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  * @internal documentation reviewed 15 Mar 2010
  34  */
  35 class Title {
  36         /** @var MapCacheLRU */
  37         static private $titleCache = null;
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         /** @var string Text form (spaces not underscores) of the main part */
  60         public $mTextform = '';
  61
  62         /** @var string URL-encoded form of the main part */
  63         public $mUrlform = '';
  64
  65         /** @var string Main part with underscores */
  66         public $mDbkeyform = '';
  67
  68         /** @var string Database key with the initial letter in the case specified by the user */
  69         protected $mUserCaseDBKey;
  70
  71         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  72         public $mNamespace = NS_MAIN;
  73
  74         /** @var string Interwiki prefix */
  75         public $mInterwiki = '';
  76
  77         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  78         private $mLocalInterwiki = false;
  79
  80         /** @var string Title fragment (i.e. the bit after the #) */
  81         public $mFragment = '';
  82
  83         /** @var int Article ID, fetched from the link cache on demand */
  84         public $mArticleID = -1;
  85
  86         /** @var bool|int ID of most recent revision */
  87         protected $mLatestID = false;
  88
  89         /**
  90          * @var bool|string ID of the page's content model, i.e. one of the
  91          *   CONTENT_MODEL_XXX constants
  92          */
  93         public $mContentModel = false;
  94
  95         /** @var int Estimated number of revisions; null of not loaded */
  96         private $mEstimateRevisions;
  97
  98         /** @var array Array of groups allowed to edit this article */
  99         public $mRestrictions = array();
 100
 101         /** @var bool */
 102         protected $mOldRestrictions = false;
 103
 104         /** @var bool Cascade restrictions on this page to included templates and images? */
 105         public $mCascadeRestriction;
 106
 107         /** Caching the results of getCascadeProtectionSources */
 108         public $mCascadingRestrictions;
 109
 110         /** @var array When do the restrictions on this page expire? */
 111         protected $mRestrictionsExpiry = array();
 112
 113         /** @var bool Are cascading restrictions in effect on this page? */
 114         protected $mHasCascadingRestrictions;
 115
 116         /** @var array Where are the cascading restrictions coming from on this page? */
 117         public $mCascadeSources;
 118
 119         /** @var bool Boolean for initialisation on demand */
 120         public $mRestrictionsLoaded = false;
 121
 122         /** @var string Text form including namespace/interwiki, initialised on demand */
 123         protected $mPrefixedText = null;
 124
 125         /** @var mixed Cached value for getTitleProtection (create protection) */
 126         public $mTitleProtection;
 127
 128         /**
 129          * @var int Namespace index when there is no namespace. Don't change the
 130          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 131          *   Zero except in {{transclusion}} tags.
 132          */
 133         public $mDefaultNamespace = NS_MAIN;
 134
 135         /**
 136          * @var bool Is $wgUser watching this page? null if unfilled, accessed
 137          * through userIsWatching()
 138          */
 139         protected $mWatched = null;
 140
 141         /** @var int The page length, 0 for special pages */
 142         protected $mLength = -1;
 143
 144         /** @var null Is the article at this title a redirect? */
 145         public $mRedirect = null;
 146
 147         /** @var array Associative array of user ID -> timestamp/false */
 148         private $mNotificationTimestamp = array();
 149
 150         /** @var bool Whether a page has any subpages */
 151         private $mHasSubpages;
 152
 153         /** @var bool The (string) language code of the page's language and content code. */
 154         private $mPageLanguage = false;
 155
 156         /** @var string The page language code from the database */
 157         private $mDbPageLanguage = null;
 158
 159         /** @var TitleValue A corresponding TitleValue object */
 160         private $mTitleValue = null;
 161
 162         /** @var bool Would deleting this page be a big deletion? */
 163         private $mIsBigDeletion = null;
 164         // @}
 165
 166         /**
 167          * B/C kludge: provide a TitleParser for use by Title.
 168          * Ideally, Title would have no methods that need this.
 169          * Avoid usage of this singleton by using TitleValue
 170          * and the associated services when possible.
 171          *
 172          * @return TitleParser
 173          */
 174         private static function getTitleParser() {
 175                 global $wgContLang, $wgLocalInterwikis;
 176
 177                 static $titleCodec = null;
 178                 static $titleCodecFingerprint = null;
 179
 180                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 181                 // make sure we are using the right one. To detect changes over the course
 182                 // of a request, we remember a fingerprint of the config used to create the
 183                 // codec singleton, and re-create it if the fingerprint doesn't match.
 184                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 185
 186                 if ( $fingerprint !== $titleCodecFingerprint ) {
 187                         $titleCodec = null;
 188                 }
 189
 190                 if ( !$titleCodec ) {
 191                         $titleCodec = new MediaWikiTitleCodec(
 192                                 $wgContLang,
 193                                 GenderCache::singleton(),
 194                                 $wgLocalInterwikis
 195                         );
 196                         $titleCodecFingerprint = $fingerprint;
 197                 }
 198
 199                 return $titleCodec;
 200         }
 201
 202         /**
 203          * B/C kludge: provide a TitleParser for use by Title.
 204          * Ideally, Title would have no methods that need this.
 205          * Avoid usage of this singleton by using TitleValue
 206          * and the associated services when possible.
 207          *
 208          * @return TitleFormatter
 209          */
 210         private static function getTitleFormatter() {
 211                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 212                 //      which implements TitleFormatter.
 213                 return self::getTitleParser();
 214         }
 215
 216         function __construct() {
 217         }
 218
 219         /**
 220          * Create a new Title from a prefixed DB key
 221          *
 222          * @param string $key The database key, which has underscores
 223          *      instead of spaces, possibly including namespace and
 224          *      interwiki prefixes
 225          * @return Title|null Title, or null on an error
 226          */
 227         public static function newFromDBkey( $key ) {
 228                 $t = new Title();
 229                 $t->mDbkeyform = $key;
 230                 if ( $t->secureAndSplit() ) {
 231                         return $t;
 232                 } else {
 233                         return null;
 234                 }
 235         }
 236
 237         /**
 238          * Create a new Title from a TitleValue
 239          *
 240          * @param TitleValue $titleValue Assumed to be safe.
 241          *
 242          * @return Title
 243          */
 244         public static function newFromTitleValue( TitleValue $titleValue ) {
 245                 return self::makeTitle(
 246                         $titleValue->getNamespace(),
 247                         $titleValue->getText(),
 248                         $titleValue->getFragment() );
 249         }
 250
 251         /**
 252          * Create a new Title from text, such as what one would find in a link. De-
 253          * codes any HTML entities in the text.
 254          *
 255          * @param string $text The link text; spaces, prefixes, and an
 256          *   initial ':' indicating the main namespace are accepted.
 257          * @param int $defaultNamespace The namespace to use if none is specified
 258          *   by a prefix.  If you want to force a specific namespace even if
 259          *   $text might begin with a namespace prefix, use makeTitle() or
 260          *   makeTitleSafe().
 261          * @throws MWException
 262          * @return Title|null Title or null on an error.
 263          */
 264         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 265                 if ( is_object( $text ) ) {
 266                         throw new MWException( 'Title::newFromText given an object' );
 267                 }
 268
 269                 $cache = self::getTitleCache();
 270
 271                 /**
 272                  * Wiki pages often contain multiple links to the same page.
 273                  * Title normalization and parsing can become expensive on
 274                  * pages with many links, so we can save a little time by
 275                  * caching them.
 276                  *
 277                  * In theory these are value objects and won't get changed...
 278                  */
 279                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 280                         return $cache->get( $text );
 281                 }
 282
 283                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 284                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 285
 286                 $t = new Title();
 287                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 288                 $t->mDefaultNamespace = intval( $defaultNamespace );
 289
 290                 if ( $t->secureAndSplit() ) {
 291                         if ( $defaultNamespace == NS_MAIN ) {
 292                                 $cache->set( $text, $t );
 293                         }
 294                         return $t;
 295                 } else {
 296                         return null;
 297                 }
 298         }
 299
 300         /**
 301          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 302          *
 303          * Example of wrong and broken code:
 304          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 305          *
 306          * Example of right code:
 307          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 308          *
 309          * Create a new Title from URL-encoded text. Ensures that
 310          * the given title's length does not exceed the maximum.
 311          *
 312          * @param string $url The title, as might be taken from a URL
 313          * @return Title|null The new object, or null on an error
 314          */
 315         public static function newFromURL( $url ) {
 316                 $t = new Title();
 317
 318                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 319                 # but some URLs used it as a space replacement and they still come
 320                 # from some external search tools.
 321                 if ( strpos( self::legalChars(), '+' ) === false ) {
 322                         $url = str_replace( '+', ' ', $url );
 323                 }
 324
 325                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * @return MapCacheLRU
 335          */
 336         private static function getTitleCache() {
 337                 if ( self::$titleCache == null ) {
 338                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 339                 }
 340                 return self::$titleCache;
 341         }
 342
 343         /**
 344          * Returns a list of fields that are to be selected for initializing Title
 345          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 346          * whether to include page_content_model.
 347          *
 348          * @return array
 349          */
 350         protected static function getSelectFields() {
 351                 global $wgContentHandlerUseDB;
 352
 353                 $fields = array(
 354                         'page_namespace', 'page_title', 'page_id',
 355                         'page_len', 'page_is_redirect', 'page_latest',
 356                 );
 357
 358                 if ( $wgContentHandlerUseDB ) {
 359                         $fields[] = 'page_content_model';
 360                 }
 361
 362                 return $fields;
 363         }
 364
 365         /**
 366          * Create a new Title from an article ID
 367          *
 368          * @param int $id The page_id corresponding to the Title to create
 369          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 370          * @return Title|null The new object, or null on an error
 371          */
 372         public static function newFromID( $id, $flags = 0 ) {
 373                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 374                 $row = $db->selectRow(
 375                         'page',
 376                         self::getSelectFields(),
 377                         array( 'page_id' => $id ),
 378                         __METHOD__
 379                 );
 380                 if ( $row !== false ) {
 381                         $title = Title::newFromRow( $row );
 382                 } else {
 383                         $title = null;
 384                 }
 385                 return $title;
 386         }
 387
 388         /**
 389          * Make an array of titles from an array of IDs
 390          *
 391          * @param int[] $ids Array of IDs
 392          * @return Title[] Array of Titles
 393          */
 394         public static function newFromIDs( $ids ) {
 395                 if ( !count( $ids ) ) {
 396                         return array();
 397                 }
 398                 $dbr = wfGetDB( DB_SLAVE );
 399
 400                 $res = $dbr->select(
 401                         'page',
 402                         self::getSelectFields(),
 403                         array( 'page_id' => $ids ),
 404                         __METHOD__
 405                 );
 406
 407                 $titles = array();
 408                 foreach ( $res as $row ) {
 409                         $titles[] = Title::newFromRow( $row );
 410                 }
 411                 return $titles;
 412         }
 413
 414         /**
 415          * Make a Title object from a DB row
 416          *
 417          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 418          * @return Title Corresponding Title
 419          */
 420         public static function newFromRow( $row ) {
 421                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 422                 $t->loadFromRow( $row );
 423                 return $t;
 424         }
 425
 426         /**
 427          * Load Title object fields from a DB row.
 428          * If false is given, the title will be treated as non-existing.
 429          *
 430          * @param stdClass|bool $row Database row
 431          */
 432         public function loadFromRow( $row ) {
 433                 if ( $row ) { // page found
 434                         if ( isset( $row->page_id ) ) {
 435                                 $this->mArticleID = (int)$row->page_id;
 436                         }
 437                         if ( isset( $row->page_len ) ) {
 438                                 $this->mLength = (int)$row->page_len;
 439                         }
 440                         if ( isset( $row->page_is_redirect ) ) {
 441                                 $this->mRedirect = (bool)$row->page_is_redirect;
 442                         }
 443                         if ( isset( $row->page_latest ) ) {
 444                                 $this->mLatestID = (int)$row->page_latest;
 445                         }
 446                         if ( isset( $row->page_content_model ) ) {
 447                                 $this->mContentModel = strval( $row->page_content_model );
 448                         } else {
 449                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 450                         }
 451                         if ( isset( $row->page_lang ) ) {
 452                                 $this->mDbPageLanguage = (string)$row->page_lang;
 453                         }
 454                 } else { // page not found
 455                         $this->mArticleID = 0;
 456                         $this->mLength = 0;
 457                         $this->mRedirect = false;
 458                         $this->mLatestID = 0;
 459                         $this->mContentModel = false; # initialized lazily in getContentModel()
 460                 }
 461         }
 462
 463         /**
 464          * Create a new Title from a namespace index and a DB key.
 465          * It's assumed that $ns and $title are *valid*, for instance when
 466          * they came directly from the database or a special page name.
 467          * For convenience, spaces are converted to underscores so that
 468          * eg user_text fields can be used directly.
 469          *
 470          * @param int $ns The namespace of the article
 471          * @param string $title The unprefixed database key form
 472          * @param string $fragment The link fragment (after the "#")
 473          * @param string $interwiki The interwiki prefix
 474          * @return Title The new object
 475          */
 476         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 477                 $t = new Title();
 478                 $t->mInterwiki = $interwiki;
 479                 $t->mFragment = $fragment;
 480                 $t->mNamespace = $ns = intval( $ns );
 481                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 482                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 483                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 484                 $t->mTextform = str_replace( '_', ' ', $title );
 485                 $t->mContentModel = false; # initialized lazily in getContentModel()
 486                 return $t;
 487         }
 488
 489         /**
 490          * Create a new Title from a namespace index and a DB key.
 491          * The parameters will be checked for validity, which is a bit slower
 492          * than makeTitle() but safer for user-provided data.
 493          *
 494          * @param int $ns The namespace of the article
 495          * @param string $title Database key form
 496          * @param string $fragment The link fragment (after the "#")
 497          * @param string $interwiki Interwiki prefix
 498          * @return Title The new object, or null on an error
 499          */
 500         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 501                 if ( !MWNamespace::exists( $ns ) ) {
 502                         return null;
 503                 }
 504
 505                 $t = new Title();
 506                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 507                 if ( $t->secureAndSplit() ) {
 508                         return $t;
 509                 } else {
 510                         return null;
 511                 }
 512         }
 513
 514         /**
 515          * Create a new Title for the Main Page
 516          *
 517          * @return Title The new object
 518          */
 519         public static function newMainPage() {
 520                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 521                 // Don't give fatal errors if the message is broken
 522                 if ( !$title ) {
 523                         $title = Title::newFromText( 'Main Page' );
 524                 }
 525                 return $title;
 526         }
 527
 528         /**
 529          * Extract a redirect destination from a string and return the
 530          * Title, or null if the text doesn't contain a valid redirect
 531          * This will only return the very next target, useful for
 532          * the redirect table and other checks that don't need full recursion
 533          *
 534          * @param string $text Text with possible redirect
 535          * @return Title The corresponding Title
 536          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 537          */
 538         public static function newFromRedirect( $text ) {
 539                 ContentHandler::deprecated( __METHOD__, '1.21' );
 540
 541                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 542                 return $content->getRedirectTarget();
 543         }
 544
 545         /**
 546          * Extract a redirect destination from a string and return the
 547          * Title, or null if the text doesn't contain a valid redirect
 548          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 549          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 550          *
 551          * @param string $text Text with possible redirect
 552          * @return Title
 553          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 554          */
 555         public static function newFromRedirectRecurse( $text ) {
 556                 ContentHandler::deprecated( __METHOD__, '1.21' );
 557
 558                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 559                 return $content->getUltimateRedirectTarget();
 560         }
 561
 562         /**
 563          * Extract a redirect destination from a string and return an
 564          * array of Titles, or null if the text doesn't contain a valid redirect
 565          * The last element in the array is the final destination after all redirects
 566          * have been resolved (up to $wgMaxRedirects times)
 567          *
 568          * @param string $text Text with possible redirect
 569          * @return Title[] Array of Titles, with the destination last
 570          * @deprecated since 1.21, use Content::getRedirectChain instead.
 571          */
 572         public static function newFromRedirectArray( $text ) {
 573                 ContentHandler::deprecated( __METHOD__, '1.21' );
 574
 575                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 576                 return $content->getRedirectChain();
 577         }
 578
 579         /**
 580          * Get the prefixed DB key associated with an ID
 581          *
 582          * @param int $id The page_id of the article
 583          * @return Title|null An object representing the article, or null if no such article was found
 584          */
 585         public static function nameOf( $id ) {
 586                 $dbr = wfGetDB( DB_SLAVE );
 587
 588                 $s = $dbr->selectRow(
 589                         'page',
 590                         array( 'page_namespace', 'page_title' ),
 591                         array( 'page_id' => $id ),
 592                         __METHOD__
 593                 );
 594                 if ( $s === false ) {
 595                         return null;
 596                 }
 597
 598                 $n = self::makeName( $s->page_namespace, $s->page_title );
 599                 return $n;
 600         }
 601
 602         /**
 603          * Get a regex character class describing the legal characters in a link
 604          *
 605          * @return string The list of characters, not delimited
 606          */
 607         public static function legalChars() {
 608                 global $wgLegalTitleChars;
 609                 return $wgLegalTitleChars;
 610         }
 611
 612         /**
 613          * Returns a simple regex that will match on characters and sequences invalid in titles.
 614          * Note that this doesn't pick up many things that could be wrong with titles, but that
 615          * replacing this regex with something valid will make many titles valid.
 616          *
 617          * @todo move this into MediaWikiTitleCodec
 618          *
 619          * @return string Regex string
 620          */
 621         static function getTitleInvalidRegex() {
 622                 static $rxTc = false;
 623                 if ( !$rxTc ) {
 624                         # Matching titles will be held as illegal.
 625                         $rxTc = '/' .
 626                                 # Any character not allowed is forbidden...
 627                                 '[^' . self::legalChars() . ']' .
 628                                 # URL percent encoding sequences interfere with the ability
 629                                 # to round-trip titles -- you can't link to them consistently.
 630                                 '|%[0-9A-Fa-f]{2}' .
 631                                 # XML/HTML character references produce similar issues.
 632                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 633                                 '|&#[0-9]+;' .
 634                                 '|&#x[0-9A-Fa-f]+;' .
 635                                 '/S';
 636                 }
 637
 638                 return $rxTc;
 639         }
 640
 641         /**
 642          * Utility method for converting a character sequence from bytes to Unicode.
 643          *
 644          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 645          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 646          *
 647          * @param string $byteClass
 648          * @return string
 649          */
 650         public static function convertByteClassToUnicodeClass( $byteClass ) {
 651                 $length = strlen( $byteClass );
 652                 // Input token queue
 653                 $x0 = $x1 = $x2 = '';
 654                 // Decoded queue
 655                 $d0 = $d1 = $d2 = '';
 656                 // Decoded integer codepoints
 657                 $ord0 = $ord1 = $ord2 = 0;
 658                 // Re-encoded queue
 659                 $r0 = $r1 = $r2 = '';
 660                 // Output
 661                 $out = '';
 662                 // Flags
 663                 $allowUnicode = false;
 664                 for ( $pos = 0; $pos < $length; $pos++ ) {
 665                         // Shift the queues down
 666                         $x2 = $x1;
 667                         $x1 = $x0;
 668                         $d2 = $d1;
 669                         $d1 = $d0;
 670                         $ord2 = $ord1;
 671                         $ord1 = $ord0;
 672                         $r2 = $r1;
 673                         $r1 = $r0;
 674                         // Load the current input token and decoded values
 675                         $inChar = $byteClass[$pos];
 676                         if ( $inChar == '\\' ) {
 677                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 678                                         $x0 = $inChar . $m[0];
 679                                         $d0 = chr( hexdec( $m[1] ) );
 680                                         $pos += strlen( $m[0] );
 681                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 682                                         $x0 = $inChar . $m[0];
 683                                         $d0 = chr( octdec( $m[0] ) );
 684                                         $pos += strlen( $m[0] );
 685                                 } elseif ( $pos + 1 >= $length ) {
 686                                         $x0 = $d0 = '\\';
 687                                 } else {
 688                                         $d0 = $byteClass[$pos + 1];
 689                                         $x0 = $inChar . $d0;
 690                                         $pos += 1;
 691                                 }
 692                         } else {
 693                                 $x0 = $d0 = $inChar;
 694                         }
 695                         $ord0 = ord( $d0 );
 696                         // Load the current re-encoded value
 697                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 698                                 $r0 = sprintf( '\x%02x', $ord0 );
 699                         } elseif ( $ord0 >= 0x80 ) {
 700                                 // Allow unicode if a single high-bit character appears
 701                                 $r0 = sprintf( '\x%02x', $ord0 );
 702                                 $allowUnicode = true;
 703                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 704                                 $r0 = '\\' . $d0;
 705                         } else {
 706                                 $r0 = $d0;
 707                         }
 708                         // Do the output
 709                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 710                                 // Range
 711                                 if ( $ord2 > $ord0 ) {
 712                                         // Empty range
 713                                 } elseif ( $ord0 >= 0x80 ) {
 714                                         // Unicode range
 715                                         $allowUnicode = true;
 716                                         if ( $ord2 < 0x80 ) {
 717                                                 // Keep the non-unicode section of the range
 718                                                 $out .= "$r2-\\x7F";
 719                                         }
 720                                 } else {
 721                                         // Normal range
 722                                         $out .= "$r2-$r0";
 723                                 }
 724                                 // Reset state to the initial value
 725                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 726                         } elseif ( $ord2 < 0x80 ) {
 727                                 // ASCII character
 728                                 $out .= $r2;
 729                         }
 730                 }
 731                 if ( $ord1 < 0x80 ) {
 732                         $out .= $r1;
 733                 }
 734                 if ( $ord0 < 0x80 ) {
 735                         $out .= $r0;
 736                 }
 737                 if ( $allowUnicode ) {
 738                         $out .= '\u0080-\uFFFF';
 739                 }
 740                 return $out;
 741         }
 742
 743         /**
 744          * Make a prefixed DB key from a DB key and a namespace index
 745          *
 746          * @param int $ns Numerical representation of the namespace
 747          * @param string $title The DB key form the title
 748          * @param string $fragment The link fragment (after the "#")
 749          * @param string $interwiki The interwiki prefix
 750          * @param bool $canoncialNamespace If true, use the canonical name for
 751          *   $ns instead of the localized version.
 752          * @return string The prefixed form of the title
 753          */
 754         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 755                 $canoncialNamespace = false
 756         ) {
 757                 global $wgContLang;
 758
 759                 if ( $canoncialNamespace ) {
 760                         $namespace = MWNamespace::getCanonicalName( $ns );
 761                 } else {
 762                         $namespace = $wgContLang->getNsText( $ns );
 763                 }
 764                 $name = $namespace == '' ? $title : "$namespace:$title";
 765                 if ( strval( $interwiki ) != '' ) {
 766                         $name = "$interwiki:$name";
 767                 }
 768                 if ( strval( $fragment ) != '' ) {
 769                         $name .= '#' . $fragment;
 770                 }
 771                 return $name;
 772         }
 773
 774         /**
 775          * Escape a text fragment, say from a link, for a URL
 776          *
 777          * @param string $fragment Containing a URL or link fragment (after the "#")
 778          * @return string Escaped string
 779          */
 780         static function escapeFragmentForURL( $fragment ) {
 781                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 782                 # fragments appear not to work in IE (at least up to 7) or in at least
 783                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 784                 # to care if they aren't encoded.
 785                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 786         }
 787
 788         /**
 789          * Callback for usort() to do title sorts by (namespace, title)
 790          *
 791          * @param Title $a
 792          * @param Title $b
 793          *
 794          * @return int Result of string comparison, or namespace comparison
 795          */
 796         public static function compare( $a, $b ) {
 797                 if ( $a->getNamespace() == $b->getNamespace() ) {
 798                         return strcmp( $a->getText(), $b->getText() );
 799                 } else {
 800                         return $a->getNamespace() - $b->getNamespace();
 801                 }
 802         }
 803
 804         /**
 805          * Determine whether the object refers to a page within
 806          * this project (either this wiki or a wiki with a local
 807          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 808          *
 809          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 810          */
 811         public function isLocal() {
 812                 if ( $this->isExternal() ) {
 813                         $iw = Interwiki::fetch( $this->mInterwiki );
 814                         if ( $iw ) {
 815                                 return $iw->isLocal();
 816                         }
 817                 }
 818                 return true;
 819         }
 820
 821         /**
 822          * Is this Title interwiki?
 823          *
 824          * @return bool
 825          */
 826         public function isExternal() {
 827                 return $this->mInterwiki !== '';
 828         }
 829
 830         /**
 831          * Get the interwiki prefix
 832          *
 833          * Use Title::isExternal to check if a interwiki is set
 834          *
 835          * @return string Interwiki prefix
 836          */
 837         public function getInterwiki() {
 838                 return $this->mInterwiki;
 839         }
 840
 841         /**
 842          * Was this a local interwiki link?
 843          *
 844          * @return bool
 845          */
 846         public function wasLocalInterwiki() {
 847                 return $this->mLocalInterwiki;
 848         }
 849
 850         /**
 851          * Determine whether the object refers to a page within
 852          * this project and is transcludable.
 853          *
 854          * @return bool True if this is transcludable
 855          */
 856         public function isTrans() {
 857                 if ( !$this->isExternal() ) {
 858                         return false;
 859                 }
 860
 861                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 862         }
 863
 864         /**
 865          * Returns the DB name of the distant wiki which owns the object.
 866          *
 867          * @return string The DB name
 868          */
 869         public function getTransWikiID() {
 870                 if ( !$this->isExternal() ) {
 871                         return false;
 872                 }
 873
 874                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 875         }
 876
 877         /**
 878          * Get a TitleValue object representing this Title.
 879          *
 880          * @note Not all valid Titles have a corresponding valid TitleValue
 881          * (e.g. TitleValues cannot represent page-local links that have a
 882          * fragment but no title text).
 883          *
 884          * @return TitleValue|null
 885          */
 886         public function getTitleValue() {
 887                 if ( $this->mTitleValue === null ) {
 888                         try {
 889                                 $this->mTitleValue = new TitleValue(
 890                                         $this->getNamespace(),
 891                                         $this->getDBkey(),
 892                                         $this->getFragment() );
 893                         } catch ( InvalidArgumentException $ex ) {
 894                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 895                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 896                         }
 897                 }
 898
 899                 return $this->mTitleValue;
 900         }
 901
 902         /**
 903          * Get the text form (spaces not underscores) of the main part
 904          *
 905          * @return string Main part of the title
 906          */
 907         public function getText() {
 908                 return $this->mTextform;
 909         }
 910
 911         /**
 912          * Get the URL-encoded form of the main part
 913          *
 914          * @return string Main part of the title, URL-encoded
 915          */
 916         public function getPartialURL() {
 917                 return $this->mUrlform;
 918         }
 919
 920         /**
 921          * Get the main part with underscores
 922          *
 923          * @return string Main part of the title, with underscores
 924          */
 925         public function getDBkey() {
 926                 return $this->mDbkeyform;
 927         }
 928
 929         /**
 930          * Get the DB key with the initial letter case as specified by the user
 931          *
 932          * @return string DB key
 933          */
 934         function getUserCaseDBKey() {
 935                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 936                         return $this->mUserCaseDBKey;
 937                 } else {
 938                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 939                         return $this->mDbkeyform;
 940                 }
 941         }
 942
 943         /**
 944          * Get the namespace index, i.e. one of the NS_xxxx constants.
 945          *
 946          * @return int Namespace index
 947          */
 948         public function getNamespace() {
 949                 return $this->mNamespace;
 950         }
 951
 952         /**
 953          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 954          *
 955          * @throws MWException
 956          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 957          * @return string Content model id
 958          */
 959         public function getContentModel( $flags = 0 ) {
 960                 # Calling getArticleID() loads the field from cache as needed
 961                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 962                         $linkCache = LinkCache::singleton();
 963                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 964                 }
 965
 966                 if ( !$this->mContentModel ) {
 967                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 968                 }
 969
 970                 if ( !$this->mContentModel ) {
 971                         throw new MWException( 'Failed to determine content model!' );
 972                 }
 973
 974                 return $this->mContentModel;
 975         }
 976
 977         /**
 978          * Convenience method for checking a title's content model name
 979          *
 980          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 981          * @return bool True if $this->getContentModel() == $id
 982          */
 983         public function hasContentModel( $id ) {
 984                 return $this->getContentModel() == $id;
 985         }
 986
 987         /**
 988          * Get the namespace text
 989          *
 990          * @return string Namespace text
 991          */
 992         public function getNsText() {
 993                 if ( $this->isExternal() ) {
 994                         // This probably shouldn't even happen. ohh man, oh yuck.
 995                         // But for interwiki transclusion it sometimes does.
 996                         // Shit. Shit shit shit.
 997                         //
 998                         // Use the canonical namespaces if possible to try to
 999                         // resolve a foreign namespace.
1000                         if ( MWNamespace::exists( $this->mNamespace ) ) {
1001                                 return MWNamespace::getCanonicalName( $this->mNamespace );
1002                         }
1003                 }
1004
1005                 try {
1006                         $formatter = self::getTitleFormatter();
1007                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
1008                 } catch ( InvalidArgumentException $ex ) {
1009                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1010                         return false;
1011                 }
1012         }
1013
1014         /**
1015          * Get the namespace text of the subject (rather than talk) page
1016          *
1017          * @return string Namespace text
1018          */
1019         public function getSubjectNsText() {
1020                 global $wgContLang;
1021                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1022         }
1023
1024         /**
1025          * Get the namespace text of the talk page
1026          *
1027          * @return string Namespace text
1028          */
1029         public function getTalkNsText() {
1030                 global $wgContLang;
1031                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1032         }
1033
1034         /**
1035          * Could this title have a corresponding talk page?
1036          *
1037          * @return bool
1038          */
1039         public function canTalk() {
1040                 return MWNamespace::canTalk( $this->mNamespace );
1041         }
1042
1043         /**
1044          * Is this in a namespace that allows actual pages?
1045          *
1046          * @return bool
1047          */
1048         public function canExist() {
1049                 return $this->mNamespace >= NS_MAIN;
1050         }
1051
1052         /**
1053          * Can this title be added to a user's watchlist?
1054          *
1055          * @return bool
1056          */
1057         public function isWatchable() {
1058                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1059         }
1060
1061         /**
1062          * Returns true if this is a special page.
1063          *
1064          * @return bool
1065          */
1066         public function isSpecialPage() {
1067                 return $this->getNamespace() == NS_SPECIAL;
1068         }
1069
1070         /**
1071          * Returns true if this title resolves to the named special page
1072          *
1073          * @param string $name The special page name
1074          * @return bool
1075          */
1076         public function isSpecial( $name ) {
1077                 if ( $this->isSpecialPage() ) {
1078                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1079                         if ( $name == $thisName ) {
1080                                 return true;
1081                         }
1082                 }
1083                 return false;
1084         }
1085
1086         /**
1087          * If the Title refers to a special page alias which is not the local default, resolve
1088          * the alias, and localise the name as necessary.  Otherwise, return $this
1089          *
1090          * @return Title
1091          */
1092         public function fixSpecialName() {
1093                 if ( $this->isSpecialPage() ) {
1094                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1095                         if ( $canonicalName ) {
1096                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1097                                 if ( $localName != $this->mDbkeyform ) {
1098                                         return Title::makeTitle( NS_SPECIAL, $localName );
1099                                 }
1100                         }
1101                 }
1102                 return $this;
1103         }
1104
1105         /**
1106          * Returns true if the title is inside the specified namespace.
1107          *
1108          * Please make use of this instead of comparing to getNamespace()
1109          * This function is much more resistant to changes we may make
1110          * to namespaces than code that makes direct comparisons.
1111          * @param int $ns The namespace
1112          * @return bool
1113          * @since 1.19
1114          */
1115         public function inNamespace( $ns ) {
1116                 return MWNamespace::equals( $this->getNamespace(), $ns );
1117         }
1118
1119         /**
1120          * Returns true if the title is inside one of the specified namespaces.
1121          *
1122          * @param int $namespaces,... The namespaces to check for
1123          * @return bool
1124          * @since 1.19
1125          */
1126         public function inNamespaces( /* ... */ ) {
1127                 $namespaces = func_get_args();
1128                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1129                         $namespaces = $namespaces[0];
1130                 }
1131
1132                 foreach ( $namespaces as $ns ) {
1133                         if ( $this->inNamespace( $ns ) ) {
1134                                 return true;
1135                         }
1136                 }
1137
1138                 return false;
1139         }
1140
1141         /**
1142          * Returns true if the title has the same subject namespace as the
1143          * namespace specified.
1144          * For example this method will take NS_USER and return true if namespace
1145          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1146          * as their subject namespace.
1147          *
1148          * This is MUCH simpler than individually testing for equivalence
1149          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1150          * @since 1.19
1151          * @param int $ns
1152          * @return bool
1153          */
1154         public function hasSubjectNamespace( $ns ) {
1155                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1156         }
1157
1158         /**
1159          * Is this Title in a namespace which contains content?
1160          * In other words, is this a content page, for the purposes of calculating
1161          * statistics, etc?
1162          *
1163          * @return bool
1164          */
1165         public function isContentPage() {
1166                 return MWNamespace::isContent( $this->getNamespace() );
1167         }
1168
1169         /**
1170          * Would anybody with sufficient privileges be able to move this page?
1171          * Some pages just aren't movable.
1172          *
1173          * @return bool
1174          */
1175         public function isMovable() {
1176                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1177                         // Interwiki title or immovable namespace. Hooks don't get to override here
1178                         return false;
1179                 }
1180
1181                 $result = true;
1182                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1183                 return $result;
1184         }
1185
1186         /**
1187          * Is this the mainpage?
1188          * @note Title::newFromText seems to be sufficiently optimized by the title
1189          * cache that we don't need to over-optimize by doing direct comparisons and
1190          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1191          * ends up reporting something differently than $title->isMainPage();
1192          *
1193          * @since 1.18
1194          * @return bool
1195          */
1196         public function isMainPage() {
1197                 return $this->equals( Title::newMainPage() );
1198         }
1199
1200         /**
1201          * Is this a subpage?
1202          *
1203          * @return bool
1204          */
1205         public function isSubpage() {
1206                 return MWNamespace::hasSubpages( $this->mNamespace )
1207                         ? strpos( $this->getText(), '/' ) !== false
1208                         : false;
1209         }
1210
1211         /**
1212          * Is this a conversion table for the LanguageConverter?
1213          *
1214          * @return bool
1215          */
1216         public function isConversionTable() {
1217                 // @todo ConversionTable should become a separate content model.
1218
1219                 return $this->getNamespace() == NS_MEDIAWIKI &&
1220                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1221         }
1222
1223         /**
1224          * Does that page contain wikitext, or it is JS, CSS or whatever?
1225          *
1226          * @return bool
1227          */
1228         public function isWikitextPage() {
1229                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1230         }
1231
1232         /**
1233          * Could this page contain custom CSS or JavaScript for the global UI.
1234          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1235          * or CONTENT_MODEL_JAVASCRIPT.
1236          *
1237          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1238          * for that!
1239          *
1240          * Note that this method should not return true for pages that contain and
1241          * show "inactive" CSS or JS.
1242          *
1243          * @return bool
1244          */
1245         public function isCssOrJsPage() {
1246                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1247                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1248                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1249
1250                 # @note This hook is also called in ContentHandler::getDefaultModel.
1251                 #   It's called here again to make sure hook functions can force this
1252                 #   method to return true even outside the MediaWiki namespace.
1253
1254                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1255
1256                 return $isCssOrJsPage;
1257         }
1258
1259         /**
1260          * Is this a .css or .js subpage of a user page?
1261          * @return bool
1262          */
1263         public function isCssJsSubpage() {
1264                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1265                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1266                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1267         }
1268
1269         /**
1270          * Trim down a .css or .js subpage title to get the corresponding skin name
1271          *
1272          * @return string Containing skin name from .css or .js subpage title
1273          */
1274         public function getSkinFromCssJsSubpage() {
1275                 $subpage = explode( '/', $this->mTextform );
1276                 $subpage = $subpage[count( $subpage ) - 1];
1277                 $lastdot = strrpos( $subpage, '.' );
1278                 if ( $lastdot === false ) {
1279                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1280                 }
1281                 return substr( $subpage, 0, $lastdot );
1282         }
1283
1284         /**
1285          * Is this a .css subpage of a user page?
1286          *
1287          * @return bool
1288          */
1289         public function isCssSubpage() {
1290                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1291                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1292         }
1293
1294         /**
1295          * Is this a .js subpage of a user page?
1296          *
1297          * @return bool
1298          */
1299         public function isJsSubpage() {
1300                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1301                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1302         }
1303
1304         /**
1305          * Is this a talk page of some sort?
1306          *
1307          * @return bool
1308          */
1309         public function isTalkPage() {
1310                 return MWNamespace::isTalk( $this->getNamespace() );
1311         }
1312
1313         /**
1314          * Get a Title object associated with the talk page of this article
1315          *
1316          * @return Title The object for the talk page
1317          */
1318         public function getTalkPage() {
1319                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1320         }
1321
1322         /**
1323          * Get a title object associated with the subject page of this
1324          * talk page
1325          *
1326          * @return Title The object for the subject page
1327          */
1328         public function getSubjectPage() {
1329                 // Is this the same title?
1330                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1331                 if ( $this->getNamespace() == $subjectNS ) {
1332                         return $this;
1333                 }
1334                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1335         }
1336
1337         /**
1338          * Get the other title for this page, if this is a subject page
1339          * get the talk page, if it is a subject page get the talk page
1340          *
1341          * @since 1.25
1342          * @throws MWException
1343          * @return Title
1344          */
1345         public function getOtherPage() {
1346                 if ( $this->isSpecialPage() ) {
1347                         throw new MWException( 'Special pages cannot have other pages' );
1348                 }
1349                 if ( $this->isTalkPage() ) {
1350                         return $this->getSubjectPage();
1351                 } else {
1352                         return $this->getTalkPage();
1353                 }
1354         }
1355
1356         /**
1357          * Get the default namespace index, for when there is no namespace
1358          *
1359          * @return int Default namespace index
1360          */
1361         public function getDefaultNamespace() {
1362                 return $this->mDefaultNamespace;
1363         }
1364
1365         /**
1366          * Get the Title fragment (i.e.\ the bit after the #) in text form
1367          *
1368          * Use Title::hasFragment to check for a fragment
1369          *
1370          * @return string Title fragment
1371          */
1372         public function getFragment() {
1373                 return $this->mFragment;
1374         }
1375
1376         /**
1377          * Check if a Title fragment is set
1378          *
1379          * @return bool
1380          * @since 1.23
1381          */
1382         public function hasFragment() {
1383                 return $this->mFragment !== '';
1384         }
1385
1386         /**
1387          * Get the fragment in URL form, including the "#" character if there is one
1388          * @return string Fragment in URL form
1389          */
1390         public function getFragmentForURL() {
1391                 if ( !$this->hasFragment() ) {
1392                         return '';
1393                 } else {
1394                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1395                 }
1396         }
1397
1398         /**
1399          * Set the fragment for this title. Removes the first character from the
1400          * specified fragment before setting, so it assumes you're passing it with
1401          * an initial "#".
1402          *
1403          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1404          * Still in active use privately.
1405          *
1406          * @param string $fragment Text
1407          */
1408         public function setFragment( $fragment ) {
1409                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1410         }
1411
1412         /**
1413          * Prefix some arbitrary text with the namespace or interwiki prefix
1414          * of this object
1415          *
1416          * @param string $name The text
1417          * @return string The prefixed text
1418          */
1419         private function prefix( $name ) {
1420                 $p = '';
1421                 if ( $this->isExternal() ) {
1422                         $p = $this->mInterwiki . ':';
1423                 }
1424
1425                 if ( 0 != $this->mNamespace ) {
1426                         $p .= $this->getNsText() . ':';
1427                 }
1428                 return $p . $name;
1429         }
1430
1431         /**
1432          * Get the prefixed database key form
1433          *
1434          * @return string The prefixed title, with underscores and
1435          *  any interwiki and namespace prefixes
1436          */
1437         public function getPrefixedDBkey() {
1438                 $s = $this->prefix( $this->mDbkeyform );
1439                 $s = str_replace( ' ', '_', $s );
1440                 return $s;
1441         }
1442
1443         /**
1444          * Get the prefixed title with spaces.
1445          * This is the form usually used for display
1446          *
1447          * @return string The prefixed title, with spaces
1448          */
1449         public function getPrefixedText() {
1450                 if ( $this->mPrefixedText === null ) {
1451                         $s = $this->prefix( $this->mTextform );
1452                         $s = str_replace( '_', ' ', $s );
1453                         $this->mPrefixedText = $s;
1454                 }
1455                 return $this->mPrefixedText;
1456         }
1457
1458         /**
1459          * Return a string representation of this title
1460          *
1461          * @return string Representation of this title
1462          */
1463         public function __toString() {
1464                 return $this->getPrefixedText();
1465         }
1466
1467         /**
1468          * Get the prefixed title with spaces, plus any fragment
1469          * (part beginning with '#')
1470          *
1471          * @return string The prefixed title, with spaces and the fragment, including '#'
1472          */
1473         public function getFullText() {
1474                 $text = $this->getPrefixedText();
1475                 if ( $this->hasFragment() ) {
1476                         $text .= '#' . $this->getFragment();
1477                 }
1478                 return $text;
1479         }
1480
1481         /**
1482          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1483          *
1484          * @par Example:
1485          * @code
1486          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1487          * # returns: 'Foo'
1488          * @endcode
1489          *
1490          * @return string Root name
1491          * @since 1.20
1492          */
1493         public function getRootText() {
1494                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1495                         return $this->getText();
1496                 }
1497
1498                 return strtok( $this->getText(), '/' );
1499         }
1500
1501         /**
1502          * Get the root page name title, i.e. the leftmost part before any slashes
1503          *
1504          * @par Example:
1505          * @code
1506          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1507          * # returns: Title{User:Foo}
1508          * @endcode
1509          *
1510          * @return Title Root title
1511          * @since 1.20
1512          */
1513         public function getRootTitle() {
1514                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1515         }
1516
1517         /**
1518          * Get the base page name without a namespace, i.e. the part before the subpage name
1519          *
1520          * @par Example:
1521          * @code
1522          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1523          * # returns: 'Foo/Bar'
1524          * @endcode
1525          *
1526          * @return string Base name
1527          */
1528         public function getBaseText() {
1529                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1530                         return $this->getText();
1531                 }
1532
1533                 $parts = explode( '/', $this->getText() );
1534                 # Don't discard the real title if there's no subpage involved
1535                 if ( count( $parts ) > 1 ) {
1536                         unset( $parts[count( $parts ) - 1] );
1537                 }
1538                 return implode( '/', $parts );
1539         }
1540
1541         /**
1542          * Get the base page name title, i.e. the part before the subpage name
1543          *
1544          * @par Example:
1545          * @code
1546          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1547          * # returns: Title{User:Foo/Bar}
1548          * @endcode
1549          *
1550          * @return Title Base title
1551          * @since 1.20
1552          */
1553         public function getBaseTitle() {
1554                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1555         }
1556
1557         /**
1558          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1559          *
1560          * @par Example:
1561          * @code
1562          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1563          * # returns: "Baz"
1564          * @endcode
1565          *
1566          * @return string Subpage name
1567          */
1568         public function getSubpageText() {
1569                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1570                         return $this->mTextform;
1571                 }
1572                 $parts = explode( '/', $this->mTextform );
1573                 return $parts[count( $parts ) - 1];
1574         }
1575
1576         /**
1577          * Get the title for a subpage of the current page
1578          *
1579          * @par Example:
1580          * @code
1581          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1582          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1583          * @endcode
1584          *
1585          * @param string $text The subpage name to add to the title
1586          * @return Title Subpage title
1587          * @since 1.20
1588          */
1589         public function getSubpage( $text ) {
1590                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1591         }
1592
1593         /**
1594          * Get a URL-encoded form of the subpage text
1595          *
1596          * @return string URL-encoded subpage name
1597          */
1598         public function getSubpageUrlForm() {
1599                 $text = $this->getSubpageText();
1600                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1601                 return $text;
1602         }
1603
1604         /**
1605          * Get a URL-encoded title (not an actual URL) including interwiki
1606          *
1607          * @return string The URL-encoded form
1608          */
1609         public function getPrefixedURL() {
1610                 $s = $this->prefix( $this->mDbkeyform );
1611                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1612                 return $s;
1613         }
1614
1615         /**
1616          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1617          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1618          * second argument named variant. This was deprecated in favor
1619          * of passing an array of option with a "variant" key
1620          * Once $query2 is removed for good, this helper can be dropped
1621          * and the wfArrayToCgi moved to getLocalURL();
1622          *
1623          * @since 1.19 (r105919)
1624          * @param array|string $query
1625          * @param bool $query2
1626          * @return string
1627          */
1628         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1629                 if ( $query2 !== false ) {
1630                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1631                                 "method called with a second parameter is deprecated. Add your " .
1632                                 "parameter to an array passed as the first parameter.", "1.19" );
1633                 }
1634                 if ( is_array( $query ) ) {
1635                         $query = wfArrayToCgi( $query );
1636                 }
1637                 if ( $query2 ) {
1638                         if ( is_string( $query2 ) ) {
1639                                 // $query2 is a string, we will consider this to be
1640                                 // a deprecated $variant argument and add it to the query
1641                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1642                         } else {
1643                                 $query2 = wfArrayToCgi( $query2 );
1644                         }
1645                         // If we have $query content add a & to it first
1646                         if ( $query ) {
1647                                 $query .= '&';
1648                         }
1649                         // Now append the queries together
1650                         $query .= $query2;
1651                 }
1652                 return $query;
1653         }
1654
1655         /**
1656          * Get a real URL referring to this title, with interwiki link and
1657          * fragment
1658          *
1659          * @see self::getLocalURL for the arguments.
1660          * @see wfExpandUrl
1661          * @param array|string $query
1662          * @param bool $query2
1663          * @param string $proto Protocol type to use in URL
1664          * @return string The URL
1665          */
1666         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1667                 $query = self::fixUrlQueryArgs( $query, $query2 );
1668
1669                 # Hand off all the decisions on urls to getLocalURL
1670                 $url = $this->getLocalURL( $query );
1671
1672                 # Expand the url to make it a full url. Note that getLocalURL has the
1673                 # potential to output full urls for a variety of reasons, so we use
1674                 # wfExpandUrl instead of simply prepending $wgServer
1675                 $url = wfExpandUrl( $url, $proto );
1676
1677                 # Finally, add the fragment.
1678                 $url .= $this->getFragmentForURL();
1679
1680                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1681                 return $url;
1682         }
1683
1684         /**
1685          * Get a URL with no fragment or server name (relative URL) from a Title object.
1686          * If this page is generated with action=render, however,
1687          * $wgServer is prepended to make an absolute URL.
1688          *
1689          * @see self::getFullURL to always get an absolute URL.
1690          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1691          *  valid to link, locally, to the current Title.
1692          * @see self::newFromText to produce a Title object.
1693          *
1694          * @param string|array $query An optional query string,
1695          *   not used for interwiki links. Can be specified as an associative array as well,
1696          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1697          *   Some query patterns will trigger various shorturl path replacements.
1698          * @param array $query2 An optional secondary query array. This one MUST
1699          *   be an array. If a string is passed it will be interpreted as a deprecated
1700          *   variant argument and urlencoded into a variant= argument.
1701          *   This second query argument will be added to the $query
1702          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1703          *   pair in the first parameter array instead.
1704          *
1705          * @return string String of the URL.
1706          */
1707         public function getLocalURL( $query = '', $query2 = false ) {
1708                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1709
1710                 $query = self::fixUrlQueryArgs( $query, $query2 );
1711
1712                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1713                 if ( $interwiki ) {
1714                         $namespace = $this->getNsText();
1715                         if ( $namespace != '' ) {
1716                                 # Can this actually happen? Interwikis shouldn't be parsed.
1717                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1718                                 $namespace .= ':';
1719                         }
1720                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1721                         $url = wfAppendQuery( $url, $query );
1722                 } else {
1723                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1724                         if ( $query == '' ) {
1725                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1726                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1727                         } else {
1728                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1729                                 $url = false;
1730                                 $matches = array();
1731
1732                                 if ( !empty( $wgActionPaths )
1733                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1734                                 ) {
1735                                         $action = urldecode( $matches[2] );
1736                                         if ( isset( $wgActionPaths[$action] ) ) {
1737                                                 $query = $matches[1];
1738                                                 if ( isset( $matches[4] ) ) {
1739                                                         $query .= $matches[4];
1740                                                 }
1741                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1742                                                 if ( $query != '' ) {
1743                                                         $url = wfAppendQuery( $url, $query );
1744                                                 }
1745                                         }
1746                                 }
1747
1748                                 if ( $url === false
1749                                         && $wgVariantArticlePath
1750                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1751                                         && $this->getPageLanguage()->hasVariants()
1752                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1753                                 ) {
1754                                         $variant = urldecode( $matches[1] );
1755                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1756                                                 // Only do the variant replacement if the given variant is a valid
1757                                                 // variant for the page's language.
1758                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1759                                                 $url = str_replace( '$1', $dbkey, $url );
1760                                         }
1761                                 }
1762
1763                                 if ( $url === false ) {
1764                                         if ( $query == '-' ) {
1765                                                 $query = '';
1766                                         }
1767                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1768                                 }
1769                         }
1770
1771                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1772
1773                         // @todo FIXME: This causes breakage in various places when we
1774                         // actually expected a local URL and end up with dupe prefixes.
1775                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1776                                 $url = $wgServer . $url;
1777                         }
1778                 }
1779                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1780                 return $url;
1781         }
1782
1783         /**
1784          * Get a URL that's the simplest URL that will be valid to link, locally,
1785          * to the current Title.  It includes the fragment, but does not include
1786          * the server unless action=render is used (or the link is external).  If
1787          * there's a fragment but the prefixed text is empty, we just return a link
1788          * to the fragment.
1789          *
1790          * The result obviously should not be URL-escaped, but does need to be
1791          * HTML-escaped if it's being output in HTML.
1792          *
1793          * @param array $query
1794          * @param bool $query2
1795          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1796          * @see self::getLocalURL for the arguments.
1797          * @return string The URL
1798          */
1799         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1800                 wfProfileIn( __METHOD__ );
1801                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1802                         $ret = $this->getFullURL( $query, $query2, $proto );
1803                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1804                         $ret = $this->getFragmentForURL();
1805                 } else {
1806                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1807                 }
1808                 wfProfileOut( __METHOD__ );
1809                 return $ret;
1810         }
1811
1812         /**
1813          * Get the URL form for an internal link.
1814          * - Used in various Squid-related code, in case we have a different
1815          * internal hostname for the server from the exposed one.
1816          *
1817          * This uses $wgInternalServer to qualify the path, or $wgServer
1818          * if $wgInternalServer is not set. If the server variable used is
1819          * protocol-relative, the URL will be expanded to http://
1820          *
1821          * @see self::getLocalURL for the arguments.
1822          * @return string The URL
1823          */
1824         public function getInternalURL( $query = '', $query2 = false ) {
1825                 global $wgInternalServer, $wgServer;
1826                 $query = self::fixUrlQueryArgs( $query, $query2 );
1827                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1828                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1829                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1830                 return $url;
1831         }
1832
1833         /**
1834          * Get the URL for a canonical link, for use in things like IRC and
1835          * e-mail notifications. Uses $wgCanonicalServer and the
1836          * GetCanonicalURL hook.
1837          *
1838          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1839          *
1840          * @see self::getLocalURL for the arguments.
1841          * @return string The URL
1842          * @since 1.18
1843          */
1844         public function getCanonicalURL( $query = '', $query2 = false ) {
1845                 $query = self::fixUrlQueryArgs( $query, $query2 );
1846                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1847                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1848                 return $url;
1849         }
1850
1851         /**
1852          * Get the edit URL for this Title
1853          *
1854          * @return string The URL, or a null string if this is an interwiki link
1855          */
1856         public function getEditURL() {
1857                 if ( $this->isExternal() ) {
1858                         return '';
1859                 }
1860                 $s = $this->getLocalURL( 'action=edit' );
1861
1862                 return $s;
1863         }
1864
1865         /**
1866          * Is $wgUser watching this page?
1867          *
1868          * @deprecated since 1.20; use User::isWatched() instead.
1869          * @return bool
1870          */
1871         public function userIsWatching() {
1872                 global $wgUser;
1873
1874                 if ( is_null( $this->mWatched ) ) {
1875                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1876                                 $this->mWatched = false;
1877                         } else {
1878                                 $this->mWatched = $wgUser->isWatched( $this );
1879                         }
1880                 }
1881                 return $this->mWatched;
1882         }
1883
1884         /**
1885          * Can $user perform $action on this page?
1886          * This skips potentially expensive cascading permission checks
1887          * as well as avoids expensive error formatting
1888          *
1889          * Suitable for use for nonessential UI controls in common cases, but
1890          * _not_ for functional access control.
1891          *
1892          * May provide false positives, but should never provide a false negative.
1893          *
1894          * @param string $action Action that permission needs to be checked for
1895          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1896          * @return bool
1897          */
1898         public function quickUserCan( $action, $user = null ) {
1899                 return $this->userCan( $action, $user, false );
1900         }
1901
1902         /**
1903          * Can $user perform $action on this page?
1904          *
1905          * @param string $action Action that permission needs to be checked for
1906          * @param User $user User to check (since 1.19); $wgUser will be used if not
1907          *   provided.
1908          * @param bool $doExpensiveQueries Set this to false to avoid doing
1909          *   unnecessary queries.
1910          * @return bool
1911          */
1912         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1913                 if ( !$user instanceof User ) {
1914                         global $wgUser;
1915                         $user = $wgUser;
1916                 }
1917
1918                 return !count( $this->getUserPermissionsErrorsInternal(
1919                         $action, $user, $doExpensiveQueries, 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 bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1930          *   queries by skipping checks for cascading protections and user blocks.
1931          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1932          *   whose corresponding errors may be ignored.
1933          * @return array Array of arguments to wfMessage to explain permissions problems.
1934          */
1935         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true,
1936                 $ignoreErrors = array()
1937         ) {
1938                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1939
1940                 // Remove the errors being ignored.
1941                 foreach ( $errors as $index => $error ) {
1942                         $error_key = is_array( $error ) ? $error[0] : $error;
1943
1944                         if ( in_array( $error_key, $ignoreErrors ) ) {
1945                                 unset( $errors[$index] );
1946                         }
1947                 }
1948
1949                 return $errors;
1950         }
1951
1952         /**
1953          * Permissions checks that fail most often, and which are easiest to test.
1954          *
1955          * @param string $action The action to check
1956          * @param User $user User to check
1957          * @param array $errors List of current errors
1958          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1959          * @param bool $short Short circuit on first error
1960          *
1961          * @return array List of errors
1962          */
1963         private function checkQuickPermissions( $action, $user, $errors,
1964                 $doExpensiveQueries, $short
1965         ) {
1966                 if ( !Hooks::run( 'TitleQuickPermissions',
1967                         array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) )
1968                 ) {
1969                         return $errors;
1970                 }
1971
1972                 if ( $action == 'create' ) {
1973                         if (
1974                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1975                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1976                         ) {
1977                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1978                         }
1979                 } elseif ( $action == 'move' ) {
1980                         if ( !$user->isAllowed( 'move-rootuserpages' )
1981                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1982                                 // Show user page-specific message only if the user can move other pages
1983                                 $errors[] = array( 'cant-move-user-page' );
1984                         }
1985
1986                         // Check if user is allowed to move files if it's a file
1987                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1988                                 $errors[] = array( 'movenotallowedfile' );
1989                         }
1990
1991                         // Check if user is allowed to move category pages if it's a category page
1992                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1993                                 $errors[] = array( 'cant-move-category-page' );
1994                         }
1995
1996                         if ( !$user->isAllowed( 'move' ) ) {
1997                                 // User can't move anything
1998                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1999                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2000                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2001                                         // custom message if logged-in users without any special rights can move
2002                                         $errors[] = array( 'movenologintext' );
2003                                 } else {
2004                                         $errors[] = array( 'movenotallowed' );
2005                                 }
2006                         }
2007                 } elseif ( $action == 'move-target' ) {
2008                         if ( !$user->isAllowed( 'move' ) ) {
2009                                 // User can't move anything
2010                                 $errors[] = array( 'movenotallowed' );
2011                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2012                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2013                                 // Show user page-specific message only if the user can move other pages
2014                                 $errors[] = array( 'cant-move-to-user-page' );
2015                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2016                                         && $this->mNamespace == NS_CATEGORY ) {
2017                                 // Show category page-specific message only if the user can move other pages
2018                                 $errors[] = array( 'cant-move-to-category-page' );
2019                         }
2020                 } elseif ( !$user->isAllowed( $action ) ) {
2021                         $errors[] = $this->missingPermissionError( $action, $short );
2022                 }
2023
2024                 return $errors;
2025         }
2026
2027         /**
2028          * Add the resulting error code to the errors array
2029          *
2030          * @param array $errors List of current errors
2031          * @param array $result Result of errors
2032          *
2033          * @return array List of errors
2034          */
2035         private function resultToError( $errors, $result ) {
2036                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2037                         // A single array representing an error
2038                         $errors[] = $result;
2039                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2040                         // A nested array representing multiple errors
2041                         $errors = array_merge( $errors, $result );
2042                 } elseif ( $result !== '' && is_string( $result ) ) {
2043                         // A string representing a message-id
2044                         $errors[] = array( $result );
2045                 } elseif ( $result === false ) {
2046                         // a generic "We don't want them to do that"
2047                         $errors[] = array( 'badaccess-group0' );
2048                 }
2049                 return $errors;
2050         }
2051
2052         /**
2053          * Check various permission hooks
2054          *
2055          * @param string $action The action to check
2056          * @param User $user User to check
2057          * @param array $errors List of current errors
2058          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2059          * @param bool $short Short circuit on first error
2060          *
2061          * @return array List of errors
2062          */
2063         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
2064                 // Use getUserPermissionsErrors instead
2065                 $result = '';
2066                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2067                         return $result ? array() : array( array( 'badaccess-group0' ) );
2068                 }
2069                 // Check getUserPermissionsErrors hook
2070                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2071                         $errors = $this->resultToError( $errors, $result );
2072                 }
2073                 // Check getUserPermissionsErrorsExpensive hook
2074                 if (
2075                         $doExpensiveQueries
2076                         && !( $short && count( $errors ) > 0 )
2077                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2078                 ) {
2079                         $errors = $this->resultToError( $errors, $result );
2080                 }
2081
2082                 return $errors;
2083         }
2084
2085         /**
2086          * Check permissions on special pages & namespaces
2087          *
2088          * @param string $action The action to check
2089          * @param User $user User to check
2090          * @param array $errors List of current errors
2091          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2092          * @param bool $short Short circuit on first error
2093          *
2094          * @return array List of errors
2095          */
2096         private function checkSpecialsAndNSPermissions( $action, $user, $errors,
2097                 $doExpensiveQueries, $short
2098         ) {
2099                 # Only 'createaccount' can be performed on special pages,
2100                 # which don't actually exist in the DB.
2101                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2102                         $errors[] = array( 'ns-specialprotected' );
2103                 }
2104
2105                 # Check $wgNamespaceProtection for restricted namespaces
2106                 if ( $this->isNamespaceProtected( $user ) ) {
2107                         $ns = $this->mNamespace == NS_MAIN ?
2108                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2109                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2110                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2111                 }
2112
2113                 return $errors;
2114         }
2115
2116         /**
2117          * Check CSS/JS sub-page permissions
2118          *
2119          * @param string $action The action to check
2120          * @param User $user User to check
2121          * @param array $errors List of current errors
2122          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2123          * @param bool $short Short circuit on first error
2124          *
2125          * @return array List of errors
2126          */
2127         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2128                 # Protect css/js subpages of user pages
2129                 # XXX: this might be better using restrictions
2130                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2131                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2132                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2133                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2134                                         $errors[] = array( 'mycustomcssprotected', $action );
2135                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2136                                         $errors[] = array( 'mycustomjsprotected', $action );
2137                                 }
2138                         } else {
2139                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2140                                         $errors[] = array( 'customcssprotected', $action );
2141                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2142                                         $errors[] = array( 'customjsprotected', $action );
2143                                 }
2144                         }
2145                 }
2146
2147                 return $errors;
2148         }
2149
2150         /**
2151          * Check against page_restrictions table requirements on this
2152          * page. The user must possess all required rights for this
2153          * action.
2154          *
2155          * @param string $action The action to check
2156          * @param User $user User to check
2157          * @param array $errors List of current errors
2158          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2159          * @param bool $short Short circuit on first error
2160          *
2161          * @return array List of errors
2162          */
2163         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2164                 foreach ( $this->getRestrictions( $action ) as $right ) {
2165                         // Backwards compatibility, rewrite sysop -> editprotected
2166                         if ( $right == 'sysop' ) {
2167                                 $right = 'editprotected';
2168                         }
2169                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2170                         if ( $right == 'autoconfirmed' ) {
2171                                 $right = 'editsemiprotected';
2172                         }
2173                         if ( $right == '' ) {
2174                                 continue;
2175                         }
2176                         if ( !$user->isAllowed( $right ) ) {
2177                                 $errors[] = array( 'protectedpagetext', $right, $action );
2178                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2179                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2180                         }
2181                 }
2182
2183                 return $errors;
2184         }
2185
2186         /**
2187          * Check restrictions on cascading pages.
2188          *
2189          * @param string $action The action to check
2190          * @param User $user User to check
2191          * @param array $errors List of current errors
2192          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2193          * @param bool $short Short circuit on first error
2194          *
2195          * @return array List of errors
2196          */
2197         private function checkCascadingSourcesRestrictions( $action, $user, $errors,
2198                 $doExpensiveQueries, $short
2199         ) {
2200                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2201                         # We /could/ use the protection level on the source page, but it's
2202                         # fairly ugly as we have to establish a precedence hierarchy for pages
2203                         # included by multiple cascade-protected pages. So just restrict
2204                         # it to people with 'protect' permission, as they could remove the
2205                         # protection anyway.
2206                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2207                         # Cascading protection depends on more than this page...
2208                         # Several cascading protected pages may include this page...
2209                         # Check each cascading level
2210                         # This is only for protection restrictions, not for all actions
2211                         if ( isset( $restrictions[$action] ) ) {
2212                                 foreach ( $restrictions[$action] as $right ) {
2213                                         // Backwards compatibility, rewrite sysop -> editprotected
2214                                         if ( $right == 'sysop' ) {
2215                                                 $right = 'editprotected';
2216                                         }
2217                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2218                                         if ( $right == 'autoconfirmed' ) {
2219                                                 $right = 'editsemiprotected';
2220                                         }
2221                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2222                                                 $pages = '';
2223                                                 foreach ( $cascadingSources as $page ) {
2224                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2225                                                 }
2226                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2227                                         }
2228                                 }
2229                         }
2230                 }
2231
2232                 return $errors;
2233         }
2234
2235         /**
2236          * Check action permissions not already checked in checkQuickPermissions
2237          *
2238          * @param string $action The action to check
2239          * @param User $user User to check
2240          * @param array $errors List of current errors
2241          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2242          * @param bool $short Short circuit on first error
2243          *
2244          * @return array List of errors
2245          */
2246         private function checkActionPermissions( $action, $user, $errors,
2247                 $doExpensiveQueries, $short
2248         ) {
2249                 global $wgDeleteRevisionsLimit, $wgLang;
2250
2251                 if ( $action == 'protect' ) {
2252                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit',
2253                                 $user, $doExpensiveQueries, true ) )
2254                         ) {
2255                                 // If they can't edit, they shouldn't protect.
2256                                 $errors[] = array( 'protect-cantedit' );
2257                         }
2258                 } elseif ( $action == 'create' ) {
2259                         $title_protection = $this->getTitleProtection();
2260                         if ( $title_protection ) {
2261                                 if ( $title_protection['permission'] == ''
2262                                         || !$user->isAllowed( $title_protection['permission'] )
2263                                 ) {
2264                                         $errors[] = array(
2265                                                 'titleprotected',
2266                                                 User::whoIs( $title_protection['user'] ),
2267                                                 $title_protection['reason']
2268                                         );
2269                                 }
2270                         }
2271                 } elseif ( $action == 'move' ) {
2272                         // Check for immobile pages
2273                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2274                                 // Specific message for this case
2275                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2276                         } elseif ( !$this->isMovable() ) {
2277                                 // Less specific message for rarer cases
2278                                 $errors[] = array( 'immobile-source-page' );
2279                         }
2280                 } elseif ( $action == 'move-target' ) {
2281                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2282                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2283                         } elseif ( !$this->isMovable() ) {
2284                                 $errors[] = array( 'immobile-target-page' );
2285                         }
2286                 } elseif ( $action == 'delete' ) {
2287                         $tempErrors = $this->checkPageRestrictions( 'edit',
2288                                 $user, array(), $doExpensiveQueries, true );
2289                         if ( !$tempErrors ) {
2290                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2291                                         $user, $tempErrors, $doExpensiveQueries, true );
2292                         }
2293                         if ( $tempErrors ) {
2294                                 // If protection keeps them from editing, they shouldn't be able to delete.
2295                                 $errors[] = array( 'deleteprotected' );
2296                         }
2297                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2298                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2299                         ) {
2300                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2301                         }
2302                 }
2303                 return $errors;
2304         }
2305
2306         /**
2307          * Check that the user isn't blocked from editing.
2308          *
2309          * @param string $action The action to check
2310          * @param User $user User to check
2311          * @param array $errors List of current errors
2312          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2313          * @param bool $short Short circuit on first error
2314          *
2315          * @return array List of errors
2316          */
2317         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2318                 // Account creation blocks handled at userlogin.
2319                 // Unblocking handled in SpecialUnblock
2320                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2321                         return $errors;
2322                 }
2323
2324                 global $wgEmailConfirmToEdit;
2325
2326                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2327                         $errors[] = array( 'confirmedittext' );
2328                 }
2329
2330                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
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->mBlock->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 bool $doExpensiveQueries Whether or not to perform expensive queries
2348          * @param bool $short Short circuit on first error
2349          *
2350          * @return array List of errors
2351          */
2352         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $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 bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2456          * @param bool $short Set this to true to stop after the first permission error.
2457          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2458          */
2459         protected function getUserPermissionsErrorsInternal( $action, $user,
2460                 $doExpensiveQueries = true, $short = false
2461         ) {
2462                 wfProfileIn( __METHOD__ );
2463
2464                 # Read has special handling
2465                 if ( $action == 'read' ) {
2466                         $checks = array(
2467                                 'checkPermissionHooks',
2468                                 'checkReadPermissions',
2469                         );
2470                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2471                 # here as it will lead to duplicate error messages. This is okay to do
2472                 # since anywhere that checks for create will also check for edit, and
2473                 # those checks are called for edit.
2474                 } elseif ( $action == 'create' ) {
2475                         $checks = array(
2476                                 'checkQuickPermissions',
2477                                 'checkPermissionHooks',
2478                                 'checkPageRestrictions',
2479                                 'checkCascadingSourcesRestrictions',
2480                                 'checkActionPermissions',
2481                                 'checkUserBlock'
2482                         );
2483                 } else {
2484                         $checks = array(
2485                                 'checkQuickPermissions',
2486                                 'checkPermissionHooks',
2487                                 'checkSpecialsAndNSPermissions',
2488                                 'checkCSSandJSPermissions',
2489                                 'checkPageRestrictions',
2490                                 'checkCascadingSourcesRestrictions',
2491                                 'checkActionPermissions',
2492                                 'checkUserBlock'
2493                         );
2494                 }
2495
2496                 $errors = array();
2497                 while ( count( $checks ) > 0 &&
2498                                 !( $short && count( $errors ) > 0 ) ) {
2499                         $method = array_shift( $checks );
2500                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2501                 }
2502
2503                 wfProfileOut( __METHOD__ );
2504                 return $errors;
2505         }
2506
2507         /**
2508          * Get a filtered list of all restriction types supported by this wiki.
2509          * @param bool $exists True to get all restriction types that apply to
2510          * titles that do exist, False for all restriction types that apply to
2511          * titles that do not exist
2512          * @return array
2513          */
2514         public static function getFilteredRestrictionTypes( $exists = true ) {
2515                 global $wgRestrictionTypes;
2516                 $types = $wgRestrictionTypes;
2517                 if ( $exists ) {
2518                         # Remove the create restriction for existing titles
2519                         $types = array_diff( $types, array( 'create' ) );
2520                 } else {
2521                         # Only the create and upload restrictions apply to non-existing titles
2522                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2523                 }
2524                 return $types;
2525         }
2526
2527         /**
2528          * Returns restriction types for the current Title
2529          *
2530          * @return array Applicable restriction types
2531          */
2532         public function getRestrictionTypes() {
2533                 if ( $this->isSpecialPage() ) {
2534                         return array();
2535                 }
2536
2537                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2538
2539                 if ( $this->getNamespace() != NS_FILE ) {
2540                         # Remove the upload restriction for non-file titles
2541                         $types = array_diff( $types, array( 'upload' ) );
2542                 }
2543
2544                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2545
2546                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2547                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2548
2549                 return $types;
2550         }
2551
2552         /**
2553          * Is this title subject to title protection?
2554          * Title protection is the one applied against creation of such title.
2555          *
2556          * @return array|bool An associative array representing any existent title
2557          *   protection, or false if there's none.
2558          */
2559         public function getTitleProtection() {
2560                 // Can't protect pages in special namespaces
2561                 if ( $this->getNamespace() < 0 ) {
2562                         return false;
2563                 }
2564
2565                 // Can't protect pages that exist.
2566                 if ( $this->exists() ) {
2567                         return false;
2568                 }
2569
2570                 if ( $this->mTitleProtection === null ) {
2571                         $dbr = wfGetDB( DB_SLAVE );
2572                         $res = $dbr->select(
2573                                 'protected_titles',
2574                                 array(
2575                                         'user' => 'pt_user',
2576                                         'reason' => 'pt_reason',
2577                                         'expiry' => 'pt_expiry',
2578                                         'permission' => 'pt_create_perm'
2579                                 ),
2580                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2581                                 __METHOD__
2582                         );
2583
2584                         // fetchRow returns false if there are no rows.
2585                         $row = $dbr->fetchRow( $res );
2586                         if ( $row ) {
2587                                 if ( $row['permission'] == 'sysop' ) {
2588                                         $row['permission'] = 'editprotected'; // B/C
2589                                 }
2590                                 if ( $row['permission'] == 'autoconfirmed' ) {
2591                                         $row['permission'] = 'editsemiprotected'; // B/C
2592                                 }
2593                         }
2594                         $this->mTitleProtection = $row;
2595                 }
2596                 return $this->mTitleProtection;
2597         }
2598
2599         /**
2600          * Remove any title protection due to page existing
2601          */
2602         public function deleteTitleProtection() {
2603                 $dbw = wfGetDB( DB_MASTER );
2604
2605                 $dbw->delete(
2606                         'protected_titles',
2607                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2608                         __METHOD__
2609                 );
2610                 $this->mTitleProtection = false;
2611         }
2612
2613         /**
2614          * Is this page "semi-protected" - the *only* protection levels are listed
2615          * in $wgSemiprotectedRestrictionLevels?
2616          *
2617          * @param string $action Action to check (default: edit)
2618          * @return bool
2619          */
2620         public function isSemiProtected( $action = 'edit' ) {
2621                 global $wgSemiprotectedRestrictionLevels;
2622
2623                 $restrictions = $this->getRestrictions( $action );
2624                 $semi = $wgSemiprotectedRestrictionLevels;
2625                 if ( !$restrictions || !$semi ) {
2626                         // Not protected, or all protection is full protection
2627                         return false;
2628                 }
2629
2630                 // Remap autoconfirmed to editsemiprotected for BC
2631                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2632                         $semi[$key] = 'editsemiprotected';
2633                 }
2634                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2635                         $restrictions[$key] = 'editsemiprotected';
2636                 }
2637
2638                 return !array_diff( $restrictions, $semi );
2639         }
2640
2641         /**
2642          * Does the title correspond to a protected article?
2643          *
2644          * @param string $action The action the page is protected from,
2645          * by default checks all actions.
2646          * @return bool
2647          */
2648         public function isProtected( $action = '' ) {
2649                 global $wgRestrictionLevels;
2650
2651                 $restrictionTypes = $this->getRestrictionTypes();
2652
2653                 # Special pages have inherent protection
2654                 if ( $this->isSpecialPage() ) {
2655                         return true;
2656                 }
2657
2658                 # Check regular protection levels
2659                 foreach ( $restrictionTypes as $type ) {
2660                         if ( $action == $type || $action == '' ) {
2661                                 $r = $this->getRestrictions( $type );
2662                                 foreach ( $wgRestrictionLevels as $level ) {
2663                                         if ( in_array( $level, $r ) && $level != '' ) {
2664                                                 return true;
2665                                         }
2666                                 }
2667                         }
2668                 }
2669
2670                 return false;
2671         }
2672
2673         /**
2674          * Determines if $user is unable to edit this page because it has been protected
2675          * by $wgNamespaceProtection.
2676          *
2677          * @param User $user User object to check permissions
2678          * @return bool
2679          */
2680         public function isNamespaceProtected( User $user ) {
2681                 global $wgNamespaceProtection;
2682
2683                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2684                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2685                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2686                                         return true;
2687                                 }
2688                         }
2689                 }
2690                 return false;
2691         }
2692
2693         /**
2694          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2695          *
2696          * @return bool If the page is subject to cascading restrictions.
2697          */
2698         public function isCascadeProtected() {
2699                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2700                 return ( $sources > 0 );
2701         }
2702
2703         /**
2704          * Determines whether cascading protection sources have already been loaded from
2705          * the database.
2706          *
2707          * @param bool $getPages True to check if the pages are loaded, or false to check
2708          * if the status is loaded.
2709          * @return bool Whether or not the specified information has been loaded
2710          * @since 1.23
2711          */
2712         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2713                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2714         }
2715
2716         /**
2717          * Cascading protection: Get the source of any cascading restrictions on this page.
2718          *
2719          * @param bool $getPages Whether or not to retrieve the actual pages
2720          *        that the restrictions have come from and the actual restrictions
2721          *        themselves.
2722          * @return array Two elements: First is an array of Title objects of the
2723          *        pages from which cascading restrictions have come, false for
2724          *        none, or true if such restrictions exist but $getPages was not
2725          *        set. Second is an array like that returned by
2726          *        Title::getAllRestrictions(), or an empty array if $getPages is
2727          *        false.
2728          */
2729         public function getCascadeProtectionSources( $getPages = true ) {
2730                 global $wgContLang;
2731                 $pagerestrictions = array();
2732
2733                 if ( $this->mCascadeSources !== null && $getPages ) {
2734                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2735                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2736                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2737                 }
2738
2739                 wfProfileIn( __METHOD__ );
2740
2741                 $dbr = wfGetDB( DB_SLAVE );
2742
2743                 if ( $this->getNamespace() == NS_FILE ) {
2744                         $tables = array( 'imagelinks', 'page_restrictions' );
2745                         $where_clauses = array(
2746                                 'il_to' => $this->getDBkey(),
2747                                 'il_from=pr_page',
2748                                 'pr_cascade' => 1
2749                         );
2750                 } else {
2751                         $tables = array( 'templatelinks', 'page_restrictions' );
2752                         $where_clauses = array(
2753                                 'tl_namespace' => $this->getNamespace(),
2754                                 'tl_title' => $this->getDBkey(),
2755                                 'tl_from=pr_page',
2756                                 'pr_cascade' => 1
2757                         );
2758                 }
2759
2760                 if ( $getPages ) {
2761                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2762                                 'pr_expiry', 'pr_type', 'pr_level' );
2763                         $where_clauses[] = 'page_id=pr_page';
2764                         $tables[] = 'page';
2765                 } else {
2766                         $cols = array( 'pr_expiry' );
2767                 }
2768
2769                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2770
2771                 $sources = $getPages ? array() : false;
2772                 $now = wfTimestampNow();
2773                 $purgeExpired = false;
2774
2775                 foreach ( $res as $row ) {
2776                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2777                         if ( $expiry > $now ) {
2778                                 if ( $getPages ) {
2779                                         $page_id = $row->pr_page;
2780                                         $page_ns = $row->page_namespace;
2781                                         $page_title = $row->page_title;
2782                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2783                                         # Add groups needed for each restriction type if its not already there
2784                                         # Make sure this restriction type still exists
2785
2786                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2787                                                 $pagerestrictions[$row->pr_type] = array();
2788                                         }
2789
2790                                         if (
2791                                                 isset( $pagerestrictions[$row->pr_type] )
2792                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2793                                         ) {
2794                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2795                                         }
2796                                 } else {
2797                                         $sources = true;
2798                                 }
2799                         } else {
2800                                 // Trigger lazy purge of expired restrictions from the db
2801                                 $purgeExpired = true;
2802                         }
2803                 }
2804                 if ( $purgeExpired ) {
2805                         Title::purgeExpiredRestrictions();
2806                 }
2807
2808                 if ( $getPages ) {
2809                         $this->mCascadeSources = $sources;
2810                         $this->mCascadingRestrictions = $pagerestrictions;
2811                 } else {
2812                         $this->mHasCascadingRestrictions = $sources;
2813                 }
2814
2815                 wfProfileOut( __METHOD__ );
2816                 return array( $sources, $pagerestrictions );
2817         }
2818
2819         /**
2820          * Accessor for mRestrictionsLoaded
2821          *
2822          * @return bool Whether or not the page's restrictions have already been
2823          * loaded from the database
2824          * @since 1.23
2825          */
2826         public function areRestrictionsLoaded() {
2827                 return $this->mRestrictionsLoaded;
2828         }
2829
2830         /**
2831          * Accessor/initialisation for mRestrictions
2832          *
2833          * @param string $action Action that permission needs to be checked for
2834          * @return array Restriction levels needed to take the action. All levels are
2835          *     required. Note that restriction levels are normally user rights, but 'sysop'
2836          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2837          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2838          */
2839         public function getRestrictions( $action ) {
2840                 if ( !$this->mRestrictionsLoaded ) {
2841                         $this->loadRestrictions();
2842                 }
2843                 return isset( $this->mRestrictions[$action] )
2844                                 ? $this->mRestrictions[$action]
2845                                 : array();
2846         }
2847
2848         /**
2849          * Accessor/initialisation for mRestrictions
2850          *
2851          * @return array Keys are actions, values are arrays as returned by
2852          *     Title::getRestrictions()
2853          * @since 1.23
2854          */
2855         public function getAllRestrictions() {
2856                 if ( !$this->mRestrictionsLoaded ) {
2857                         $this->loadRestrictions();
2858                 }
2859                 return $this->mRestrictions;
2860         }
2861
2862         /**
2863          * Get the expiry time for the restriction against a given action
2864          *
2865          * @param string $action
2866          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2867          *     or not protected at all, or false if the action is not recognised.
2868          */
2869         public function getRestrictionExpiry( $action ) {
2870                 if ( !$this->mRestrictionsLoaded ) {
2871                         $this->loadRestrictions();
2872                 }
2873                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2874         }
2875
2876         /**
2877          * Returns cascading restrictions for the current article
2878          *
2879          * @return bool
2880          */
2881         function areRestrictionsCascading() {
2882                 if ( !$this->mRestrictionsLoaded ) {
2883                         $this->loadRestrictions();
2884                 }
2885
2886                 return $this->mCascadeRestriction;
2887         }
2888
2889         /**
2890          * Loads a string into mRestrictions array
2891          *
2892          * @param ResultWrapper $res Resource restrictions as an SQL result.
2893          * @param string $oldFashionedRestrictions Comma-separated list of page
2894          *        restrictions from page table (pre 1.10)
2895          */
2896         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2897                 $rows = array();
2898
2899                 foreach ( $res as $row ) {
2900                         $rows[] = $row;
2901                 }
2902
2903                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2904         }
2905
2906         /**
2907          * Compiles list of active page restrictions from both page table (pre 1.10)
2908          * and page_restrictions table for this existing page.
2909          * Public for usage by LiquidThreads.
2910          *
2911          * @param array $rows Array of db result objects
2912          * @param string $oldFashionedRestrictions Comma-separated list of page
2913          *   restrictions from page table (pre 1.10)
2914          */
2915         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2916                 global $wgContLang;
2917                 $dbr = wfGetDB( DB_SLAVE );
2918
2919                 $restrictionTypes = $this->getRestrictionTypes();
2920
2921                 foreach ( $restrictionTypes as $type ) {
2922                         $this->mRestrictions[$type] = array();
2923                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2924                 }
2925
2926                 $this->mCascadeRestriction = false;
2927
2928                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2929
2930                 if ( $oldFashionedRestrictions === null ) {
2931                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2932                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2933                 }
2934
2935                 if ( $oldFashionedRestrictions != '' ) {
2936
2937                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2938                                 $temp = explode( '=', trim( $restrict ) );
2939                                 if ( count( $temp ) == 1 ) {
2940                                         // old old format should be treated as edit/move restriction
2941                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2942                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2943                                 } else {
2944                                         $restriction = trim( $temp[1] );
2945                                         if ( $restriction != '' ) { //some old entries are empty
2946                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2947                                         }
2948                                 }
2949                         }
2950
2951                         $this->mOldRestrictions = true;
2952
2953                 }
2954
2955                 if ( count( $rows ) ) {
2956                         # Current system - load second to make them override.
2957                         $now = wfTimestampNow();
2958                         $purgeExpired = false;
2959
2960                         # Cycle through all the restrictions.
2961                         foreach ( $rows as $row ) {
2962
2963                                 // Don't take care of restrictions types that aren't allowed
2964                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2965                                         continue;
2966                                 }
2967
2968                                 // This code should be refactored, now that it's being used more generally,
2969                                 // But I don't really see any harm in leaving it in Block for now -werdna
2970                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2971
2972                                 // Only apply the restrictions if they haven't expired!
2973                                 if ( !$expiry || $expiry > $now ) {
2974                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2975                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2976
2977                                         $this->mCascadeRestriction |= $row->pr_cascade;
2978                                 } else {
2979                                         // Trigger a lazy purge of expired restrictions
2980                                         $purgeExpired = true;
2981                                 }
2982                         }
2983
2984                         if ( $purgeExpired ) {
2985                                 Title::purgeExpiredRestrictions();
2986                         }
2987                 }
2988
2989                 $this->mRestrictionsLoaded = true;
2990         }
2991
2992         /**
2993          * Load restrictions from the page_restrictions table
2994          *
2995          * @param string $oldFashionedRestrictions Comma-separated list of page
2996          *   restrictions from page table (pre 1.10)
2997          */
2998         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2999                 global $wgContLang;
3000                 if ( !$this->mRestrictionsLoaded ) {
3001                         if ( $this->exists() ) {
3002                                 $dbr = wfGetDB( DB_SLAVE );
3003
3004                                 $res = $dbr->select(
3005                                         'page_restrictions',
3006                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
3007                                         array( 'pr_page' => $this->getArticleID() ),
3008                                         __METHOD__
3009                                 );
3010
3011                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
3012                         } else {
3013                                 $title_protection = $this->getTitleProtection();
3014
3015                                 if ( $title_protection ) {
3016                                         $now = wfTimestampNow();
3017                                         $expiry = $wgContLang->formatExpiry( $title_protection['expiry'], TS_MW );
3018
3019                                         if ( !$expiry || $expiry > $now ) {
3020                                                 // Apply the restrictions
3021                                                 $this->mRestrictionsExpiry['create'] = $expiry;
3022                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
3023                                         } else { // Get rid of the old restrictions
3024                                                 Title::purgeExpiredRestrictions();
3025                                                 $this->mTitleProtection = false;
3026                                         }
3027                                 } else {
3028                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
3029                                 }
3030                                 $this->mRestrictionsLoaded = true;
3031                         }
3032                 }
3033         }
3034
3035         /**
3036          * Flush the protection cache in this object and force reload from the database.
3037          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3038          */
3039         public function flushRestrictions() {
3040                 $this->mRestrictionsLoaded = false;
3041                 $this->mTitleProtection = null;
3042         }
3043
3044         /**
3045          * Purge expired restrictions from the page_restrictions table
3046          */
3047         static function purgeExpiredRestrictions() {
3048                 if ( wfReadOnly() ) {
3049                         return;
3050                 }
3051
3052                 $method = __METHOD__;
3053                 $dbw = wfGetDB( DB_MASTER );
3054                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3055                         $dbw->delete(
3056                                 'page_restrictions',
3057                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3058                                 $method
3059                         );
3060                         $dbw->delete(
3061                                 'protected_titles',
3062                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3063                                 $method
3064                         );
3065                 } );
3066         }
3067
3068         /**
3069          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3070          *
3071          * @return bool
3072          */
3073         public function hasSubpages() {
3074                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3075                         # Duh
3076                         return false;
3077                 }
3078
3079                 # We dynamically add a member variable for the purpose of this method
3080                 # alone to cache the result.  There's no point in having it hanging
3081                 # around uninitialized in every Title object; therefore we only add it
3082                 # if needed and don't declare it statically.
3083                 if ( $this->mHasSubpages === null ) {
3084                         $this->mHasSubpages = false;
3085                         $subpages = $this->getSubpages( 1 );
3086                         if ( $subpages instanceof TitleArray ) {
3087                                 $this->mHasSubpages = (bool)$subpages->count();
3088                         }
3089                 }
3090
3091                 return $this->mHasSubpages;
3092         }
3093
3094         /**
3095          * Get all subpages of this page.
3096          *
3097          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3098          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3099          *  doesn't allow subpages
3100          */
3101         public function getSubpages( $limit = -1 ) {
3102                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3103                         return array();
3104                 }
3105
3106                 $dbr = wfGetDB( DB_SLAVE );
3107                 $conds['page_namespace'] = $this->getNamespace();
3108                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3109                 $options = array();
3110                 if ( $limit > -1 ) {
3111                         $options['LIMIT'] = $limit;
3112                 }
3113                 $this->mSubpages = TitleArray::newFromResult(
3114                         $dbr->select( 'page',
3115                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3116                                 $conds,
3117                                 __METHOD__,
3118                                 $options
3119                         )
3120                 );
3121                 return $this->mSubpages;
3122         }
3123
3124         /**
3125          * Is there a version of this page in the deletion archive?
3126          *
3127          * @return int The number of archived revisions
3128          */
3129         public function isDeleted() {
3130                 if ( $this->getNamespace() < 0 ) {
3131                         $n = 0;
3132                 } else {
3133                         $dbr = wfGetDB( DB_SLAVE );
3134
3135                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3136                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3137                                 __METHOD__
3138                         );
3139                         if ( $this->getNamespace() == NS_FILE ) {
3140                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3141                                         array( 'fa_name' => $this->getDBkey() ),
3142                                         __METHOD__
3143                                 );
3144                         }
3145                 }
3146                 return (int)$n;
3147         }
3148
3149         /**
3150          * Is there a version of this page in the deletion archive?
3151          *
3152          * @return bool
3153          */
3154         public function isDeletedQuick() {
3155                 if ( $this->getNamespace() < 0 ) {
3156                         return false;
3157                 }
3158                 $dbr = wfGetDB( DB_SLAVE );
3159                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3160                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3161                         __METHOD__
3162                 );
3163                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3164                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3165                                 array( 'fa_name' => $this->getDBkey() ),
3166                                 __METHOD__
3167                         );
3168                 }
3169                 return $deleted;
3170         }
3171
3172         /**
3173          * Get the article ID for this Title from the link cache,
3174          * adding it if necessary
3175          *
3176          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3177          *  for update
3178          * @return int The ID
3179          */
3180         public function getArticleID( $flags = 0 ) {
3181                 if ( $this->getNamespace() < 0 ) {
3182                         $this->mArticleID = 0;
3183                         return $this->mArticleID;
3184                 }
3185                 $linkCache = LinkCache::singleton();
3186                 if ( $flags & self::GAID_FOR_UPDATE ) {
3187                         $oldUpdate = $linkCache->forUpdate( true );
3188                         $linkCache->clearLink( $this );
3189                         $this->mArticleID = $linkCache->addLinkObj( $this );
3190                         $linkCache->forUpdate( $oldUpdate );
3191                 } else {
3192                         if ( -1 == $this->mArticleID ) {
3193                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3194                         }
3195                 }
3196                 return $this->mArticleID;
3197         }
3198
3199         /**
3200          * Is this an article that is a redirect page?
3201          * Uses link cache, adding it if necessary
3202          *
3203          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3204          * @return bool
3205          */
3206         public function isRedirect( $flags = 0 ) {
3207                 if ( !is_null( $this->mRedirect ) ) {
3208                         return $this->mRedirect;
3209                 }
3210                 # Calling getArticleID() loads the field from cache as needed
3211                 if ( !$this->getArticleID( $flags ) ) {
3212                         $this->mRedirect = false;
3213                         return $this->mRedirect;
3214                 }
3215
3216                 $linkCache = LinkCache::singleton();
3217                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3218                 if ( $cached === null ) {
3219                         # Trust LinkCache's state over our own
3220                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3221                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3222                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3223                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3224                         # LinkCache to refresh its data from the master.
3225                         $this->mRedirect = false;
3226                         return $this->mRedirect;
3227                 }
3228
3229                 $this->mRedirect = (bool)$cached;
3230
3231                 return $this->mRedirect;
3232         }
3233
3234         /**
3235          * What is the length of this page?
3236          * Uses link cache, adding it if necessary
3237          *
3238          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3239          * @return int
3240          */
3241         public function getLength( $flags = 0 ) {
3242                 if ( $this->mLength != -1 ) {
3243                         return $this->mLength;
3244                 }
3245                 # Calling getArticleID() loads the field from cache as needed
3246                 if ( !$this->getArticleID( $flags ) ) {
3247                         $this->mLength = 0;
3248                         return $this->mLength;
3249                 }
3250                 $linkCache = LinkCache::singleton();
3251                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3252                 if ( $cached === null ) {
3253                         # Trust LinkCache's state over our own, as for isRedirect()
3254                         $this->mLength = 0;
3255                         return $this->mLength;
3256                 }
3257
3258                 $this->mLength = intval( $cached );
3259
3260                 return $this->mLength;
3261         }
3262
3263         /**
3264          * What is the page_latest field for this page?
3265          *
3266          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3267          * @return int Int or 0 if the page doesn't exist
3268          */
3269         public function getLatestRevID( $flags = 0 ) {
3270                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3271                         return intval( $this->mLatestID );
3272                 }
3273                 # Calling getArticleID() loads the field from cache as needed
3274                 if ( !$this->getArticleID( $flags ) ) {
3275                         $this->mLatestID = 0;
3276                         return $this->mLatestID;
3277                 }
3278                 $linkCache = LinkCache::singleton();
3279                 $linkCache->addLinkObj( $this );
3280                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3281                 if ( $cached === null ) {
3282                         # Trust LinkCache's state over our own, as for isRedirect()
3283                         $this->mLatestID = 0;
3284                         return $this->mLatestID;
3285                 }
3286
3287                 $this->mLatestID = intval( $cached );
3288
3289                 return $this->mLatestID;
3290         }
3291
3292         /**
3293          * This clears some fields in this object, and clears any associated
3294          * keys in the "bad links" section of the link cache.
3295          *
3296          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3297          * loading of the new page_id. It's also called from
3298          * WikiPage::doDeleteArticleReal()
3299          *
3300          * @param int $newid The new Article ID
3301          */
3302         public function resetArticleID( $newid ) {
3303                 $linkCache = LinkCache::singleton();
3304                 $linkCache->clearLink( $this );
3305
3306                 if ( $newid === false ) {
3307                         $this->mArticleID = -1;
3308                 } else {
3309                         $this->mArticleID = intval( $newid );
3310                 }
3311                 $this->mRestrictionsLoaded = false;
3312                 $this->mRestrictions = array();
3313                 $this->mRedirect = null;
3314                 $this->mLength = -1;
3315                 $this->mLatestID = false;
3316                 $this->mContentModel = false;
3317                 $this->mEstimateRevisions = null;
3318                 $this->mPageLanguage = false;
3319                 $this->mDbPageLanguage = null;
3320                 $this->mIsBigDeletion = null;
3321         }
3322
3323         /**
3324          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3325          *
3326          * @param string $text Containing title to capitalize
3327          * @param int $ns Namespace index, defaults to NS_MAIN
3328          * @return string Containing capitalized title
3329          */
3330         public static function capitalize( $text, $ns = NS_MAIN ) {
3331                 global $wgContLang;
3332
3333                 if ( MWNamespace::isCapitalized( $ns ) ) {
3334                         return $wgContLang->ucfirst( $text );
3335                 } else {
3336                         return $text;
3337                 }
3338         }
3339
3340         /**
3341          * Secure and split - main initialisation function for this object
3342          *
3343          * Assumes that mDbkeyform has been set, and is urldecoded
3344          * and uses underscores, but not otherwise munged.  This function
3345          * removes illegal characters, splits off the interwiki and
3346          * namespace prefixes, sets the other forms, and canonicalizes
3347          * everything.
3348          *
3349          * @return bool True on success
3350          */
3351         private function secureAndSplit() {
3352                 # Initialisation
3353                 $this->mInterwiki = '';
3354                 $this->mFragment = '';
3355                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3356
3357                 $dbkey = $this->mDbkeyform;
3358
3359                 try {
3360                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3361                         //        the parsing code with Title, while avoiding massive refactoring.
3362                         // @todo: get rid of secureAndSplit, refactor parsing code.
3363                         $titleParser = self::getTitleParser();
3364                         $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3365                 } catch ( MalformedTitleException $ex ) {
3366                         return false;
3367                 }
3368
3369                 # Fill fields
3370                 $this->setFragment( '#' . $parts['fragment'] );
3371                 $this->mInterwiki = $parts['interwiki'];
3372                 $this->mLocalInterwiki = $parts['local_interwiki'];
3373                 $this->mNamespace = $parts['namespace'];
3374                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3375
3376                 $this->mDbkeyform = $parts['dbkey'];
3377                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3378                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3379
3380                 # We already know that some pages won't be in the database!
3381                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3382                         $this->mArticleID = 0;
3383                 }
3384
3385                 return true;
3386         }
3387
3388         /**
3389          * Get an array of Title objects linking to this Title
3390          * Also stores the IDs in the link cache.
3391          *
3392          * WARNING: do not use this function on arbitrary user-supplied titles!
3393          * On heavily-used templates it will max out the memory.
3394          *
3395          * @param array $options May be FOR UPDATE
3396          * @param string $table Table name
3397          * @param string $prefix Fields prefix
3398          * @return Title[] Array of Title objects linking here
3399          */
3400         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3401                 if ( count( $options ) > 0 ) {
3402                         $db = wfGetDB( DB_MASTER );
3403                 } else {
3404                         $db = wfGetDB( DB_SLAVE );
3405                 }
3406
3407                 $res = $db->select(
3408                         array( 'page', $table ),
3409                         self::getSelectFields(),
3410                         array(
3411                                 "{$prefix}_from=page_id",
3412                                 "{$prefix}_namespace" => $this->getNamespace(),
3413                                 "{$prefix}_title" => $this->getDBkey() ),
3414                         __METHOD__,
3415                         $options
3416                 );
3417
3418                 $retVal = array();
3419                 if ( $res->numRows() ) {
3420                         $linkCache = LinkCache::singleton();
3421                         foreach ( $res as $row ) {
3422                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3423                                 if ( $titleObj ) {
3424                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3425                                         $retVal[] = $titleObj;
3426                                 }
3427                         }
3428                 }
3429                 return $retVal;
3430         }
3431
3432         /**
3433          * Get an array of Title objects using this Title as a template
3434          * Also stores the IDs in the link cache.
3435          *
3436          * WARNING: do not use this function on arbitrary user-supplied titles!
3437          * On heavily-used templates it will max out the memory.
3438          *
3439          * @param array $options May be FOR UPDATE
3440          * @return Title[] Array of Title the Title objects linking here
3441          */
3442         public function getTemplateLinksTo( $options = array() ) {
3443                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3444         }
3445
3446         /**
3447          * Get an array of Title objects linked from this Title
3448          * Also stores the IDs in the link cache.
3449          *
3450          * WARNING: do not use this function on arbitrary user-supplied titles!
3451          * On heavily-used templates it will max out the memory.
3452          *
3453          * @param array $options May be FOR UPDATE
3454          * @param string $table Table name
3455          * @param string $prefix Fields prefix
3456          * @return array Array of Title objects linking here
3457          */
3458         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3459                 global $wgContentHandlerUseDB;
3460
3461                 $id = $this->getArticleID();
3462
3463                 # If the page doesn't exist; there can't be any link from this page
3464                 if ( !$id ) {
3465                         return array();
3466                 }
3467
3468                 if ( count( $options ) > 0 ) {
3469                         $db = wfGetDB( DB_MASTER );
3470                 } else {
3471                         $db = wfGetDB( DB_SLAVE );
3472                 }
3473
3474                 $namespaceFiled = "{$prefix}_namespace";
3475                 $titleField = "{$prefix}_title";
3476
3477                 $fields = array(
3478                         $namespaceFiled,
3479                         $titleField,
3480                         'page_id',
3481                         'page_len',
3482                         'page_is_redirect',
3483                         'page_latest'
3484                 );
3485
3486                 if ( $wgContentHandlerUseDB ) {
3487                         $fields[] = 'page_content_model';
3488                 }
3489
3490                 $res = $db->select(
3491                         array( $table, 'page' ),
3492                         $fields,
3493                         array( "{$prefix}_from" => $id ),
3494                         __METHOD__,
3495                         $options,
3496                         array( 'page' => array(
3497                                 'LEFT JOIN',
3498                                 array( "page_namespace=$namespaceFiled", "page_title=$titleField" )
3499                         ) )
3500                 );
3501
3502                 $retVal = array();
3503                 if ( $res->numRows() ) {
3504                         $linkCache = LinkCache::singleton();
3505                         foreach ( $res as $row ) {
3506                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3507                                 if ( $titleObj ) {
3508                                         if ( $row->page_id ) {
3509                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3510                                         } else {
3511                                                 $linkCache->addBadLinkObj( $titleObj );
3512                                         }
3513                                         $retVal[] = $titleObj;
3514                                 }
3515                         }
3516                 }
3517                 return $retVal;
3518         }
3519
3520         /**
3521          * Get an array of Title objects used on this Title as a template
3522          * Also stores the IDs in the link cache.
3523          *
3524          * WARNING: do not use this function on arbitrary user-supplied titles!
3525          * On heavily-used templates it will max out the memory.
3526          *
3527          * @param array $options May be FOR UPDATE
3528          * @return Title[] Array of Title the Title objects used here
3529          */
3530         public function getTemplateLinksFrom( $options = array() ) {
3531                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3532         }
3533
3534         /**
3535          * Get an array of Title objects referring to non-existent articles linked
3536          * from this page.
3537          *
3538          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3539          *   should use redirect table in this case).
3540          * @return Title[] Array of Title the Title objects
3541          */
3542         public function getBrokenLinksFrom() {
3543                 if ( $this->getArticleID() == 0 ) {
3544                         # All links from article ID 0 are false positives
3545                         return array();
3546                 }
3547
3548                 $dbr = wfGetDB( DB_SLAVE );
3549                 $res = $dbr->select(
3550                         array( 'page', 'pagelinks' ),
3551                         array( 'pl_namespace', 'pl_title' ),
3552                         array(
3553                                 'pl_from' => $this->getArticleID(),
3554                                 'page_namespace IS NULL'
3555                         ),
3556                         __METHOD__, array(),
3557                         array(
3558                                 'page' => array(
3559                                         'LEFT JOIN',
3560                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3561                                 )
3562                         )
3563                 );
3564
3565                 $retVal = array();
3566                 foreach ( $res as $row ) {
3567                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3568                 }
3569                 return $retVal;
3570         }
3571
3572         /**
3573          * Get a list of URLs to purge from the Squid cache when this
3574          * page changes
3575          *
3576          * @return string[] Array of String the URLs
3577          */
3578         public function getSquidURLs() {
3579                 $urls = array(
3580                         $this->getInternalURL(),
3581                         $this->getInternalURL( 'action=history' )
3582                 );
3583
3584                 $pageLang = $this->getPageLanguage();
3585                 if ( $pageLang->hasVariants() ) {
3586                         $variants = $pageLang->getVariants();
3587                         foreach ( $variants as $vCode ) {
3588                                 $urls[] = $this->getInternalURL( '', $vCode );
3589                         }
3590                 }
3591
3592                 // If we are looking at a css/js user subpage, purge the action=raw.
3593                 if ( $this->isJsSubpage() ) {
3594                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3595                 } elseif ( $this->isCssSubpage() ) {
3596                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3597                 }
3598
3599                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3600                 return $urls;
3601         }
3602
3603         /**
3604          * Purge all applicable Squid URLs
3605          */
3606         public function purgeSquid() {
3607                 global $wgUseSquid;
3608                 if ( $wgUseSquid ) {
3609                         $urls = $this->getSquidURLs();
3610                         $u = new SquidUpdate( $urls );
3611                         $u->doUpdate();
3612                 }
3613         }
3614
3615         /**
3616          * Move this page without authentication
3617          *
3618          * @deprecated since 1.25 use MovePage class instead
3619          * @param Title $nt The new page Title
3620          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3621          */
3622         public function moveNoAuth( &$nt ) {
3623                 wfDeprecated( __METHOD__, '1.25' );
3624                 return $this->moveTo( $nt, false );
3625         }
3626
3627         /**
3628          * Check whether a given move operation would be valid.
3629          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3630          *
3631          * @deprecated since 1.25, use MovePage's methods instead
3632          * @param Title $nt The new title
3633          * @param bool $auth Ignored
3634          * @param string $reason Is the log summary of the move, used for spam checking
3635          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3636          */
3637         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3638                 global $wgUser;
3639
3640                 if ( !( $nt instanceof Title ) ) {
3641                         // Normally we'd add this to $errors, but we'll get
3642                         // lots of syntax errors if $nt is not an object
3643                         return array( array( 'badtitletext' ) );
3644                 }
3645
3646                 $mp = new MovePage( $this, $nt );
3647                 $errors = wfMergeErrorArrays(
3648                         $mp->isValidMove()->getErrorsArray(),
3649                         $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3650                 );
3651
3652                 return $errors ? : true;
3653         }
3654
3655         /**
3656          * Check if the requested move target is a valid file move target
3657          * @todo move this to MovePage
3658          * @param Title $nt Target title
3659          * @return array List of errors
3660          */
3661         protected function validateFileMoveOperation( $nt ) {
3662                 global $wgUser;
3663
3664                 $errors = array();
3665
3666                 $destFile = wfLocalFile( $nt );
3667                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3668                         $errors[] = array( 'file-exists-sharedrepo' );
3669                 }
3670
3671                 return $errors;
3672         }
3673
3674         /**
3675          * Move a title to a new location
3676          *
3677          * @deprecated since 1.25, use the MovePage class instead
3678          * @param Title $nt The new title
3679          * @param bool $auth Indicates whether $wgUser's permissions
3680          *  should be checked
3681          * @param string $reason The reason for the move
3682          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3683          *  Ignored if the user doesn't have the suppressredirect right.
3684          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3685          */
3686         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3687                 global $wgUser;
3688                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3689                 if ( is_array( $err ) ) {
3690                         // Auto-block user's IP if the account was "hard" blocked
3691                         $wgUser->spreadAnyEditBlock();
3692                         return $err;
3693                 }
3694                 // Check suppressredirect permission
3695                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3696                         $createRedirect = true;
3697                 }
3698
3699                 $mp = new MovePage( $this, $nt );
3700                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3701                 if ( $status->isOK() ) {
3702                         return true;
3703                 } else {
3704                         return $status->getErrorsArray();
3705                 }
3706         }
3707
3708         /**
3709          * Move this page's subpages to be subpages of $nt
3710          *
3711          * @param Title $nt Move target
3712          * @param bool $auth Whether $wgUser's permissions should be checked
3713          * @param string $reason The reason for the move
3714          * @param bool $createRedirect Whether to create redirects from the old subpages to
3715          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3716          * @return array Array with old page titles as keys, and strings (new page titles) or
3717          *     arrays (errors) as values, or an error array with numeric indices if no pages
3718          *     were moved
3719          */
3720         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3721                 global $wgMaximumMovedPages;
3722                 // Check permissions
3723                 if ( !$this->userCan( 'move-subpages' ) ) {
3724                         return array( 'cant-move-subpages' );
3725                 }
3726                 // Do the source and target namespaces support subpages?
3727                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3728                         return array( 'namespace-nosubpages',
3729                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3730                 }
3731                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3732                         return array( 'namespace-nosubpages',
3733                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3734                 }
3735
3736                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3737                 $retval = array();
3738                 $count = 0;
3739                 foreach ( $subpages as $oldSubpage ) {
3740                         $count++;
3741                         if ( $count > $wgMaximumMovedPages ) {
3742                                 $retval[$oldSubpage->getPrefixedText()] =
3743                                                 array( 'movepage-max-pages',
3744                                                         $wgMaximumMovedPages );
3745                                 break;
3746                         }
3747
3748                         // We don't know whether this function was called before
3749                         // or after moving the root page, so check both
3750                         // $this and $nt
3751                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3752                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3753                         ) {
3754                                 // When moving a page to a subpage of itself,
3755                                 // don't move it twice
3756                                 continue;
3757                         }
3758                         $newPageName = preg_replace(
3759                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3760                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3761                                         $oldSubpage->getDBkey() );
3762                         if ( $oldSubpage->isTalkPage() ) {
3763                                 $newNs = $nt->getTalkPage()->getNamespace();
3764                         } else {
3765                                 $newNs = $nt->getSubjectPage()->getNamespace();
3766                         }
3767                         # Bug 14385: we need makeTitleSafe because the new page names may
3768                         # be longer than 255 characters.
3769                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3770
3771                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3772                         if ( $success === true ) {
3773                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3774                         } else {
3775                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3776                         }
3777                 }
3778                 return $retval;
3779         }
3780
3781         /**
3782          * Checks if this page is just a one-rev redirect.
3783          * Adds lock, so don't use just for light purposes.
3784          *
3785          * @return bool
3786          */
3787         public function isSingleRevRedirect() {
3788                 global $wgContentHandlerUseDB;
3789
3790                 $dbw = wfGetDB( DB_MASTER );
3791
3792                 # Is it a redirect?
3793                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3794                 if ( $wgContentHandlerUseDB ) {
3795                         $fields[] = 'page_content_model';
3796                 }
3797
3798                 $row = $dbw->selectRow( 'page',
3799                         $fields,
3800                         $this->pageCond(),
3801                         __METHOD__,
3802                         array( 'FOR UPDATE' )
3803                 );
3804                 # Cache some fields we may want
3805                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3806                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3807                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3808                 $this->mContentModel = $row && isset( $row->page_content_model )
3809                         ? strval( $row->page_content_model )
3810                         : false;
3811
3812                 if ( !$this->mRedirect ) {
3813                         return false;
3814                 }
3815                 # Does the article have a history?
3816                 $row = $dbw->selectField( array( 'page', 'revision' ),
3817                         'rev_id',
3818                         array( 'page_namespace' => $this->getNamespace(),
3819                                 'page_title' => $this->getDBkey(),
3820                                 'page_id=rev_page',
3821                                 'page_latest != rev_id'
3822                         ),
3823                         __METHOD__,
3824                         array( 'FOR UPDATE' )
3825                 );
3826                 # Return true if there was no history
3827                 return ( $row === false );
3828         }
3829
3830         /**
3831          * Checks if $this can be moved to a given Title
3832          * - Selects for update, so don't call it unless you mean business
3833          *
3834          * @deprecated since 1.25, use MovePage's methods instead
3835          * @param Title $nt The new title to check
3836          * @return bool
3837          */
3838         public function isValidMoveTarget( $nt ) {
3839                 # Is it an existing file?
3840                 if ( $nt->getNamespace() == NS_FILE ) {
3841                         $file = wfLocalFile( $nt );
3842                         if ( $file->exists() ) {
3843                                 wfDebug( __METHOD__ . ": file exists\n" );
3844                                 return false;
3845                         }
3846                 }
3847                 # Is it a redirect with no history?
3848                 if ( !$nt->isSingleRevRedirect() ) {
3849                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3850                         return false;
3851                 }
3852                 # Get the article text
3853                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3854                 if ( !is_object( $rev ) ) {
3855                         return false;
3856                 }
3857                 $content = $rev->getContent();
3858                 # Does the redirect point to the source?
3859                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3860                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3861
3862                 if ( $redirTitle ) {
3863                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3864                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3865                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3866                                 return false;
3867                         } else {
3868                                 return true;
3869                         }
3870                 } else {
3871                         # Fail safe (not a redirect after all. strange.)
3872                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3873                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3874                         return false;
3875                 }
3876         }
3877
3878         /**
3879          * Get categories to which this Title belongs and return an array of
3880          * categories' names.
3881          *
3882          * @return array Array of parents in the form:
3883          *        $parent => $currentarticle
3884          */
3885         public function getParentCategories() {
3886                 global $wgContLang;
3887
3888                 $data = array();
3889
3890                 $titleKey = $this->getArticleID();
3891
3892                 if ( $titleKey === 0 ) {
3893                         return $data;
3894                 }
3895
3896                 $dbr = wfGetDB( DB_SLAVE );
3897
3898                 $res = $dbr->select(
3899                         'categorylinks',
3900                         'cl_to',
3901                         array( 'cl_from' => $titleKey ),
3902                         __METHOD__
3903                 );
3904
3905                 if ( $res->numRows() > 0 ) {
3906                         foreach ( $res as $row ) {
3907                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3908                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3909                         }
3910                 }
3911                 return $data;
3912         }
3913
3914         /**
3915          * Get a tree of parent categories
3916          *
3917          * @param array $children Array with the children in the keys, to check for circular refs
3918          * @return array Tree of parent categories
3919          */
3920         public function getParentCategoryTree( $children = array() ) {
3921                 $stack = array();
3922                 $parents = $this->getParentCategories();
3923
3924                 if ( $parents ) {
3925                         foreach ( $parents as $parent => $current ) {
3926                                 if ( array_key_exists( $parent, $children ) ) {
3927                                         # Circular reference
3928                                         $stack[$parent] = array();
3929                                 } else {
3930                                         $nt = Title::newFromText( $parent );
3931                                         if ( $nt ) {
3932                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3933                                         }
3934                                 }
3935                         }
3936                 }
3937
3938                 return $stack;
3939         }
3940
3941         /**
3942          * Get an associative array for selecting this title from
3943          * the "page" table
3944          *
3945          * @return array Array suitable for the $where parameter of DB::select()
3946          */
3947         public function pageCond() {
3948                 if ( $this->mArticleID > 0 ) {
3949                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3950                         return array( 'page_id' => $this->mArticleID );
3951                 } else {
3952                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3953                 }
3954         }
3955
3956         /**
3957          * Get the revision ID of the previous revision
3958          *
3959          * @param int $revId Revision ID. Get the revision that was before this one.
3960          * @param int $flags Title::GAID_FOR_UPDATE
3961          * @return int|bool Old revision ID, or false if none exists
3962          */
3963         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3964                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3965                 $revId = $db->selectField( 'revision', 'rev_id',
3966                         array(
3967                                 'rev_page' => $this->getArticleID( $flags ),
3968                                 'rev_id < ' . intval( $revId )
3969                         ),
3970                         __METHOD__,
3971                         array( 'ORDER BY' => 'rev_id DESC' )
3972                 );
3973
3974                 if ( $revId === false ) {
3975                         return false;
3976                 } else {
3977                         return intval( $revId );
3978                 }
3979         }
3980
3981         /**
3982          * Get the revision ID of the next revision
3983          *
3984          * @param int $revId Revision ID. Get the revision that was after this one.
3985          * @param int $flags Title::GAID_FOR_UPDATE
3986          * @return int|bool Next revision ID, or false if none exists
3987          */
3988         public function getNextRevisionID( $revId, $flags = 0 ) {
3989                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3990                 $revId = $db->selectField( 'revision', 'rev_id',
3991                         array(
3992                                 'rev_page' => $this->getArticleID( $flags ),
3993                                 'rev_id > ' . intval( $revId )
3994                         ),
3995                         __METHOD__,
3996                         array( 'ORDER BY' => 'rev_id' )
3997                 );
3998
3999                 if ( $revId === false ) {
4000                         return false;
4001                 } else {
4002                         return intval( $revId );
4003                 }
4004         }
4005
4006         /**
4007          * Get the first revision of the page
4008          *
4009          * @param int $flags Title::GAID_FOR_UPDATE
4010          * @return Revision|null If page doesn't exist
4011          */
4012         public function getFirstRevision( $flags = 0 ) {
4013                 $pageId = $this->getArticleID( $flags );
4014                 if ( $pageId ) {
4015                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4016                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4017                                 array( 'rev_page' => $pageId ),
4018                                 __METHOD__,
4019                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4020                         );
4021                         if ( $row ) {
4022                                 return new Revision( $row );
4023                         }
4024                 }
4025                 return null;
4026         }
4027
4028         /**
4029          * Get the oldest revision timestamp of this page
4030          *
4031          * @param int $flags Title::GAID_FOR_UPDATE
4032          * @return string MW timestamp
4033          */
4034         public function getEarliestRevTime( $flags = 0 ) {
4035                 $rev = $this->getFirstRevision( $flags );
4036                 return $rev ? $rev->getTimestamp() : null;
4037         }
4038
4039         /**
4040          * Check if this is a new page
4041          *
4042          * @return bool
4043          */
4044         public function isNewPage() {
4045                 $dbr = wfGetDB( DB_SLAVE );
4046                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4047         }
4048
4049         /**
4050          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4051          *
4052          * @return bool
4053          */
4054         public function isBigDeletion() {
4055                 global $wgDeleteRevisionsLimit;
4056
4057                 if ( !$wgDeleteRevisionsLimit ) {
4058                         return false;
4059                 }
4060
4061                 if ( $this->mIsBigDeletion === null ) {
4062                         $dbr = wfGetDB( DB_SLAVE );
4063
4064                         $innerQuery = $dbr->selectSQLText(
4065                                 'revision',
4066                                 '1',
4067                                 array( 'rev_page' => $this->getArticleID() ),
4068                                 __METHOD__,
4069                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4070                         );
4071
4072                         $revCount = $dbr->query(
4073                                 'SELECT COUNT(*) FROM (' . $innerQuery . ') AS innerQuery',
4074                                 __METHOD__
4075                         );
4076                         $revCount = $revCount->fetchRow();
4077                         $revCount = $revCount['COUNT(*)'];
4078
4079                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4080                 }
4081
4082                 return $this->mIsBigDeletion;
4083         }
4084
4085         /**
4086          * Get the approximate revision count of this page.
4087          *
4088          * @return int
4089          */
4090         public function estimateRevisionCount() {
4091                 if ( !$this->exists() ) {
4092                         return 0;
4093                 }
4094
4095                 if ( $this->mEstimateRevisions === null ) {
4096                         $dbr = wfGetDB( DB_SLAVE );
4097                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4098                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4099                 }
4100
4101                 return $this->mEstimateRevisions;
4102         }
4103
4104         /**
4105          * Get the number of revisions between the given revision.
4106          * Used for diffs and other things that really need it.
4107          *
4108          * @param int|Revision $old Old revision or rev ID (first before range)
4109          * @param int|Revision $new New revision or rev ID (first after range)
4110          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4111          * @return int Number of revisions between these revisions.
4112          */
4113         public function countRevisionsBetween( $old, $new, $max = null ) {
4114                 if ( !( $old instanceof Revision ) ) {
4115                         $old = Revision::newFromTitle( $this, (int)$old );
4116                 }
4117                 if ( !( $new instanceof Revision ) ) {
4118                         $new = Revision::newFromTitle( $this, (int)$new );
4119                 }
4120                 if ( !$old || !$new ) {
4121                         return 0; // nothing to compare
4122                 }
4123                 $dbr = wfGetDB( DB_SLAVE );
4124                 $conds = array(
4125                         'rev_page' => $this->getArticleID(),
4126                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4127                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4128                 );
4129                 if ( $max !== null ) {
4130                         $res = $dbr->select( 'revision', '1',
4131                                 $conds,
4132                                 __METHOD__,
4133                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4134                         );
4135                         return $res->numRows();
4136                 } else {
4137                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4138                 }
4139         }
4140
4141         /**
4142          * Get the authors between the given revisions or revision IDs.
4143          * Used for diffs and other things that really need it.
4144          *
4145          * @since 1.23
4146          *
4147          * @param int|Revision $old Old revision or rev ID (first before range by default)
4148          * @param int|Revision $new New revision or rev ID (first after range by default)
4149          * @param int $limit Maximum number of authors
4150          * @param string|array $options (Optional): Single option, or an array of options:
4151          *     'include_old' Include $old in the range; $new is excluded.
4152          *     'include_new' Include $new in the range; $old is excluded.
4153          *     'include_both' Include both $old and $new in the range.
4154          *     Unknown option values are ignored.
4155          * @return array|null Names of revision authors in the range; null if not both revisions exist
4156          */
4157         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4158                 if ( !( $old instanceof Revision ) ) {
4159                         $old = Revision::newFromTitle( $this, (int)$old );
4160                 }
4161                 if ( !( $new instanceof Revision ) ) {
4162                         $new = Revision::newFromTitle( $this, (int)$new );
4163                 }
4164                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4165                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4166                 // in the sanity check below?
4167                 if ( !$old || !$new ) {
4168                         return null; // nothing to compare
4169                 }
4170                 $authors = array();
4171                 $old_cmp = '>';
4172                 $new_cmp = '<';
4173                 $options = (array)$options;
4174                 if ( in_array( 'include_old', $options ) ) {
4175                         $old_cmp = '>=';
4176                 }
4177                 if ( in_array( 'include_new', $options ) ) {
4178                         $new_cmp = '<=';
4179                 }
4180                 if ( in_array( 'include_both', $options ) ) {
4181                         $old_cmp = '>=';
4182                         $new_cmp = '<=';
4183                 }
4184                 // No DB query needed if $old and $new are the same or successive revisions:
4185                 if ( $old->getId() === $new->getId() ) {
4186                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4187                 } elseif ( $old->getId() === $new->getParentId() ) {
4188                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4189                                 $authors[] = $old->getRawUserText();
4190                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4191                                         $authors[] = $new->getRawUserText();
4192                                 }
4193                         } elseif ( $old_cmp === '>=' ) {
4194                                 $authors[] = $old->getRawUserText();
4195                         } elseif ( $new_cmp === '<=' ) {
4196                                 $authors[] = $new->getRawUserText();
4197                         }
4198                         return $authors;
4199                 }
4200                 $dbr = wfGetDB( DB_SLAVE );
4201                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4202                         array(
4203                                 'rev_page' => $this->getArticleID(),
4204                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4205                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4206                         ), __METHOD__,
4207                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4208                 );
4209                 foreach ( $res as $row ) {
4210                         $authors[] = $row->rev_user_text;
4211                 }
4212                 return $authors;
4213         }
4214
4215         /**
4216          * Get the number of authors between the given revisions or revision IDs.
4217          * Used for diffs and other things that really need it.
4218          *
4219          * @param int|Revision $old Old revision or rev ID (first before range by default)
4220          * @param int|Revision $new New revision or rev ID (first after range by default)
4221          * @param int $limit Maximum number of authors
4222          * @param string|array $options (Optional): Single option, or an array of options:
4223          *     'include_old' Include $old in the range; $new is excluded.
4224          *     'include_new' Include $new in the range; $old is excluded.
4225          *     'include_both' Include both $old and $new in the range.
4226          *     Unknown option values are ignored.
4227          * @return int Number of revision authors in the range; zero if not both revisions exist
4228          */
4229         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4230                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4231                 return $authors ? count( $authors ) : 0;
4232         }
4233
4234         /**
4235          * Compare with another title.
4236          *
4237          * @param Title $title
4238          * @return bool
4239          */
4240         public function equals( Title $title ) {
4241                 // Note: === is necessary for proper matching of number-like titles.
4242                 return $this->getInterwiki() === $title->getInterwiki()
4243                         && $this->getNamespace() == $title->getNamespace()
4244                         && $this->getDBkey() === $title->getDBkey();
4245         }
4246
4247         /**
4248          * Check if this title is a subpage of another title
4249          *
4250          * @param Title $title
4251          * @return bool
4252          */
4253         public function isSubpageOf( Title $title ) {
4254                 return $this->getInterwiki() === $title->getInterwiki()
4255                         && $this->getNamespace() == $title->getNamespace()
4256                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4257         }
4258
4259         /**
4260          * Check if page exists.  For historical reasons, this function simply
4261          * checks for the existence of the title in the page table, and will
4262          * thus return false for interwiki links, special pages and the like.
4263          * If you want to know if a title can be meaningfully viewed, you should
4264          * probably call the isKnown() method instead.
4265          *
4266          * @return bool
4267          */
4268         public function exists() {
4269                 $exists = $this->getArticleID() != 0;
4270                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4271                 return $exists;
4272         }
4273
4274         /**
4275          * Should links to this title be shown as potentially viewable (i.e. as
4276          * "bluelinks"), even if there's no record by this title in the page
4277          * table?
4278          *
4279          * This function is semi-deprecated for public use, as well as somewhat
4280          * misleadingly named.  You probably just want to call isKnown(), which
4281          * calls this function internally.
4282          *
4283          * (ISSUE: Most of these checks are cheap, but the file existence check
4284          * can potentially be quite expensive.  Including it here fixes a lot of
4285          * existing code, but we might want to add an optional parameter to skip
4286          * it and any other expensive checks.)
4287          *
4288          * @return bool
4289          */
4290         public function isAlwaysKnown() {
4291                 $isKnown = null;
4292
4293                 /**
4294                  * Allows overriding default behavior for determining if a page exists.
4295                  * If $isKnown is kept as null, regular checks happen. If it's
4296                  * a boolean, this value is returned by the isKnown method.
4297                  *
4298                  * @since 1.20
4299                  *
4300                  * @param Title $title
4301                  * @param bool|null $isKnown
4302                  */
4303                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4304
4305                 if ( !is_null( $isKnown ) ) {
4306                         return $isKnown;
4307                 }
4308
4309                 if ( $this->isExternal() ) {
4310                         return true;  // any interwiki link might be viewable, for all we know
4311                 }
4312
4313                 switch ( $this->mNamespace ) {
4314                         case NS_MEDIA:
4315                         case NS_FILE:
4316                                 // file exists, possibly in a foreign repo
4317                                 return (bool)wfFindFile( $this );
4318                         case NS_SPECIAL:
4319                                 // valid special page
4320                                 return SpecialPageFactory::exists( $this->getDBkey() );
4321                         case NS_MAIN:
4322                                 // selflink, possibly with fragment
4323                                 return $this->mDbkeyform == '';
4324                         case NS_MEDIAWIKI:
4325                                 // known system message
4326                                 return $this->hasSourceText() !== false;
4327                         default:
4328                                 return false;
4329                 }
4330         }
4331
4332         /**
4333          * Does this title refer to a page that can (or might) be meaningfully
4334          * viewed?  In particular, this function may be used to determine if
4335          * links to the title should be rendered as "bluelinks" (as opposed to
4336          * "redlinks" to non-existent pages).
4337          * Adding something else to this function will cause inconsistency
4338          * since LinkHolderArray calls isAlwaysKnown() and does its own
4339          * page existence check.
4340          *
4341          * @return bool
4342          */
4343         public function isKnown() {
4344                 return $this->isAlwaysKnown() || $this->exists();
4345         }
4346
4347         /**
4348          * Does this page have source text?
4349          *
4350          * @return bool
4351          */
4352         public function hasSourceText() {
4353                 if ( $this->exists() ) {
4354                         return true;
4355                 }
4356
4357                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4358                         // If the page doesn't exist but is a known system message, default
4359                         // message content will be displayed, same for language subpages-
4360                         // Use always content language to avoid loading hundreds of languages
4361                         // to get the link color.
4362                         global $wgContLang;
4363                         list( $name, ) = MessageCache::singleton()->figureMessage(
4364                                 $wgContLang->lcfirst( $this->getText() )
4365                         );
4366                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4367                         return $message->exists();
4368                 }
4369
4370                 return false;
4371         }
4372
4373         /**
4374          * Get the default message text or false if the message doesn't exist
4375          *
4376          * @return string|bool
4377          */
4378         public function getDefaultMessageText() {
4379                 global $wgContLang;
4380
4381                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4382                         return false;
4383                 }
4384
4385                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4386                         $wgContLang->lcfirst( $this->getText() )
4387                 );
4388                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4389
4390                 if ( $message->exists() ) {
4391                         return $message->plain();
4392                 } else {
4393                         return false;
4394                 }
4395         }
4396
4397         /**
4398          * Updates page_touched for this page; called from LinksUpdate.php
4399          *
4400          * @return bool True if the update succeeded
4401          */
4402         public function invalidateCache() {
4403                 if ( wfReadOnly() ) {
4404                         return false;
4405                 }
4406
4407                 if ( $this->mArticleID === 0 ) {
4408                         return true; // avoid gap locking if we know it's not there
4409                 }
4410
4411                 $method = __METHOD__;
4412                 $dbw = wfGetDB( DB_MASTER );
4413                 $conds = $this->pageCond();
4414                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method ) {
4415                         $dbw->update(
4416                                 'page',
4417                                 array( 'page_touched' => $dbw->timestamp() ),
4418                                 $conds,
4419                                 $method
4420                         );
4421                 } );
4422
4423                 return true;
4424         }
4425
4426         /**
4427          * Update page_touched timestamps and send squid purge messages for
4428          * pages linking to this title. May be sent to the job queue depending
4429          * on the number of links. Typically called on create and delete.
4430          */
4431         public function touchLinks() {
4432                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4433                 $u->doUpdate();
4434
4435                 if ( $this->getNamespace() == NS_CATEGORY ) {
4436                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4437                         $u->doUpdate();
4438                 }
4439         }
4440
4441         /**
4442          * Get the last touched timestamp
4443          *
4444          * @param DatabaseBase $db Optional db
4445          * @return string Last-touched timestamp
4446          */
4447         public function getTouched( $db = null ) {
4448                 if ( $db === null ) {
4449                         $db = wfGetDB( DB_SLAVE );
4450                 }
4451                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4452                 return $touched;
4453         }
4454
4455         /**
4456          * Get the timestamp when this page was updated since the user last saw it.
4457          *
4458          * @param User $user
4459          * @return string|null
4460          */
4461         public function getNotificationTimestamp( $user = null ) {
4462                 global $wgUser, $wgShowUpdatedMarker;
4463                 // Assume current user if none given
4464                 if ( !$user ) {
4465                         $user = $wgUser;
4466                 }
4467                 // Check cache first
4468                 $uid = $user->getId();
4469                 // avoid isset here, as it'll return false for null entries
4470                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4471                         return $this->mNotificationTimestamp[$uid];
4472                 }
4473                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4474                         $this->mNotificationTimestamp[$uid] = false;
4475                         return $this->mNotificationTimestamp[$uid];
4476                 }
4477                 // Don't cache too much!
4478                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4479                         $this->mNotificationTimestamp = array();
4480                 }
4481                 $dbr = wfGetDB( DB_SLAVE );
4482                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4483                         'wl_notificationtimestamp',
4484                         array(
4485                                 'wl_user' => $user->getId(),
4486                                 'wl_namespace' => $this->getNamespace(),
4487                                 'wl_title' => $this->getDBkey(),
4488                         ),
4489                         __METHOD__
4490                 );
4491                 return $this->mNotificationTimestamp[$uid];
4492         }
4493
4494         /**
4495          * Generate strings used for xml 'id' names in monobook tabs
4496          *
4497          * @param string $prepend Defaults to 'nstab-'
4498          * @return string XML 'id' name
4499          */
4500         public function getNamespaceKey( $prepend = 'nstab-' ) {
4501                 global $wgContLang;
4502                 // Gets the subject namespace if this title
4503                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4504                 // Checks if canonical namespace name exists for namespace
4505                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4506                         // Uses canonical namespace name
4507                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4508                 } else {
4509                         // Uses text of namespace
4510                         $namespaceKey = $this->getSubjectNsText();
4511                 }
4512                 // Makes namespace key lowercase
4513                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4514                 // Uses main
4515                 if ( $namespaceKey == '' ) {
4516                         $namespaceKey = 'main';
4517                 }
4518                 // Changes file to image for backwards compatibility
4519                 if ( $namespaceKey == 'file' ) {
4520                         $namespaceKey = 'image';
4521                 }
4522                 return $prepend . $namespaceKey;
4523         }
4524
4525         /**
4526          * Get all extant redirects to this Title
4527          *
4528          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4529          * @return Title[] Array of Title redirects to this title
4530          */
4531         public function getRedirectsHere( $ns = null ) {
4532                 $redirs = array();
4533
4534                 $dbr = wfGetDB( DB_SLAVE );
4535                 $where = array(
4536                         'rd_namespace' => $this->getNamespace(),
4537                         'rd_title' => $this->getDBkey(),
4538                         'rd_from = page_id'
4539                 );
4540                 if ( $this->isExternal() ) {
4541                         $where['rd_interwiki'] = $this->getInterwiki();
4542                 } else {
4543                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4544                 }
4545                 if ( !is_null( $ns ) ) {
4546                         $where['page_namespace'] = $ns;
4547                 }
4548
4549                 $res = $dbr->select(
4550                         array( 'redirect', 'page' ),
4551                         array( 'page_namespace', 'page_title' ),
4552                         $where,
4553                         __METHOD__
4554                 );
4555
4556                 foreach ( $res as $row ) {
4557                         $redirs[] = self::newFromRow( $row );
4558                 }
4559                 return $redirs;
4560         }
4561
4562         /**
4563          * Check if this Title is a valid redirect target
4564          *
4565          * @return bool
4566          */
4567         public function isValidRedirectTarget() {
4568                 global $wgInvalidRedirectTargets;
4569
4570                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4571                 if ( $this->isSpecial( 'Userlogout' ) ) {
4572                         return false;
4573                 }
4574
4575                 foreach ( $wgInvalidRedirectTargets as $target ) {
4576                         if ( $this->isSpecial( $target ) ) {
4577                                 return false;
4578                         }
4579                 }
4580
4581                 return true;
4582         }
4583
4584         /**
4585          * Get a backlink cache object
4586          *
4587          * @return BacklinkCache
4588          */
4589         public function getBacklinkCache() {
4590                 return BacklinkCache::get( $this );
4591         }
4592
4593         /**
4594          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4595          *
4596          * @return bool
4597          */
4598         public function canUseNoindex() {
4599                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4600
4601                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4602                         ? $wgContentNamespaces
4603                         : $wgExemptFromUserRobotsControl;
4604
4605                 return !in_array( $this->mNamespace, $bannedNamespaces );
4606
4607         }
4608
4609         /**
4610          * Returns the raw sort key to be used for categories, with the specified
4611          * prefix.  This will be fed to Collation::getSortKey() to get a
4612          * binary sortkey that can be used for actual sorting.
4613          *
4614          * @param string $prefix The prefix to be used, specified using
4615          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4616          *   prefix.
4617          * @return string
4618          */
4619         public function getCategorySortkey( $prefix = '' ) {
4620                 $unprefixed = $this->getText();
4621
4622                 // Anything that uses this hook should only depend
4623                 // on the Title object passed in, and should probably
4624                 // tell the users to run updateCollations.php --force
4625                 // in order to re-sort existing category relations.
4626                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4627                 if ( $prefix !== '' ) {
4628                         # Separate with a line feed, so the unprefixed part is only used as
4629                         # a tiebreaker when two pages have the exact same prefix.
4630                         # In UCA, tab is the only character that can sort above LF
4631                         # so we strip both of them from the original prefix.
4632                         $prefix = strtr( $prefix, "\n\t", '  ' );
4633                         return "$prefix\n$unprefixed";
4634                 }
4635                 return $unprefixed;
4636         }
4637
4638         /**
4639          * Get the language in which the content of this page is written in
4640          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4641          * e.g. $wgLang (such as special pages, which are in the user language).
4642          *
4643          * @since 1.18
4644          * @return Language
4645          */
4646         public function getPageLanguage() {
4647                 global $wgLang, $wgLanguageCode;
4648                 wfProfileIn( __METHOD__ );
4649                 if ( $this->isSpecialPage() ) {
4650                         // special pages are in the user language
4651                         wfProfileOut( __METHOD__ );
4652                         return $wgLang;
4653                 }
4654
4655                 // Checking if DB language is set
4656                 if ( $this->mDbPageLanguage ) {
4657                         wfProfileOut( __METHOD__ );
4658                         return wfGetLangObj( $this->mDbPageLanguage );
4659                 }
4660
4661                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4662                         // Note that this may depend on user settings, so the cache should
4663                         // be only per-request.
4664                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4665                         // content to determine the page language!
4666                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4667                         // tests.
4668                         $contentHandler = ContentHandler::getForTitle( $this );
4669                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4670                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4671                 } else {
4672                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4673                 }
4674
4675                 wfProfileOut( __METHOD__ );
4676                 return $langObj;
4677         }
4678
4679         /**
4680          * Get the language in which the content of this page is written when
4681          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4682          * e.g. $wgLang (such as special pages, which are in the user language).
4683          *
4684          * @since 1.20
4685          * @return Language
4686          */
4687         public function getPageViewLanguage() {
4688                 global $wgLang;
4689
4690                 if ( $this->isSpecialPage() ) {
4691                         // If the user chooses a variant, the content is actually
4692                         // in a language whose code is the variant code.
4693                         $variant = $wgLang->getPreferredVariant();
4694                         if ( $wgLang->getCode() !== $variant ) {
4695                                 return Language::factory( $variant );
4696                         }
4697
4698                         return $wgLang;
4699                 }
4700
4701                 // @note Can't be cached persistently, depends on user settings.
4702                 // @note ContentHandler::getPageViewLanguage() may need to load the
4703                 //   content to determine the page language!
4704                 $contentHandler = ContentHandler::getForTitle( $this );
4705                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4706                 return $pageLang;
4707         }
4708
4709         /**
4710          * Get a list of rendered edit notices for this page.
4711          *
4712          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4713          * they will already be wrapped in paragraphs.
4714          *
4715          * @since 1.21
4716          * @param int $oldid Revision ID that's being edited
4717          * @return array
4718          */
4719         public function getEditNotices( $oldid = 0 ) {
4720                 $notices = array();
4721
4722                 # Optional notices on a per-namespace and per-page basis
4723                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4724                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4725                 if ( $editnotice_ns_message->exists() ) {
4726                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4727                 }
4728                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4729                         $parts = explode( '/', $this->getDBkey() );
4730                         $editnotice_base = $editnotice_ns;
4731                         while ( count( $parts ) > 0 ) {
4732                                 $editnotice_base .= '-' . array_shift( $parts );
4733                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4734                                 if ( $editnotice_base_msg->exists() ) {
4735                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4736                                 }
4737                         }
4738                 } else {
4739                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4740                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4741                         $editnoticeMsg = wfMessage( $editnoticeText );
4742                         if ( $editnoticeMsg->exists() ) {
4743                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4744                         }
4745                 }
4746
4747                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4748                 return $notices;
4749         }
4750 }