGetAllCallers( 5 ) );
 276                         return null;
 277                 }
 278                 if ( $text === null ) {
 279                         return null;
 280                 }
 281
 282                 try {
 283                         return Title::newFromTextThrow( strval( $text ), $defaultNamespace );
 284                 } catch ( MalformedTitleException $ex ) {
 285                         return null;
 286                 }
 287         }
 288
 289         /**
 290          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 291          * rather than returning null.
 292          *
 293          * The exception subclasses encode detailed information about why the title is invalid.
 294          *
 295          * @see Title::newFromText
 296          *
 297          * @since 1.25
 298          * @param string $text Title text to check
 299          * @param int $defaultNamespace
 300          * @throws MalformedTitleException If the title is invalid
 301          * @return Title
 302          */
 303         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 304                 if ( is_object( $text ) ) {
 305                         throw new MWException( '$text must be a string, given an object' );
 306                 }
 307
 308                 $titleCache = self::getTitleCache();
 309
 310                 // Wiki pages often contain multiple links to the same page.
 311                 // Title normalization and parsing can become expensive on pages with many
 312                 // links, so we can save a little time by caching them.
 313                 // In theory these are value objects and won't get changed...
 314                 if ( $defaultNamespace == NS_MAIN ) {
 315                         $t = $titleCache->get( $text );
 316                         if ( $t ) {
 317                                 return $t;
 318                         }
 319                 }
 320
 321                 // Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 322                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 323
 324                 $t = new Title();
 325                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 326                 $t->mDefaultNamespace = intval( $defaultNamespace );
 327
 328                 $t->secureAndSplit();
 329                 if ( $defaultNamespace == NS_MAIN ) {
 330                         $titleCache->set( $text, $t );
 331                 }
 332                 return $t;
 333         }
 334
 335         /**
 336          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 337          *
 338          * Example of wrong and broken code:
 339          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 340          *
 341          * Example of right code:
 342          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 343          *
 344          * Create a new Title from URL-encoded text. Ensures that
 345          * the given title's length does not exceed the maximum.
 346          *
 347          * @param string $url The title, as might be taken from a URL
 348          * @return Title|null The new object, or null on an error
 349          */
 350         public static function newFromURL( $url ) {
 351                 $t = new Title();
 352
 353                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 354                 # but some URLs used it as a space replacement and they still come
 355                 # from some external search tools.
 356                 if ( strpos( self::legalChars(), '+' ) === false ) {
 357                         $url = strtr( $url, '+', ' ' );
 358                 }
 359
 360                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 361
 362                 try {
 363                         $t->secureAndSplit();
 364                         return $t;
 365                 } catch ( MalformedTitleException $ex ) {
 366                         return null;
 367                 }
 368         }
 369
 370         /**
 371          * @return HashBagOStuff
 372          */
 373         private static function getTitleCache() {
 374                 if ( self::$titleCache == null ) {
 375                         self::$titleCache = new HashBagOStuff( array( 'maxKeys' => self::CACHE_MAX ) );
 376                 }
 377                 return self::$titleCache;
 378         }
 379
 380         /**
 381          * Returns a list of fields that are to be selected for initializing Title
 382          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 383          * whether to include page_content_model.
 384          *
 385          * @return array
 386          */
 387         protected static function getSelectFields() {
 388                 global $wgContentHandlerUseDB;
 389
 390                 $fields = array(
 391                         'page_namespace', 'page_title', 'page_id',
 392                         'page_len', 'page_is_redirect', 'page_latest',
 393                 );
 394
 395                 if ( $wgContentHandlerUseDB ) {
 396                         $fields[] = 'page_content_model';
 397                 }
 398
 399                 return $fields;
 400         }
 401
 402         /**
 403          * Create a new Title from an article ID
 404          *
 405          * @param int $id The page_id corresponding to the Title to create
 406          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 407          * @return Title|null The new object, or null on an error
 408          */
 409         public static function newFromID( $id, $flags = 0 ) {
 410                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 411                 $row = $db->selectRow(
 412                         'page',
 413                         self::getSelectFields(),
 414                         array( 'page_id' => $id ),
 415                         __METHOD__
 416                 );
 417                 if ( $row !== false ) {
 418                         $title = Title::newFromRow( $row );
 419                 } else {
 420                         $title = null;
 421                 }
 422                 return $title;
 423         }
 424
 425         /**
 426          * Make an array of titles from an array of IDs
 427          *
 428          * @param int[] $ids Array of IDs
 429          * @return Title[] Array of Titles
 430          */
 431         public static function newFromIDs( $ids ) {
 432                 if ( !count( $ids ) ) {
 433                         return array();
 434                 }
 435                 $dbr = wfGetDB( DB_SLAVE );
 436
 437                 $res = $dbr->select(
 438                         'page',
 439                         self::getSelectFields(),
 440                         array( 'page_id' => $ids ),
 441                         __METHOD__
 442                 );
 443
 444                 $titles = array();
 445                 foreach ( $res as $row ) {
 446                         $titles[] = Title::newFromRow( $row );
 447                 }
 448                 return $titles;
 449         }
 450
 451         /**
 452          * Make a Title object from a DB row
 453          *
 454          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 455          * @return Title Corresponding Title
 456          */
 457         public static function newFromRow( $row ) {
 458                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 459                 $t->loadFromRow( $row );
 460                 return $t;
 461         }
 462
 463         /**
 464          * Load Title object fields from a DB row.
 465          * If false is given, the title will be treated as non-existing.
 466          *
 467          * @param stdClass|bool $row Database row
 468          */
 469         public function loadFromRow( $row ) {
 470                 if ( $row ) { // page found
 471                         if ( isset( $row->page_id ) ) {
 472                                 $this->mArticleID = (int)$row->page_id;
 473                         }
 474                         if ( isset( $row->page_len ) ) {
 475                                 $this->mLength = (int)$row->page_len;
 476                         }
 477                         if ( isset( $row->page_is_redirect ) ) {
 478                                 $this->mRedirect = (bool)$row->page_is_redirect;
 479                         }
 480                         if ( isset( $row->page_latest ) ) {
 481                                 $this->mLatestID = (int)$row->page_latest;
 482                         }
 483                         if ( isset( $row->page_content_model ) ) {
 484                                 $this->mContentModel = strval( $row->page_content_model );
 485                         } else {
 486                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 487                         }
 488                         if ( isset( $row->page_lang ) ) {
 489                                 $this->mDbPageLanguage = (string)$row->page_lang;
 490                         }
 491                         if ( isset( $row->page_restrictions ) ) {
 492                                 $this->mOldRestrictions = $row->page_restrictions;
 493                         }
 494                 } else { // page not found
 495                         $this->mArticleID = 0;
 496                         $this->mLength = 0;
 497                         $this->mRedirect = false;
 498                         $this->mLatestID = 0;
 499                         $this->mContentModel = false; # initialized lazily in getContentModel()
 500                 }
 501         }
 502
 503         /**
 504          * Create a new Title from a namespace index and a DB key.
 505          * It's assumed that $ns and $title are *valid*, for instance when
 506          * they came directly from the database or a special page name.
 507          * For convenience, spaces are converted to underscores so that
 508          * eg user_text fields can be used directly.
 509          *
 510          * @param int $ns The namespace of the article
 511          * @param string $title The unprefixed database key form
 512          * @param string $fragment The link fragment (after the "#")
 513          * @param string $interwiki The interwiki prefix
 514          * @return Title The new object
 515          */
 516         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 517                 $t = new Title();
 518                 $t->mInterwiki = $interwiki;
 519                 $t->mFragment = $fragment;
 520                 $t->mNamespace = $ns = intval( $ns );
 521                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 522                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 523                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 524                 $t->mTextform = strtr( $title, '_', ' ' );
 525                 $t->mContentModel = false; # initialized lazily in getContentModel()
 526                 return $t;
 527         }
 528
 529         /**
 530          * Create a new Title from a namespace index and a DB key.
 531          * The parameters will be checked for validity, which is a bit slower
 532          * than makeTitle() but safer for user-provided data.
 533          *
 534          * @param int $ns The namespace of the article
 535          * @param string $title Database key form
 536          * @param string $fragment The link fragment (after the "#")
 537          * @param string $interwiki Interwiki prefix
 538          * @return Title|null The new object, or null on an error
 539          */
 540         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 541                 if ( !MWNamespace::exists( $ns ) ) {
 542                         return null;
 543                 }
 544
 545                 $t = new Title();
 546                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 547
 548                 try {
 549                         $t->secureAndSplit();
 550                         return $t;
 551                 } catch ( MalformedTitleException $ex ) {
 552                         return null;
 553                 }
 554         }
 555
 556         /**
 557          * Create a new Title for the Main Page
 558          *
 559          * @return Title The new object
 560          */
 561         public static function newMainPage() {
 562                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 563                 // Don't give fatal errors if the message is broken
 564                 if ( !$title ) {
 565                         $title = Title::newFromText( 'Main Page' );
 566                 }
 567                 return $title;
 568         }
 569
 570         /**
 571          * Extract a redirect destination from a string and return the
 572          * Title, or null if the text doesn't contain a valid redirect
 573          * This will only return the very next target, useful for
 574          * the redirect table and other checks that don't need full recursion
 575          *
 576          * @param string $text Text with possible redirect
 577          * @return Title The corresponding Title
 578          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 579          */
 580         public static function newFromRedirect( $text ) {
 581                 ContentHandler::deprecated( __METHOD__, '1.21' );
 582
 583                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 584                 return $content->getRedirectTarget();
 585         }
 586
 587         /**
 588          * Extract a redirect destination from a string and return the
 589          * Title, or null if the text doesn't contain a valid redirect
 590          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 591          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 592          *
 593          * @param string $text Text with possible redirect
 594          * @return Title
 595          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 596          */
 597         public static function newFromRedirectRecurse( $text ) {
 598                 ContentHandler::deprecated( __METHOD__, '1.21' );
 599
 600                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 601                 return $content->getUltimateRedirectTarget();
 602         }
 603
 604         /**
 605          * Extract a redirect destination from a string and return an
 606          * array of Titles, or null if the text doesn't contain a valid redirect
 607          * The last element in the array is the final destination after all redirects
 608          * have been resolved (up to $wgMaxRedirects times)
 609          *
 610          * @param string $text Text with possible redirect
 611          * @return Title[] Array of Titles, with the destination last
 612          * @deprecated since 1.21, use Content::getRedirectChain instead.
 613          */
 614         public static function newFromRedirectArray( $text ) {
 615                 ContentHandler::deprecated( __METHOD__, '1.21' );
 616
 617                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 618                 return $content->getRedirectChain();
 619         }
 620
 621         /**
 622          * Get the prefixed DB key associated with an ID
 623          *
 624          * @param int $id The page_id of the article
 625          * @return Title|null An object representing the article, or null if no such article was found
 626          */
 627         public static function nameOf( $id ) {
 628                 $dbr = wfGetDB( DB_SLAVE );
 629
 630                 $s = $dbr->selectRow(
 631                         'page',
 632                         array( 'page_namespace', 'page_title' ),
 633                         array( 'page_id' => $id ),
 634                         __METHOD__
 635                 );
 636                 if ( $s === false ) {
 637                         return null;
 638                 }
 639
 640                 $n = self::makeName( $s->page_namespace, $s->page_title );
 641                 return $n;
 642         }
 643
 644         /**
 645          * Get a regex character class describing the legal characters in a link
 646          *
 647          * @return string The list of characters, not delimited
 648          */
 649         public static function legalChars() {
 650                 global $wgLegalTitleChars;
 651                 return $wgLegalTitleChars;
 652         }
 653
 654         /**
 655          * Returns a simple regex that will match on characters and sequences invalid in titles.
 656          * Note that this doesn't pick up many things that could be wrong with titles, but that
 657          * replacing this regex with something valid will make many titles valid.
 658          *
 659          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 660          *
 661          * @return string Regex string
 662          */
 663         static function getTitleInvalidRegex() {
 664                 wfDeprecated( __METHOD__, '1.25' );
 665                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 666         }
 667
 668         /**
 669          * Utility method for converting a character sequence from bytes to Unicode.
 670          *
 671          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 672          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 673          *
 674          * @param string $byteClass
 675          * @return string
 676          */
 677         public static function convertByteClassToUnicodeClass( $byteClass ) {
 678                 $length = strlen( $byteClass );
 679                 // Input token queue
 680                 $x0 = $x1 = $x2 = '';
 681                 // Decoded queue
 682                 $d0 = $d1 = $d2 = '';
 683                 // Decoded integer codepoints
 684                 $ord0 = $ord1 = $ord2 = 0;
 685                 // Re-encoded queue
 686                 $r0 = $r1 = $r2 = '';
 687                 // Output
 688                 $out = '';
 689                 // Flags
 690                 $allowUnicode = false;
 691                 for ( $pos = 0; $pos < $length; $pos++ ) {
 692                         // Shift the queues down
 693                         $x2 = $x1;
 694                         $x1 = $x0;
 695                         $d2 = $d1;
 696                         $d1 = $d0;
 697                         $ord2 = $ord1;
 698                         $ord1 = $ord0;
 699                         $r2 = $r1;
 700                         $r1 = $r0;
 701                         // Load the current input token and decoded values
 702                         $inChar = $byteClass[$pos];
 703                         if ( $inChar == '\\' ) {
 704                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 705                                         $x0 = $inChar . $m[0];
 706                                         $d0 = chr( hexdec( $m[1] ) );
 707                                         $pos += strlen( $m[0] );
 708                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 709                                         $x0 = $inChar . $m[0];
 710                                         $d0 = chr( octdec( $m[0] ) );
 711                                         $pos += strlen( $m[0] );
 712                                 } elseif ( $pos + 1 >= $length ) {
 713                                         $x0 = $d0 = '\\';
 714                                 } else {
 715                                         $d0 = $byteClass[$pos + 1];
 716                                         $x0 = $inChar . $d0;
 717                                         $pos += 1;
 718                                 }
 719                         } else {
 720                                 $x0 = $d0 = $inChar;
 721                         }
 722                         $ord0 = ord( $d0 );
 723                         // Load the current re-encoded value
 724                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 725                                 $r0 = sprintf( '\x%02x', $ord0 );
 726                         } elseif ( $ord0 >= 0x80 ) {
 727                                 // Allow unicode if a single high-bit character appears
 728                                 $r0 = sprintf( '\x%02x', $ord0 );
 729                                 $allowUnicode = true;
 730                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 731                                 $r0 = '\\' . $d0;
 732                         } else {
 733                                 $r0 = $d0;
 734                         }
 735                         // Do the output
 736                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 737                                 // Range
 738                                 if ( $ord2 > $ord0 ) {
 739                                         // Empty range
 740                                 } elseif ( $ord0 >= 0x80 ) {
 741                                         // Unicode range
 742                                         $allowUnicode = true;
 743                                         if ( $ord2 < 0x80 ) {
 744                                                 // Keep the non-unicode section of the range
 745                                                 $out .= "$r2-\\x7F";
 746                                         }
 747                                 } else {
 748                                         // Normal range
 749                                         $out .= "$r2-$r0";
 750                                 }
 751                                 // Reset state to the initial value
 752                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 753                         } elseif ( $ord2 < 0x80 ) {
 754                                 // ASCII character
 755                                 $out .= $r2;
 756                         }
 757                 }
 758                 if ( $ord1 < 0x80 ) {
 759                         $out .= $r1;
 760                 }
 761                 if ( $ord0 < 0x80 ) {
 762                         $out .= $r0;
 763                 }
 764                 if ( $allowUnicode ) {
 765                         $out .= '\u0080-\uFFFF';
 766                 }
 767                 return $out;
 768         }
 769
 770         /**
 771          * Make a prefixed DB key from a DB key and a namespace index
 772          *
 773          * @param int $ns Numerical representation of the namespace
 774          * @param string $title The DB key form the title
 775          * @param string $fragment The link fragment (after the "#")
 776          * @param string $interwiki The interwiki prefix
 777          * @param bool $canonicalNamespace If true, use the canonical name for
 778          *   $ns instead of the localized version.
 779          * @return string The prefixed form of the title
 780          */
 781         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 782                 $canonicalNamespace = false
 783         ) {
 784                 global $wgContLang;
 785
 786                 if ( $canonicalNamespace ) {
 787                         $namespace = MWNamespace::getCanonicalName( $ns );
 788                 } else {
 789                         $namespace = $wgContLang->getNsText( $ns );
 790                 }
 791                 $name = $namespace == '' ? $title : "$namespace:$title";
 792                 if ( strval( $interwiki ) != '' ) {
 793                         $name = "$interwiki:$name";
 794                 }
 795                 if ( strval( $fragment ) != '' ) {
 796                         $name .= '#' . $fragment;
 797                 }
 798                 return $name;
 799         }
 800
 801         /**
 802          * Escape a text fragment, say from a link, for a URL
 803          *
 804          * @param string $fragment Containing a URL or link fragment (after the "#")
 805          * @return string Escaped string
 806          */
 807         static function escapeFragmentForURL( $fragment ) {
 808                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 809                 # fragments appear not to work in IE (at least up to 7) or in at least
 810                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 811                 # to care if they aren't encoded.
 812                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 813         }
 814
 815         /**
 816          * Callback for usort() to do title sorts by (namespace, title)
 817          *
 818          * @param Title $a
 819          * @param Title $b
 820          *
 821          * @return int Result of string comparison, or namespace comparison
 822          */
 823         public static function compare( $a, $b ) {
 824                 if ( $a->getNamespace() == $b->getNamespace() ) {
 825                         return strcmp( $a->getText(), $b->getText() );
 826                 } else {
 827                         return $a->getNamespace() - $b->getNamespace();
 828                 }
 829         }
 830
 831         /**
 832          * Determine whether the object refers to a page within
 833          * this project (either this wiki or a wiki with a local
 834          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 835          *
 836          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 837          */
 838         public function isLocal() {
 839                 if ( $this->isExternal() ) {
 840                         $iw = Interwiki::fetch( $this->mInterwiki );
 841                         if ( $iw ) {
 842                                 return $iw->isLocal();
 843                         }
 844                 }
 845                 return true;
 846         }
 847
 848         /**
 849          * Is this Title interwiki?
 850          *
 851          * @return bool
 852          */
 853         public function isExternal() {
 854                 return $this->mInterwiki !== '';
 855         }
 856
 857         /**
 858          * Get the interwiki prefix
 859          *
 860          * Use Title::isExternal to check if a interwiki is set
 861          *
 862          * @return string Interwiki prefix
 863          */
 864         public function getInterwiki() {
 865                 return $this->mInterwiki;
 866         }
 867
 868         /**
 869          * Was this a local interwiki link?
 870          *
 871          * @return bool
 872          */
 873         public function wasLocalInterwiki() {
 874                 return $this->mLocalInterwiki;
 875         }
 876
 877         /**
 878          * Determine whether the object refers to a page within
 879          * this project and is transcludable.
 880          *
 881          * @return bool True if this is transcludable
 882          */
 883         public function isTrans() {
 884                 if ( !$this->isExternal() ) {
 885                         return false;
 886                 }
 887
 888                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 889         }
 890
 891         /**
 892          * Returns the DB name of the distant wiki which owns the object.
 893          *
 894          * @return string The DB name
 895          */
 896         public function getTransWikiID() {
 897                 if ( !$this->isExternal() ) {
 898                         return false;
 899                 }
 900
 901                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 902         }
 903
 904         /**
 905          * Get a TitleValue object representing this Title.
 906          *
 907          * @note Not all valid Titles have a corresponding valid TitleValue
 908          * (e.g. TitleValues cannot represent page-local links that have a
 909          * fragment but no title text).
 910          *
 911          * @return TitleValue|null
 912          */
 913         public function getTitleValue() {
 914                 if ( $this->mTitleValue === null ) {
 915                         try {
 916                                 $this->mTitleValue = new TitleValue(
 917                                         $this->getNamespace(),
 918                                         $this->getDBkey(),
 919                                         $this->getFragment() );
 920                         } catch ( InvalidArgumentException $ex ) {
 921                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 922                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 923                         }
 924                 }
 925
 926                 return $this->mTitleValue;
 927         }
 928
 929         /**
 930          * Get the text form (spaces not underscores) of the main part
 931          *
 932          * @return string Main part of the title
 933          */
 934         public function getText() {
 935                 return $this->mTextform;
 936         }
 937
 938         /**
 939          * Get the URL-encoded form of the main part
 940          *
 941          * @return string Main part of the title, URL-encoded
 942          */
 943         public function getPartialURL() {
 944                 return $this->mUrlform;
 945         }
 946
 947         /**
 948          * Get the main part with underscores
 949          *
 950          * @return string Main part of the title, with underscores
 951          */
 952         public function getDBkey() {
 953                 return $this->mDbkeyform;
 954         }
 955
 956         /**
 957          * Get the DB key with the initial letter case as specified by the user
 958          *
 959          * @return string DB key
 960          */
 961         function getUserCaseDBKey() {
 962                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 963                         return $this->mUserCaseDBKey;
 964                 } else {
 965                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 966                         return $this->mDbkeyform;
 967                 }
 968         }
 969
 970         /**
 971          * Get the namespace index, i.e. one of the NS_xxxx constants.
 972          *
 973          * @return int Namespace index
 974          */
 975         public function getNamespace() {
 976                 return $this->mNamespace;
 977         }
 978
 979         /**
 980          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 981          *
 982          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 983          * @return string Content model id
 984          */
 985         public function getContentModel( $flags = 0 ) {
 986                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 987                         $linkCache = LinkCache::singleton();
 988                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 989                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 990                 }
 991
 992                 if ( !$this->mContentModel ) {
 993                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 994                 }
 995
 996                 return $this->mContentModel;
 997         }
 998
 999         /**
1000          * Convenience method for checking a title's content model name
1001          *
1002          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
1003          * @return bool True if $this->getContentModel() == $id
1004          */
1005         public function hasContentModel( $id ) {
1006                 return $this->getContentModel() == $id;
1007         }
1008
1009         /**
1010          * Get the namespace text
1011          *
1012          * @return string Namespace text
1013          */
1014         public function getNsText() {
1015                 if ( $this->isExternal() ) {
1016                         // This probably shouldn't even happen,
1017                         // but for interwiki transclusion it sometimes does.
1018                         // Use the canonical namespaces if possible to try to
1019                         // resolve a foreign namespace.
1020                         if ( MWNamespace::exists( $this->mNamespace ) ) {
1021                                 return MWNamespace::getCanonicalName( $this->mNamespace );
1022                         }
1023                 }
1024
1025                 try {
1026                         $formatter = self::getTitleFormatter();
1027                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
1028                 } catch ( InvalidArgumentException $ex ) {
1029                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1030                         return false;
1031                 }
1032         }
1033
1034         /**
1035          * Get the namespace text of the subject (rather than talk) page
1036          *
1037          * @return string Namespace text
1038          */
1039         public function getSubjectNsText() {
1040                 global $wgContLang;
1041                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1042         }
1043
1044         /**
1045          * Get the namespace text of the talk page
1046          *
1047          * @return string Namespace text
1048          */
1049         public function getTalkNsText() {
1050                 global $wgContLang;
1051                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1052         }
1053
1054         /**
1055          * Could this title have a corresponding talk page?
1056          *
1057          * @return bool
1058          */
1059         public function canTalk() {
1060                 return MWNamespace::canTalk( $this->mNamespace );
1061         }
1062
1063         /**
1064          * Is this in a namespace that allows actual pages?
1065          *
1066          * @return bool
1067          */
1068         public function canExist() {
1069                 return $this->mNamespace >= NS_MAIN;
1070         }
1071
1072         /**
1073          * Can this title be added to a user's watchlist?
1074          *
1075          * @return bool
1076          */
1077         public function isWatchable() {
1078                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1079         }
1080
1081         /**
1082          * Returns true if this is a special page.
1083          *
1084          * @return bool
1085          */
1086         public function isSpecialPage() {
1087                 return $this->getNamespace() == NS_SPECIAL;
1088         }
1089
1090         /**
1091          * Returns true if this title resolves to the named special page
1092          *
1093          * @param string $name The special page name
1094          * @return bool
1095          */
1096         public function isSpecial( $name ) {
1097                 if ( $this->isSpecialPage() ) {
1098                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1099                         if ( $name == $thisName ) {
1100                                 return true;
1101                         }
1102                 }
1103                 return false;
1104         }
1105
1106         /**
1107          * If the Title refers to a special page alias which is not the local default, resolve
1108          * the alias, and localise the name as necessary.  Otherwise, return $this
1109          *
1110          * @return Title
1111          */
1112         public function fixSpecialName() {
1113                 if ( $this->isSpecialPage() ) {
1114                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1115                         if ( $canonicalName ) {
1116                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1117                                 if ( $localName != $this->mDbkeyform ) {
1118                                         return Title::makeTitle( NS_SPECIAL, $localName );
1119                                 }
1120                         }
1121                 }
1122                 return $this;
1123         }
1124
1125         /**
1126          * Returns true if the title is inside the specified namespace.
1127          *
1128          * Please make use of this instead of comparing to getNamespace()
1129          * This function is much more resistant to changes we may make
1130          * to namespaces than code that makes direct comparisons.
1131          * @param int $ns The namespace
1132          * @return bool
1133          * @since 1.19
1134          */
1135         public function inNamespace( $ns ) {
1136                 return MWNamespace::equals( $this->getNamespace(), $ns );
1137         }
1138
1139         /**
1140          * Returns true if the title is inside one of the specified namespaces.
1141          *
1142          * @param int $namespaces,... The namespaces to check for
1143          * @return bool
1144          * @since 1.19
1145          */
1146         public function inNamespaces( /* ... */ ) {
1147                 $namespaces = func_get_args();
1148                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1149                         $namespaces = $namespaces[0];
1150                 }
1151
1152                 foreach ( $namespaces as $ns ) {
1153                         if ( $this->inNamespace( $ns ) ) {
1154                                 return true;
1155                         }
1156                 }
1157
1158                 return false;
1159         }
1160
1161         /**
1162          * Returns true if the title has the same subject namespace as the
1163          * namespace specified.
1164          * For example this method will take NS_USER and return true if namespace
1165          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1166          * as their subject namespace.
1167          *
1168          * This is MUCH simpler than individually testing for equivalence
1169          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1170          * @since 1.19
1171          * @param int $ns
1172          * @return bool
1173          */
1174         public function hasSubjectNamespace( $ns ) {
1175                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1176         }
1177
1178         /**
1179          * Is this Title in a namespace which contains content?
1180          * In other words, is this a content page, for the purposes of calculating
1181          * statistics, etc?
1182          *
1183          * @return bool
1184          */
1185         public function isContentPage() {
1186                 return MWNamespace::isContent( $this->getNamespace() );
1187         }
1188
1189         /**
1190          * Would anybody with sufficient privileges be able to move this page?
1191          * Some pages just aren't movable.
1192          *
1193          * @return bool
1194          */
1195         public function isMovable() {
1196                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1197                         // Interwiki title or immovable namespace. Hooks don't get to override here
1198                         return false;
1199                 }
1200
1201                 $result = true;
1202                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1203                 return $result;
1204         }
1205
1206         /**
1207          * Is this the mainpage?
1208          * @note Title::newFromText seems to be sufficiently optimized by the title
1209          * cache that we don't need to over-optimize by doing direct comparisons and
1210          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1211          * ends up reporting something differently than $title->isMainPage();
1212          *
1213          * @since 1.18
1214          * @return bool
1215          */
1216         public function isMainPage() {
1217                 return $this->equals( Title::newMainPage() );
1218         }
1219
1220         /**
1221          * Is this a subpage?
1222          *
1223          * @return bool
1224          */
1225         public function isSubpage() {
1226                 return MWNamespace::hasSubpages( $this->mNamespace )
1227                         ? strpos( $this->getText(), '/' ) !== false
1228                         : false;
1229         }
1230
1231         /**
1232          * Is this a conversion table for the LanguageConverter?
1233          *
1234          * @return bool
1235          */
1236         public function isConversionTable() {
1237                 // @todo ConversionTable should become a separate content model.
1238
1239                 return $this->getNamespace() == NS_MEDIAWIKI &&
1240                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1241         }
1242
1243         /**
1244          * Does that page contain wikitext, or it is JS, CSS or whatever?
1245          *
1246          * @return bool
1247          */
1248         public function isWikitextPage() {
1249                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1250         }
1251
1252         /**
1253          * Could this page contain custom CSS or JavaScript for the global UI.
1254          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1255          * or CONTENT_MODEL_JAVASCRIPT.
1256          *
1257          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1258          * for that!
1259          *
1260          * Note that this method should not return true for pages that contain and
1261          * show "inactive" CSS or JS.
1262          *
1263          * @return bool
1264          * @todo FIXME: Rename to isSiteConfigPage() and remove deprecated hook
1265          */
1266         public function isCssOrJsPage() {
1267                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1268                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1269                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1270
1271                 # @note This hook is also called in ContentHandler::getDefaultModel.
1272                 #   It's called here again to make sure hook functions can force this
1273                 #   method to return true even outside the MediaWiki namespace.
1274
1275                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1276
1277                 return $isCssOrJsPage;
1278         }
1279
1280         /**
1281          * Is this a .css or .js subpage of a user page?
1282          * @return bool
1283          * @todo FIXME: Rename to isUserConfigPage()
1284          */
1285         public function isCssJsSubpage() {
1286                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1287                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1288                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1289         }
1290
1291         /**
1292          * Trim down a .css or .js subpage title to get the corresponding skin name
1293          *
1294          * @return string Containing skin name from .css or .js subpage title
1295          */
1296         public function getSkinFromCssJsSubpage() {
1297                 $subpage = explode( '/', $this->mTextform );
1298                 $subpage = $subpage[count( $subpage ) - 1];
1299                 $lastdot = strrpos( $subpage, '.' );
1300                 if ( $lastdot === false ) {
1301                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1302                 }
1303                 return substr( $subpage, 0, $lastdot );
1304         }
1305
1306         /**
1307          * Is this a .css subpage of a user page?
1308          *
1309          * @return bool
1310          */
1311         public function isCssSubpage() {
1312                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1313                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1314         }
1315
1316         /**
1317          * Is this a .js subpage of a user page?
1318          *
1319          * @return bool
1320          */
1321         public function isJsSubpage() {
1322                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1323                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1324         }
1325
1326         /**
1327          * Is this a talk page of some sort?
1328          *
1329          * @return bool
1330          */
1331         public function isTalkPage() {
1332                 return MWNamespace::isTalk( $this->getNamespace() );
1333         }
1334
1335         /**
1336          * Get a Title object associated with the talk page of this article
1337          *
1338          * @return Title The object for the talk page
1339          */
1340         public function getTalkPage() {
1341                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1342         }
1343
1344         /**
1345          * Get a title object associated with the subject page of this
1346          * talk page
1347          *
1348          * @return Title The object for the subject page
1349          */
1350         public function getSubjectPage() {
1351                 // Is this the same title?
1352                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1353                 if ( $this->getNamespace() == $subjectNS ) {
1354                         return $this;
1355                 }
1356                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1357         }
1358
1359         /**
1360          * Get the other title for this page, if this is a subject page
1361          * get the talk page, if it is a subject page get the talk page
1362          *
1363          * @since 1.25
1364          * @throws MWException
1365          * @return Title
1366          */
1367         public function getOtherPage() {
1368                 if ( $this->isSpecialPage() ) {
1369                         throw new MWException( 'Special pages cannot have other pages' );
1370                 }
1371                 if ( $this->isTalkPage() ) {
1372                         return $this->getSubjectPage();
1373                 } else {
1374                         return $this->getTalkPage();
1375                 }
1376         }
1377
1378         /**
1379          * Get the default namespace index, for when there is no namespace
1380          *
1381          * @return int Default namespace index
1382          */
1383         public function getDefaultNamespace() {
1384                 return $this->mDefaultNamespace;
1385         }
1386
1387         /**
1388          * Get the Title fragment (i.e.\ the bit after the #) in text form
1389          *
1390          * Use Title::hasFragment to check for a fragment
1391          *
1392          * @return string Title fragment
1393          */
1394         public function getFragment() {
1395                 return $this->mFragment;
1396         }
1397
1398         /**
1399          * Check if a Title fragment is set
1400          *
1401          * @return bool
1402          * @since 1.23
1403          */
1404         public function hasFragment() {
1405                 return $this->mFragment !== '';
1406         }
1407
1408         /**
1409          * Get the fragment in URL form, including the "#" character if there is one
1410          * @return string Fragment in URL form
1411          */
1412         public function getFragmentForURL() {
1413                 if ( !$this->hasFragment() ) {
1414                         return '';
1415                 } else {
1416                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1417                 }
1418         }
1419
1420         /**
1421          * Set the fragment for this title. Removes the first character from the
1422          * specified fragment before setting, so it assumes you're passing it with
1423          * an initial "#".
1424          *
1425          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1426          * Still in active use privately.
1427          *
1428          * @private
1429          * @param string $fragment Text
1430          */
1431         public function setFragment( $fragment ) {
1432                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1433         }
1434
1435         /**
1436          * Prefix some arbitrary text with the namespace or interwiki prefix
1437          * of this object
1438          *
1439          * @param string $name The text
1440          * @return string The prefixed text
1441          */
1442         private function prefix( $name ) {
1443                 $p = '';
1444                 if ( $this->isExternal() ) {
1445                         $p = $this->mInterwiki . ':';
1446                 }
1447
1448                 if ( 0 != $this->mNamespace ) {
1449                         $p .= $this->getNsText() . ':';
1450                 }
1451                 return $p . $name;
1452         }
1453
1454         /**
1455          * Get the prefixed database key form
1456          *
1457          * @return string The prefixed title, with underscores and
1458          *  any interwiki and namespace prefixes
1459          */
1460         public function getPrefixedDBkey() {
1461                 $s = $this->prefix( $this->mDbkeyform );
1462                 $s = strtr( $s, ' ', '_' );
1463                 return $s;
1464         }
1465
1466         /**
1467          * Get the prefixed title with spaces.
1468          * This is the form usually used for display
1469          *
1470          * @return string The prefixed title, with spaces
1471          */
1472         public function getPrefixedText() {
1473                 if ( $this->mPrefixedText === null ) {
1474                         $s = $this->prefix( $this->mTextform );
1475                         $s = strtr( $s, '_', ' ' );
1476                         $this->mPrefixedText = $s;
1477                 }
1478                 return $this->mPrefixedText;
1479         }
1480
1481         /**
1482          * Return a string representation of this title
1483          *
1484          * @return string Representation of this title
1485          */
1486         public function __toString() {
1487                 return $this->getPrefixedText();
1488         }
1489
1490         /**
1491          * Get the prefixed title with spaces, plus any fragment
1492          * (part beginning with '#')
1493          *
1494          * @return string The prefixed title, with spaces and the fragment, including '#'
1495          */
1496         public function getFullText() {
1497                 $text = $this->getPrefixedText();
1498                 if ( $this->hasFragment() ) {
1499                         $text .= '#' . $this->getFragment();
1500                 }
1501                 return $text;
1502         }
1503
1504         /**
1505          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1506          *
1507          * @par Example:
1508          * @code
1509          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1510          * # returns: 'Foo'
1511          * @endcode
1512          *
1513          * @return string Root name
1514          * @since 1.20
1515          */
1516         public function getRootText() {
1517                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1518                         return $this->getText();
1519                 }
1520
1521                 return strtok( $this->getText(), '/' );
1522         }
1523
1524         /**
1525          * Get the root page name title, i.e. the leftmost part before any slashes
1526          *
1527          * @par Example:
1528          * @code
1529          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1530          * # returns: Title{User:Foo}
1531          * @endcode
1532          *
1533          * @return Title Root title
1534          * @since 1.20
1535          */
1536         public function getRootTitle() {
1537                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1538         }
1539
1540         /**
1541          * Get the base page name without a namespace, i.e. the part before the subpage name
1542          *
1543          * @par Example:
1544          * @code
1545          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1546          * # returns: 'Foo/Bar'
1547          * @endcode
1548          *
1549          * @return string Base name
1550          */
1551         public function getBaseText() {
1552                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1553                         return $this->getText();
1554                 }
1555
1556                 $parts = explode( '/', $this->getText() );
1557                 # Don't discard the real title if there's no subpage involved
1558                 if ( count( $parts ) > 1 ) {
1559                         unset( $parts[count( $parts ) - 1] );
1560                 }
1561                 return implode( '/', $parts );
1562         }
1563
1564         /**
1565          * Get the base page name title, i.e. the part before the subpage name
1566          *
1567          * @par Example:
1568          * @code
1569          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1570          * # returns: Title{User:Foo/Bar}
1571          * @endcode
1572          *
1573          * @return Title Base title
1574          * @since 1.20
1575          */
1576         public function getBaseTitle() {
1577                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1578         }
1579
1580         /**
1581          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1582          *
1583          * @par Example:
1584          * @code
1585          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1586          * # returns: "Baz"
1587          * @endcode
1588          *
1589          * @return string Subpage name
1590          */
1591         public function getSubpageText() {
1592                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1593                         return $this->mTextform;
1594                 }
1595                 $parts = explode( '/', $this->mTextform );
1596                 return $parts[count( $parts ) - 1];
1597         }
1598
1599         /**
1600          * Get the title for a subpage of the current page
1601          *
1602          * @par Example:
1603          * @code
1604          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1605          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1606          * @endcode
1607          *
1608          * @param string $text The subpage name to add to the title
1609          * @return Title Subpage title
1610          * @since 1.20
1611          */
1612         public function getSubpage( $text ) {
1613                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1614         }
1615
1616         /**
1617          * Get a URL-encoded form of the subpage text
1618          *
1619          * @return string URL-encoded subpage name
1620          */
1621         public function getSubpageUrlForm() {
1622                 $text = $this->getSubpageText();
1623                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1624                 return $text;
1625         }
1626
1627         /**
1628          * Get a URL-encoded title (not an actual URL) including interwiki
1629          *
1630          * @return string The URL-encoded form
1631          */
1632         public function getPrefixedURL() {
1633                 $s = $this->prefix( $this->mDbkeyform );
1634                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1635                 return $s;
1636         }
1637
1638         /**
1639          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1640          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1641          * second argument named variant. This was deprecated in favor
1642          * of passing an array of option with a "variant" key
1643          * Once $query2 is removed for good, this helper can be dropped
1644          * and the wfArrayToCgi moved to getLocalURL();
1645          *
1646          * @since 1.19 (r105919)
1647          * @param array|string $query
1648          * @param bool $query2
1649          * @return string
1650          */
1651         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1652                 if ( $query2 !== false ) {
1653                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1654                                 "method called with a second parameter is deprecated. Add your " .
1655                                 "parameter to an array passed as the first parameter.", "1.19" );
1656                 }
1657                 if ( is_array( $query ) ) {
1658                         $query = wfArrayToCgi( $query );
1659                 }
1660                 if ( $query2 ) {
1661                         if ( is_string( $query2 ) ) {
1662                                 // $query2 is a string, we will consider this to be
1663                                 // a deprecated $variant argument and add it to the query
1664                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1665                         } else {
1666                                 $query2 = wfArrayToCgi( $query2 );
1667                         }
1668                         // If we have $query content add a & to it first
1669                         if ( $query ) {
1670                                 $query .= '&';
1671                         }
1672                         // Now append the queries together
1673                         $query .= $query2;
1674                 }
1675                 return $query;
1676         }
1677
1678         /**
1679          * Get a real URL referring to this title, with interwiki link and
1680          * fragment
1681          *
1682          * @see self::getLocalURL for the arguments.
1683          * @see wfExpandUrl
1684          * @param array|string $query
1685          * @param bool $query2
1686          * @param string $proto Protocol type to use in URL
1687          * @return string The URL
1688          */
1689         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1690                 $query = self::fixUrlQueryArgs( $query, $query2 );
1691
1692                 # Hand off all the decisions on urls to getLocalURL
1693                 $url = $this->getLocalURL( $query );
1694
1695                 # Expand the url to make it a full url. Note that getLocalURL has the
1696                 # potential to output full urls for a variety of reasons, so we use
1697                 # wfExpandUrl instead of simply prepending $wgServer
1698                 $url = wfExpandUrl( $url, $proto );
1699
1700                 # Finally, add the fragment.
1701                 $url .= $this->getFragmentForURL();
1702
1703                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1704                 return $url;
1705         }
1706
1707         /**
1708          * Get a URL with no fragment or server name (relative URL) from a Title object.
1709          * If this page is generated with action=render, however,
1710          * $wgServer is prepended to make an absolute URL.
1711          *
1712          * @see self::getFullURL to always get an absolute URL.
1713          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1714          *  valid to link, locally, to the current Title.
1715          * @see self::newFromText to produce a Title object.
1716          *
1717          * @param string|array $query An optional query string,
1718          *   not used for interwiki links. Can be specified as an associative array as well,
1719          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1720          *   Some query patterns will trigger various shorturl path replacements.
1721          * @param array $query2 An optional secondary query array. This one MUST
1722          *   be an array. If a string is passed it will be interpreted as a deprecated
1723          *   variant argument and urlencoded into a variant= argument.
1724          *   This second query argument will be added to the $query
1725          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1726          *   pair in the first parameter array instead.
1727          *
1728          * @return string String of the URL.
1729          */
1730         public function getLocalURL( $query = '', $query2 = false ) {
1731                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1732
1733                 $query = self::fixUrlQueryArgs( $query, $query2 );
1734
1735                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1736                 if ( $interwiki ) {
1737                         $namespace = $this->getNsText();
1738                         if ( $namespace != '' ) {
1739                                 # Can this actually happen? Interwikis shouldn't be parsed.
1740                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1741                                 $namespace .= ':';
1742                         }
1743                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1744                         $url = wfAppendQuery( $url, $query );
1745                 } else {
1746                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1747                         if ( $query == '' ) {
1748                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1749                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1750                         } else {
1751                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1752                                 $url = false;
1753                                 $matches = array();
1754
1755                                 if ( !empty( $wgActionPaths )
1756                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1757                                 ) {
1758                                         $action = urldecode( $matches[2] );
1759                                         if ( isset( $wgActionPaths[$action] ) ) {
1760                                                 $query = $matches[1];
1761                                                 if ( isset( $matches[4] ) ) {
1762                                                         $query .= $matches[4];
1763                                                 }
1764                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1765                                                 if ( $query != '' ) {
1766                                                         $url = wfAppendQuery( $url, $query );
1767                                                 }
1768                                         }
1769                                 }
1770
1771                                 if ( $url === false
1772                                         && $wgVariantArticlePath
1773                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1774                                         && $this->getPageLanguage()->hasVariants()
1775                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1776                                 ) {
1777                                         $variant = urldecode( $matches[1] );
1778                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1779                                                 // Only do the variant replacement if the given variant is a valid
1780                                                 // variant for the page's language.
1781                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1782                                                 $url = str_replace( '$1', $dbkey, $url );
1783                                         }
1784                                 }
1785
1786                                 if ( $url === false ) {
1787                                         if ( $query == '-' ) {
1788                                                 $query = '';
1789                                         }
1790                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1791                                 }
1792                         }
1793
1794                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1795
1796                         // @todo FIXME: This causes breakage in various places when we
1797                         // actually expected a local URL and end up with dupe prefixes.
1798                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1799                                 $url = $wgServer . $url;
1800                         }
1801                 }
1802                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1803                 return $url;
1804         }
1805
1806         /**
1807          * Get a URL that's the simplest URL that will be valid to link, locally,
1808          * to the current Title.  It includes the fragment, but does not include
1809          * the server unless action=render is used (or the link is external).  If
1810          * there's a fragment but the prefixed text is empty, we just return a link
1811          * to the fragment.
1812          *
1813          * The result obviously should not be URL-escaped, but does need to be
1814          * HTML-escaped if it's being output in HTML.
1815          *
1816          * @param array $query
1817          * @param bool $query2
1818          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1819          * @see self::getLocalURL for the arguments.
1820          * @return string The URL
1821          */
1822         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1823                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1824                         $ret = $this->getFullURL( $query, $query2, $proto );
1825                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1826                         $ret = $this->getFragmentForURL();
1827                 } else {
1828                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1829                 }
1830                 return $ret;
1831         }
1832
1833         /**
1834          * Get the URL form for an internal link.
1835          * - Used in various CDN-related code, in case we have a different
1836          * internal hostname for the server from the exposed one.
1837          *
1838          * This uses $wgInternalServer to qualify the path, or $wgServer
1839          * if $wgInternalServer is not set. If the server variable used is
1840          * protocol-relative, the URL will be expanded to http://
1841          *
1842          * @see self::getLocalURL for the arguments.
1843          * @return string The URL
1844          */
1845         public function getInternalURL( $query = '', $query2 = false ) {
1846                 global $wgInternalServer, $wgServer;
1847                 $query = self::fixUrlQueryArgs( $query, $query2 );
1848                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1849                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1850                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1851                 return $url;
1852         }
1853
1854         /**
1855          * Get the URL for a canonical link, for use in things like IRC and
1856          * e-mail notifications. Uses $wgCanonicalServer and the
1857          * GetCanonicalURL hook.
1858          *
1859          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1860          *
1861          * @see self::getLocalURL for the arguments.
1862          * @return string The URL
1863          * @since 1.18
1864          */
1865         public function getCanonicalURL( $query = '', $query2 = false ) {
1866                 $query = self::fixUrlQueryArgs( $query, $query2 );
1867                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1868                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1869                 return $url;
1870         }
1871
1872         /**
1873          * Get the edit URL for this Title
1874          *
1875          * @return string The URL, or a null string if this is an interwiki link
1876          */
1877         public function getEditURL() {
1878                 if ( $this->isExternal() ) {
1879                         return '';
1880                 }
1881                 $s = $this->getLocalURL( 'action=edit' );
1882
1883                 return $s;
1884         }
1885
1886         /**
1887          * Can $user perform $action on this page?
1888          * This skips potentially expensive cascading permission checks
1889          * as well as avoids expensive error formatting
1890          *
1891          * Suitable for use for nonessential UI controls in common cases, but
1892          * _not_ for functional access control.
1893          *
1894          * May provide false positives, but should never provide a false negative.
1895          *
1896          * @param string $action Action that permission needs to be checked for
1897          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1898          * @return bool
1899          */
1900         public function quickUserCan( $action, $user = null ) {
1901                 return $this->userCan( $action, $user, false );
1902         }
1903
1904         /**
1905          * Can $user perform $action on this page?
1906          *
1907          * @param string $action Action that permission needs to be checked for
1908          * @param User $user User to check (since 1.19); $wgUser will be used if not
1909          *   provided.
1910          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1911          * @return bool
1912          */
1913         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1914                 if ( !$user instanceof User ) {
1915                         global $wgUser;
1916                         $user = $wgUser;
1917                 }
1918
1919                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1920         }
1921
1922         /**
1923          * Can $user perform $action on this page?
1924          *
1925          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1926          *
1927          * @param string $action Action that permission needs to be checked for
1928          * @param User $user User to check
1929          * @param string $rigor One of (quick,full,secure)
1930          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1931          *   - full   : does cheap and expensive checks possibly from a slave
1932          *   - secure : does cheap and expensive checks, using the master as needed
1933          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1934          *   whose corresponding errors may be ignored.
1935          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1936          */
1937         public function getUserPermissionsErrors(
1938                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1939         ) {
1940                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1941
1942                 // Remove the errors being ignored.
1943                 foreach ( $errors as $index => $error ) {
1944                         $errKey = is_array( $error ) ? $error[0] : $error;
1945
1946                         if ( in_array( $errKey, $ignoreErrors ) ) {
1947                                 unset( $errors[$index] );
1948                         }
1949                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
1950                                 unset( $errors[$index] );
1951                         }
1952                 }
1953
1954                 return $errors;
1955         }
1956
1957         /**
1958          * Permissions checks that fail most often, and which are easiest to test.
1959          *
1960          * @param string $action The action to check
1961          * @param User $user User to check
1962          * @param array $errors List of current errors
1963          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1964          * @param bool $short Short circuit on first error
1965          *
1966          * @return array List of errors
1967          */
1968         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1969                 if ( !Hooks::run( 'TitleQuickPermissions',
1970                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1971                 ) {
1972                         return $errors;
1973                 }
1974
1975                 if ( $action == 'create' ) {
1976                         if (
1977                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1978                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1979                         ) {
1980                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1981                         }
1982                 } elseif ( $action == 'move' ) {
1983                         if ( !$user->isAllowed( 'move-rootuserpages' )
1984                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1985                                 // Show user page-specific message only if the user can move other pages
1986                                 $errors[] = array( 'cant-move-user-page' );
1987                         }
1988
1989                         // Check if user is allowed to move files if it's a file
1990                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1991                                 $errors[] = array( 'movenotallowedfile' );
1992                         }
1993
1994                         // Check if user is allowed to move category pages if it's a category page
1995                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1996                                 $errors[] = array( 'cant-move-category-page' );
1997                         }
1998
1999                         if ( !$user->isAllowed( 'move' ) ) {
2000                                 // User can't move anything
2001                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
2002                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2003                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2004                                         // custom message if logged-in users without any special rights can move
2005                                         $errors[] = array( 'movenologintext' );
2006                                 } else {
2007                                         $errors[] = array( 'movenotallowed' );
2008                                 }
2009                         }
2010                 } elseif ( $action == 'move-target' ) {
2011                         if ( !$user->isAllowed( 'move' ) ) {
2012                                 // User can't move anything
2013                                 $errors[] = array( 'movenotallowed' );
2014                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2015                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2016                                 // Show user page-specific message only if the user can move other pages
2017                                 $errors[] = array( 'cant-move-to-user-page' );
2018                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2019                                         && $this->mNamespace == NS_CATEGORY ) {
2020                                 // Show category page-specific message only if the user can move other pages
2021                                 $errors[] = array( 'cant-move-to-category-page' );
2022                         }
2023                 } elseif ( !$user->isAllowed( $action ) ) {
2024                         $errors[] = $this->missingPermissionError( $action, $short );
2025                 }
2026
2027                 return $errors;
2028         }
2029
2030         /**
2031          * Add the resulting error code to the errors array
2032          *
2033          * @param array $errors List of current errors
2034          * @param array $result Result of errors
2035          *
2036          * @return array List of errors
2037          */
2038         private function resultToError( $errors, $result ) {
2039                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2040                         // A single array representing an error
2041                         $errors[] = $result;
2042                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2043                         // A nested array representing multiple errors
2044                         $errors = array_merge( $errors, $result );
2045                 } elseif ( $result !== '' && is_string( $result ) ) {
2046                         // A string representing a message-id
2047                         $errors[] = array( $result );
2048                 } elseif ( $result instanceof MessageSpecifier ) {
2049                         // A message specifier representing an error
2050                         $errors[] = array( $result );
2051                 } elseif ( $result === false ) {
2052                         // a generic "We don't want them to do that"
2053                         $errors[] = array( 'badaccess-group0' );
2054                 }
2055                 return $errors;
2056         }
2057
2058         /**
2059          * Check various permission hooks
2060          *
2061          * @param string $action The action to check
2062          * @param User $user User to check
2063          * @param array $errors List of current errors
2064          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2065          * @param bool $short Short circuit on first error
2066          *
2067          * @return array List of errors
2068          */
2069         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2070                 // Use getUserPermissionsErrors instead
2071                 $result = '';
2072                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2073                         return $result ? array() : array( array( 'badaccess-group0' ) );
2074                 }
2075                 // Check getUserPermissionsErrors hook
2076                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2077                         $errors = $this->resultToError( $errors, $result );
2078                 }
2079                 // Check getUserPermissionsErrorsExpensive hook
2080                 if (
2081                         $rigor !== 'quick'
2082                         && !( $short && count( $errors ) > 0 )
2083                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2084                 ) {
2085                         $errors = $this->resultToError( $errors, $result );
2086                 }
2087
2088                 return $errors;
2089         }
2090
2091         /**
2092          * Check permissions on special pages & namespaces
2093          *
2094          * @param string $action The action to check
2095          * @param User $user User to check
2096          * @param array $errors List of current errors
2097          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2098          * @param bool $short Short circuit on first error
2099          *
2100          * @return array List of errors
2101          */
2102         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2103                 # Only 'createaccount' can be performed on special pages,
2104                 # which don't actually exist in the DB.
2105                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2106                         $errors[] = array( 'ns-specialprotected' );
2107                 }
2108
2109                 # Check $wgNamespaceProtection for restricted namespaces
2110                 if ( $this->isNamespaceProtected( $user ) ) {
2111                         $ns = $this->mNamespace == NS_MAIN ?
2112                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2113                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2114                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2115                 }
2116
2117                 return $errors;
2118         }
2119
2120         /**
2121          * Check CSS/JS sub-page permissions
2122          *
2123          * @param string $action The action to check
2124          * @param User $user User to check
2125          * @param array $errors List of current errors
2126          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2127          * @param bool $short Short circuit on first error
2128          *
2129          * @return array List of errors
2130          */
2131         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2132                 # Protect css/js subpages of user pages
2133                 # XXX: this might be better using restrictions
2134                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2135                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2136                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2137                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2138                                         $errors[] = array( 'mycustomcssprotected', $action );
2139                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2140                                         $errors[] = array( 'mycustomjsprotected', $action );
2141                                 }
2142                         } else {
2143                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2144                                         $errors[] = array( 'customcssprotected', $action );
2145                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2146                                         $errors[] = array( 'customjsprotected', $action );
2147                                 }
2148                         }
2149                 }
2150
2151                 return $errors;
2152         }
2153
2154         /**
2155          * Check against page_restrictions table requirements on this
2156          * page. The user must possess all required rights for this
2157          * action.
2158          *
2159          * @param string $action The action to check
2160          * @param User $user User to check
2161          * @param array $errors List of current errors
2162          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2163          * @param bool $short Short circuit on first error
2164          *
2165          * @return array List of errors
2166          */
2167         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2168                 foreach ( $this->getRestrictions( $action ) as $right ) {
2169                         // Backwards compatibility, rewrite sysop -> editprotected
2170                         if ( $right == 'sysop' ) {
2171                                 $right = 'editprotected';
2172                         }
2173                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2174                         if ( $right == 'autoconfirmed' ) {
2175                                 $right = 'editsemiprotected';
2176                         }
2177                         if ( $right == '' ) {
2178                                 continue;
2179                         }
2180                         if ( !$user->isAllowed( $right ) ) {
2181                                 $errors[] = array( 'protectedpagetext', $right, $action );
2182                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2183                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2184                         }
2185                 }
2186
2187                 return $errors;
2188         }
2189
2190         /**
2191          * Check restrictions on cascading pages.
2192          *
2193          * @param string $action The action to check
2194          * @param User $user User to check
2195          * @param array $errors List of current errors
2196          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2197          * @param bool $short Short circuit on first error
2198          *
2199          * @return array List of errors
2200          */
2201         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2202                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2203                         # We /could/ use the protection level on the source page, but it's
2204                         # fairly ugly as we have to establish a precedence hierarchy for pages
2205                         # included by multiple cascade-protected pages. So just restrict
2206                         # it to people with 'protect' permission, as they could remove the
2207                         # protection anyway.
2208                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2209                         # Cascading protection depends on more than this page...
2210                         # Several cascading protected pages may include this page...
2211                         # Check each cascading level
2212                         # This is only for protection restrictions, not for all actions
2213                         if ( isset( $restrictions[$action] ) ) {
2214                                 foreach ( $restrictions[$action] as $right ) {
2215                                         // Backwards compatibility, rewrite sysop -> editprotected
2216                                         if ( $right == 'sysop' ) {
2217                                                 $right = 'editprotected';
2218                                         }
2219                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2220                                         if ( $right == 'autoconfirmed' ) {
2221                                                 $right = 'editsemiprotected';
2222                                         }
2223                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2224                                                 $pages = '';
2225                                                 foreach ( $cascadingSources as $page ) {
2226                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2227                                                 }
2228                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2229                                         }
2230                                 }
2231                         }
2232                 }
2233
2234                 return $errors;
2235         }
2236
2237         /**
2238          * Check action permissions not already checked in checkQuickPermissions
2239          *
2240          * @param string $action The action to check
2241          * @param User $user User to check
2242          * @param array $errors List of current errors
2243          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2244          * @param bool $short Short circuit on first error
2245          *
2246          * @return array List of errors
2247          */
2248         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2249                 global $wgDeleteRevisionsLimit, $wgLang;
2250
2251                 if ( $action == 'protect' ) {
2252                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2253                                 // If they can't edit, they shouldn't protect.
2254                                 $errors[] = array( 'protect-cantedit' );
2255                         }
2256                 } elseif ( $action == 'create' ) {
2257                         $title_protection = $this->getTitleProtection();
2258                         if ( $title_protection ) {
2259                                 if ( $title_protection['permission'] == ''
2260                                         || !$user->isAllowed( $title_protection['permission'] )
2261                                 ) {
2262                                         $errors[] = array(
2263                                                 'titleprotected',
2264                                                 User::whoIs( $title_protection['user'] ),
2265                                                 $title_protection['reason']
2266                                         );
2267                                 }
2268                         }
2269                 } elseif ( $action == 'move' ) {
2270                         // Check for immobile pages
2271                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2272                                 // Specific message for this case
2273                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2274                         } elseif ( !$this->isMovable() ) {
2275                                 // Less specific message for rarer cases
2276                                 $errors[] = array( 'immobile-source-page' );
2277                         }
2278                 } elseif ( $action == 'move-target' ) {
2279                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2280                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2281                         } elseif ( !$this->isMovable() ) {
2282                                 $errors[] = array( 'immobile-target-page' );
2283                         }
2284                 } elseif ( $action == 'delete' ) {
2285                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2286                         if ( !$tempErrors ) {
2287                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2288                                         $user, $tempErrors, $rigor, true );
2289                         }
2290                         if ( $tempErrors ) {
2291                                 // If protection keeps them from editing, they shouldn't be able to delete.
2292                                 $errors[] = array( 'deleteprotected' );
2293                         }
2294                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2295                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2296                         ) {
2297                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2298                         }
2299                 }
2300                 return $errors;
2301         }
2302
2303         /**
2304          * Check that the user isn't blocked from editing.
2305          *
2306          * @param string $action The action to check
2307          * @param User $user User to check
2308          * @param array $errors List of current errors
2309          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2310          * @param bool $short Short circuit on first error
2311          *
2312          * @return array List of errors
2313          */
2314         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2315                 // Account creation blocks handled at userlogin.
2316                 // Unblocking handled in SpecialUnblock
2317                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2318                         return $errors;
2319                 }
2320
2321                 global $wgEmailConfirmToEdit;
2322
2323                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2324                         $errors[] = array( 'confirmedittext' );
2325                 }
2326
2327                 $useSlave = ( $rigor !== 'secure' );
2328                 if ( ( $action == 'edit' || $action == 'create' )
2329                         && !$user->isBlockedFrom( $this, $useSlave )
2330                 ) {
2331                         // Don't block the user from editing their own talk page unless they've been
2332                         // explicitly blocked from that too.
2333                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2334                         // @todo FIXME: Pass the relevant context into this function.
2335                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2336                 }
2337
2338                 return $errors;
2339         }
2340
2341         /**
2342          * Check that the user is allowed to read this page.
2343          *
2344          * @param string $action The action to check
2345          * @param User $user User to check
2346          * @param array $errors List of current errors
2347          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2348          * @param bool $short Short circuit on first error
2349          *
2350          * @return array List of errors
2351          */
2352         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2353                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2354
2355                 $whitelisted = false;
2356                 if ( User::isEveryoneAllowed( 'read' ) ) {
2357                         # Shortcut for public wikis, allows skipping quite a bit of code
2358                         $whitelisted = true;
2359                 } elseif ( $user->isAllowed( 'read' ) ) {
2360                         # If the user is allowed to read pages, he is allowed to read all pages
2361                         $whitelisted = true;
2362                 } elseif ( $this->isSpecial( 'Userlogin' )
2363                         || $this->isSpecial( 'ChangePassword' )
2364                         || $this->isSpecial( 'PasswordReset' )
2365                 ) {
2366                         # Always grant access to the login page.
2367                         # Even anons need to be able to log in.
2368                         $whitelisted = true;
2369                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2370                         # Time to check the whitelist
2371                         # Only do these checks is there's something to check against
2372                         $name = $this->getPrefixedText();
2373                         $dbName = $this->getPrefixedDBkey();
2374
2375                         // Check for explicit whitelisting with and without underscores
2376                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2377                                 $whitelisted = true;
2378                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2379                                 # Old settings might have the title prefixed with
2380                                 # a colon for main-namespace pages
2381                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2382                                         $whitelisted = true;
2383                                 }
2384                         } elseif ( $this->isSpecialPage() ) {
2385                                 # If it's a special page, ditch the subpage bit and check again
2386                                 $name = $this->getDBkey();
2387                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2388                                 if ( $name ) {
2389                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2390                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2391                                                 $whitelisted = true;
2392                                         }
2393                                 }
2394                         }
2395                 }
2396
2397                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2398                         $name = $this->getPrefixedText();
2399                         // Check for regex whitelisting
2400                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2401                                 if ( preg_match( $listItem, $name ) ) {
2402                                         $whitelisted = true;
2403                                         break;
2404                                 }
2405                         }
2406                 }
2407
2408                 if ( !$whitelisted ) {
2409                         # If the title is not whitelisted, give extensions a chance to do so...
2410                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2411                         if ( !$whitelisted ) {
2412                                 $errors[] = $this->missingPermissionError( $action, $short );
2413                         }
2414                 }
2415
2416                 return $errors;
2417         }
2418
2419         /**
2420          * Get a description array when the user doesn't have the right to perform
2421          * $action (i.e. when User::isAllowed() returns false)
2422          *
2423          * @param string $action The action to check
2424          * @param bool $short Short circuit on first error
2425          * @return array List of errors
2426          */
2427         private function missingPermissionError( $action, $short ) {
2428                 // We avoid expensive display logic for quickUserCan's and such
2429                 if ( $short ) {
2430                         return array( 'badaccess-group0' );
2431                 }
2432
2433                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2434                         User::getGroupsWithPermission( $action ) );
2435
2436                 if ( count( $groups ) ) {
2437                         global $wgLang;
2438                         return array(
2439                                 'badaccess-groups',
2440                                 $wgLang->commaList( $groups ),
2441                                 count( $groups )
2442                         );
2443                 } else {
2444                         return array( 'badaccess-group0' );
2445                 }
2446         }
2447
2448         /**
2449          * Can $user perform $action on this page? This is an internal function,
2450          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2451          * checks on wfReadOnly() and blocks)
2452          *
2453          * @param string $action Action that permission needs to be checked for
2454          * @param User $user User to check
2455          * @param string $rigor One of (quick,full,secure)
2456          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2457          *   - full   : does cheap and expensive checks possibly from a slave
2458          *   - secure : does cheap and expensive checks, using the master as needed
2459          * @param bool $short Set this to true to stop after the first permission error.
2460          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2461          */
2462         protected function getUserPermissionsErrorsInternal(
2463                 $action, $user, $rigor = 'secure', $short = false
2464         ) {
2465                 if ( $rigor === true ) {
2466                         $rigor = 'secure'; // b/c
2467                 } elseif ( $rigor === false ) {
2468                         $rigor = 'quick'; // b/c
2469                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2470                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2471                 }
2472
2473                 # Read has special handling
2474                 if ( $action == 'read' ) {
2475                         $checks = array(
2476                                 'checkPermissionHooks',
2477                                 'checkReadPermissions',
2478                         );
2479                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2480                 # here as it will lead to duplicate error messages. This is okay to do
2481                 # since anywhere that checks for create will also check for edit, and
2482                 # those checks are called for edit.
2483                 } elseif ( $action == 'create' ) {
2484                         $checks = array(
2485                                 'checkQuickPermissions',
2486                                 'checkPermissionHooks',
2487                                 'checkPageRestrictions',
2488                                 'checkCascadingSourcesRestrictions',
2489                                 'checkActionPermissions',
2490                                 'checkUserBlock'
2491                         );
2492                 } else {
2493                         $checks = array(
2494                                 'checkQuickPermissions',
2495                                 'checkPermissionHooks',
2496                                 'checkSpecialsAndNSPermissions',
2497                                 'checkCSSandJSPermissions',
2498                                 'checkPageRestrictions',
2499                                 'checkCascadingSourcesRestrictions',
2500                                 'checkActionPermissions',
2501                                 'checkUserBlock'
2502                         );
2503                 }
2504
2505                 $errors = array();
2506                 while ( count( $checks ) > 0 &&
2507                                 !( $short && count( $errors ) > 0 ) ) {
2508                         $method = array_shift( $checks );
2509                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2510                 }
2511
2512                 return $errors;
2513         }
2514
2515         /**
2516          * Get a filtered list of all restriction types supported by this wiki.
2517          * @param bool $exists True to get all restriction types that apply to
2518          * titles that do exist, False for all restriction types that apply to
2519          * titles that do not exist
2520          * @return array
2521          */
2522         public static function getFilteredRestrictionTypes( $exists = true ) {
2523                 global $wgRestrictionTypes;
2524                 $types = $wgRestrictionTypes;
2525                 if ( $exists ) {
2526                         # Remove the create restriction for existing titles
2527                         $types = array_diff( $types, array( 'create' ) );
2528                 } else {
2529                         # Only the create and upload restrictions apply to non-existing titles
2530                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2531                 }
2532                 return $types;
2533         }
2534
2535         /**
2536          * Returns restriction types for the current Title
2537          *
2538          * @return array Applicable restriction types
2539          */
2540         public function getRestrictionTypes() {
2541                 if ( $this->isSpecialPage() ) {
2542                         return array();
2543                 }
2544
2545                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2546
2547                 if ( $this->getNamespace() != NS_FILE ) {
2548                         # Remove the upload restriction for non-file titles
2549                         $types = array_diff( $types, array( 'upload' ) );
2550                 }
2551
2552                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2553
2554                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2555                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2556
2557                 return $types;
2558         }
2559
2560         /**
2561          * Is this title subject to title protection?
2562          * Title protection is the one applied against creation of such title.
2563          *
2564          * @return array|bool An associative array representing any existent title
2565          *   protection, or false if there's none.
2566          */
2567         public function getTitleProtection() {
2568                 // Can't protect pages in special namespaces
2569                 if ( $this->getNamespace() < 0 ) {
2570                         return false;
2571                 }
2572
2573                 // Can't protect pages that exist.
2574                 if ( $this->exists() ) {
2575                         return false;
2576                 }
2577
2578                 if ( $this->mTitleProtection === null ) {
2579                         $dbr = wfGetDB( DB_SLAVE );
2580                         $res = $dbr->select(
2581                                 'protected_titles',
2582                                 array(
2583                                         'user' => 'pt_user',
2584                                         'reason' => 'pt_reason',
2585                                         'expiry' => 'pt_expiry',
2586                                         'permission' => 'pt_create_perm'
2587                                 ),
2588                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2589                                 __METHOD__
2590                         );
2591
2592                         // fetchRow returns false if there are no rows.
2593                         $row = $dbr->fetchRow( $res );
2594                         if ( $row ) {
2595                                 if ( $row['permission'] == 'sysop' ) {
2596                                         $row['permission'] = 'editprotected'; // B/C
2597                                 }
2598                                 if ( $row['permission'] == 'autoconfirmed' ) {
2599                                         $row['permission'] = 'editsemiprotected'; // B/C
2600                                 }
2601                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2602                         }
2603                         $this->mTitleProtection = $row;
2604                 }
2605                 return $this->mTitleProtection;
2606         }
2607
2608         /**
2609          * Remove any title protection due to page existing
2610          */
2611         public function deleteTitleProtection() {
2612                 $dbw = wfGetDB( DB_MASTER );
2613
2614                 $dbw->delete(
2615                         'protected_titles',
2616                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2617                         __METHOD__
2618                 );
2619                 $this->mTitleProtection = false;
2620         }
2621
2622         /**
2623          * Is this page "semi-protected" - the *only* protection levels are listed
2624          * in $wgSemiprotectedRestrictionLevels?
2625          *
2626          * @param string $action Action to check (default: edit)
2627          * @return bool
2628          */
2629         public function isSemiProtected( $action = 'edit' ) {
2630                 global $wgSemiprotectedRestrictionLevels;
2631
2632                 $restrictions = $this->getRestrictions( $action );
2633                 $semi = $wgSemiprotectedRestrictionLevels;
2634                 if ( !$restrictions || !$semi ) {
2635                         // Not protected, or all protection is full protection
2636                         return false;
2637                 }
2638
2639                 // Remap autoconfirmed to editsemiprotected for BC
2640                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2641                         $semi[$key] = 'editsemiprotected';
2642                 }
2643                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2644                         $restrictions[$key] = 'editsemiprotected';
2645                 }
2646
2647                 return !array_diff( $restrictions, $semi );
2648         }
2649
2650         /**
2651          * Does the title correspond to a protected article?
2652          *
2653          * @param string $action The action the page is protected from,
2654          * by default checks all actions.
2655          * @return bool
2656          */
2657         public function isProtected( $action = '' ) {
2658                 global $wgRestrictionLevels;
2659
2660                 $restrictionTypes = $this->getRestrictionTypes();
2661
2662                 # Special pages have inherent protection
2663                 if ( $this->isSpecialPage() ) {
2664                         return true;
2665                 }
2666
2667                 # Check regular protection levels
2668                 foreach ( $restrictionTypes as $type ) {
2669                         if ( $action == $type || $action == '' ) {
2670                                 $r = $this->getRestrictions( $type );
2671                                 foreach ( $wgRestrictionLevels as $level ) {
2672                                         if ( in_array( $level, $r ) && $level != '' ) {
2673                                                 return true;
2674                                         }
2675                                 }
2676                         }
2677                 }
2678
2679                 return false;
2680         }
2681
2682         /**
2683          * Determines if $user is unable to edit this page because it has been protected
2684          * by $wgNamespaceProtection.
2685          *
2686          * @param User $user User object to check permissions
2687          * @return bool
2688          */
2689         public function isNamespaceProtected( User $user ) {
2690                 global $wgNamespaceProtection;
2691
2692                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2693                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2694                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2695                                         return true;
2696                                 }
2697                         }
2698                 }
2699                 return false;
2700         }
2701
2702         /**
2703          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2704          *
2705          * @return bool If the page is subject to cascading restrictions.
2706          */
2707         public function isCascadeProtected() {
2708                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2709                 return ( $sources > 0 );
2710         }
2711
2712         /**
2713          * Determines whether cascading protection sources have already been loaded from
2714          * the database.
2715          *
2716          * @param bool $getPages True to check if the pages are loaded, or false to check
2717          * if the status is loaded.
2718          * @return bool Whether or not the specified information has been loaded
2719          * @since 1.23
2720          */
2721         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2722                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2723         }
2724
2725         /**
2726          * Cascading protection: Get the source of any cascading restrictions on this page.
2727          *
2728          * @param bool $getPages Whether or not to retrieve the actual pages
2729          *        that the restrictions have come from and the actual restrictions
2730          *        themselves.
2731          * @return array Two elements: First is an array of Title objects of the
2732          *        pages from which cascading restrictions have come, false for
2733          *        none, or true if such restrictions exist but $getPages was not
2734          *        set. Second is an array like that returned by
2735          *        Title::getAllRestrictions(), or an empty array if $getPages is
2736          *        false.
2737          */
2738         public function getCascadeProtectionSources( $getPages = true ) {
2739                 $pagerestrictions = array();
2740
2741                 if ( $this->mCascadeSources !== null && $getPages ) {
2742                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2743                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2744                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2745                 }
2746
2747                 $dbr = wfGetDB( DB_SLAVE );
2748
2749                 if ( $this->getNamespace() == NS_FILE ) {
2750                         $tables = array( 'imagelinks', 'page_restrictions' );
2751                         $where_clauses = array(
2752                                 'il_to' => $this->getDBkey(),
2753                                 'il_from=pr_page',
2754                                 'pr_cascade' => 1
2755                         );
2756                 } else {
2757                         $tables = array( 'templatelinks', 'page_restrictions' );
2758                         $where_clauses = array(
2759                                 'tl_namespace' => $this->getNamespace(),
2760                                 'tl_title' => $this->getDBkey(),
2761                                 'tl_from=pr_page',
2762                                 'pr_cascade' => 1
2763                         );
2764                 }
2765
2766                 if ( $getPages ) {
2767                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2768                                 'pr_expiry', 'pr_type', 'pr_level' );
2769                         $where_clauses[] = 'page_id=pr_page';
2770                         $tables[] = 'page';
2771                 } else {
2772                         $cols = array( 'pr_expiry' );
2773                 }
2774
2775                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2776
2777                 $sources = $getPages ? array() : false;
2778                 $now = wfTimestampNow();
2779
2780                 foreach ( $res as $row ) {
2781                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2782                         if ( $expiry > $now ) {
2783                                 if ( $getPages ) {
2784                                         $page_id = $row->pr_page;
2785                                         $page_ns = $row->page_namespace;
2786                                         $page_title = $row->page_title;
2787                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2788                                         # Add groups needed for each restriction type if its not already there
2789                                         # Make sure this restriction type still exists
2790
2791                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2792                                                 $pagerestrictions[$row->pr_type] = array();
2793                                         }
2794
2795                                         if (
2796                                                 isset( $pagerestrictions[$row->pr_type] )
2797                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2798                                         ) {
2799                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2800                                         }
2801                                 } else {
2802                                         $sources = true;
2803                                 }
2804                         }
2805                 }
2806
2807                 if ( $getPages ) {
2808                         $this->mCascadeSources = $sources;
2809                         $this->mCascadingRestrictions = $pagerestrictions;
2810                 } else {
2811                         $this->mHasCascadingRestrictions = $sources;
2812                 }
2813
2814                 return array( $sources, $pagerestrictions );
2815         }
2816
2817         /**
2818          * Accessor for mRestrictionsLoaded
2819          *
2820          * @return bool Whether or not the page's restrictions have already been
2821          * loaded from the database
2822          * @since 1.23
2823          */
2824         public function areRestrictionsLoaded() {
2825                 return $this->mRestrictionsLoaded;
2826         }
2827
2828         /**
2829          * Accessor/initialisation for mRestrictions
2830          *
2831          * @param string $action Action that permission needs to be checked for
2832          * @return array Restriction levels needed to take the action. All levels are
2833          *     required. Note that restriction levels are normally user rights, but 'sysop'
2834          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2835          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2836          */
2837         public function getRestrictions( $action ) {
2838                 if ( !$this->mRestrictionsLoaded ) {
2839                         $this->loadRestrictions();
2840                 }
2841                 return isset( $this->mRestrictions[$action] )
2842                                 ? $this->mRestrictions[$action]
2843                                 : array();
2844         }
2845
2846         /**
2847          * Accessor/initialisation for mRestrictions
2848          *
2849          * @return array Keys are actions, values are arrays as returned by
2850          *     Title::getRestrictions()
2851          * @since 1.23
2852          */
2853         public function getAllRestrictions() {
2854                 if ( !$this->mRestrictionsLoaded ) {
2855                         $this->loadRestrictions();
2856                 }
2857                 return $this->mRestrictions;
2858         }
2859
2860         /**
2861          * Get the expiry time for the restriction against a given action
2862          *
2863          * @param string $action
2864          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2865          *     or not protected at all, or false if the action is not recognised.
2866          */
2867         public function getRestrictionExpiry( $action ) {
2868                 if ( !$this->mRestrictionsLoaded ) {
2869                         $this->loadRestrictions();
2870                 }
2871                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2872         }
2873
2874         /**
2875          * Returns cascading restrictions for the current article
2876          *
2877          * @return bool
2878          */
2879         function areRestrictionsCascading() {
2880                 if ( !$this->mRestrictionsLoaded ) {
2881                         $this->loadRestrictions();
2882                 }
2883
2884                 return $this->mCascadeRestriction;
2885         }
2886
2887         /**
2888          * Loads a string into mRestrictions array
2889          *
2890          * @param ResultWrapper $res Resource restrictions as an SQL result.
2891          * @param string $oldFashionedRestrictions Comma-separated list of page
2892          *        restrictions from page table (pre 1.10)
2893          */
2894         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2895                 $rows = array();
2896
2897                 foreach ( $res as $row ) {
2898                         $rows[] = $row;
2899                 }
2900
2901                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2902         }
2903
2904         /**
2905          * Compiles list of active page restrictions from both page table (pre 1.10)
2906          * and page_restrictions table for this existing page.
2907          * Public for usage by LiquidThreads.
2908          *
2909          * @param array $rows Array of db result objects
2910          * @param string $oldFashionedRestrictions Comma-separated list of page
2911          *   restrictions from page table (pre 1.10)
2912          */
2913         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2914                 $dbr = wfGetDB( DB_SLAVE );
2915
2916                 $restrictionTypes = $this->getRestrictionTypes();
2917
2918                 foreach ( $restrictionTypes as $type ) {
2919                         $this->mRestrictions[$type] = array();
2920                         $this->mRestrictionsExpiry[$type] = 'infinity';
2921                 }
2922
2923                 $this->mCascadeRestriction = false;
2924
2925                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2926                 if ( $oldFashionedRestrictions !== null ) {
2927                         $this->mOldRestrictions = $oldFashionedRestrictions;
2928                 }
2929
2930                 if ( $this->mOldRestrictions === false ) {
2931                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2932                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2933                 }
2934
2935                 if ( $this->mOldRestrictions != '' ) {
2936                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2937                                 $temp = explode( '=', trim( $restrict ) );
2938                                 if ( count( $temp ) == 1 ) {
2939                                         // old old format should be treated as edit/move restriction
2940                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2941                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2942                                 } else {
2943                                         $restriction = trim( $temp[1] );
2944                                         if ( $restriction != '' ) { // some old entries are empty
2945                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2946                                         }
2947                                 }
2948                         }
2949                 }
2950
2951                 if ( count( $rows ) ) {
2952                         # Current system - load second to make them override.
2953                         $now = wfTimestampNow();
2954
2955                         # Cycle through all the restrictions.
2956                         foreach ( $rows as $row ) {
2957
2958                                 // Don't take care of restrictions types that aren't allowed
2959                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2960                                         continue;
2961                                 }
2962
2963                                 // This code should be refactored, now that it's being used more generally,
2964                                 // But I don't really see any harm in leaving it in Block for now -werdna
2965                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2966
2967                                 // Only apply the restrictions if they haven't expired!
2968                                 if ( !$expiry || $expiry > $now ) {
2969                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2970                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2971
2972                                         $this->mCascadeRestriction |= $row->pr_cascade;
2973                                 }
2974                         }
2975                 }
2976
2977                 $this->mRestrictionsLoaded = true;
2978         }
2979
2980         /**
2981          * Load restrictions from the page_restrictions table
2982          *
2983          * @param string $oldFashionedRestrictions Comma-separated list of page
2984          *   restrictions from page table (pre 1.10)
2985          */
2986         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2987                 if ( !$this->mRestrictionsLoaded ) {
2988                         $dbr = wfGetDB( DB_SLAVE );
2989                         if ( $this->exists() ) {
2990                                 $res = $dbr->select(
2991                                         'page_restrictions',
2992                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2993                                         array( 'pr_page' => $this->getArticleID() ),
2994                                         __METHOD__
2995                                 );
2996
2997                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2998                         } else {
2999                                 $title_protection = $this->getTitleProtection();
3000
3001                                 if ( $title_protection ) {
3002                                         $now = wfTimestampNow();
3003                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
3004
3005                                         if ( !$expiry || $expiry > $now ) {
3006                                                 // Apply the restrictions
3007                                                 $this->mRestrictionsExpiry['create'] = $expiry;
3008                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
3009                                         } else { // Get rid of the old restrictions
3010                                                 $this->mTitleProtection = false;
3011                                         }
3012                                 } else {
3013                                         $this->mRestrictionsExpiry['create'] = 'infinity';
3014                                 }
3015                                 $this->mRestrictionsLoaded = true;
3016                         }
3017                 }
3018         }
3019
3020         /**
3021          * Flush the protection cache in this object and force reload from the database.
3022          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3023          */
3024         public function flushRestrictions() {
3025                 $this->mRestrictionsLoaded = false;
3026                 $this->mTitleProtection = null;
3027         }
3028
3029         /**
3030          * Purge expired restrictions from the page_restrictions table
3031          */
3032         static function purgeExpiredRestrictions() {
3033                 if ( wfReadOnly() ) {
3034                         return;
3035                 }
3036
3037                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3038                         wfGetDB( DB_MASTER ),
3039                         __METHOD__,
3040                         function ( IDatabase $dbw, $fname ) {
3041                                 $dbw->delete(
3042                                         'page_restrictions',
3043                                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3044                                         $fname
3045                                 );
3046                                 $dbw->delete(
3047                                         'protected_titles',
3048                                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3049                                         $fname
3050                                 );
3051                         }
3052                 ) );
3053         }
3054
3055         /**
3056          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3057          *
3058          * @return bool
3059          */
3060         public function hasSubpages() {
3061                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3062                         # Duh
3063                         return false;
3064                 }
3065
3066                 # We dynamically add a member variable for the purpose of this method
3067                 # alone to cache the result.  There's no point in having it hanging
3068                 # around uninitialized in every Title object; therefore we only add it
3069                 # if needed and don't declare it statically.
3070                 if ( $this->mHasSubpages === null ) {
3071                         $this->mHasSubpages = false;
3072                         $subpages = $this->getSubpages( 1 );
3073                         if ( $subpages instanceof TitleArray ) {
3074                                 $this->mHasSubpages = (bool)$subpages->count();
3075                         }
3076                 }
3077
3078                 return $this->mHasSubpages;
3079         }
3080
3081         /**
3082          * Get all subpages of this page.
3083          *
3084          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3085          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3086          *  doesn't allow subpages
3087          */
3088         public function getSubpages( $limit = -1 ) {
3089                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3090                         return array();
3091                 }
3092
3093                 $dbr = wfGetDB( DB_SLAVE );
3094                 $conds['page_namespace'] = $this->getNamespace();
3095                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3096                 $options = array();
3097                 if ( $limit > -1 ) {
3098                         $options['LIMIT'] = $limit;
3099                 }
3100                 $this->mSubpages = TitleArray::newFromResult(
3101                         $dbr->select( 'page',
3102                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3103                                 $conds,
3104                                 __METHOD__,
3105                                 $options
3106                         )
3107                 );
3108                 return $this->mSubpages;
3109         }
3110
3111         /**
3112          * Is there a version of this page in the deletion archive?
3113          *
3114          * @return int The number of archived revisions
3115          */
3116         public function isDeleted() {
3117                 if ( $this->getNamespace() < 0 ) {
3118                         $n = 0;
3119                 } else {
3120                         $dbr = wfGetDB( DB_SLAVE );
3121
3122                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3123                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3124                                 __METHOD__
3125                         );
3126                         if ( $this->getNamespace() == NS_FILE ) {
3127                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3128                                         array( 'fa_name' => $this->getDBkey() ),
3129                                         __METHOD__
3130                                 );
3131                         }
3132                 }
3133                 return (int)$n;
3134         }
3135
3136         /**
3137          * Is there a version of this page in the deletion archive?
3138          *
3139          * @return bool
3140          */
3141         public function isDeletedQuick() {
3142                 if ( $this->getNamespace() < 0 ) {
3143                         return false;
3144                 }
3145                 $dbr = wfGetDB( DB_SLAVE );
3146                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3147                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3148                         __METHOD__
3149                 );
3150                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3151                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3152                                 array( 'fa_name' => $this->getDBkey() ),
3153                                 __METHOD__
3154                         );
3155                 }
3156                 return $deleted;
3157         }
3158
3159         /**
3160          * Get the article ID for this Title from the link cache,
3161          * adding it if necessary
3162          *
3163          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3164          *  for update
3165          * @return int The ID
3166          */
3167         public function getArticleID( $flags = 0 ) {
3168                 if ( $this->getNamespace() < 0 ) {
3169                         $this->mArticleID = 0;
3170                         return $this->mArticleID;
3171                 }
3172                 $linkCache = LinkCache::singleton();
3173                 if ( $flags & self::GAID_FOR_UPDATE ) {
3174                         $oldUpdate = $linkCache->forUpdate( true );
3175                         $linkCache->clearLink( $this );
3176                         $this->mArticleID = $linkCache->addLinkObj( $this );
3177                         $linkCache->forUpdate( $oldUpdate );
3178                 } else {
3179                         if ( -1 == $this->mArticleID ) {
3180                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3181                         }
3182                 }
3183                 return $this->mArticleID;
3184         }
3185
3186         /**
3187          * Is this an article that is a redirect page?
3188          * Uses link cache, adding it if necessary
3189          *
3190          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3191          * @return bool
3192          */
3193         public function isRedirect( $flags = 0 ) {
3194                 if ( !is_null( $this->mRedirect ) ) {
3195                         return $this->mRedirect;
3196                 }
3197                 if ( !$this->getArticleID( $flags ) ) {
3198                         $this->mRedirect = false;
3199                         return $this->mRedirect;
3200                 }
3201
3202                 $linkCache = LinkCache::singleton();
3203                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3204                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3205                 if ( $cached === null ) {
3206                         # Trust LinkCache's state over our own
3207                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3208                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3209                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3210                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3211                         # LinkCache to refresh its data from the master.
3212                         $this->mRedirect = false;
3213                         return $this->mRedirect;
3214                 }
3215
3216                 $this->mRedirect = (bool)$cached;
3217
3218                 return $this->mRedirect;
3219         }
3220
3221         /**
3222          * What is the length of this page?
3223          * Uses link cache, adding it if necessary
3224          *
3225          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3226          * @return int
3227          */
3228         public function getLength( $flags = 0 ) {
3229                 if ( $this->mLength != -1 ) {
3230                         return $this->mLength;
3231                 }
3232                 if ( !$this->getArticleID( $flags ) ) {
3233                         $this->mLength = 0;
3234                         return $this->mLength;
3235                 }
3236                 $linkCache = LinkCache::singleton();
3237                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3238                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3239                 if ( $cached === null ) {
3240                         # Trust LinkCache's state over our own, as for isRedirect()
3241                         $this->mLength = 0;
3242                         return $this->mLength;
3243                 }
3244
3245                 $this->mLength = intval( $cached );
3246
3247                 return $this->mLength;
3248         }
3249
3250         /**
3251          * What is the page_latest field for this page?
3252          *
3253          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3254          * @return int Int or 0 if the page doesn't exist
3255          */
3256         public function getLatestRevID( $flags = 0 ) {
3257                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3258                         return intval( $this->mLatestID );
3259                 }
3260                 if ( !$this->getArticleID( $flags ) ) {
3261                         $this->mLatestID = 0;
3262                         return $this->mLatestID;
3263                 }
3264                 $linkCache = LinkCache::singleton();
3265                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3266                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3267                 if ( $cached === null ) {
3268                         # Trust LinkCache's state over our own, as for isRedirect()
3269                         $this->mLatestID = 0;
3270                         return $this->mLatestID;
3271                 }
3272
3273                 $this->mLatestID = intval( $cached );
3274
3275                 return $this->mLatestID;
3276         }
3277
3278         /**
3279          * This clears some fields in this object, and clears any associated
3280          * keys in the "bad links" section of the link cache.
3281          *
3282          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3283          * loading of the new page_id. It's also called from
3284          * WikiPage::doDeleteArticleReal()
3285          *
3286          * @param int $newid The new Article ID
3287          */
3288         public function resetArticleID( $newid ) {
3289                 $linkCache = LinkCache::singleton();
3290                 $linkCache->clearLink( $this );
3291
3292                 if ( $newid === false ) {
3293                         $this->mArticleID = -1;
3294                 } else {
3295                         $this->mArticleID = intval( $newid );
3296                 }
3297                 $this->mRestrictionsLoaded = false;
3298                 $this->mRestrictions = array();
3299                 $this->mOldRestrictions = false;
3300                 $this->mRedirect = null;
3301                 $this->mLength = -1;
3302                 $this->mLatestID = false;
3303                 $this->mContentModel = false;
3304                 $this->mEstimateRevisions = null;
3305                 $this->mPageLanguage = false;
3306                 $this->mDbPageLanguage = null;
3307                 $this->mIsBigDeletion = null;
3308         }
3309
3310         public static function clearCaches() {
3311                 $linkCache = LinkCache::singleton();
3312                 $linkCache->clear();
3313
3314                 $titleCache = self::getTitleCache();
3315                 $titleCache->clear();
3316         }
3317
3318         /**
3319          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3320          *
3321          * @param string $text Containing title to capitalize
3322          * @param int $ns Namespace index, defaults to NS_MAIN
3323          * @return string Containing capitalized title
3324          */
3325         public static function capitalize( $text, $ns = NS_MAIN ) {
3326                 global $wgContLang;
3327
3328                 if ( MWNamespace::isCapitalized( $ns ) ) {
3329                         return $wgContLang->ucfirst( $text );
3330                 } else {
3331                         return $text;
3332                 }
3333         }
3334
3335         /**
3336          * Secure and split - main initialisation function for this object
3337          *
3338          * Assumes that mDbkeyform has been set, and is urldecoded
3339          * and uses underscores, but not otherwise munged.  This function
3340          * removes illegal characters, splits off the interwiki and
3341          * namespace prefixes, sets the other forms, and canonicalizes
3342          * everything.
3343          *
3344          * @throws MalformedTitleException On invalid titles
3345          * @return bool True on success
3346          */
3347         private function secureAndSplit() {
3348                 # Initialisation
3349                 $this->mInterwiki = '';
3350                 $this->mFragment = '';
3351                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3352
3353                 $dbkey = $this->mDbkeyform;
3354
3355                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3356                 //        the parsing code with Title, while avoiding massive refactoring.
3357                 // @todo: get rid of secureAndSplit, refactor parsing code.
3358                 $titleParser = self::getMediaWikiTitleCodec();
3359                 // MalformedTitleException can be thrown here
3360                 $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3361
3362                 # Fill fields
3363                 $this->setFragment( '#' . $parts['fragment'] );
3364                 $this->mInterwiki = $parts['interwiki'];
3365                 $this->mLocalInterwiki = $parts['local_interwiki'];
3366                 $this->mNamespace = $parts['namespace'];
3367                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3368
3369                 $this->mDbkeyform = $parts['dbkey'];
3370                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3371                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3372
3373                 # We already know that some pages won't be in the database!
3374                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3375                         $this->mArticleID = 0;
3376                 }
3377
3378                 return true;
3379         }
3380
3381         /**
3382          * Get an array of Title objects linking to this Title
3383          * Also stores the IDs in the link cache.
3384          *
3385          * WARNING: do not use this function on arbitrary user-supplied titles!
3386          * On heavily-used templates it will max out the memory.
3387          *
3388          * @param array $options May be FOR UPDATE
3389          * @param string $table Table name
3390          * @param string $prefix Fields prefix
3391          * @return Title[] Array of Title objects linking here
3392          */
3393         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3394                 if ( count( $options ) > 0 ) {
3395                         $db = wfGetDB( DB_MASTER );
3396                 } else {
3397                         $db = wfGetDB( DB_SLAVE );
3398                 }
3399
3400                 $res = $db->select(
3401                         array( 'page', $table ),
3402                         self::getSelectFields(),
3403                         array(
3404                                 "{$prefix}_from=page_id",
3405                                 "{$prefix}_namespace" => $this->getNamespace(),
3406                                 "{$prefix}_title" => $this->getDBkey() ),
3407                         __METHOD__,
3408                         $options
3409                 );
3410
3411                 $retVal = array();
3412                 if ( $res->numRows() ) {
3413                         $linkCache = LinkCache::singleton();
3414                         foreach ( $res as $row ) {
3415                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3416                                 if ( $titleObj ) {
3417                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3418                                         $retVal[] = $titleObj;
3419                                 }
3420                         }
3421                 }
3422                 return $retVal;
3423         }
3424
3425         /**
3426          * Get an array of Title objects using this Title as a template
3427          * Also stores the IDs in the link cache.
3428          *
3429          * WARNING: do not use this function on arbitrary user-supplied titles!
3430          * On heavily-used templates it will max out the memory.
3431          *
3432          * @param array $options May be FOR UPDATE
3433          * @return Title[] Array of Title the Title objects linking here
3434          */
3435         public function getTemplateLinksTo( $options = array() ) {
3436                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3437         }
3438
3439         /**
3440          * Get an array of Title objects linked from this Title
3441          * Also stores the IDs in the link cache.
3442          *
3443          * WARNING: do not use this function on arbitrary user-supplied titles!
3444          * On heavily-used templates it will max out the memory.
3445          *
3446          * @param array $options May be FOR UPDATE
3447          * @param string $table Table name
3448          * @param string $prefix Fields prefix
3449          * @return array Array of Title objects linking here
3450          */
3451         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3452                 $id = $this->getArticleID();
3453
3454                 # If the page doesn't exist; there can't be any link from this page
3455                 if ( !$id ) {
3456                         return array();
3457                 }
3458
3459                 if ( count( $options ) > 0 ) {
3460                         $db = wfGetDB( DB_MASTER );
3461                 } else {
3462                         $db = wfGetDB( DB_SLAVE );
3463                 }
3464
3465                 $blNamespace = "{$prefix}_namespace";
3466                 $blTitle = "{$prefix}_title";
3467
3468                 $res = $db->select(
3469                         array( $table, 'page' ),
3470                         array_merge(
3471                                 array( $blNamespace, $blTitle ),
3472                                 WikiPage::selectFields()
3473                         ),
3474                         array( "{$prefix}_from" => $id ),
3475                         __METHOD__,
3476                         $options,
3477                         array( 'page' => array(
3478                                 'LEFT JOIN',
3479                                 array( "page_namespace=$blNamespace", "page_title=$blTitle" )
3480                         ) )
3481                 );
3482
3483                 $retVal = array();
3484                 $linkCache = LinkCache::singleton();
3485                 foreach ( $res as $row ) {
3486                         if ( $row->page_id ) {
3487                                 $titleObj = Title::newFromRow( $row );
3488                         } else {
3489                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3490                                 $linkCache->addBadLinkObj( $titleObj );
3491                         }
3492                         $retVal[] = $titleObj;
3493                 }
3494
3495                 return $retVal;
3496         }
3497
3498         /**
3499          * Get an array of Title objects used on this Title as a template
3500          * Also stores the IDs in the link cache.
3501          *
3502          * WARNING: do not use this function on arbitrary user-supplied titles!
3503          * On heavily-used templates it will max out the memory.
3504          *
3505          * @param array $options May be FOR UPDATE
3506          * @return Title[] Array of Title the Title objects used here
3507          */
3508         public function getTemplateLinksFrom( $options = array() ) {
3509                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3510         }
3511
3512         /**
3513          * Get an array of Title objects referring to non-existent articles linked
3514          * from this page.
3515          *
3516          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3517          *   should use redirect table in this case).
3518          * @return Title[] Array of Title the Title objects
3519          */
3520         public function getBrokenLinksFrom() {
3521                 if ( $this->getArticleID() == 0 ) {
3522                         # All links from article ID 0 are false positives
3523                         return array();
3524                 }
3525
3526                 $dbr = wfGetDB( DB_SLAVE );
3527                 $res = $dbr->select(
3528                         array( 'page', 'pagelinks' ),
3529                         array( 'pl_namespace', 'pl_title' ),
3530                         array(
3531                                 'pl_from' => $this->getArticleID(),
3532                                 'page_namespace IS NULL'
3533                         ),
3534                         __METHOD__, array(),
3535                         array(
3536                                 'page' => array(
3537                                         'LEFT JOIN',
3538                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3539                                 )
3540                         )
3541                 );
3542
3543                 $retVal = array();
3544                 foreach ( $res as $row ) {
3545                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3546                 }
3547                 return $retVal;
3548         }
3549
3550         /**
3551          * Get a list of URLs to purge from the CDN cache when this
3552          * page changes
3553          *
3554          * @return string[] Array of String the URLs
3555          */
3556         public function getCdnUrls() {
3557                 $urls = array(
3558                         $this->getInternalURL(),
3559                         $this->getInternalURL( 'action=history' )
3560                 );
3561
3562                 $pageLang = $this->getPageLanguage();
3563                 if ( $pageLang->hasVariants() ) {
3564                         $variants = $pageLang->getVariants();
3565                         foreach ( $variants as $vCode ) {
3566                                 $urls[] = $this->getInternalURL( $vCode );
3567                         }
3568                 }
3569
3570                 // If we are looking at a css/js user subpage, purge the action=raw.
3571                 if ( $this->isJsSubpage() ) {
3572                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3573                 } elseif ( $this->isCssSubpage() ) {
3574                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3575                 }
3576
3577                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3578                 return $urls;
3579         }
3580
3581         /**
3582          * @deprecated since 1.27 use getCdnUrls()
3583          */
3584         public function getSquidURLs() {
3585                 return $this->getCdnUrls();
3586         }
3587
3588         /**
3589          * Purge all applicable CDN URLs
3590          */
3591         public function purgeSquid() {
3592                 DeferredUpdates::addUpdate(
3593                         new CdnCacheUpdate( $this->getCdnUrls() ),
3594                         DeferredUpdates::PRESEND
3595                 );
3596         }
3597
3598         /**
3599          * Move this page without authentication
3600          *
3601          * @deprecated since 1.25 use MovePage class instead
3602          * @param Title $nt The new page Title
3603          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3604          */
3605         public function moveNoAuth( &$nt ) {
3606                 wfDeprecated( __METHOD__, '1.25' );
3607                 return $this->moveTo( $nt, false );
3608         }
3609
3610         /**
3611          * Check whether a given move operation would be valid.
3612          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3613          *
3614          * @deprecated since 1.25, use MovePage's methods instead
3615          * @param Title $nt The new title
3616          * @param bool $auth Whether to check user permissions (uses $wgUser)
3617          * @param string $reason Is the log summary of the move, used for spam checking
3618          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3619          */
3620         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3621                 global $wgUser;
3622
3623                 if ( !( $nt instanceof Title ) ) {
3624                         // Normally we'd add this to $errors, but we'll get
3625                         // lots of syntax errors if $nt is not an object
3626                         return array( array( 'badtitletext' ) );
3627                 }
3628
3629                 $mp = new MovePage( $this, $nt );
3630                 $errors = $mp->isValidMove()->getErrorsArray();
3631                 if ( $auth ) {
3632                         $errors = wfMergeErrorArrays(
3633                                 $errors,
3634                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3635                         );
3636                 }
3637
3638                 return $errors ?: true;
3639         }
3640
3641         /**
3642          * Check if the requested move target is a valid file move target
3643          * @todo move this to MovePage
3644          * @param Title $nt Target title
3645          * @return array List of errors
3646          */
3647         protected function validateFileMoveOperation( $nt ) {
3648                 global $wgUser;
3649
3650                 $errors = array();
3651
3652                 $destFile = wfLocalFile( $nt );
3653                 $destFile->load( File::READ_LATEST );
3654                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3655                         && !$destFile->exists() && wfFindFile( $nt )
3656                 ) {
3657                         $errors[] = array( 'file-exists-sharedrepo' );
3658                 }
3659
3660                 return $errors;
3661         }
3662
3663         /**
3664          * Move a title to a new location
3665          *
3666          * @deprecated since 1.25, use the MovePage class instead
3667          * @param Title $nt The new title
3668          * @param bool $auth Indicates whether $wgUser's permissions
3669          *  should be checked
3670          * @param string $reason The reason for the move
3671          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3672          *  Ignored if the user doesn't have the suppressredirect right.
3673          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3674          */
3675         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3676                 global $wgUser;
3677                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3678                 if ( is_array( $err ) ) {
3679                         // Auto-block user's IP if the account was "hard" blocked
3680                         $wgUser->spreadAnyEditBlock();
3681                         return $err;
3682                 }
3683                 // Check suppressredirect permission
3684                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3685                         $createRedirect = true;
3686                 }
3687
3688                 $mp = new MovePage( $this, $nt );
3689                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3690                 if ( $status->isOK() ) {
3691                         return true;
3692                 } else {
3693                         return $status->getErrorsArray();
3694                 }
3695         }
3696
3697         /**
3698          * Move this page's subpages to be subpages of $nt
3699          *
3700          * @param Title $nt Move target
3701          * @param bool $auth Whether $wgUser's permissions should be checked
3702          * @param string $reason The reason for the move
3703          * @param bool $createRedirect Whether to create redirects from the old subpages to
3704          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3705          * @return array Array with old page titles as keys, and strings (new page titles) or
3706          *     arrays (errors) as values, or an error array with numeric indices if no pages
3707          *     were moved
3708          */
3709         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3710                 global $wgMaximumMovedPages;
3711                 // Check permissions
3712                 if ( !$this->userCan( 'move-subpages' ) ) {
3713                         return array( 'cant-move-subpages' );
3714                 }
3715                 // Do the source and target namespaces support subpages?
3716                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3717                         return array( 'namespace-nosubpages',
3718                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3719                 }
3720                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3721                         return array( 'namespace-nosubpages',
3722                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3723                 }
3724
3725                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3726                 $retval = array();
3727                 $count = 0;
3728                 foreach ( $subpages as $oldSubpage ) {
3729                         $count++;
3730                         if ( $count > $wgMaximumMovedPages ) {
3731                                 $retval[$oldSubpage->getPrefixedText()] =
3732                                                 array( 'movepage-max-pages',
3733                                                         $wgMaximumMovedPages );
3734                                 break;
3735                         }
3736
3737                         // We don't know whether this function was called before
3738                         // or after moving the root page, so check both
3739                         // $this and $nt
3740                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3741                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3742                         ) {
3743                                 // When moving a page to a subpage of itself,
3744                                 // don't move it twice
3745                                 continue;
3746                         }
3747                         $newPageName = preg_replace(
3748                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3749                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3750                                         $oldSubpage->getDBkey() );
3751                         if ( $oldSubpage->isTalkPage() ) {
3752                                 $newNs = $nt->getTalkPage()->getNamespace();
3753                         } else {
3754                                 $newNs = $nt->getSubjectPage()->getNamespace();
3755                         }
3756                         # Bug 14385: we need makeTitleSafe because the new page names may
3757                         # be longer than 255 characters.
3758                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3759
3760                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3761                         if ( $success === true ) {
3762                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3763                         } else {
3764                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3765                         }
3766                 }
3767                 return $retval;
3768         }
3769
3770         /**
3771          * Checks if this page is just a one-rev redirect.
3772          * Adds lock, so don't use just for light purposes.
3773          *
3774          * @return bool
3775          */
3776         public function isSingleRevRedirect() {
3777                 global $wgContentHandlerUseDB;
3778
3779                 $dbw = wfGetDB( DB_MASTER );
3780
3781                 # Is it a redirect?
3782                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3783                 if ( $wgContentHandlerUseDB ) {
3784                         $fields[] = 'page_content_model';
3785                 }
3786
3787                 $row = $dbw->selectRow( 'page',
3788                         $fields,
3789                         $this->pageCond(),
3790                         __METHOD__,
3791                         array( 'FOR UPDATE' )
3792                 );
3793                 # Cache some fields we may want
3794                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3795                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3796                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3797                 $this->mContentModel = $row && isset( $row->page_content_model )
3798                         ? strval( $row->page_content_model )
3799                         : false;
3800
3801                 if ( !$this->mRedirect ) {
3802                         return false;
3803                 }
3804                 # Does the article have a history?
3805                 $row = $dbw->selectField( array( 'page', 'revision' ),
3806                         'rev_id',
3807                         array( 'page_namespace' => $this->getNamespace(),
3808                                 'page_title' => $this->getDBkey(),
3809                                 'page_id=rev_page',
3810                                 'page_latest != rev_id'
3811                         ),
3812                         __METHOD__,
3813                         array( 'FOR UPDATE' )
3814                 );
3815                 # Return true if there was no history
3816                 return ( $row === false );
3817         }
3818
3819         /**
3820          * Checks if $this can be moved to a given Title
3821          * - Selects for update, so don't call it unless you mean business
3822          *
3823          * @deprecated since 1.25, use MovePage's methods instead
3824          * @param Title $nt The new title to check
3825          * @return bool
3826          */
3827         public function isValidMoveTarget( $nt ) {
3828                 # Is it an existing file?
3829                 if ( $nt->getNamespace() == NS_FILE ) {
3830                         $file = wfLocalFile( $nt );
3831                         $file->load( File::READ_LATEST );
3832                         if ( $file->exists() ) {
3833                                 wfDebug( __METHOD__ . ": file exists\n" );
3834                                 return false;
3835                         }
3836                 }
3837                 # Is it a redirect with no history?
3838                 if ( !$nt->isSingleRevRedirect() ) {
3839                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3840                         return false;
3841                 }
3842                 # Get the article text
3843                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3844                 if ( !is_object( $rev ) ) {
3845                         return false;
3846                 }
3847                 $content = $rev->getContent();
3848                 # Does the redirect point to the source?
3849                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3850                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3851
3852                 if ( $redirTitle ) {
3853                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3854                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3855                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3856                                 return false;
3857                         } else {
3858                                 return true;
3859                         }
3860                 } else {
3861                         # Fail safe (not a redirect after all. strange.)
3862                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3863                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3864                         return false;
3865                 }
3866         }
3867
3868         /**
3869          * Get categories to which this Title belongs and return an array of
3870          * categories' names.
3871          *
3872          * @return array Array of parents in the form:
3873          *        $parent => $currentarticle
3874          */
3875         public function getParentCategories() {
3876                 global $wgContLang;
3877
3878                 $data = array();
3879
3880                 $titleKey = $this->getArticleID();
3881
3882                 if ( $titleKey === 0 ) {
3883                         return $data;
3884                 }
3885
3886                 $dbr = wfGetDB( DB_SLAVE );
3887
3888                 $res = $dbr->select(
3889                         'categorylinks',
3890                         'cl_to',
3891                         array( 'cl_from' => $titleKey ),
3892                         __METHOD__
3893                 );
3894
3895                 if ( $res->numRows() > 0 ) {
3896                         foreach ( $res as $row ) {
3897                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3898                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3899                         }
3900                 }
3901                 return $data;
3902         }
3903
3904         /**
3905          * Get a tree of parent categories
3906          *
3907          * @param array $children Array with the children in the keys, to check for circular refs
3908          * @return array Tree of parent categories
3909          */
3910         public function getParentCategoryTree( $children = array() ) {
3911                 $stack = array();
3912                 $parents = $this->getParentCategories();
3913
3914                 if ( $parents ) {
3915                         foreach ( $parents as $parent => $current ) {
3916                                 if ( array_key_exists( $parent, $children ) ) {
3917                                         # Circular reference
3918                                         $stack[$parent] = array();
3919                                 } else {
3920                                         $nt = Title::newFromText( $parent );
3921                                         if ( $nt ) {
3922                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3923                                         }
3924                                 }
3925                         }
3926                 }
3927
3928                 return $stack;
3929         }
3930
3931         /**
3932          * Get an associative array for selecting this title from
3933          * the "page" table
3934          *
3935          * @return array Array suitable for the $where parameter of DB::select()
3936          */
3937         public function pageCond() {
3938                 if ( $this->mArticleID > 0 ) {
3939                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3940                         return array( 'page_id' => $this->mArticleID );
3941                 } else {
3942                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3943                 }
3944         }
3945
3946         /**
3947          * Get the revision ID of the previous revision
3948          *
3949          * @param int $revId Revision ID. Get the revision that was before this one.
3950          * @param int $flags Title::GAID_FOR_UPDATE
3951          * @return int|bool Old revision ID, or false if none exists
3952          */
3953         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3954                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3955                 $revId = $db->selectField( 'revision', 'rev_id',
3956                         array(
3957                                 'rev_page' => $this->getArticleID( $flags ),
3958                                 'rev_id < ' . intval( $revId )
3959                         ),
3960                         __METHOD__,
3961                         array( 'ORDER BY' => 'rev_id DESC' )
3962                 );
3963
3964                 if ( $revId === false ) {
3965                         return false;
3966                 } else {
3967                         return intval( $revId );
3968                 }
3969         }
3970
3971         /**
3972          * Get the revision ID of the next revision
3973          *
3974          * @param int $revId Revision ID. Get the revision that was after this one.
3975          * @param int $flags Title::GAID_FOR_UPDATE
3976          * @return int|bool Next revision ID, or false if none exists
3977          */
3978         public function getNextRevisionID( $revId, $flags = 0 ) {
3979                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3980                 $revId = $db->selectField( 'revision', 'rev_id',
3981                         array(
3982                                 'rev_page' => $this->getArticleID( $flags ),
3983                                 'rev_id > ' . intval( $revId )
3984                         ),
3985                         __METHOD__,
3986                         array( 'ORDER BY' => 'rev_id' )
3987                 );
3988
3989                 if ( $revId === false ) {
3990                         return false;
3991                 } else {
3992                         return intval( $revId );
3993                 }
3994         }
3995
3996         /**
3997          * Get the first revision of the page
3998          *
3999          * @param int $flags Title::GAID_FOR_UPDATE
4000          * @return Revision|null If page doesn't exist
4001          */
4002         public function getFirstRevision( $flags = 0 ) {
4003                 $pageId = $this->getArticleID( $flags );
4004                 if ( $pageId ) {
4005                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4006                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4007                                 array( 'rev_page' => $pageId ),
4008                                 __METHOD__,
4009                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4010                         );
4011                         if ( $row ) {
4012                                 return new Revision( $row );
4013                         }
4014                 }
4015                 return null;
4016         }
4017
4018         /**
4019          * Get the oldest revision timestamp of this page
4020          *
4021          * @param int $flags Title::GAID_FOR_UPDATE
4022          * @return string MW timestamp
4023          */
4024         public function getEarliestRevTime( $flags = 0 ) {
4025                 $rev = $this->getFirstRevision( $flags );
4026                 return $rev ? $rev->getTimestamp() : null;
4027         }
4028
4029         /**
4030          * Check if this is a new page
4031          *
4032          * @return bool
4033          */
4034         public function isNewPage() {
4035                 $dbr = wfGetDB( DB_SLAVE );
4036                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4037         }
4038
4039         /**
4040          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4041          *
4042          * @return bool
4043          */
4044         public function isBigDeletion() {
4045                 global $wgDeleteRevisionsLimit;
4046
4047                 if ( !$wgDeleteRevisionsLimit ) {
4048                         return false;
4049                 }
4050
4051                 if ( $this->mIsBigDeletion === null ) {
4052                         $dbr = wfGetDB( DB_SLAVE );
4053
4054                         $revCount = $dbr->selectRowCount(
4055                                 'revision',
4056                                 '1',
4057                                 array( 'rev_page' => $this->getArticleID() ),
4058                                 __METHOD__,
4059                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4060                         );
4061
4062                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4063                 }
4064
4065                 return $this->mIsBigDeletion;
4066         }
4067
4068         /**
4069          * Get the approximate revision count of this page.
4070          *
4071          * @return int
4072          */
4073         public function estimateRevisionCount() {
4074                 if ( !$this->exists() ) {
4075                         return 0;
4076                 }
4077
4078                 if ( $this->mEstimateRevisions === null ) {
4079                         $dbr = wfGetDB( DB_SLAVE );
4080                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4081                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4082                 }
4083
4084                 return $this->mEstimateRevisions;
4085         }
4086
4087         /**
4088          * Get the number of revisions between the given revision.
4089          * Used for diffs and other things that really need it.
4090          *
4091          * @param int|Revision $old Old revision or rev ID (first before range)
4092          * @param int|Revision $new New revision or rev ID (first after range)
4093          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4094          * @return int Number of revisions between these revisions.
4095          */
4096         public function countRevisionsBetween( $old, $new, $max = null ) {
4097                 if ( !( $old instanceof Revision ) ) {
4098                         $old = Revision::newFromTitle( $this, (int)$old );
4099                 }
4100                 if ( !( $new instanceof Revision ) ) {
4101                         $new = Revision::newFromTitle( $this, (int)$new );
4102                 }
4103                 if ( !$old || !$new ) {
4104                         return 0; // nothing to compare
4105                 }
4106                 $dbr = wfGetDB( DB_SLAVE );
4107                 $conds = array(
4108                         'rev_page' => $this->getArticleID(),
4109                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4110                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4111                 );
4112                 if ( $max !== null ) {
4113                         return $dbr->selectRowCount( 'revision', '1',
4114                                 $conds,
4115                                 __METHOD__,
4116                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4117                         );
4118                 } else {
4119                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4120                 }
4121         }
4122
4123         /**
4124          * Get the authors between the given revisions or revision IDs.
4125          * Used for diffs and other things that really need it.
4126          *
4127          * @since 1.23
4128          *
4129          * @param int|Revision $old Old revision or rev ID (first before range by default)
4130          * @param int|Revision $new New revision or rev ID (first after range by default)
4131          * @param int $limit Maximum number of authors
4132          * @param string|array $options (Optional): Single option, or an array of options:
4133          *     'include_old' Include $old in the range; $new is excluded.
4134          *     'include_new' Include $new in the range; $old is excluded.
4135          *     'include_both' Include both $old and $new in the range.
4136          *     Unknown option values are ignored.
4137          * @return array|null Names of revision authors in the range; null if not both revisions exist
4138          */
4139         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4140                 if ( !( $old instanceof Revision ) ) {
4141                         $old = Revision::newFromTitle( $this, (int)$old );
4142                 }
4143                 if ( !( $new instanceof Revision ) ) {
4144                         $new = Revision::newFromTitle( $this, (int)$new );
4145                 }
4146                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4147                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4148                 // in the sanity check below?
4149                 if ( !$old || !$new ) {
4150                         return null; // nothing to compare
4151                 }
4152                 $authors = array();
4153                 $old_cmp = '>';
4154                 $new_cmp = '<';
4155                 $options = (array)$options;
4156                 if ( in_array( 'include_old', $options ) ) {
4157                         $old_cmp = '>=';
4158                 }
4159                 if ( in_array( 'include_new', $options ) ) {
4160                         $new_cmp = '<=';
4161                 }
4162                 if ( in_array( 'include_both', $options ) ) {
4163                         $old_cmp = '>=';
4164                         $new_cmp = '<=';
4165                 }
4166                 // No DB query needed if $old and $new are the same or successive revisions:
4167                 if ( $old->getId() === $new->getId() ) {
4168                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4169                                 array() :
4170                                 array( $old->getUserText( Revision::RAW ) );
4171                 } elseif ( $old->getId() === $new->getParentId() ) {
4172                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4173                                 $authors[] = $old->getUserText( Revision::RAW );
4174                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4175                                         $authors[] = $new->getUserText( Revision::RAW );
4176                                 }
4177                         } elseif ( $old_cmp === '>=' ) {
4178                                 $authors[] = $old->getUserText( Revision::RAW );
4179                         } elseif ( $new_cmp === '<=' ) {
4180                                 $authors[] = $new->getUserText( Revision::RAW );
4181                         }
4182                         return $authors;
4183                 }
4184                 $dbr = wfGetDB( DB_SLAVE );
4185                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4186                         array(
4187                                 'rev_page' => $this->getArticleID(),
4188                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4189                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4190                         ), __METHOD__,
4191                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4192                 );
4193                 foreach ( $res as $row ) {
4194                         $authors[] = $row->rev_user_text;
4195                 }
4196                 return $authors;
4197         }
4198
4199         /**
4200          * Get the number of authors between the given revisions or revision IDs.
4201          * Used for diffs and other things that really need it.
4202          *
4203          * @param int|Revision $old Old revision or rev ID (first before range by default)
4204          * @param int|Revision $new New revision or rev ID (first after range by default)
4205          * @param int $limit Maximum number of authors
4206          * @param string|array $options (Optional): Single option, or an array of options:
4207          *     'include_old' Include $old in the range; $new is excluded.
4208          *     'include_new' Include $new in the range; $old is excluded.
4209          *     'include_both' Include both $old and $new in the range.
4210          *     Unknown option values are ignored.
4211          * @return int Number of revision authors in the range; zero if not both revisions exist
4212          */
4213         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4214                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4215                 return $authors ? count( $authors ) : 0;
4216         }
4217
4218         /**
4219          * Compare with another title.
4220          *
4221          * @param Title $title
4222          * @return bool
4223          */
4224         public function equals( Title $title ) {
4225                 // Note: === is necessary for proper matching of number-like titles.
4226                 return $this->getInterwiki() === $title->getInterwiki()
4227                         && $this->getNamespace() == $title->getNamespace()
4228                         && $this->getDBkey() === $title->getDBkey();
4229         }
4230
4231         /**
4232          * Check if this title is a subpage of another title
4233          *
4234          * @param Title $title
4235          * @return bool
4236          */
4237         public function isSubpageOf( Title $title ) {
4238                 return $this->getInterwiki() === $title->getInterwiki()
4239                         && $this->getNamespace() == $title->getNamespace()
4240                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4241         }
4242
4243         /**
4244          * Check if page exists.  For historical reasons, this function simply
4245          * checks for the existence of the title in the page table, and will
4246          * thus return false for interwiki links, special pages and the like.
4247          * If you want to know if a title can be meaningfully viewed, you should
4248          * probably call the isKnown() method instead.
4249          *
4250          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4251          *   from master/for update
4252          * @return bool
4253          */
4254         public function exists( $flags = 0 ) {
4255                 $exists = $this->getArticleID( $flags ) != 0;
4256                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4257                 return $exists;
4258         }
4259
4260         /**
4261          * Should links to this title be shown as potentially viewable (i.e. as
4262          * "bluelinks"), even if there's no record by this title in the page
4263          * table?
4264          *
4265          * This function is semi-deprecated for public use, as well as somewhat
4266          * misleadingly named.  You probably just want to call isKnown(), which
4267          * calls this function internally.
4268          *
4269          * (ISSUE: Most of these checks are cheap, but the file existence check
4270          * can potentially be quite expensive.  Including it here fixes a lot of
4271          * existing code, but we might want to add an optional parameter to skip
4272          * it and any other expensive checks.)
4273          *
4274          * @return bool
4275          */
4276         public function isAlwaysKnown() {
4277                 $isKnown = null;
4278
4279                 /**
4280                  * Allows overriding default behavior for determining if a page exists.
4281                  * If $isKnown is kept as null, regular checks happen. If it's
4282                  * a boolean, this value is returned by the isKnown method.
4283                  *
4284                  * @since 1.20
4285                  *
4286                  * @param Title $title
4287                  * @param bool|null $isKnown
4288                  */
4289                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4290
4291                 if ( !is_null( $isKnown ) ) {
4292                         return $isKnown;
4293                 }
4294
4295                 if ( $this->isExternal() ) {
4296                         return true;  // any interwiki link might be viewable, for all we know
4297                 }
4298
4299                 switch ( $this->mNamespace ) {
4300                         case NS_MEDIA:
4301                         case NS_FILE:
4302                                 // file exists, possibly in a foreign repo
4303                                 return (bool)wfFindFile( $this );
4304                         case NS_SPECIAL:
4305                                 // valid special page
4306                                 return SpecialPageFactory::exists( $this->getDBkey() );
4307                         case NS_MAIN:
4308                                 // selflink, possibly with fragment
4309                                 return $this->mDbkeyform == '';
4310                         case NS_MEDIAWIKI:
4311                                 // known system message
4312                                 return $this->hasSourceText() !== false;
4313                         default:
4314                                 return false;
4315                 }
4316         }
4317
4318         /**
4319          * Does this title refer to a page that can (or might) be meaningfully
4320          * viewed?  In particular, this function may be used to determine if
4321          * links to the title should be rendered as "bluelinks" (as opposed to
4322          * "redlinks" to non-existent pages).
4323          * Adding something else to this function will cause inconsistency
4324          * since LinkHolderArray calls isAlwaysKnown() and does its own
4325          * page existence check.
4326          *
4327          * @return bool
4328          */
4329         public function isKnown() {
4330                 return $this->isAlwaysKnown() || $this->exists();
4331         }
4332
4333         /**
4334          * Does this page have source text?
4335          *
4336          * @return bool
4337          */
4338         public function hasSourceText() {
4339                 if ( $this->exists() ) {
4340                         return true;
4341                 }
4342
4343                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4344                         // If the page doesn't exist but is a known system message, default
4345                         // message content will be displayed, same for language subpages-
4346                         // Use always content language to avoid loading hundreds of languages
4347                         // to get the link color.
4348                         global $wgContLang;
4349                         list( $name, ) = MessageCache::singleton()->figureMessage(
4350                                 $wgContLang->lcfirst( $this->getText() )
4351                         );
4352                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4353                         return $message->exists();
4354                 }
4355
4356                 return false;
4357         }
4358
4359         /**
4360          * Get the default message text or false if the message doesn't exist
4361          *
4362          * @return string|bool
4363          */
4364         public function getDefaultMessageText() {
4365                 global $wgContLang;
4366
4367                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4368                         return false;
4369                 }
4370
4371                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4372                         $wgContLang->lcfirst( $this->getText() )
4373                 );
4374                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4375
4376                 if ( $message->exists() ) {
4377                         return $message->plain();
4378                 } else {
4379                         return false;
4380                 }
4381         }
4382
4383         /**
4384          * Updates page_touched for this page; called from LinksUpdate.php
4385          *
4386          * @param string $purgeTime [optional] TS_MW timestamp
4387          * @return bool True if the update succeeded
4388          */
4389         public function invalidateCache( $purgeTime = null ) {
4390                 if ( wfReadOnly() ) {
4391                         return false;
4392                 }
4393
4394                 if ( $this->mArticleID === 0 ) {
4395                         return true; // avoid gap locking if we know it's not there
4396                 }
4397
4398                 $method = __METHOD__;
4399                 $dbw = wfGetDB( DB_MASTER );
4400                 $conds = $this->pageCond();
4401                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4402                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4403
4404                         $dbw->update(
4405                                 'page',
4406                                 array( 'page_touched' => $dbTimestamp ),
4407                                 $conds + array( 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ),
4408                                 $method
4409                         );
4410                 } );
4411
4412                 return true;
4413         }
4414
4415         /**
4416          * Update page_touched timestamps and send CDN purge messages for
4417          * pages linking to this title. May be sent to the job queue depending
4418          * on the number of links. Typically called on create and delete.
4419          */
4420         public function touchLinks() {
4421                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4422                 if ( $this->getNamespace() == NS_CATEGORY ) {
4423                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4424                 }
4425         }
4426
4427         /**
4428          * Get the last touched timestamp
4429          *
4430          * @param IDatabase $db Optional db
4431          * @return string Last-touched timestamp
4432          */
4433         public function getTouched( $db = null ) {
4434                 if ( $db === null ) {
4435                         $db = wfGetDB( DB_SLAVE );
4436                 }
4437                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4438                 return $touched;
4439         }
4440
4441         /**
4442          * Get the timestamp when this page was updated since the user last saw it.
4443          *
4444          * @param User $user
4445          * @return string|null
4446          */
4447         public function getNotificationTimestamp( $user = null ) {
4448                 global $wgUser;
4449
4450                 // Assume current user if none given
4451                 if ( !$user ) {
4452                         $user = $wgUser;
4453                 }
4454                 // Check cache first
4455                 $uid = $user->getId();
4456                 if ( !$uid ) {
4457                         return false;
4458                 }
4459                 // avoid isset here, as it'll return false for null entries
4460                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4461                         return $this->mNotificationTimestamp[$uid];
4462                 }
4463                 // Don't cache too much!
4464                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4465                         $this->mNotificationTimestamp = array();
4466                 }
4467
4468                 $watchedItem = WatchedItem::fromUserTitle( $user, $this );
4469                 $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4470
4471                 return $this->mNotificationTimestamp[$uid];
4472         }
4473
4474         /**
4475          * Generate strings used for xml 'id' names in monobook tabs
4476          *
4477          * @param string $prepend Defaults to 'nstab-'
4478          * @return string XML 'id' name
4479          */
4480         public function getNamespaceKey( $prepend = 'nstab-' ) {
4481                 global $wgContLang;
4482                 // Gets the subject namespace if this title
4483                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4484                 // Checks if canonical namespace name exists for namespace
4485                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4486                         // Uses canonical namespace name
4487                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4488                 } else {
4489                         // Uses text of namespace
4490                         $namespaceKey = $this->getSubjectNsText();
4491                 }
4492                 // Makes namespace key lowercase
4493                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4494                 // Uses main
4495                 if ( $namespaceKey == '' ) {
4496                         $namespaceKey = 'main';
4497                 }
4498                 // Changes file to image for backwards compatibility
4499                 if ( $namespaceKey == 'file' ) {
4500                         $namespaceKey = 'image';
4501                 }
4502                 return $prepend . $namespaceKey;
4503         }
4504
4505         /**
4506          * Get all extant redirects to this Title
4507          *
4508          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4509          * @return Title[] Array of Title redirects to this title
4510          */
4511         public function getRedirectsHere( $ns = null ) {
4512                 $redirs = array();
4513
4514                 $dbr = wfGetDB( DB_SLAVE );
4515                 $where = array(
4516                         'rd_namespace' => $this->getNamespace(),
4517                         'rd_title' => $this->getDBkey(),
4518                         'rd_from = page_id'
4519                 );
4520                 if ( $this->isExternal() ) {
4521                         $where['rd_interwiki'] = $this->getInterwiki();
4522                 } else {
4523                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4524                 }
4525                 if ( !is_null( $ns ) ) {
4526                         $where['page_namespace'] = $ns;
4527                 }
4528
4529                 $res = $dbr->select(
4530                         array( 'redirect', 'page' ),
4531                         array( 'page_namespace', 'page_title' ),
4532                         $where,
4533                         __METHOD__
4534                 );
4535
4536                 foreach ( $res as $row ) {
4537                         $redirs[] = self::newFromRow( $row );
4538                 }
4539                 return $redirs;
4540         }
4541
4542         /**
4543          * Check if this Title is a valid redirect target
4544          *
4545          * @return bool
4546          */
4547         public function isValidRedirectTarget() {
4548                 global $wgInvalidRedirectTargets;
4549
4550                 if ( $this->isSpecialPage() ) {
4551                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4552                         if ( $this->isSpecial( 'Userlogout' ) ) {
4553                                 return false;
4554                         }
4555
4556                         foreach ( $wgInvalidRedirectTargets as $target ) {
4557                                 if ( $this->isSpecial( $target ) ) {
4558                                         return false;
4559                                 }
4560                         }
4561                 }
4562
4563                 return true;
4564         }
4565
4566         /**
4567          * Get a backlink cache object
4568          *
4569          * @return BacklinkCache
4570          */
4571         public function getBacklinkCache() {
4572                 return BacklinkCache::get( $this );
4573         }
4574
4575         /**
4576          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4577          *
4578          * @return bool
4579          */
4580         public function canUseNoindex() {
4581                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4582
4583                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4584                         ? $wgContentNamespaces
4585                         : $wgExemptFromUserRobotsControl;
4586
4587                 return !in_array( $this->mNamespace, $bannedNamespaces );
4588
4589         }
4590
4591         /**
4592          * Returns the raw sort key to be used for categories, with the specified
4593          * prefix.  This will be fed to Collation::getSortKey() to get a
4594          * binary sortkey that can be used for actual sorting.
4595          *
4596          * @param string $prefix The prefix to be used, specified using
4597          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4598          *   prefix.
4599          * @return string
4600          */
4601         public function getCategorySortkey( $prefix = '' ) {
4602                 $unprefixed = $this->getText();
4603
4604                 // Anything that uses this hook should only depend
4605                 // on the Title object passed in, and should probably
4606                 // tell the users to run updateCollations.php --force
4607                 // in order to re-sort existing category relations.
4608                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4609                 if ( $prefix !== '' ) {
4610                         # Separate with a line feed, so the unprefixed part is only used as
4611                         # a tiebreaker when two pages have the exact same prefix.
4612                         # In UCA, tab is the only character that can sort above LF
4613                         # so we strip both of them from the original prefix.
4614                         $prefix = strtr( $prefix, "\n\t", '  ' );
4615                         return "$prefix\n$unprefixed";
4616                 }
4617                 return $unprefixed;
4618         }
4619
4620         /**
4621          * Get the language in which the content of this page is written in
4622          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4623          * e.g. $wgLang (such as special pages, which are in the user language).
4624          *
4625          * @since 1.18
4626          * @return Language
4627          */
4628         public function getPageLanguage() {
4629                 global $wgLang, $wgLanguageCode;
4630                 if ( $this->isSpecialPage() ) {
4631                         // special pages are in the user language
4632                         return $wgLang;
4633                 }
4634
4635                 // Checking if DB language is set
4636                 if ( $this->mDbPageLanguage ) {
4637                         return wfGetLangObj( $this->mDbPageLanguage );
4638                 }
4639
4640                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4641                         // Note that this may depend on user settings, so the cache should
4642                         // be only per-request.
4643                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4644                         // content to determine the page language!
4645                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4646                         // tests.
4647                         $contentHandler = ContentHandler::getForTitle( $this );
4648                         $langObj = $contentHandler->getPageLanguage( $this );
4649                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4650                 } else {
4651                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4652                 }
4653
4654                 return $langObj;
4655         }
4656
4657         /**
4658          * Get the language in which the content of this page is written when
4659          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4660          * e.g. $wgLang (such as special pages, which are in the user language).
4661          *
4662          * @since 1.20
4663          * @return Language
4664          */
4665         public function getPageViewLanguage() {
4666                 global $wgLang;
4667
4668                 if ( $this->isSpecialPage() ) {
4669                         // If the user chooses a variant, the content is actually
4670                         // in a language whose code is the variant code.
4671                         $variant = $wgLang->getPreferredVariant();
4672                         if ( $wgLang->getCode() !== $variant ) {
4673                                 return Language::factory( $variant );
4674                         }
4675
4676                         return $wgLang;
4677                 }
4678
4679                 // @note Can't be cached persistently, depends on user settings.
4680                 // @note ContentHandler::getPageViewLanguage() may need to load the
4681                 //   content to determine the page language!
4682                 $contentHandler = ContentHandler::getForTitle( $this );
4683                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4684                 return $pageLang;
4685         }
4686
4687         /**
4688          * Get a list of rendered edit notices for this page.
4689          *
4690          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4691          * they will already be wrapped in paragraphs.
4692          *
4693          * @since 1.21
4694          * @param int $oldid Revision ID that's being edited
4695          * @return array
4696          */
4697         public function getEditNotices( $oldid = 0 ) {
4698                 $notices = array();
4699
4700                 // Optional notice for the entire namespace
4701                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4702                 $msg = wfMessage( $editnotice_ns );
4703                 if ( $msg->exists() ) {
4704                         $html = $msg->parseAsBlock();
4705                         // Edit notices may have complex logic, but output nothing (T91715)
4706                         if ( trim( $html ) !== '' ) {
4707                                 $notices[$editnotice_ns] = Html::rawElement(
4708                                         'div',
4709                                         array( 'class' => array(
4710                                                 'mw-editnotice',
4711                                                 'mw-editnotice-namespace',
4712                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4713                                         ) ),
4714                                         $html
4715                                 );
4716                         }
4717                 }
4718
4719                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4720                         // Optional notice for page itself and any parent page
4721                         $parts = explode( '/', $this->getDBkey() );
4722                         $editnotice_base = $editnotice_ns;
4723                         while ( count( $parts ) > 0 ) {
4724                                 $editnotice_base .= '-' . array_shift( $parts );
4725                                 $msg = wfMessage( $editnotice_base );
4726                                 if ( $msg->exists() ) {
4727                                         $html = $msg->parseAsBlock();
4728                                         if ( trim( $html ) !== '' ) {
4729                                                 $notices[$editnotice_base] = Html::rawElement(
4730                                                         'div',
4731                                                         array( 'class' => array(
4732                                                                 'mw-editnotice',
4733                                                                 'mw-editnotice-base',
4734                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4735                                                         ) ),
4736                                                         $html
4737                                                 );
4738                                         }
4739                                 }
4740                         }
4741                 } else {
4742                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4743                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4744                         $msg = wfMessage( $editnoticeText );
4745                         if ( $msg->exists() ) {
4746                                 $html = $msg->parseAsBlock();
4747                                 if ( trim( $html ) !== '' ) {
4748                                         $notices[$editnoticeText] = Html::rawElement(
4749                                                 'div',
4750                                                 array( 'class' => array(
4751                                                         'mw-editnotice',
4752                                                         'mw-editnotice-page',
4753                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4754                                                 ) ),
4755                                                 $html
4756                                         );
4757                                 }
4758                         }
4759                 }
4760
4761                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4762                 return $notices;
4763         }
4764
4765         /**
4766          * @return array
4767          */
4768         public function __sleep() {
4769                 return array(
4770                         'mNamespace',
4771                         'mDbkeyform',
4772                         'mFragment',
4773                         'mInterwiki',
4774                         'mLocalInterwiki',
4775                         'mUserCaseDBKey',
4776                         'mDefaultNamespace',
4777                 );
4778         }
4779
4780         public function __wakeup() {
4781                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4782                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4783                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4784         }
4785
4786 }