includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50
  51         /**
  52          * @name Private member variables
  53          * Please use the accessor functions instead.
  54          * @private
  55          */
  56         // @{
  57
  58         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  59         var $mUrlform = '';               // /< URL-encoded form of the main part
  60         var $mDbkeyform = '';             // /< Main part with underscores
  61         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  62         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  63         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  64         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  65         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  66         var $mLatestID = false;           // /< ID of most recent revision
  67         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  68         var $mOldRestrictions = false;
  69         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  70         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  71         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  72         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  73         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  74         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  75         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  76         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  77         # Don't change the following default, NS_MAIN is hardcoded in several
  78         # places.  See bug 696.
  79         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  80                                                                           # Zero except in {{transclusion}} tags
  81         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  82         var $mLength = -1;                // /< The page length, 0 for special pages
  83         var $mRedirect = null;            // /< Is the article at this title a redirect?
  84         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  85         var $mBacklinkCache = null;       // /< Cache of links to this title
  86         // @}
  87
  88
  89         /**
  90          * Constructor
  91          */
  92         /*protected*/ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255                 $t->loadFromRow( $row );
 256                 return $t;
 257         }
 258
 259         /**
 260          * Load Title object fields from a DB row.
 261          * If false is given, the title will be treated as non-existing.
 262          *
 263          * @param $row Object|false database row
 264          * @return void
 265          */
 266         public function loadFromRow( $row ) {
 267                 if ( $row ) { // page found
 268                         if ( isset( $row->page_id ) )
 269                                 $this->mArticleID = (int)$row->page_id;
 270                         if ( isset( $row->page_len ) )
 271                                 $this->mLength = (int)$row->page_len;
 272                         if ( isset( $row->page_is_redirect ) )
 273                                 $this->mRedirect = (bool)$row->page_is_redirect;
 274                         if ( isset( $row->page_latest ) )
 275                                 $this->mLatestID = (int)$row->page_latest;
 276                 } else { // page not found
 277                         $this->mArticleID = 0;
 278                         $this->mLength = 0;
 279                         $this->mRedirect = false;
 280                         $this->mLatestID = 0;
 281                 }
 282         }
 283
 284         /**
 285          * Create a new Title from a namespace index and a DB key.
 286          * It's assumed that $ns and $title are *valid*, for instance when
 287          * they came directly from the database or a special page name.
 288          * For convenience, spaces are converted to underscores so that
 289          * eg user_text fields can be used directly.
 290          *
 291          * @param $ns Int the namespace of the article
 292          * @param $title String the unprefixed database key form
 293          * @param $fragment String the link fragment (after the "#")
 294          * @param $interwiki String the interwiki prefix
 295          * @return Title the new object
 296          */
 297         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 298                 $t = new Title();
 299                 $t->mInterwiki = $interwiki;
 300                 $t->mFragment = $fragment;
 301                 $t->mNamespace = $ns = intval( $ns );
 302                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 303                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 304                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 305                 $t->mTextform = str_replace( '_', ' ', $title );
 306                 return $t;
 307         }
 308
 309         /**
 310          * Create a new Title from a namespace index and a DB key.
 311          * The parameters will be checked for validity, which is a bit slower
 312          * than makeTitle() but safer for user-provided data.
 313          *
 314          * @param $ns Int the namespace of the article
 315          * @param $title String database key form
 316          * @param $fragment String the link fragment (after the "#")
 317          * @param $interwiki String interwiki prefix
 318          * @return Title the new object, or NULL on an error
 319          */
 320         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 321                 $t = new Title();
 322                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 323                 if ( $t->secureAndSplit() ) {
 324                         return $t;
 325                 } else {
 326                         return null;
 327                 }
 328         }
 329
 330         /**
 331          * Create a new Title for the Main Page
 332          *
 333          * @return Title the new object
 334          */
 335         public static function newMainPage() {
 336                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 337                 // Don't give fatal errors if the message is broken
 338                 if ( !$title ) {
 339                         $title = Title::newFromText( 'Main Page' );
 340                 }
 341                 return $title;
 342         }
 343
 344         /**
 345          * Extract a redirect destination from a string and return the
 346          * Title, or null if the text doesn't contain a valid redirect
 347          * This will only return the very next target, useful for
 348          * the redirect table and other checks that don't need full recursion
 349          *
 350          * @param $text String: Text with possible redirect
 351          * @return Title: The corresponding Title
 352          */
 353         public static function newFromRedirect( $text ) {
 354                 return self::newFromRedirectInternal( $text );
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 361          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 362          *
 363          * @param $text String Text with possible redirect
 364          * @return Title
 365          */
 366         public static function newFromRedirectRecurse( $text ) {
 367                 $titles = self::newFromRedirectArray( $text );
 368                 return $titles ? array_pop( $titles ) : null;
 369         }
 370
 371         /**
 372          * Extract a redirect destination from a string and return an
 373          * array of Titles, or null if the text doesn't contain a valid redirect
 374          * The last element in the array is the final destination after all redirects
 375          * have been resolved (up to $wgMaxRedirects times)
 376          *
 377          * @param $text String Text with possible redirect
 378          * @return Array of Titles, with the destination last
 379          */
 380         public static function newFromRedirectArray( $text ) {
 381                 global $wgMaxRedirects;
 382                 $title = self::newFromRedirectInternal( $text );
 383                 if ( is_null( $title ) ) {
 384                         return null;
 385                 }
 386                 // recursive check to follow double redirects
 387                 $recurse = $wgMaxRedirects;
 388                 $titles = array( $title );
 389                 while ( --$recurse > 0 ) {
 390                         if ( $title->isRedirect() ) {
 391                                 $article = new Article( $title, 0 );
 392                                 $newtitle = $article->getRedirectTarget();
 393                         } else {
 394                                 break;
 395                         }
 396                         // Redirects to some special pages are not permitted
 397                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 398                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 399                                 $title = $newtitle;
 400                                 $titles[] = $newtitle;
 401                         } else {
 402                                 break;
 403                         }
 404                 }
 405                 return $titles;
 406         }
 407
 408         /**
 409          * Really extract the redirect destination
 410          * Do not call this function directly, use one of the newFromRedirect* functions above
 411          *
 412          * @param $text String Text with possible redirect
 413          * @return Title
 414          */
 415         protected static function newFromRedirectInternal( $text ) {
 416                 global $wgMaxRedirects;
 417                 if ( $wgMaxRedirects < 1 ) {
 418                         //redirects are disabled, so quit early
 419                         return null;
 420                 }
 421                 $redir = MagicWord::get( 'redirect' );
 422                 $text = trim( $text );
 423                 if ( $redir->matchStartAndRemove( $text ) ) {
 424                         // Extract the first link and see if it's usable
 425                         // Ensure that it really does come directly after #REDIRECT
 426                         // Some older redirects included a colon, so don't freak about that!
 427                         $m = array();
 428                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 429                                 // Strip preceding colon used to "escape" categories, etc.
 430                                 // and URL-decode links
 431                                 if ( strpos( $m[1], '%' ) !== false ) {
 432                                         // Match behavior of inline link parsing here;
 433                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 434                                 }
 435                                 $title = Title::newFromText( $m[1] );
 436                                 // If the title is a redirect to bad special pages or is invalid, return null
 437                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 438                                         return null;
 439                                 }
 440                                 return $title;
 441                         }
 442                 }
 443                 return null;
 444         }
 445
 446 # ----------------------------------------------------------------------------
 447 #       Static functions
 448 # ----------------------------------------------------------------------------
 449
 450         /**
 451          * Get the prefixed DB key associated with an ID
 452          *
 453          * @param $id Int the page_id of the article
 454          * @return Title an object representing the article, or NULL if no such article was found
 455          */
 456         public static function nameOf( $id ) {
 457                 $dbr = wfGetDB( DB_SLAVE );
 458
 459                 $s = $dbr->selectRow(
 460                         'page',
 461                         array( 'page_namespace', 'page_title' ),
 462                         array( 'page_id' => $id ),
 463                         __METHOD__
 464                 );
 465                 if ( $s === false ) {
 466                         return null;
 467                 }
 468
 469                 $n = self::makeName( $s->page_namespace, $s->page_title );
 470                 return $n;
 471         }
 472
 473         /**
 474          * Get a regex character class describing the legal characters in a link
 475          *
 476          * @return String the list of characters, not delimited
 477          */
 478         public static function legalChars() {
 479                 global $wgLegalTitleChars;
 480                 return $wgLegalTitleChars;
 481         }
 482
 483         /**
 484          * Get a string representation of a title suitable for
 485          * including in a search index
 486          *
 487          * @param $ns Int a namespace index
 488          * @param $title String text-form main part
 489          * @return String a stripped-down title string ready for the search index
 490          */
 491         public static function indexTitle( $ns, $title ) {
 492                 global $wgContLang;
 493
 494                 $lc = SearchEngine::legalSearchChars() . '&#;';
 495                 $t = $wgContLang->normalizeForSearch( $title );
 496                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 497                 $t = $wgContLang->lc( $t );
 498
 499                 # Handle 's, s'
 500                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 501                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 502
 503                 $t = preg_replace( "/\\s+/", ' ', $t );
 504
 505                 if ( $ns == NS_FILE ) {
 506                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 507                 }
 508                 return trim( $t );
 509         }
 510
 511         /**
 512          * Make a prefixed DB key from a DB key and a namespace index
 513          *
 514          * @param $ns Int numerical representation of the namespace
 515          * @param $title String the DB key form the title
 516          * @param $fragment String The link fragment (after the "#")
 517          * @param $interwiki String The interwiki prefix
 518          * @return String the prefixed form of the title
 519          */
 520         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 521                 global $wgContLang;
 522
 523                 $namespace = $wgContLang->getNsText( $ns );
 524                 $name = $namespace == '' ? $title : "$namespace:$title";
 525                 if ( strval( $interwiki ) != '' ) {
 526                         $name = "$interwiki:$name";
 527                 }
 528                 if ( strval( $fragment ) != '' ) {
 529                         $name .= '#' . $fragment;
 530                 }
 531                 return $name;
 532         }
 533
 534         /**
 535          * Determine whether the object refers to a page within
 536          * this project.
 537          *
 538          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 539          */
 540         public function isLocal() {
 541                 if ( $this->mInterwiki != '' ) {
 542                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 543                 } else {
 544                         return true;
 545                 }
 546         }
 547
 548         /**
 549          * Determine whether the object refers to a page within
 550          * this project and is transcludable.
 551          *
 552          * @return Bool TRUE if this is transcludable
 553          */
 554         public function isTrans() {
 555                 if ( $this->mInterwiki == '' ) {
 556                         return false;
 557                 }
 558
 559                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 560         }
 561
 562         /**
 563          * Returns the DB name of the distant wiki which owns the object.
 564          *
 565          * @return String the DB name
 566          */
 567         public function getTransWikiID() {
 568                 if ( $this->mInterwiki == '' ) {
 569                         return false;
 570                 }
 571
 572                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 573         }
 574
 575         /**
 576          * Escape a text fragment, say from a link, for a URL
 577          *
 578          * @param $fragment string containing a URL or link fragment (after the "#")
 579          * @return String: escaped string
 580          */
 581         static function escapeFragmentForURL( $fragment ) {
 582                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 583                 # fragments appear not to work in IE (at least up to 7) or in at least
 584                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 585                 # to care if they aren't encoded.
 586                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 587         }
 588
 589 # ----------------------------------------------------------------------------
 590 #       Other stuff
 591 # ----------------------------------------------------------------------------
 592
 593         /** Simple accessors */
 594         /**
 595          * Get the text form (spaces not underscores) of the main part
 596          *
 597          * @return String Main part of the title
 598          */
 599         public function getText() { return $this->mTextform; }
 600
 601         /**
 602          * Get the URL-encoded form of the main part
 603          *
 604          * @return String Main part of the title, URL-encoded
 605          */
 606         public function getPartialURL() { return $this->mUrlform; }
 607
 608         /**
 609          * Get the main part with underscores
 610          *
 611          * @return String: Main part of the title, with underscores
 612          */
 613         public function getDBkey() { return $this->mDbkeyform; }
 614
 615         /**
 616          * Get the namespace index, i.e. one of the NS_xxxx constants.
 617          *
 618          * @return Integer: Namespace index
 619          */
 620         public function getNamespace() { return $this->mNamespace; }
 621
 622         /**
 623          * Get the namespace text
 624          *
 625          * @return String: Namespace text
 626          */
 627         public function getNsText() {
 628                 global $wgContLang;
 629
 630                 if ( $this->mInterwiki != '' ) {
 631                         // This probably shouldn't even happen. ohh man, oh yuck.
 632                         // But for interwiki transclusion it sometimes does.
 633                         // Shit. Shit shit shit.
 634                         //
 635                         // Use the canonical namespaces if possible to try to
 636                         // resolve a foreign namespace.
 637                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 638                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 639                         }
 640                 }
 641
 642                 if ( $wgContLang->needsGenderDistinction() &&
 643                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 644                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 645                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 646                 }
 647
 648                 return $wgContLang->getNsText( $this->mNamespace );
 649         }
 650
 651         /**
 652          * Get the DB key with the initial letter case as specified by the user
 653          *
 654          * @return String DB key
 655          */
 656         function getUserCaseDBKey() {
 657                 return $this->mUserCaseDBKey;
 658         }
 659
 660         /**
 661          * Get the namespace text of the subject (rather than talk) page
 662          *
 663          * @return String Namespace text
 664          */
 665         public function getSubjectNsText() {
 666                 global $wgContLang;
 667                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 668         }
 669
 670         /**
 671          * Get the namespace text of the talk page
 672          *
 673          * @return String Namespace text
 674          */
 675         public function getTalkNsText() {
 676                 global $wgContLang;
 677                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 678         }
 679
 680         /**
 681          * Could this title have a corresponding talk page?
 682          *
 683          * @return Bool TRUE or FALSE
 684          */
 685         public function canTalk() {
 686                 return( MWNamespace::canTalk( $this->mNamespace ) );
 687         }
 688
 689         /**
 690          * Get the interwiki prefix (or null string)
 691          *
 692          * @return String Interwiki prefix
 693          */
 694         public function getInterwiki() { return $this->mInterwiki; }
 695
 696         /**
 697          * Get the Title fragment (i.e.\ the bit after the #) in text form
 698          *
 699          * @return String Title fragment
 700          */
 701         public function getFragment() { return $this->mFragment; }
 702
 703         /**
 704          * Get the fragment in URL form, including the "#" character if there is one
 705          * @return String Fragment in URL form
 706          */
 707         public function getFragmentForURL() {
 708                 if ( $this->mFragment == '' ) {
 709                         return '';
 710                 } else {
 711                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 712                 }
 713         }
 714
 715         /**
 716          * Get the default namespace index, for when there is no namespace
 717          *
 718          * @return Int Default namespace index
 719          */
 720         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 721
 722         /**
 723          * Get title for search index
 724          *
 725          * @return String a stripped-down title string ready for the
 726          *  search index
 727          */
 728         public function getIndexTitle() {
 729                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 730         }
 731
 732         /**
 733          * Get the prefixed database key form
 734          *
 735          * @return String the prefixed title, with underscores and
 736          *  any interwiki and namespace prefixes
 737          */
 738         public function getPrefixedDBkey() {
 739                 $s = $this->prefix( $this->mDbkeyform );
 740                 $s = str_replace( ' ', '_', $s );
 741                 return $s;
 742         }
 743
 744         /**
 745          * Get the prefixed title with spaces.
 746          * This is the form usually used for display
 747          *
 748          * @return String the prefixed title, with spaces
 749          */
 750         public function getPrefixedText() {
 751                 // @todo FIXME: Bad usage of empty() ?
 752                 if ( empty( $this->mPrefixedText ) ) {
 753                         $s = $this->prefix( $this->mTextform );
 754                         $s = str_replace( '_', ' ', $s );
 755                         $this->mPrefixedText = $s;
 756                 }
 757                 return $this->mPrefixedText;
 758         }
 759
 760         /**
 761          * Return the prefixed title with spaces _without_ the interwiki prefix
 762          *
 763          * @return \type{\string} the title, prefixed by the namespace but not by the interwiki prefix, with spaces
 764          */
 765         public function getSemiPrefixedText() {
 766                 if ( !isset( $this->mSemiPrefixedText ) ){
 767                         $s = ( $this->mNamespace === NS_MAIN ? '' : $this->getNsText() . ':' ) . $this->mTextform;
 768                         $s = str_replace( '_', ' ', $s );
 769                         $this->mSemiPrefixedText = $s;
 770                 }
 771                 return $this->mSemiPrefixedText;
 772         }
 773
 774         /**
 775          * Get the prefixed title with spaces, plus any fragment
 776          * (part beginning with '#')
 777          *
 778          * @return String the prefixed title, with spaces and the fragment, including '#'
 779          */
 780         public function getFullText() {
 781                 $text = $this->getPrefixedText();
 782                 if ( $this->mFragment != '' ) {
 783                         $text .= '#' . $this->mFragment;
 784                 }
 785                 return $text;
 786         }
 787
 788         /**
 789          * Get the base page name, i.e. the leftmost part before any slashes
 790          *
 791          * @return String Base name
 792          */
 793         public function getBaseText() {
 794                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 795                         return $this->getText();
 796                 }
 797
 798                 $parts = explode( '/', $this->getText() );
 799                 # Don't discard the real title if there's no subpage involved
 800                 if ( count( $parts ) > 1 ) {
 801                         unset( $parts[count( $parts ) - 1] );
 802                 }
 803                 return implode( '/', $parts );
 804         }
 805
 806         /**
 807          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 808          *
 809          * @return String Subpage name
 810          */
 811         public function getSubpageText() {
 812                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 813                         return( $this->mTextform );
 814                 }
 815                 $parts = explode( '/', $this->mTextform );
 816                 return( $parts[count( $parts ) - 1] );
 817         }
 818
 819         /**
 820          * Get a URL-encoded form of the subpage text
 821          *
 822          * @return String URL-encoded subpage name
 823          */
 824         public function getSubpageUrlForm() {
 825                 $text = $this->getSubpageText();
 826                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 827                 return( $text );
 828         }
 829
 830         /**
 831          * Get a URL-encoded title (not an actual URL) including interwiki
 832          *
 833          * @return String the URL-encoded form
 834          */
 835         public function getPrefixedURL() {
 836                 $s = $this->prefix( $this->mDbkeyform );
 837                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 838                 return $s;
 839         }
 840
 841         /**
 842          * Get a real URL referring to this title, with interwiki link and
 843          * fragment
 844          *
 845          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 846          *   links. Can be specified as an associative array as well, e.g.,
 847          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 848          * @param $variant String language variant of url (for sr, zh..)
 849          * @return String the URL
 850          */
 851         public function getFullURL( $query = '', $variant = false ) {
 852                 # Hand off all the decisions on urls to getLocalURL
 853                 $url = $this->getLocalURL( $query, $variant );
 854
 855                 # Expand the url to make it a full url. Note that getLocalURL has the
 856                 # potential to output full urls for a variety of reasons, so we use
 857                 # wfExpandUrl instead of simply prepending $wgServer
 858                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 859
 860                 # Finally, add the fragment.
 861                 $url .= $this->getFragmentForURL();
 862
 863                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
 864                 return $url;
 865         }
 866
 867         /**
 868          * Get a URL with no fragment or server name.  If this page is generated
 869          * with action=render, $wgServer is prepended.
 870          *
 871          * @param $query Mixed: an optional query string; if not specified,
 872          *   $wgArticlePath will be used.  Can be specified as an associative array
 873          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 874          *   URL-escaped).
 875          * @param $variant String language variant of url (for sr, zh..)
 876          * @return String the URL
 877          */
 878         public function getLocalURL( $query = '', $variant = false ) {
 879                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 880                 global $wgVariantArticlePath, $wgContLang;
 881
 882                 if ( is_array( $query ) ) {
 883                         $query = wfArrayToCGI( $query );
 884                 }
 885
 886                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 887                 if ( $interwiki ) {
 888                         $namespace = $this->getNsText();
 889                         if ( $namespace != '' ) {
 890                                 # Can this actually happen? Interwikis shouldn't be parsed.
 891                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 892                                 $namespace .= ':';
 893                         }
 894                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 895                         $url = wfAppendQuery( $url, $query );
 896                 } else {
 897                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 898                         if ( $query == '' ) {
 899                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 900                                         if ( !$wgVariantArticlePath ) {
 901                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 902                                         } else {
 903                                                 $variantArticlePath = $wgVariantArticlePath;
 904                                         }
 905                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 906                                         $url = str_replace( '$1', $dbkey, $url  );
 907                                 } else {
 908                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 909                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 910                                 }
 911                         } else {
 912                                 global $wgActionPaths;
 913                                 $url = false;
 914                                 $matches = array();
 915                                 if ( !empty( $wgActionPaths ) &&
 916                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 917                                 {
 918                                         $action = urldecode( $matches[2] );
 919                                         if ( isset( $wgActionPaths[$action] ) ) {
 920                                                 $query = $matches[1];
 921                                                 if ( isset( $matches[4] ) ) {
 922                                                         $query .= $matches[4];
 923                                                 }
 924                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 925                                                 if ( $query != '' ) {
 926                                                         $url = wfAppendQuery( $url, $query );
 927                                                 }
 928                                         }
 929                                 }
 930
 931                                 if ( $url === false ) {
 932                                         if ( $query == '-' ) {
 933                                                 $query = '';
 934                                         }
 935                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 936                                 }
 937                         }
 938
 939                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 940
 941                         // @todo FIXME: This causes breakage in various places when we
 942                         // actually expected a local URL and end up with dupe prefixes.
 943                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 944                                 $url = $wgServer . $url;
 945                         }
 946                 }
 947                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 948                 return $url;
 949         }
 950
 951         /**
 952          * Get a URL that's the simplest URL that will be valid to link, locally,
 953          * to the current Title.  It includes the fragment, but does not include
 954          * the server unless action=render is used (or the link is external).  If
 955          * there's a fragment but the prefixed text is empty, we just return a link
 956          * to the fragment.
 957          *
 958          * The result obviously should not be URL-escaped, but does need to be
 959          * HTML-escaped if it's being output in HTML.
 960          *
 961          * @param $query Array of Strings An associative array of key => value pairs for the
 962          *   query string.  Keys and values will be escaped.
 963          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 964          *   for external links.  Default is "false" (same variant as current page,
 965          *   for anonymous users).
 966          * @return String the URL
 967          */
 968         public function getLinkUrl( $query = array(), $variant = false ) {
 969                 wfProfileIn( __METHOD__ );
 970                 if ( $this->isExternal() ) {
 971                         $ret = $this->getFullURL( $query );
 972                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 973                         $ret = $this->getFragmentForURL();
 974                 } else {
 975                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 976                 }
 977                 wfProfileOut( __METHOD__ );
 978                 return $ret;
 979         }
 980
 981         /**
 982          * Get an HTML-escaped version of the URL form, suitable for
 983          * using in a link, without a server name or fragment
 984          *
 985          * @param $query String an optional query string
 986          * @return String the URL
 987          */
 988         public function escapeLocalURL( $query = '' ) {
 989                 return htmlspecialchars( $this->getLocalURL( $query ) );
 990         }
 991
 992         /**
 993          * Get an HTML-escaped version of the URL form, suitable for
 994          * using in a link, including the server name and fragment
 995          *
 996          * @param $query String an optional query string
 997          * @return String the URL
 998          */
 999         public function escapeFullURL( $query = '' ) {
1000                 return htmlspecialchars( $this->getFullURL( $query ) );
1001         }
1002
1003         /**
1004          * HTML-escaped version of getCanonicalURL()
1005          */
1006         public function escapeCanonicalURL( $query = '', $variant = false ) {
1007                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1008         }
1009
1010         /**
1011          * Get the URL form for an internal link.
1012          * - Used in various Squid-related code, in case we have a different
1013          * internal hostname for the server from the exposed one.
1014          *
1015          * This uses $wgInternalServer to qualify the path, or $wgServer
1016          * if $wgInternalServer is not set. If the server variable used is
1017          * protocol-relative, the URL will be expanded to http://
1018          *
1019          * @param $query String an optional query string
1020          * @param $variant String language variant of url (for sr, zh..)
1021          * @return String the URL
1022          */
1023         public function getInternalURL( $query = '', $variant = false ) {
1024                 if ( $this->isExternal( ) ) {
1025                         $server = '';
1026                 } else {
1027                         global $wgInternalServer, $wgServer;
1028                         $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1029                 }
1030                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1031                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1032                 return $url;
1033         }
1034
1035         /**
1036          * Get the URL for a canonical link, for use in things like IRC and
1037          * e-mail notifications. Uses $wgCanonicalServer and the
1038          * GetCanonicalURL hook.
1039          *
1040          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1041          *
1042          * @param $query string An optional query string
1043          * @param $variant string Language variant of URL (for sr, zh, ...)
1044          * @return string The URL
1045          */
1046         public function getCanonicalURL( $query = '', $variant = false ) {
1047                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1048                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1049                 return $url;
1050         }
1051
1052         /**
1053          * Get the edit URL for this Title
1054          *
1055          * @return String the URL, or a null string if this is an
1056          *  interwiki link
1057          */
1058         public function getEditURL() {
1059                 if ( $this->mInterwiki != '' ) {
1060                         return '';
1061                 }
1062                 $s = $this->getLocalURL( 'action=edit' );
1063
1064                 return $s;
1065         }
1066
1067         /**
1068          * Get the HTML-escaped displayable text form.
1069          * Used for the title field in <a> tags.
1070          *
1071          * @return String the text, including any prefixes
1072          */
1073         public function getEscapedText() {
1074                 return htmlspecialchars( $this->getPrefixedText() );
1075         }
1076
1077         /**
1078          * Is this Title interwiki?
1079          *
1080          * @return Bool
1081          */
1082         public function isExternal() {
1083                 return ( $this->mInterwiki != '' );
1084         }
1085
1086         /**
1087          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1088          *
1089          * @param $action String Action to check (default: edit)
1090          * @return Bool
1091          */
1092         public function isSemiProtected( $action = 'edit' ) {
1093                 if ( $this->exists() ) {
1094                         $restrictions = $this->getRestrictions( $action );
1095                         if ( count( $restrictions ) > 0 ) {
1096                                 foreach ( $restrictions as $restriction ) {
1097                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1098                                                 return false;
1099                                         }
1100                                 }
1101                         } else {
1102                                 # Not protected
1103                                 return false;
1104                         }
1105                         return true;
1106                 } else {
1107                         # If it doesn't exist, it can't be protected
1108                         return false;
1109                 }
1110         }
1111
1112         /**
1113          * Does the title correspond to a protected article?
1114          *
1115          * @param $action String the action the page is protected from,
1116          * by default checks all actions.
1117          * @return Bool
1118          */
1119         public function isProtected( $action = '' ) {
1120                 global $wgRestrictionLevels;
1121
1122                 $restrictionTypes = $this->getRestrictionTypes();
1123
1124                 # Special pages have inherent protection
1125                 if( $this->getNamespace() == NS_SPECIAL ) {
1126                         return true;
1127                 }
1128
1129                 # Check regular protection levels
1130                 foreach ( $restrictionTypes as $type ) {
1131                         if ( $action == $type || $action == '' ) {
1132                                 $r = $this->getRestrictions( $type );
1133                                 foreach ( $wgRestrictionLevels as $level ) {
1134                                         if ( in_array( $level, $r ) && $level != '' ) {
1135                                                 return true;
1136                                         }
1137                                 }
1138                         }
1139                 }
1140
1141                 return false;
1142         }
1143
1144         /**
1145          * Is this a conversion table for the LanguageConverter?
1146          *
1147          * @return Bool
1148          */
1149         public function isConversionTable() {
1150                 if(
1151                         $this->getNamespace() == NS_MEDIAWIKI &&
1152                         strpos( $this->getText(), 'Conversiontable' ) !== false
1153                 )
1154                 {
1155                         return true;
1156                 }
1157
1158                 return false;
1159         }
1160
1161         /**
1162          * Is $wgUser watching this page?
1163          *
1164          * @return Bool
1165          */
1166         public function userIsWatching() {
1167                 global $wgUser;
1168
1169                 if ( is_null( $this->mWatched ) ) {
1170                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1171                                 $this->mWatched = false;
1172                         } else {
1173                                 $this->mWatched = $wgUser->isWatched( $this );
1174                         }
1175                 }
1176                 return $this->mWatched;
1177         }
1178
1179         /**
1180          * Can $wgUser perform $action on this page?
1181          * This skips potentially expensive cascading permission checks
1182          * as well as avoids expensive error formatting
1183          *
1184          * Suitable for use for nonessential UI controls in common cases, but
1185          * _not_ for functional access control.
1186          *
1187          * May provide false positives, but should never provide a false negative.
1188          *
1189          * @param $action String action that permission needs to be checked for
1190          * @return Bool
1191          */
1192         public function quickUserCan( $action ) {
1193                 return $this->userCan( $action, false );
1194         }
1195
1196         /**
1197          * Determines if $user is unable to edit this page because it has been protected
1198          * by $wgNamespaceProtection.
1199          *
1200          * @param $user User object to check permissions
1201          * @return Bool
1202          */
1203         public function isNamespaceProtected( User $user ) {
1204                 global $wgNamespaceProtection;
1205
1206                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1207                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1208                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1209                                         return true;
1210                                 }
1211                         }
1212                 }
1213                 return false;
1214         }
1215
1216         /**
1217          * Can $wgUser perform $action on this page?
1218          *
1219          * @param $action String action that permission needs to be checked for
1220          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1221          * @return Bool
1222          */
1223         public function userCan( $action, $doExpensiveQueries = true ) {
1224                 global $wgUser;
1225                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1226         }
1227
1228         /**
1229          * Can $user perform $action on this page?
1230          *
1231          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1232          *
1233          * @param $action String action that permission needs to be checked for
1234          * @param $user User to check
1235          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1236          *   skipping checks for cascading protections and user blocks.
1237          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1238          * @return Array of arguments to wfMsg to explain permissions problems.
1239          */
1240         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1241                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1242
1243                 // Remove the errors being ignored.
1244                 foreach ( $errors as $index => $error ) {
1245                         $error_key = is_array( $error ) ? $error[0] : $error;
1246
1247                         if ( in_array( $error_key, $ignoreErrors ) ) {
1248                                 unset( $errors[$index] );
1249                         }
1250                 }
1251
1252                 return $errors;
1253         }
1254
1255         /**
1256          * Permissions checks that fail most often, and which are easiest to test.
1257          *
1258          * @param $action String the action to check
1259          * @param $user User user to check
1260          * @param $errors Array list of current errors
1261          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1262          * @param $short Boolean short circuit on first error
1263          *
1264          * @return Array list of errors
1265          */
1266         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1267                 $ns = $this->getNamespace();
1268
1269                 if ( $action == 'create' ) {
1270                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1271                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1272                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1273                         }
1274                 } elseif ( $action == 'move' ) {
1275                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1276                                         && $ns == NS_USER && !$this->isSubpage() ) {
1277                                 // Show user page-specific message only if the user can move other pages
1278                                 $errors[] = array( 'cant-move-user-page' );
1279                         }
1280
1281                         // Check if user is allowed to move files if it's a file
1282                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1283                                 $errors[] = array( 'movenotallowedfile' );
1284                         }
1285
1286                         if ( !$user->isAllowed( 'move', $ns) ) {
1287                                 // User can't move anything
1288
1289                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1290                                         array( 'user' ), $ns ), true );
1291                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1292                                         array( 'autoconfirmed' ), $ns ), true );
1293
1294                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1295                                         // custom message if logged-in users without any special rights can move
1296                                         $errors[] = array( 'movenologintext' );
1297                                 } else {
1298                                         $errors[] = array( 'movenotallowed' );
1299                                 }
1300                         }
1301                 } elseif ( $action == 'move-target' ) {
1302                         if ( !$user->isAllowed( 'move', $ns ) ) {
1303                                 // User can't move anything
1304                                 $errors[] = array( 'movenotallowed' );
1305                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1306                                         && $ns == NS_USER && !$this->isSubpage() ) {
1307                                 // Show user page-specific message only if the user can move other pages
1308                                 $errors[] = array( 'cant-move-to-user-page' );
1309                         }
1310                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1311                         // We avoid expensive display logic for quickUserCan's and such
1312                         $groups = false;
1313                         if ( !$short ) {
1314                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1315                                         User::getGroupsWithPermission( $action, $ns ) );
1316                         }
1317
1318                         if ( $groups ) {
1319                                 global $wgLang;
1320                                 $return = array(
1321                                         'badaccess-groups',
1322                                         $wgLang->commaList( $groups ),
1323                                         count( $groups )
1324                                 );
1325                         } else {
1326                                 $return = array( 'badaccess-group0' );
1327                         }
1328                         $errors[] = $return;
1329                 }
1330
1331                 return $errors;
1332         }
1333
1334         /**
1335          * Add the resulting error code to the errors array
1336          *
1337          * @param $errors Array list of current errors
1338          * @param $result Mixed result of errors
1339          *
1340          * @return Array list of errors
1341          */
1342         private function resultToError( $errors, $result ) {
1343                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1344                         // A single array representing an error
1345                         $errors[] = $result;
1346                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1347                         // A nested array representing multiple errors
1348                         $errors = array_merge( $errors, $result );
1349                 } elseif ( $result !== '' && is_string( $result ) ) {
1350                         // A string representing a message-id
1351                         $errors[] = array( $result );
1352                 } elseif ( $result === false ) {
1353                         // a generic "We don't want them to do that"
1354                         $errors[] = array( 'badaccess-group0' );
1355                 }
1356                 return $errors;
1357         }
1358
1359         /**
1360          * Check various permission hooks
1361          *
1362          * @param $action String the action to check
1363          * @param $user User user to check
1364          * @param $errors Array list of current errors
1365          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1366          * @param $short Boolean short circuit on first error
1367          *
1368          * @return Array list of errors
1369          */
1370         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1371                 // Use getUserPermissionsErrors instead
1372                 $result = '';
1373                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1374                         return $result ? array() : array( array( 'badaccess-group0' ) );
1375                 }
1376                 // Check getUserPermissionsErrors hook
1377                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1378                         $errors = $this->resultToError( $errors, $result );
1379                 }
1380                 // Check getUserPermissionsErrorsExpensive hook
1381                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1382                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1383                         $errors = $this->resultToError( $errors, $result );
1384                 }
1385
1386                 return $errors;
1387         }
1388
1389         /**
1390          * Check permissions on special pages & namespaces
1391          *
1392          * @param $action String the action to check
1393          * @param $user User user to check
1394          * @param $errors Array list of current errors
1395          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1396          * @param $short Boolean short circuit on first error
1397          *
1398          * @return Array list of errors
1399          */
1400         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1401                 # Only 'createaccount' and 'execute' can be performed on
1402                 # special pages, which don't actually exist in the DB.
1403                 $specialOKActions = array( 'createaccount', 'execute' );
1404                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1405                         $errors[] = array( 'ns-specialprotected' );
1406                 }
1407
1408                 # Check $wgNamespaceProtection for restricted namespaces
1409                 if ( $this->isNamespaceProtected( $user ) ) {
1410                         $ns = $this->mNamespace == NS_MAIN ?
1411                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1412                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1413                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1414                 }
1415
1416                 return $errors;
1417         }
1418
1419         /**
1420          * Check CSS/JS sub-page permissions
1421          *
1422          * @param $action String the action to check
1423          * @param $user User user to check
1424          * @param $errors Array list of current errors
1425          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1426          * @param $short Boolean short circuit on first error
1427          *
1428          * @return Array list of errors
1429          */
1430         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1431                 # Protect css/js subpages of user pages
1432                 # XXX: this might be better using restrictions
1433                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1434                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1435                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1436                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1437                                 $errors[] = array( 'customcssprotected' );
1438                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1439                                 $errors[] = array( 'customjsprotected' );
1440                         }
1441                 }
1442
1443                 return $errors;
1444         }
1445
1446         /**
1447          * Check against page_restrictions table requirements on this
1448          * page. The user must possess all required rights for this
1449          * action.
1450          *
1451          * @param $action String the action to check
1452          * @param $user User user to check
1453          * @param $errors Array list of current errors
1454          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1455          * @param $short Boolean short circuit on first error
1456          *
1457          * @return Array list of errors
1458          */
1459         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1460                 foreach ( $this->getRestrictions( $action ) as $right ) {
1461                         // Backwards compatibility, rewrite sysop -> protect
1462                         if ( $right == 'sysop' ) {
1463                                 $right = 'protect';
1464                         }
1465                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1466                                 // Users with 'editprotected' permission can edit protected pages
1467                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1468                                         // Users with 'editprotected' permission cannot edit protected pages
1469                                         // with cascading option turned on.
1470                                         if ( $this->mCascadeRestriction ) {
1471                                                 $errors[] = array( 'protectedpagetext', $right );
1472                                         }
1473                                 } else {
1474                                         $errors[] = array( 'protectedpagetext', $right );
1475                                 }
1476                         }
1477                 }
1478
1479                 return $errors;
1480         }
1481
1482         /**
1483          * Check restrictions on cascading pages.
1484          *
1485          * @param $action String the action to check
1486          * @param $user User to check
1487          * @param $errors Array list of current errors
1488          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1489          * @param $short Boolean short circuit on first error
1490          *
1491          * @return Array list of errors
1492          */
1493         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1494                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1495                         # We /could/ use the protection level on the source page, but it's
1496                         # fairly ugly as we have to establish a precedence hierarchy for pages
1497                         # included by multiple cascade-protected pages. So just restrict
1498                         # it to people with 'protect' permission, as they could remove the
1499                         # protection anyway.
1500                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1501                         # Cascading protection depends on more than this page...
1502                         # Several cascading protected pages may include this page...
1503                         # Check each cascading level
1504                         # This is only for protection restrictions, not for all actions
1505                         if ( isset( $restrictions[$action] ) ) {
1506                                 foreach ( $restrictions[$action] as $right ) {
1507                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1508                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1509                                                 $pages = '';
1510                                                 foreach ( $cascadingSources as $page )
1511                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1512                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1513                                         }
1514                                 }
1515                         }
1516                 }
1517
1518                 return $errors;
1519         }
1520
1521         /**
1522          * Check action permissions not already checked in checkQuickPermissions
1523          *
1524          * @param $action String the action to check
1525          * @param $user User to check
1526          * @param $errors Array list of current errors
1527          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1528          * @param $short Boolean short circuit on first error
1529          *
1530          * @return Array list of errors
1531          */
1532         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1533                 if ( $action == 'protect' ) {
1534                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1535                                 // If they can't edit, they shouldn't protect.
1536                                 $errors[] = array( 'protect-cantedit' );
1537                         }
1538                 } elseif ( $action == 'create' ) {
1539                         $title_protection = $this->getTitleProtection();
1540                         if( $title_protection ) {
1541                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1542                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1543                                 }
1544                                 if( $title_protection['pt_create_perm'] == '' ||
1545                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1546                                                 $this->mNamespace ) ) {
1547                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1548                                 }
1549                         }
1550                 } elseif ( $action == 'move' ) {
1551                         // Check for immobile pages
1552                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1553                                 // Specific message for this case
1554                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1555                         } elseif ( !$this->isMovable() ) {
1556                                 // Less specific message for rarer cases
1557                                 $errors[] = array( 'immobile-source-page' );
1558                         }
1559                 } elseif ( $action == 'move-target' ) {
1560                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1561                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1562                         } elseif ( !$this->isMovable() ) {
1563                                 $errors[] = array( 'immobile-target-page' );
1564                         }
1565                 }
1566                 return $errors;
1567         }
1568
1569         /**
1570          * Check that the user isn't blocked from editting.
1571          *
1572          * @param $action String the action to check
1573          * @param $user User to check
1574          * @param $errors Array list of current errors
1575          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1576          * @param $short Boolean short circuit on first error
1577          *
1578          * @return Array list of errors
1579          */
1580         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1581                 if( !$doExpensiveQueries ) {
1582                         return $errors;
1583                 }
1584
1585                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1586
1587                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1588                         $errors[] = array( 'confirmedittext' );
1589                 }
1590
1591                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1592                         // Edit blocks should not affect reading.
1593                         // Account creation blocks handled at userlogin.
1594                         // Unblocking handled in SpecialUnblock
1595                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1596                         // Don't block the user from editing their own talk page unless they've been
1597                         // explicitly blocked from that too.
1598                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1599                         $block = $user->mBlock;
1600
1601                         // This is from OutputPage::blockedPage
1602                         // Copied at r23888 by werdna
1603
1604                         $id = $user->blockedBy();
1605                         $reason = $user->blockedFor();
1606                         if ( $reason == '' ) {
1607                                 $reason = wfMsg( 'blockednoreason' );
1608                         }
1609                         $ip = $user->getRequest()->getIP();
1610
1611                         if ( is_numeric( $id ) ) {
1612                                 $name = User::whoIs( $id );
1613                         } else {
1614                                 $name = $id;
1615                         }
1616
1617                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1618                         $blockid = $block->getId();
1619                         $blockExpiry = $user->mBlock->mExpiry;
1620                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1621                         if ( $blockExpiry == 'infinity' ) {
1622                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1623                         } else {
1624                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1625                         }
1626
1627                         $intended = strval( $user->mBlock->getTarget() );
1628
1629                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1630                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1631                 }
1632
1633                 return $errors;
1634         }
1635
1636         /**
1637          * Can $user perform $action on this page? This is an internal function,
1638          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1639          * checks on wfReadOnly() and blocks)
1640          *
1641          * @param $action String action that permission needs to be checked for
1642          * @param $user User to check
1643          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1644          * @param $short Bool Set this to true to stop after the first permission error.
1645          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1646          */
1647         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1648                 wfProfileIn( __METHOD__ );
1649
1650                 $errors = array();
1651                 $checks = array(
1652                         'checkQuickPermissions',
1653                         'checkPermissionHooks',
1654                         'checkSpecialsAndNSPermissions',
1655                         'checkCSSandJSPermissions',
1656                         'checkPageRestrictions',
1657                         'checkCascadingSourcesRestrictions',
1658                         'checkActionPermissions',
1659                         'checkUserBlock'
1660                 );
1661
1662                 while( count( $checks ) > 0 &&
1663                            !( $short && count( $errors ) > 0 ) ) {
1664                         $method = array_shift( $checks );
1665                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1666                 }
1667
1668                 wfProfileOut( __METHOD__ );
1669                 return $errors;
1670         }
1671
1672         /**
1673          * Is this title subject to title protection?
1674          * Title protection is the one applied against creation of such title.
1675          *
1676          * @return Mixed An associative array representing any existent title
1677          *   protection, or false if there's none.
1678          */
1679         private function getTitleProtection() {
1680                 // Can't protect pages in special namespaces
1681                 if ( $this->getNamespace() < 0 ) {
1682                         return false;
1683                 }
1684
1685                 // Can't protect pages that exist.
1686                 if ( $this->exists() ) {
1687                         return false;
1688                 }
1689
1690                 if ( !isset( $this->mTitleProtection ) ) {
1691                         $dbr = wfGetDB( DB_SLAVE );
1692                         $res = $dbr->select( 'protected_titles', '*',
1693                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1694                                 __METHOD__ );
1695
1696                         // fetchRow returns false if there are no rows.
1697                         $this->mTitleProtection = $dbr->fetchRow( $res );
1698                 }
1699                 return $this->mTitleProtection;
1700         }
1701
1702         /**
1703          * Update the title protection status
1704          *
1705          * @param $create_perm String Permission required for creation
1706          * @param $reason String Reason for protection
1707          * @param $expiry String Expiry timestamp
1708          * @return boolean true
1709          */
1710         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1711                 global $wgUser, $wgContLang;
1712
1713                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1714                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1715                         // No change
1716                         return true;
1717                 }
1718
1719                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1720
1721                 $dbw = wfGetDB( DB_MASTER );
1722
1723                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1724
1725                 $expiry_description = '';
1726                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1727                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1728                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1729                 } else {
1730                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1731                 }
1732
1733                 # Update protection table
1734                 if ( $create_perm != '' ) {
1735                         $this->mTitleProtection = array(
1736                                         'pt_namespace' => $namespace,
1737                                         'pt_title' => $title,
1738                                         'pt_create_perm' => $create_perm,
1739                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1740                                         'pt_expiry' => $encodedExpiry,
1741                                         'pt_user' => $wgUser->getId(),
1742                                         'pt_reason' => $reason,
1743                                 );
1744                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1745                                 $this->mTitleProtection, __METHOD__     );
1746                 } else {
1747                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1748                                 'pt_title' => $title ), __METHOD__ );
1749                         $this->mTitleProtection = false;
1750                 }
1751
1752                 # Update the protection log
1753                 if ( $dbw->affectedRows() ) {
1754                         $log = new LogPage( 'protect' );
1755
1756                         if ( $create_perm ) {
1757                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1758                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1759                         } else {
1760                                 $log->addEntry( 'unprotect', $this, $reason );
1761                         }
1762                 }
1763
1764                 return true;
1765         }
1766
1767         /**
1768          * Remove any title protection due to page existing
1769          */
1770         public function deleteTitleProtection() {
1771                 $dbw = wfGetDB( DB_MASTER );
1772
1773                 $dbw->delete(
1774                         'protected_titles',
1775                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1776                         __METHOD__
1777                 );
1778                 $this->mTitleProtection = false;
1779         }
1780
1781         /**
1782          * Would anybody with sufficient privileges be able to move this page?
1783          * Some pages just aren't movable.
1784          *
1785          * @return Bool TRUE or FALSE
1786          */
1787         public function isMovable() {
1788                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
1789                         // Interwiki title or immovable namespace. Hooks don't get to override here
1790                         return false;
1791                 }
1792
1793                 $result = true;
1794                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1795                 return $result;
1796         }
1797
1798         /**
1799          * Can $wgUser read this page?
1800          *
1801          * @return Bool
1802          * @todo fold these checks into userCan()
1803          */
1804         public function userCanRead() {
1805                 global $wgUser, $wgGroupPermissions;
1806
1807                 static $useShortcut = null;
1808
1809                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1810                 if ( is_null( $useShortcut ) ) {
1811                         global $wgRevokePermissions;
1812                         $useShortcut = true;
1813                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1814                                 # Not a public wiki, so no shortcut
1815                                 $useShortcut = false;
1816                         } elseif ( !empty( $wgRevokePermissions ) ) {
1817                                 /**
1818                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1819                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1820                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1821                                  * reading is allowed.
1822                                  */
1823                                 foreach ( $wgRevokePermissions as $perms ) {
1824                                         if ( !empty( $perms['read'] ) ) {
1825                                                 # We might be removing the read right from the user, so no shortcut
1826                                                 $useShortcut = false;
1827                                                 break;
1828                                         }
1829                                 }
1830                         }
1831                 }
1832
1833                 $result = null;
1834                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1835                 if ( $result !== null ) {
1836                         return $result;
1837                 }
1838
1839                 # Shortcut for public wikis, allows skipping quite a bit of code
1840                 if ( $useShortcut ) {
1841                         return true;
1842                 }
1843
1844                 if ( $wgUser->isAllowed( 'read' ) ) {
1845                         return true;
1846                 } else {
1847                         global $wgWhitelistRead;
1848
1849                         # Always grant access to the login page.
1850                         # Even anons need to be able to log in.
1851                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1852                                 return true;
1853                         }
1854
1855                         # Bail out if there isn't whitelist
1856                         if ( !is_array( $wgWhitelistRead ) ) {
1857                                 return false;
1858                         }
1859
1860                         # Check for explicit whitelisting
1861                         $name = $this->getPrefixedText();
1862                         $dbName = $this->getPrefixedDBKey();
1863                         // Check with and without underscores
1864                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1865                                 return true;
1866
1867                         # Old settings might have the title prefixed with
1868                         # a colon for main-namespace pages
1869                         if ( $this->getNamespace() == NS_MAIN ) {
1870                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1871                                         return true;
1872                                 }
1873                         }
1874
1875                         # If it's a special page, ditch the subpage bit and check again
1876                         if ( $this->getNamespace() == NS_SPECIAL ) {
1877                                 $name = $this->getDBkey();
1878                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1879                                 if ( $name === false ) {
1880                                         # Invalid special page, but we show standard login required message
1881                                         return false;
1882                                 }
1883
1884                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1885                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1886                                         return true;
1887                                 }
1888                         }
1889
1890                 }
1891                 return false;
1892         }
1893
1894         /**
1895          * Is this the mainpage?
1896          * @note Title::newFromText seams to be sufficiently optimized by the title
1897          * cache that we don't need to over-optimize by doing direct comparisons and
1898          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1899          * ends up reporting something differently than $title->isMainPage();
1900          *
1901          * @since 1.18
1902          * @return Bool
1903          */
1904         public function isMainPage() {
1905                 return $this->equals( Title::newMainPage() );
1906         }
1907
1908         /**
1909          * Is this a talk page of some sort?
1910          *
1911          * @return Bool
1912          */
1913         public function isTalkPage() {
1914                 return MWNamespace::isTalk( $this->getNamespace() );
1915         }
1916
1917         /**
1918          * Is this a subpage?
1919          *
1920          * @return Bool
1921          */
1922         public function isSubpage() {
1923                 return MWNamespace::hasSubpages( $this->mNamespace )
1924                         ? strpos( $this->getText(), '/' ) !== false
1925                         : false;
1926         }
1927
1928         /**
1929          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1930          *
1931          * @return Bool
1932          */
1933         public function hasSubpages() {
1934                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1935                         # Duh
1936                         return false;
1937                 }
1938
1939                 # We dynamically add a member variable for the purpose of this method
1940                 # alone to cache the result.  There's no point in having it hanging
1941                 # around uninitialized in every Title object; therefore we only add it
1942                 # if needed and don't declare it statically.
1943                 if ( isset( $this->mHasSubpages ) ) {
1944                         return $this->mHasSubpages;
1945                 }
1946
1947                 $subpages = $this->getSubpages( 1 );
1948                 if ( $subpages instanceof TitleArray ) {
1949                         return $this->mHasSubpages = (bool)$subpages->count();
1950                 }
1951                 return $this->mHasSubpages = false;
1952         }
1953
1954         /**
1955          * Get all subpages of this page.
1956          *
1957          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1958          * @return mixed TitleArray, or empty array if this page's namespace
1959          *  doesn't allow subpages
1960          */
1961         public function getSubpages( $limit = -1 ) {
1962                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1963                         return array();
1964                 }
1965
1966                 $dbr = wfGetDB( DB_SLAVE );
1967                 $conds['page_namespace'] = $this->getNamespace();
1968                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1969                 $options = array();
1970                 if ( $limit > -1 ) {
1971                         $options['LIMIT'] = $limit;
1972                 }
1973                 return $this->mSubpages = TitleArray::newFromResult(
1974                         $dbr->select( 'page',
1975                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1976                                 $conds,
1977                                 __METHOD__,
1978                                 $options
1979                         )
1980                 );
1981         }
1982
1983         /**
1984          * Does that page contain wikitext, or it is JS, CSS or whatever?
1985          *
1986          * @return Bool
1987          */
1988         public function isWikitextPage() {
1989                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1990                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1991                 return $retval;
1992         }
1993
1994         /**
1995          * Could this page contain custom CSS or JavaScript, based
1996          * on the title?
1997          *
1998          * @return Bool
1999          */
2000         public function isCssOrJsPage() {
2001                 $retval = $this->mNamespace == NS_MEDIAWIKI
2002                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
2003                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
2004                 return $retval;
2005         }
2006
2007         /**
2008          * Is this a .css or .js subpage of a user page?
2009          * @return Bool
2010          */
2011         public function isCssJsSubpage() {
2012                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2013         }
2014
2015         /**
2016          * Is this a *valid* .css or .js subpage of a user page?
2017          *
2018          * @return Bool
2019          * @deprecated since 1.17
2020          */
2021         public function isValidCssJsSubpage() {
2022                 return $this->isCssJsSubpage();
2023         }
2024
2025         /**
2026          * Trim down a .css or .js subpage title to get the corresponding skin name
2027          *
2028          * @return string containing skin name from .css or .js subpage title
2029          */
2030         public function getSkinFromCssJsSubpage() {
2031                 $subpage = explode( '/', $this->mTextform );
2032                 $subpage = $subpage[ count( $subpage ) - 1 ];
2033                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
2034         }
2035
2036         /**
2037          * Is this a .css subpage of a user page?
2038          *
2039          * @return Bool
2040          */
2041         public function isCssSubpage() {
2042                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2043         }
2044
2045         /**
2046          * Is this a .js subpage of a user page?
2047          *
2048          * @return Bool
2049          */
2050         public function isJsSubpage() {
2051                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2052         }
2053
2054         /**
2055          * Protect css subpages of user pages: can $wgUser edit
2056          * this page?
2057          *
2058          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2059          * @return Bool
2060          */
2061         public function userCanEditCssSubpage() {
2062                 global $wgUser;
2063                 wfDeprecated( __METHOD__ );
2064                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2065                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2066         }
2067
2068         /**
2069          * Protect js subpages of user pages: can $wgUser edit
2070          * this page?
2071          *
2072          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2073          * @return Bool
2074          */
2075         public function userCanEditJsSubpage() {
2076                 global $wgUser;
2077                 wfDeprecated( __METHOD__ );
2078                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2079                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2080         }
2081
2082         /**
2083          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2084          *
2085          * @return Bool If the page is subject to cascading restrictions.
2086          */
2087         public function isCascadeProtected() {
2088                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2089                 return ( $sources > 0 );
2090         }
2091
2092         /**
2093          * Cascading protection: Get the source of any cascading restrictions on this page.
2094          *
2095          * @param $getPages Bool Whether or not to retrieve the actual pages
2096          *        that the restrictions have come from.
2097          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2098          *     have come, false for none, or true if such restrictions exist, but $getPages
2099          *     was not set.  The restriction array is an array of each type, each of which
2100          *     contains a array of unique groups.
2101          */
2102         public function getCascadeProtectionSources( $getPages = true ) {
2103                 global $wgContLang;
2104                 $pagerestrictions = array();
2105
2106                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2107                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2108                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2109                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2110                 }
2111
2112                 wfProfileIn( __METHOD__ );
2113
2114                 $dbr = wfGetDB( DB_SLAVE );
2115
2116                 if ( $this->getNamespace() == NS_FILE ) {
2117                         $tables = array( 'imagelinks', 'page_restrictions' );
2118                         $where_clauses = array(
2119                                 'il_to' => $this->getDBkey(),
2120                                 'il_from=pr_page',
2121                                 'pr_cascade' => 1
2122                         );
2123                 } else {
2124                         $tables = array( 'templatelinks', 'page_restrictions' );
2125                         $where_clauses = array(
2126                                 'tl_namespace' => $this->getNamespace(),
2127                                 'tl_title' => $this->getDBkey(),
2128                                 'tl_from=pr_page',
2129                                 'pr_cascade' => 1
2130                         );
2131                 }
2132
2133                 if ( $getPages ) {
2134                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2135                                                    'pr_expiry', 'pr_type', 'pr_level' );
2136                         $where_clauses[] = 'page_id=pr_page';
2137                         $tables[] = 'page';
2138                 } else {
2139                         $cols = array( 'pr_expiry' );
2140                 }
2141
2142                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2143
2144                 $sources = $getPages ? array() : false;
2145                 $now = wfTimestampNow();
2146                 $purgeExpired = false;
2147
2148                 foreach ( $res as $row ) {
2149                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2150                         if ( $expiry > $now ) {
2151                                 if ( $getPages ) {
2152                                         $page_id = $row->pr_page;
2153                                         $page_ns = $row->page_namespace;
2154                                         $page_title = $row->page_title;
2155                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2156                                         # Add groups needed for each restriction type if its not already there
2157                                         # Make sure this restriction type still exists
2158
2159                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2160                                                 $pagerestrictions[$row->pr_type] = array();
2161                                         }
2162
2163                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2164                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2165                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2166                                         }
2167                                 } else {
2168                                         $sources = true;
2169                                 }
2170                         } else {
2171                                 // Trigger lazy purge of expired restrictions from the db
2172                                 $purgeExpired = true;
2173                         }
2174                 }
2175                 if ( $purgeExpired ) {
2176                         Title::purgeExpiredRestrictions();
2177                 }
2178
2179                 if ( $getPages ) {
2180                         $this->mCascadeSources = $sources;
2181                         $this->mCascadingRestrictions = $pagerestrictions;
2182                 } else {
2183                         $this->mHasCascadingRestrictions = $sources;
2184                 }
2185
2186                 wfProfileOut( __METHOD__ );
2187                 return array( $sources, $pagerestrictions );
2188         }
2189
2190         /**
2191          * Returns cascading restrictions for the current article
2192          *
2193          * @return Boolean
2194          */
2195         function areRestrictionsCascading() {
2196                 if ( !$this->mRestrictionsLoaded ) {
2197                         $this->loadRestrictions();
2198                 }
2199
2200                 return $this->mCascadeRestriction;
2201         }
2202
2203         /**
2204          * Loads a string into mRestrictions array
2205          *
2206          * @param $res Resource restrictions as an SQL result.
2207          * @param $oldFashionedRestrictions String comma-separated list of page
2208          *        restrictions from page table (pre 1.10)
2209          */
2210         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2211                 $rows = array();
2212
2213                 foreach ( $res as $row ) {
2214                         $rows[] = $row;
2215                 }
2216
2217                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2218         }
2219
2220         /**
2221          * Compiles list of active page restrictions from both page table (pre 1.10)
2222          * and page_restrictions table for this existing page.
2223          * Public for usage by LiquidThreads.
2224          *
2225          * @param $rows array of db result objects
2226          * @param $oldFashionedRestrictions string comma-separated list of page
2227          *        restrictions from page table (pre 1.10)
2228          */
2229         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2230                 global $wgContLang;
2231                 $dbr = wfGetDB( DB_SLAVE );
2232
2233                 $restrictionTypes = $this->getRestrictionTypes();
2234
2235                 foreach ( $restrictionTypes as $type ) {
2236                         $this->mRestrictions[$type] = array();
2237                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2238                 }
2239
2240                 $this->mCascadeRestriction = false;
2241
2242                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2243
2244                 if ( $oldFashionedRestrictions === null ) {
2245                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2246                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2247                 }
2248
2249                 if ( $oldFashionedRestrictions != '' ) {
2250
2251                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2252                                 $temp = explode( '=', trim( $restrict ) );
2253                                 if ( count( $temp ) == 1 ) {
2254                                         // old old format should be treated as edit/move restriction
2255                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2256                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2257                                 } else {
2258                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2259                                 }
2260                         }
2261
2262                         $this->mOldRestrictions = true;
2263
2264                 }
2265
2266                 if ( count( $rows ) ) {
2267                         # Current system - load second to make them override.
2268                         $now = wfTimestampNow();
2269                         $purgeExpired = false;
2270
2271                         # Cycle through all the restrictions.
2272                         foreach ( $rows as $row ) {
2273
2274                                 // Don't take care of restrictions types that aren't allowed
2275                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2276                                         continue;
2277
2278                                 // This code should be refactored, now that it's being used more generally,
2279                                 // But I don't really see any harm in leaving it in Block for now -werdna
2280                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2281
2282                                 // Only apply the restrictions if they haven't expired!
2283                                 if ( !$expiry || $expiry > $now ) {
2284                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2285                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2286
2287                                         $this->mCascadeRestriction |= $row->pr_cascade;
2288                                 } else {
2289                                         // Trigger a lazy purge of expired restrictions
2290                                         $purgeExpired = true;
2291                                 }
2292                         }
2293
2294                         if ( $purgeExpired ) {
2295                                 Title::purgeExpiredRestrictions();
2296                         }
2297                 }
2298
2299                 $this->mRestrictionsLoaded = true;
2300         }
2301
2302         /**
2303          * Load restrictions from the page_restrictions table
2304          *
2305          * @param $oldFashionedRestrictions String comma-separated list of page
2306          *        restrictions from page table (pre 1.10)
2307          */
2308         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2309                 global $wgContLang;
2310                 if ( !$this->mRestrictionsLoaded ) {
2311                         if ( $this->exists() ) {
2312                                 $dbr = wfGetDB( DB_SLAVE );
2313
2314                                 $res = $dbr->select(
2315                                         'page_restrictions',
2316                                         '*',
2317                                         array( 'pr_page' => $this->getArticleId() ),
2318                                         __METHOD__
2319                                 );
2320
2321                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2322                         } else {
2323                                 $title_protection = $this->getTitleProtection();
2324
2325                                 if ( $title_protection ) {
2326                                         $now = wfTimestampNow();
2327                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2328
2329                                         if ( !$expiry || $expiry > $now ) {
2330                                                 // Apply the restrictions
2331                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2332                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2333                                         } else { // Get rid of the old restrictions
2334                                                 Title::purgeExpiredRestrictions();
2335                                                 $this->mTitleProtection = false;
2336                                         }
2337                                 } else {
2338                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2339                                 }
2340                                 $this->mRestrictionsLoaded = true;
2341                         }
2342                 }
2343         }
2344
2345         /**
2346          * Purge expired restrictions from the page_restrictions table
2347          */
2348         static function purgeExpiredRestrictions() {
2349                 $dbw = wfGetDB( DB_MASTER );
2350                 $dbw->delete(
2351                         'page_restrictions',
2352                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2353                         __METHOD__
2354                 );
2355
2356                 $dbw->delete(
2357                         'protected_titles',
2358                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2359                         __METHOD__
2360                 );
2361         }
2362
2363         /**
2364          * Accessor/initialisation for mRestrictions
2365          *
2366          * @param $action String action that permission needs to be checked for
2367          * @return Array of Strings the array of groups allowed to edit this article
2368          */
2369         public function getRestrictions( $action ) {
2370                 if ( !$this->mRestrictionsLoaded ) {
2371                         $this->loadRestrictions();
2372                 }
2373                 return isset( $this->mRestrictions[$action] )
2374                                 ? $this->mRestrictions[$action]
2375                                 : array();
2376         }
2377
2378         /**
2379          * Get the expiry time for the restriction against a given action
2380          *
2381          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2382          *      or not protected at all, or false if the action is not recognised.
2383          */
2384         public function getRestrictionExpiry( $action ) {
2385                 if ( !$this->mRestrictionsLoaded ) {
2386                         $this->loadRestrictions();
2387                 }
2388                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2389         }
2390
2391         /**
2392          * Is there a version of this page in the deletion archive?
2393          *
2394          * @param $includeSuppressed Boolean Include suppressed revisions?
2395          * @return Int the number of archived revisions
2396          */
2397         public function isDeleted( $includeSuppressed = false ) {
2398                 if ( $this->getNamespace() < 0 ) {
2399                         $n = 0;
2400                 } else {
2401                         $dbr = wfGetDB( DB_SLAVE );
2402                         $conditions = array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() );
2403
2404                         if( !$includeSuppressed ) {
2405                                 $suppressedTextBits = Revision::DELETED_TEXT | Revision::DELETED_RESTRICTED;
2406                                 $conditions[] = $dbr->bitAnd('ar_deleted', $suppressedTextBits ) .
2407                                 ' != ' . $suppressedTextBits;
2408                         }
2409
2410                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2411                                 $conditions,
2412                                 __METHOD__
2413                         );
2414                         if ( $this->getNamespace() == NS_FILE ) {
2415                                 $fconditions = array( 'fa_name' => $this->getDBkey() );
2416                                 if( !$includeSuppressed ) {
2417                                         $suppressedTextBits = File::DELETED_FILE | File::DELETED_RESTRICTED;
2418                                         $fconditions[] = $dbr->bitAnd('fa_deleted', $suppressedTextBits ) .
2419                                         ' != ' . $suppressedTextBits;
2420                                 }
2421
2422                                 $n += $dbr->selectField( 'filearchive',
2423                                         'COUNT(*)',
2424                                         $fconditions,
2425                                         __METHOD__
2426                                 );
2427                         }
2428                 }
2429                 return (int)$n;
2430         }
2431
2432         /**
2433          * Is there a version of this page in the deletion archive?
2434          *
2435          * @return Boolean
2436          */
2437         public function isDeletedQuick() {
2438                 if ( $this->getNamespace() < 0 ) {
2439                         return false;
2440                 }
2441                 $dbr = wfGetDB( DB_SLAVE );
2442                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2443                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2444                         __METHOD__
2445                 );
2446                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2447                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2448                                 array( 'fa_name' => $this->getDBkey() ),
2449                                 __METHOD__
2450                         );
2451                 }
2452                 return $deleted;
2453         }
2454
2455         /**
2456          * Get the article ID for this Title from the link cache,
2457          * adding it if necessary
2458          *
2459          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2460          *  for update
2461          * @return Int the ID
2462          */
2463         public function getArticleID( $flags = 0 ) {
2464                 if ( $this->getNamespace() < 0 ) {
2465                         return $this->mArticleID = 0;
2466                 }
2467                 $linkCache = LinkCache::singleton();
2468                 if ( $flags & self::GAID_FOR_UPDATE ) {
2469                         $oldUpdate = $linkCache->forUpdate( true );
2470                         $linkCache->clearLink( $this );
2471                         $this->mArticleID = $linkCache->addLinkObj( $this );
2472                         $linkCache->forUpdate( $oldUpdate );
2473                 } else {
2474                         if ( -1 == $this->mArticleID ) {
2475                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2476                         }
2477                 }
2478                 return $this->mArticleID;
2479         }
2480
2481         /**
2482          * Is this an article that is a redirect page?
2483          * Uses link cache, adding it if necessary
2484          *
2485          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2486          * @return Bool
2487          */
2488         public function isRedirect( $flags = 0 ) {
2489                 if ( !is_null( $this->mRedirect ) ) {
2490                         return $this->mRedirect;
2491                 }
2492                 # Calling getArticleID() loads the field from cache as needed
2493                 if ( !$this->getArticleID( $flags ) ) {
2494                         return $this->mRedirect = false;
2495                 }
2496                 $linkCache = LinkCache::singleton();
2497                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2498
2499                 return $this->mRedirect;
2500         }
2501
2502         /**
2503          * What is the length of this page?
2504          * Uses link cache, adding it if necessary
2505          *
2506          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2507          * @return Int
2508          */
2509         public function getLength( $flags = 0 ) {
2510                 if ( $this->mLength != -1 ) {
2511                         return $this->mLength;
2512                 }
2513                 # Calling getArticleID() loads the field from cache as needed
2514                 if ( !$this->getArticleID( $flags ) ) {
2515                         return $this->mLength = 0;
2516                 }
2517                 $linkCache = LinkCache::singleton();
2518                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2519
2520                 return $this->mLength;
2521         }
2522
2523         /**
2524          * What is the page_latest field for this page?
2525          *
2526          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2527          * @return Int or 0 if the page doesn't exist
2528          */
2529         public function getLatestRevID( $flags = 0 ) {
2530                 if ( $this->mLatestID !== false ) {
2531                         return intval( $this->mLatestID );
2532                 }
2533                 # Calling getArticleID() loads the field from cache as needed
2534                 if ( !$this->getArticleID( $flags ) ) {
2535                         return $this->mLatestID = 0;
2536                 }
2537                 $linkCache = LinkCache::singleton();
2538                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2539
2540                 return $this->mLatestID;
2541         }
2542
2543         /**
2544          * This clears some fields in this object, and clears any associated
2545          * keys in the "bad links" section of the link cache.
2546          *
2547          * - This is called from Article::doEdit() and Article::insertOn() to allow
2548          * loading of the new page_id. It's also called from
2549          * Article::doDeleteArticle()
2550          *
2551          * @param $newid Int the new Article ID
2552          */
2553         public function resetArticleID( $newid ) {
2554                 $linkCache = LinkCache::singleton();
2555                 $linkCache->clearLink( $this );
2556
2557                 if ( $newid === false ) {
2558                         $this->mArticleID = -1;
2559                 } else {
2560                         $this->mArticleID = intval( $newid );
2561                 }
2562                 $this->mRestrictionsLoaded = false;
2563                 $this->mRestrictions = array();
2564                 $this->mRedirect = null;
2565                 $this->mLength = -1;
2566                 $this->mLatestID = false;
2567         }
2568
2569         /**
2570          * Updates page_touched for this page; called from LinksUpdate.php
2571          *
2572          * @return Bool true if the update succeded
2573          */
2574         public function invalidateCache() {
2575                 if ( wfReadOnly() ) {
2576                         return;
2577                 }
2578                 $dbw = wfGetDB( DB_MASTER );
2579                 $success = $dbw->update(
2580                         'page',
2581                         array( 'page_touched' => $dbw->timestamp() ),
2582                         $this->pageCond(),
2583                         __METHOD__
2584                 );
2585                 HTMLFileCache::clearFileCache( $this );
2586                 return $success;
2587         }
2588
2589         /**
2590          * Prefix some arbitrary text with the namespace or interwiki prefix
2591          * of this object
2592          *
2593          * @param $name String the text
2594          * @return String the prefixed text
2595          * @private
2596          */
2597         private function prefix( $name ) {
2598                 $p = '';
2599                 if ( $this->mInterwiki != '' ) {
2600                         $p = $this->mInterwiki . ':';
2601                 }
2602
2603                 if ( 0 != $this->mNamespace ) {
2604                         $p .= $this->getNsText() . ':';
2605                 }
2606                 return $p . $name;
2607         }
2608
2609         /**
2610          * Returns a simple regex that will match on characters and sequences invalid in titles.
2611          * Note that this doesn't pick up many things that could be wrong with titles, but that
2612          * replacing this regex with something valid will make many titles valid.
2613          *
2614          * @return String regex string
2615          */
2616         static function getTitleInvalidRegex() {
2617                 static $rxTc = false;
2618                 if ( !$rxTc ) {
2619                         # Matching titles will be held as illegal.
2620                         $rxTc = '/' .
2621                                 # Any character not allowed is forbidden...
2622                                 '[^' . Title::legalChars() . ']' .
2623                                 # URL percent encoding sequences interfere with the ability
2624                                 # to round-trip titles -- you can't link to them consistently.
2625                                 '|%[0-9A-Fa-f]{2}' .
2626                                 # XML/HTML character references produce similar issues.
2627                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2628                                 '|&#[0-9]+;' .
2629                                 '|&#x[0-9A-Fa-f]+;' .
2630                                 '/S';
2631                 }
2632
2633                 return $rxTc;
2634         }
2635
2636         /**
2637          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2638          *
2639          * @param $text String containing title to capitalize
2640          * @param $ns int namespace index, defaults to NS_MAIN
2641          * @return String containing capitalized title
2642          */
2643         public static function capitalize( $text, $ns = NS_MAIN ) {
2644                 global $wgContLang;
2645
2646                 if ( MWNamespace::isCapitalized( $ns ) ) {
2647                         return $wgContLang->ucfirst( $text );
2648                 } else {
2649                         return $text;
2650                 }
2651         }
2652
2653         /**
2654          * Secure and split - main initialisation function for this object
2655          *
2656          * Assumes that mDbkeyform has been set, and is urldecoded
2657          * and uses underscores, but not otherwise munged.  This function
2658          * removes illegal characters, splits off the interwiki and
2659          * namespace prefixes, sets the other forms, and canonicalizes
2660          * everything.
2661          *
2662          * @return Bool true on success
2663          */
2664         private function secureAndSplit() {
2665                 global $wgContLang, $wgLocalInterwiki;
2666
2667                 # Initialisation
2668                 $this->mInterwiki = $this->mFragment = '';
2669                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2670
2671                 $dbkey = $this->mDbkeyform;
2672
2673                 # Strip Unicode bidi override characters.
2674                 # Sometimes they slip into cut-n-pasted page titles, where the
2675                 # override chars get included in list displays.
2676                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2677
2678                 # Clean up whitespace
2679                 # Note: use of the /u option on preg_replace here will cause
2680                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2681                 # conveniently disabling them.
2682                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2683                 $dbkey = trim( $dbkey, '_' );
2684
2685                 if ( $dbkey == '' ) {
2686                         return false;
2687                 }
2688
2689                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2690                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2691                         return false;
2692                 }
2693
2694                 $this->mDbkeyform = $dbkey;
2695
2696                 # Initial colon indicates main namespace rather than specified default
2697                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2698                 if ( ':' == $dbkey[0] ) {
2699                         $this->mNamespace = NS_MAIN;
2700                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2701                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2702                 }
2703
2704                 # Namespace or interwiki prefix
2705                 $firstPass = true;
2706                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2707                 do {
2708                         $m = array();
2709                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2710                                 $p = $m[1];
2711                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2712                                         # Ordinary namespace
2713                                         $dbkey = $m[2];
2714                                         $this->mNamespace = $ns;
2715                                         # For Talk:X pages, check if X has a "namespace" prefix
2716                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2717                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2718                                                         # Disallow Talk:File:x type titles...
2719                                                         return false;
2720                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2721                                                         # Disallow Talk:Interwiki:x type titles...
2722                                                         return false;
2723                                                 }
2724                                         }
2725                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2726                                         if ( !$firstPass ) {
2727                                                 # Can't make a local interwiki link to an interwiki link.
2728                                                 # That's just crazy!
2729                                                 return false;
2730                                         }
2731
2732                                         # Interwiki link
2733                                         $dbkey = $m[2];
2734                                         $this->mInterwiki = $wgContLang->lc( $p );
2735
2736                                         # Redundant interwiki prefix to the local wiki
2737                                         if ( $wgLocalInterwiki !== false
2738                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2739                                         {
2740                                                 if ( $dbkey == '' ) {
2741                                                         # Can't have an empty self-link
2742                                                         return false;
2743                                                 }
2744                                                 $this->mInterwiki = '';
2745                                                 $firstPass = false;
2746                                                 # Do another namespace split...
2747                                                 continue;
2748                                         }
2749
2750                                         # If there's an initial colon after the interwiki, that also
2751                                         # resets the default namespace
2752                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2753                                                 $this->mNamespace = NS_MAIN;
2754                                                 $dbkey = substr( $dbkey, 1 );
2755                                         }
2756                                 }
2757                                 # If there's no recognized interwiki or namespace,
2758                                 # then let the colon expression be part of the title.
2759                         }
2760                         break;
2761                 } while ( true );
2762
2763                 # We already know that some pages won't be in the database!
2764                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2765                         $this->mArticleID = 0;
2766                 }
2767                 $fragment = strstr( $dbkey, '#' );
2768                 if ( false !== $fragment ) {
2769                         $this->setFragment( $fragment );
2770                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2771                         # remove whitespace again: prevents "Foo_bar_#"
2772                         # becoming "Foo_bar_"
2773                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2774                 }
2775
2776                 # Reject illegal characters.
2777                 $rxTc = self::getTitleInvalidRegex();
2778                 if ( preg_match( $rxTc, $dbkey ) ) {
2779                         return false;
2780                 }
2781
2782                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2783                 # reachable due to the way web browsers deal with 'relative' URLs.
2784                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2785                 if ( strpos( $dbkey, '.' ) !== false &&
2786                          ( $dbkey === '.' || $dbkey === '..' ||
2787                            strpos( $dbkey, './' ) === 0  ||
2788                            strpos( $dbkey, '../' ) === 0 ||
2789                            strpos( $dbkey, '/./' ) !== false ||
2790                            strpos( $dbkey, '/../' ) !== false  ||
2791                            substr( $dbkey, -2 ) == '/.' ||
2792                            substr( $dbkey, -3 ) == '/..' ) )
2793                 {
2794                         return false;
2795                 }
2796
2797                 # Magic tilde sequences? Nu-uh!
2798                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2799                         return false;
2800                 }
2801
2802                 # Limit the size of titles to 255 bytes. This is typically the size of the
2803                 # underlying database field. We make an exception for special pages, which
2804                 # don't need to be stored in the database, and may edge over 255 bytes due
2805                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2806                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2807                   strlen( $dbkey ) > 512 )
2808                 {
2809                         return false;
2810                 }
2811
2812                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2813                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2814                 # other site might be case-sensitive.
2815                 $this->mUserCaseDBKey = $dbkey;
2816                 if ( $this->mInterwiki == '' ) {
2817                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2818                 }
2819
2820                 # Can't make a link to a namespace alone... "empty" local links can only be
2821                 # self-links with a fragment identifier.
2822                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2823                         return false;
2824                 }
2825
2826                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2827                 // IP names are not allowed for accounts, and can only be referring to
2828                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2829                 // there are numerous ways to present the same IP. Having sp:contribs scan
2830                 // them all is silly and having some show the edits and others not is
2831                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2832                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2833                         ? IP::sanitizeIP( $dbkey )
2834                         : $dbkey;
2835
2836                 // Any remaining initial :s are illegal.
2837                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2838                         return false;
2839                 }
2840
2841                 # Fill fields
2842                 $this->mDbkeyform = $dbkey;
2843                 $this->mUrlform = wfUrlencode( $dbkey );
2844
2845                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2846
2847                 return true;
2848         }
2849
2850         /**
2851          * Set the fragment for this title. Removes the first character from the
2852          * specified fragment before setting, so it assumes you're passing it with
2853          * an initial "#".
2854          *
2855          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2856          * Still in active use privately.
2857          *
2858          * @param $fragment String text
2859          */
2860         public function setFragment( $fragment ) {
2861                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2862         }
2863
2864         public function setInterwiki( $interwiki ) {
2865                 $this->mInterwiki = $interwiki;
2866         }
2867
2868         /**
2869          * Get a Title object associated with the talk page of this article
2870          *
2871          * @return Title the object for the talk page
2872          */
2873         public function getTalkPage() {
2874                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2875         }
2876
2877         /**
2878          * Get a title object associated with the subject page of this
2879          * talk page
2880          *
2881          * @return Title the object for the subject page
2882          */
2883         public function getSubjectPage() {
2884                 // Is this the same title?
2885                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2886                 if ( $this->getNamespace() == $subjectNS ) {
2887                         return $this;
2888                 }
2889                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2890         }
2891
2892         /**
2893          * Get an array of Title objects linking to this Title
2894          * Also stores the IDs in the link cache.
2895          *
2896          * WARNING: do not use this function on arbitrary user-supplied titles!
2897          * On heavily-used templates it will max out the memory.
2898          *
2899          * @param $options Array: may be FOR UPDATE
2900          * @param $table String: table name
2901          * @param $prefix String: fields prefix
2902          * @return Array of Title objects linking here
2903          */
2904         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2905                 $linkCache = LinkCache::singleton();
2906
2907                 if ( count( $options ) > 0 ) {
2908                         $db = wfGetDB( DB_MASTER );
2909                 } else {
2910                         $db = wfGetDB( DB_SLAVE );
2911                 }
2912
2913                 $res = $db->select(
2914                         array( 'page', $table ),
2915                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2916                         array(
2917                                 "{$prefix}_from=page_id",
2918                                 "{$prefix}_namespace" => $this->getNamespace(),
2919                                 "{$prefix}_title"     => $this->getDBkey() ),
2920                         __METHOD__,
2921                         $options
2922                 );
2923
2924                 $retVal = array();
2925                 if ( $db->numRows( $res ) ) {
2926                         foreach ( $res as $row ) {
2927                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2928                                 if ( $titleObj ) {
2929                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2930                                         $retVal[] = $titleObj;
2931                                 }
2932                         }
2933                 }
2934                 return $retVal;
2935         }
2936
2937         /**
2938          * Get an array of Title objects using this Title as a template
2939          * Also stores the IDs in the link cache.
2940          *
2941          * WARNING: do not use this function on arbitrary user-supplied titles!
2942          * On heavily-used templates it will max out the memory.
2943          *
2944          * @param $options Array: may be FOR UPDATE
2945          * @return Array of Title the Title objects linking here
2946          */
2947         public function getTemplateLinksTo( $options = array() ) {
2948                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2949         }
2950
2951         /**
2952          * Get an array of Title objects referring to non-existent articles linked from this page
2953          *
2954          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2955          * @return Array of Title the Title objects
2956          */
2957         public function getBrokenLinksFrom() {
2958                 if ( $this->getArticleId() == 0 ) {
2959                         # All links from article ID 0 are false positives
2960                         return array();
2961                 }
2962
2963                 $dbr = wfGetDB( DB_SLAVE );
2964                 $res = $dbr->select(
2965                         array( 'page', 'pagelinks' ),
2966                         array( 'pl_namespace', 'pl_title' ),
2967                         array(
2968                                 'pl_from' => $this->getArticleId(),
2969                                 'page_namespace IS NULL'
2970                         ),
2971                         __METHOD__, array(),
2972                         array(
2973                                 'page' => array(
2974                                         'LEFT JOIN',
2975                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2976                                 )
2977                         )
2978                 );
2979
2980                 $retVal = array();
2981                 foreach ( $res as $row ) {
2982                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2983                 }
2984                 return $retVal;
2985         }
2986
2987
2988         /**
2989          * Get a list of URLs to purge from the Squid cache when this
2990          * page changes
2991          *
2992          * @return Array of String the URLs
2993          */
2994         public function getSquidURLs() {
2995                 global $wgContLang;
2996
2997                 $urls = array(
2998                         $this->getInternalURL(),
2999                         $this->getInternalURL( 'action=history' )
3000                 );
3001
3002                 // purge variant urls as well
3003                 if ( $wgContLang->hasVariants() ) {
3004                         $variants = $wgContLang->getVariants();
3005                         foreach ( $variants as $vCode ) {
3006                                 $urls[] = $this->getInternalURL( '', $vCode );
3007                         }
3008                 }
3009
3010                 return $urls;
3011         }
3012
3013         /**
3014          * Purge all applicable Squid URLs
3015          */
3016         public function purgeSquid() {
3017                 global $wgUseSquid;
3018                 if ( $wgUseSquid ) {
3019                         $urls = $this->getSquidURLs();
3020                         $u = new SquidUpdate( $urls );
3021                         $u->doUpdate();
3022                 }
3023         }
3024
3025         /**
3026          * Move this page without authentication
3027          *
3028          * @param $nt Title the new page Title
3029          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3030          */
3031         public function moveNoAuth( &$nt ) {
3032                 return $this->moveTo( $nt, false );
3033         }
3034
3035         /**
3036          * Check whether a given move operation would be valid.
3037          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3038          *
3039          * @param $nt Title the new title
3040          * @param $auth Bool indicates whether $wgUser's permissions
3041          *  should be checked
3042          * @param $reason String is the log summary of the move, used for spam checking
3043          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3044          */
3045         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3046                 global $wgUser;
3047
3048                 $errors = array();
3049                 if ( !$nt ) {
3050                         // Normally we'd add this to $errors, but we'll get
3051                         // lots of syntax errors if $nt is not an object
3052                         return array( array( 'badtitletext' ) );
3053                 }
3054                 if ( $this->equals( $nt ) ) {
3055                         $errors[] = array( 'selfmove' );
3056                 }
3057                 if ( !$this->isMovable() ) {
3058                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3059                 }
3060                 if ( $nt->getInterwiki() != '' ) {
3061                         $errors[] = array( 'immobile-target-namespace-iw' );
3062                 }
3063                 if ( !$nt->isMovable() ) {
3064                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3065                 }
3066
3067                 $oldid = $this->getArticleID();
3068                 $newid = $nt->getArticleID();
3069
3070                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3071                         $errors[] = array( 'articleexists' );
3072                 }
3073                 if ( ( $this->getDBkey() == '' ) ||
3074                          ( !$oldid ) ||
3075                          ( $nt->getDBkey() == '' ) ) {
3076                         $errors[] = array( 'badarticleerror' );
3077                 }
3078
3079                 // Image-specific checks
3080                 if ( $this->getNamespace() == NS_FILE ) {
3081                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3082                 }
3083
3084                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3085                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3086                 }
3087
3088                 if ( $auth ) {
3089                         $errors = wfMergeErrorArrays( $errors,
3090                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3091                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3092                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3093                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3094                 }
3095
3096                 $match = EditPage::matchSummarySpamRegex( $reason );
3097                 if ( $match !== false ) {
3098                         // This is kind of lame, won't display nice
3099                         $errors[] = array( 'spamprotectiontext' );
3100                 }
3101
3102                 $err = null;
3103                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3104                         $errors[] = array( 'hookaborted', $err );
3105                 }
3106
3107                 # The move is allowed only if (1) the target doesn't exist, or
3108                 # (2) the target is a redirect to the source, and has no history
3109                 # (so we can undo bad moves right after they're done).
3110
3111                 if ( 0 != $newid ) { # Target exists; check for validity
3112                         if ( !$this->isValidMoveTarget( $nt ) ) {
3113                                 $errors[] = array( 'articleexists' );
3114                         }
3115                 } else {
3116                         $tp = $nt->getTitleProtection();
3117                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3118                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3119                                 $errors[] = array( 'cantmove-titleprotected' );
3120                         }
3121                 }
3122                 if ( empty( $errors ) ) {
3123                         return true;
3124                 }
3125                 return $errors;
3126         }
3127
3128         /**
3129          * Check if the requested move target is a valid file move target
3130          * @param Title $nt Target title
3131          * @return array List of errors
3132          */
3133         protected function validateFileMoveOperation( $nt ) {
3134                 global $wgUser;
3135
3136                 $errors = array();
3137
3138                 if ( $nt->getNamespace() != NS_FILE ) {
3139                         $errors[] = array( 'imagenocrossnamespace' );
3140                 }
3141
3142                 $file = wfLocalFile( $this );
3143                 if ( $file->exists() ) {
3144                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3145                                 $errors[] = array( 'imageinvalidfilename' );
3146                         }
3147                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3148                                 $errors[] = array( 'imagetypemismatch' );
3149                         }
3150                 }
3151
3152                 $destFile = wfLocalFile( $nt );
3153                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3154                         $errors[] = array( 'file-exists-sharedrepo' );
3155                 }
3156
3157                 return $errors;
3158         }
3159
3160         /**
3161          * Move a title to a new location
3162          *
3163          * @param $nt Title the new title
3164          * @param $auth Bool indicates whether $wgUser's permissions
3165          *  should be checked
3166          * @param $reason String the reason for the move
3167          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3168          *  Ignored if the user doesn't have the suppressredirect right.
3169          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3170          */
3171         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3172                 global $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3173
3174                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3175                 if ( is_array( $err ) ) {
3176                         return $err;
3177                 }
3178
3179                 // If it is a file, move it first. It is done before all other moving stuff is
3180                 // done because it's hard to revert
3181                 $dbw = wfGetDB( DB_MASTER );
3182                 if ( $this->getNamespace() == NS_FILE ) {
3183                         $file = wfLocalFile( $this );
3184                         if ( $file->exists() ) {
3185                                 $status = $file->move( $nt );
3186                                 if ( !$status->isOk() ) {
3187                                         return $status->getErrorsArray();
3188                                 }
3189                         }
3190                 }
3191
3192                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3193                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3194                 $protected = $this->isProtected();
3195                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3196
3197                 // Do the actual move
3198                 $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3199                 if ( is_array( $err ) ) {
3200                         # @todo FIXME: What about the File we have already moved?
3201                         $dbw->rollback();
3202                         return $err;
3203                 }
3204
3205                 $redirid = $this->getArticleID();
3206
3207                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3208                 // cl_timestamp, which may disturb time-based lists on some sites.
3209                 $prefixes = $dbw->select(
3210                         'categorylinks',
3211                         array( 'cl_sortkey_prefix', 'cl_to' ),
3212                         array( 'cl_from' => $pageid ),
3213                         __METHOD__
3214                 );
3215                 foreach ( $prefixes as $prefixRow ) {
3216                         $prefix = $prefixRow->cl_sortkey_prefix;
3217                         $catTo = $prefixRow->cl_to;
3218                         $dbw->update( 'categorylinks',
3219                                 array(
3220                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3221                                                 $nt->getCategorySortkey( $prefix ) ),
3222                                         'cl_timestamp=cl_timestamp' ),
3223                                 array(
3224                                         'cl_from' => $pageid,
3225                                         'cl_to' => $catTo ),
3226                                 __METHOD__
3227                         );
3228                 }
3229
3230                 if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3231                         $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3232                         $dbw2->update( 'globaltemplatelinks',
3233                                                 array(  'gtl_from_namespace' => $nt->getNamespace(),
3234                                                                 'gtl_from_title' => $nt->getText() ),
3235                                                 array ( 'gtl_from_page' => $pageid ),
3236                                                 __METHOD__ );
3237                 }
3238
3239                 if ( $protected ) {
3240                         # Protect the redirect title as the title used to be...
3241                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3242                                 array(
3243                                         'pr_page'    => $redirid,
3244                                         'pr_type'    => 'pr_type',
3245                                         'pr_level'   => 'pr_level',
3246                                         'pr_cascade' => 'pr_cascade',
3247                                         'pr_user'    => 'pr_user',
3248                                         'pr_expiry'  => 'pr_expiry'
3249                                 ),
3250                                 array( 'pr_page' => $pageid ),
3251                                 __METHOD__,
3252                                 array( 'IGNORE' )
3253                         );
3254                         # Update the protection log
3255                         $log = new LogPage( 'protect' );
3256                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3257                         if ( $reason ) {
3258                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3259                         }
3260                         // @todo FIXME: $params?
3261                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3262                 }
3263
3264                 # Update watchlists
3265                 $oldnamespace = $this->getNamespace() & ~1;
3266                 $newnamespace = $nt->getNamespace() & ~1;
3267                 $oldtitle = $this->getDBkey();
3268                 $newtitle = $nt->getDBkey();
3269
3270                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3271                         WatchedItem::duplicateEntries( $this, $nt );
3272                 }
3273
3274                 # Update search engine
3275                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3276                 $u->doUpdate();
3277                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3278                 $u->doUpdate();
3279
3280                 $dbw->commit();
3281
3282                 # Update site_stats
3283                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3284                         # No longer a content page
3285                         # Not viewed, edited, removing
3286                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3287                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3288                         # Now a content page
3289                         # Not viewed, edited, adding
3290                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3291                 } elseif ( $pageCountChange ) {
3292                         # Redirect added
3293                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3294                 } else {
3295                         # Nothing special
3296                         $u = false;
3297                 }
3298                 if ( $u ) {
3299                         $u->doUpdate();
3300                 }
3301
3302                 # Update message cache for interface messages
3303                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3304                         # @bug 17860: old article can be deleted, if this the case,
3305                         # delete it from message cache
3306                         if ( $this->getArticleID() === 0 ) {
3307                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3308                         } else {
3309                                 $oldarticle = new Article( $this );
3310                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3311                         }
3312                 }
3313                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3314                         $newarticle = new Article( $nt );
3315                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3316                 }
3317
3318                 global $wgUser;
3319                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3320                 return true;
3321         }
3322
3323         /**
3324          * Move page to a title which is either a redirect to the
3325          * source page or nonexistent
3326          *
3327          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3328          * @param $reason String The reason for the move
3329          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3330          *   if the user doesn't have the suppressredirect right
3331          */
3332         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3333                 global $wgUser, $wgContLang, $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3334
3335                 if ( $nt->exists() ) {
3336                         $moveOverRedirect = true;
3337                         $logType = 'move_redir';
3338                 } else {
3339                         $moveOverRedirect = false;
3340                         $logType = 'move';
3341                 }
3342
3343                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3344
3345                 $logEntry = new ManualLogEntry( 'move', $logType );
3346                 $logEntry->setPerformer( $wgUser );
3347                 $logEntry->setTarget( $this );
3348                 $logEntry->setComment( $reason );
3349                 $logEntry->setParameters( array(
3350                         '4::target' => $nt->getPrefixedText(),
3351                         '5::noredir' => $redirectSuppressed ? '1': '0',
3352                 ) );
3353
3354                 $formatter = LogFormatter::newFromEntry( $logEntry );
3355                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3356                 $comment = $formatter->getPlainActionText();
3357                 if ( $reason ) {
3358                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3359                 }
3360                 # Truncate for whole multibyte characters.
3361                 $comment = $wgContLang->truncate( $comment, 255 );
3362
3363                 $oldid = $this->getArticleID();
3364                 $latest = $this->getLatestRevID();
3365
3366                 $dbw = wfGetDB( DB_MASTER );
3367
3368                 if ( $moveOverRedirect ) {
3369                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3370
3371                         $newid = $nt->getArticleID();
3372                         $newns = $nt->getNamespace();
3373                         $newdbk = $nt->getDBkey();
3374
3375                         # Delete the old redirect. We don't save it to history since
3376                         # by definition if we've got here it's rather uninteresting.
3377                         # We have to remove it so that the next step doesn't trigger
3378                         # a conflict on the unique namespace+title index...
3379                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3380                         if ( !$dbw->cascadingDeletes() ) {
3381                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3382                                 global $wgUseTrackbacks;
3383                                 if ( $wgUseTrackbacks ) {
3384                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3385                                 }
3386                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3387                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3388                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3389                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3390                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3391                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3392                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3393                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3394                         }
3395                         // If the target page was recently created, it may have an entry in recentchanges still
3396                         $dbw->delete( 'recentchanges',
3397                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3398                                 __METHOD__
3399                         );
3400
3401                          if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3402                                 $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3403                                 $dbw2->delete( 'globaltemplatelinks',
3404                                                         array(  'gtl_from_wiki' => wfGetID(),
3405                                                                         'gtl_from_page' => $newid ),
3406                                                         __METHOD__ );
3407                         }
3408                 }
3409
3410                 # Save a null revision in the page's history notifying of the move
3411                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3412                 if ( !is_object( $nullRevision ) ) {
3413                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3414                 }
3415                 $nullRevId = $nullRevision->insertOn( $dbw );
3416
3417                 $now = wfTimestampNow();
3418                 # Change the name of the target page:
3419                 $dbw->update( 'page',
3420                         /* SET */ array(
3421                                 'page_touched'   => $dbw->timestamp( $now ),
3422                                 'page_namespace' => $nt->getNamespace(),
3423                                 'page_title'     => $nt->getDBkey(),
3424                                 'page_latest'    => $nullRevId,
3425                         ),
3426                         /* WHERE */ array( 'page_id' => $oldid ),
3427                         __METHOD__
3428                 );
3429                 $nt->resetArticleID( $oldid );
3430
3431                 $article = new Article( $nt );
3432                 wfRunHooks( 'NewRevisionFromEditComplete',
3433                         array( $article, $nullRevision, $latest, $wgUser ) );
3434                 $article->setCachedLastEditTime( $now );
3435
3436                 # Recreate the redirect, this time in the other direction.
3437                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3438                         $mwRedir = MagicWord::get( 'redirect' );
3439                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3440                         $redirectArticle = new Article( $this );
3441                         $newid = $redirectArticle->insertOn( $dbw );
3442                         if ( $newid ) { // sanity
3443                                 $redirectRevision = new Revision( array(
3444                                         'page'    => $newid,
3445                                         'comment' => $comment,
3446                                         'text'    => $redirectText ) );
3447                                 $redirectRevision->insertOn( $dbw );
3448                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3449
3450                                 wfRunHooks( 'NewRevisionFromEditComplete',
3451                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3452
3453                                 # Now, we record the link from the redirect to the new title.
3454                                 # It should have no other outgoing links...
3455                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3456                                 $dbw->insert( 'pagelinks',
3457                                         array(
3458                                                 'pl_from'      => $newid,
3459                                                 'pl_namespace' => $nt->getNamespace(),
3460                                                 'pl_title'     => $nt->getDBkey() ),
3461                                         __METHOD__ );
3462                         }
3463                 } else {
3464                         $this->resetArticleID( 0 );
3465                 }
3466
3467                 # Log the move
3468                 $logid = $logEntry->insert();
3469                 $logEntry->publish( $logid );
3470
3471                 # Purge caches for old and new titles
3472                 if ( $moveOverRedirect ) {
3473                         # A simple purge is enough when moving over a redirect
3474                         $nt->purgeSquid();
3475                 } else {
3476                         # Purge caches as per article creation, including any pages that link to this title
3477                         Article::onArticleCreate( $nt );
3478                 }
3479                 $this->purgeSquid();
3480         }
3481
3482         /**
3483          * Move this page's subpages to be subpages of $nt
3484          *
3485          * @param $nt Title Move target
3486          * @param $auth bool Whether $wgUser's permissions should be checked
3487          * @param $reason string The reason for the move
3488          * @param $createRedirect bool Whether to create redirects from the old subpages to
3489          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3490          * @return mixed array with old page titles as keys, and strings (new page titles) or
3491          *     arrays (errors) as values, or an error array with numeric indices if no pages
3492          *     were moved
3493          */
3494         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3495                 global $wgMaximumMovedPages;
3496                 // Check permissions
3497                 if ( !$this->userCan( 'move-subpages' ) ) {
3498                         return array( 'cant-move-subpages' );
3499                 }
3500                 // Do the source and target namespaces support subpages?
3501                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3502                         return array( 'namespace-nosubpages',
3503                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3504                 }
3505                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3506                         return array( 'namespace-nosubpages',
3507                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3508                 }
3509
3510                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3511                 $retval = array();
3512                 $count = 0;
3513                 foreach ( $subpages as $oldSubpage ) {
3514                         $count++;
3515                         if ( $count > $wgMaximumMovedPages ) {
3516                                 $retval[$oldSubpage->getPrefixedTitle()] =
3517                                                 array( 'movepage-max-pages',
3518                                                         $wgMaximumMovedPages );
3519                                 break;
3520                         }
3521
3522                         // We don't know whether this function was called before
3523                         // or after moving the root page, so check both
3524                         // $this and $nt
3525                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3526                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3527                         {
3528                                 // When moving a page to a subpage of itself,
3529                                 // don't move it twice
3530                                 continue;
3531                         }
3532                         $newPageName = preg_replace(
3533                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3534                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3535                                         $oldSubpage->getDBkey() );
3536                         if ( $oldSubpage->isTalkPage() ) {
3537                                 $newNs = $nt->getTalkPage()->getNamespace();
3538                         } else {
3539                                 $newNs = $nt->getSubjectPage()->getNamespace();
3540                         }
3541                         # Bug 14385: we need makeTitleSafe because the new page names may
3542                         # be longer than 255 characters.
3543                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3544
3545                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3546                         if ( $success === true ) {
3547                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3548                         } else {
3549                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3550                         }
3551                 }
3552                 return $retval;
3553         }
3554
3555         /**
3556          * Checks if this page is just a one-rev redirect.
3557          * Adds lock, so don't use just for light purposes.
3558          *
3559          * @return Bool
3560          */
3561         public function isSingleRevRedirect() {
3562                 $dbw = wfGetDB( DB_MASTER );
3563                 # Is it a redirect?
3564                 $row = $dbw->selectRow( 'page',
3565                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3566                         $this->pageCond(),
3567                         __METHOD__,
3568                         array( 'FOR UPDATE' )
3569                 );
3570                 # Cache some fields we may want
3571                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3572                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3573                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3574                 if ( !$this->mRedirect ) {
3575                         return false;
3576                 }
3577                 # Does the article have a history?
3578                 $row = $dbw->selectField( array( 'page', 'revision' ),
3579                         'rev_id',
3580                         array( 'page_namespace' => $this->getNamespace(),
3581                                 'page_title' => $this->getDBkey(),
3582                                 'page_id=rev_page',
3583                                 'page_latest != rev_id'
3584                         ),
3585                         __METHOD__,
3586                         array( 'FOR UPDATE' )
3587                 );
3588                 # Return true if there was no history
3589                 return ( $row === false );
3590         }
3591
3592         /**
3593          * Checks if $this can be moved to a given Title
3594          * - Selects for update, so don't call it unless you mean business
3595          *
3596          * @param $nt Title the new title to check
3597          * @return Bool
3598          */
3599         public function isValidMoveTarget( $nt ) {
3600                 # Is it an existing file?
3601                 if ( $nt->getNamespace() == NS_FILE ) {
3602                         $file = wfLocalFile( $nt );
3603                         if ( $file->exists() ) {
3604                                 wfDebug( __METHOD__ . ": file exists\n" );
3605                                 return false;
3606                         }
3607                 }
3608                 # Is it a redirect with no history?
3609                 if ( !$nt->isSingleRevRedirect() ) {
3610                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3611                         return false;
3612                 }
3613                 # Get the article text
3614                 $rev = Revision::newFromTitle( $nt );
3615                 $text = $rev->getText();
3616                 # Does the redirect point to the source?
3617                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3618                 $m = array();
3619                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3620                         $redirTitle = Title::newFromText( $m[1] );
3621                         if ( !is_object( $redirTitle ) ||
3622                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3623                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3624                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3625                                 return false;
3626                         }
3627                 } else {
3628                         # Fail safe
3629                         wfDebug( __METHOD__ . ": failsafe\n" );
3630                         return false;
3631                 }
3632                 return true;
3633         }
3634
3635         /**
3636          * Can this title be added to a user's watchlist?
3637          *
3638          * @return Bool TRUE or FALSE
3639          */
3640         public function isWatchable() {
3641                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3642         }
3643
3644         /**
3645          * Get categories to which this Title belongs and return an array of
3646          * categories' names.
3647          *
3648          * @return Array of parents in the form:
3649          *        $parent => $currentarticle
3650          */
3651         public function getParentCategories() {
3652                 global $wgContLang;
3653
3654                 $data = array();
3655
3656                 $titleKey = $this->getArticleId();
3657
3658                 if ( $titleKey === 0 ) {
3659                         return $data;
3660                 }
3661
3662                 $dbr = wfGetDB( DB_SLAVE );
3663
3664                 $res = $dbr->select( 'categorylinks', '*',
3665                         array(
3666                                 'cl_from' => $titleKey,
3667                         ),
3668                         __METHOD__,
3669                         array()
3670                 );
3671
3672                 if ( $dbr->numRows( $res ) > 0 ) {
3673                         foreach ( $res as $row ) {
3674                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3675                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3676                         }
3677                 }
3678                 return $data;
3679         }
3680
3681         /**
3682          * Get a tree of parent categories
3683          *
3684          * @param $children Array with the children in the keys, to check for circular refs
3685          * @return Array Tree of parent categories
3686          */
3687         public function getParentCategoryTree( $children = array() ) {
3688                 $stack = array();
3689                 $parents = $this->getParentCategories();
3690
3691                 if ( $parents ) {
3692                         foreach ( $parents as $parent => $current ) {
3693                                 if ( array_key_exists( $parent, $children ) ) {
3694                                         # Circular reference
3695                                         $stack[$parent] = array();
3696                                 } else {
3697                                         $nt = Title::newFromText( $parent );
3698                                         if ( $nt ) {
3699                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3700                                         }
3701                                 }
3702                         }
3703                 }
3704
3705                 return $stack;
3706         }
3707
3708         /**
3709          * Get an associative array for selecting this title from
3710          * the "page" table
3711          *
3712          * @return Array suitable for the $where parameter of DB::select()
3713          */
3714         public function pageCond() {
3715                 if ( $this->mArticleID > 0 ) {
3716                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3717                         return array( 'page_id' => $this->mArticleID );
3718                 } else {
3719                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3720                 }
3721         }
3722
3723         /**
3724          * Get the revision ID of the previous revision
3725          *
3726          * @param $revId Int Revision ID. Get the revision that was before this one.
3727          * @param $flags Int Title::GAID_FOR_UPDATE
3728          * @return Int|Bool Old revision ID, or FALSE if none exists
3729          */
3730         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3731                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3732                 return $db->selectField( 'revision', 'rev_id',
3733                         array(
3734                                 'rev_page' => $this->getArticleId( $flags ),
3735                                 'rev_id < ' . intval( $revId )
3736                         ),
3737                         __METHOD__,
3738                         array( 'ORDER BY' => 'rev_id DESC' )
3739                 );
3740         }
3741
3742         /**
3743          * Get the revision ID of the next revision
3744          *
3745          * @param $revId Int Revision ID. Get the revision that was after this one.
3746          * @param $flags Int Title::GAID_FOR_UPDATE
3747          * @return Int|Bool Next revision ID, or FALSE if none exists
3748          */
3749         public function getNextRevisionID( $revId, $flags = 0 ) {
3750                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3751                 return $db->selectField( 'revision', 'rev_id',
3752                         array(
3753                                 'rev_page' => $this->getArticleId( $flags ),
3754                                 'rev_id > ' . intval( $revId )
3755                         ),
3756                         __METHOD__,
3757                         array( 'ORDER BY' => 'rev_id' )
3758                 );
3759         }
3760
3761         /**
3762          * Get the first revision of the page
3763          *
3764          * @param $flags Int Title::GAID_FOR_UPDATE
3765          * @return Revision|Null if page doesn't exist
3766          */
3767         public function getFirstRevision( $flags = 0 ) {
3768                 $pageId = $this->getArticleId( $flags );
3769                 if ( $pageId ) {
3770                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3771                         $row = $db->selectRow( 'revision', '*',
3772                                 array( 'rev_page' => $pageId ),
3773                                 __METHOD__,
3774                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3775                         );
3776                         if ( $row ) {
3777                                 return new Revision( $row );
3778                         }
3779                 }
3780                 return null;
3781         }
3782
3783         /**
3784          * Get the oldest revision timestamp of this page
3785          *
3786          * @param $flags Int Title::GAID_FOR_UPDATE
3787          * @return String: MW timestamp
3788          */
3789         public function getEarliestRevTime( $flags = 0 ) {
3790                 $rev = $this->getFirstRevision( $flags );
3791                 return $rev ? $rev->getTimestamp() : null;
3792         }
3793
3794         /**
3795          * Check if this is a new page
3796          *
3797          * @return bool
3798          */
3799         public function isNewPage() {
3800                 $dbr = wfGetDB( DB_SLAVE );
3801                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3802         }
3803
3804         /**
3805          * Get the number of revisions between the given revision.
3806          * Used for diffs and other things that really need it.
3807          *
3808          * @param $old int|Revision Old revision or rev ID (first before range)
3809          * @param $new int|Revision New revision or rev ID (first after range)
3810          * @return Int Number of revisions between these revisions.
3811          */
3812         public function countRevisionsBetween( $old, $new ) {
3813                 if ( !( $old instanceof Revision ) ) {
3814                         $old = Revision::newFromTitle( $this, (int)$old );
3815                 }
3816                 if ( !( $new instanceof Revision ) ) {
3817                         $new = Revision::newFromTitle( $this, (int)$new );
3818                 }
3819                 if ( !$old || !$new ) {
3820                         return 0; // nothing to compare
3821                 }
3822                 $dbr = wfGetDB( DB_SLAVE );
3823                 return (int)$dbr->selectField( 'revision', 'count(*)',
3824                         array(
3825                                 'rev_page' => $this->getArticleId(),
3826                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3827                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3828                         ),
3829                         __METHOD__
3830                 );
3831         }
3832
3833         /**
3834          * Get the number of authors between the given revision IDs.
3835          * Used for diffs and other things that really need it.
3836          *
3837          * @param $old int|Revision Old revision or rev ID (first before range)
3838          * @param $new int|Revision New revision or rev ID (first after range)
3839          * @param $limit Int Maximum number of authors
3840          * @return Int Number of revision authors between these revisions.
3841          */
3842         public function countAuthorsBetween( $old, $new, $limit ) {
3843                 if ( !( $old instanceof Revision ) ) {
3844                         $old = Revision::newFromTitle( $this, (int)$old );
3845                 }
3846                 if ( !( $new instanceof Revision ) ) {
3847                         $new = Revision::newFromTitle( $this, (int)$new );
3848                 }
3849                 if ( !$old || !$new ) {
3850                         return 0; // nothing to compare
3851                 }
3852                 $dbr = wfGetDB( DB_SLAVE );
3853                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3854                         array(
3855                                 'rev_page' => $this->getArticleID(),
3856                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3857                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3858                         ), __METHOD__,
3859                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3860                 );
3861                 return (int)$dbr->numRows( $res );
3862         }
3863
3864         /**
3865          * Compare with another title.
3866          *
3867          * @param $title Title
3868          * @return Bool
3869          */
3870         public function equals( Title $title ) {
3871                 // Note: === is necessary for proper matching of number-like titles.
3872                 return $this->getInterwiki() === $title->getInterwiki()
3873                         && $this->getNamespace() == $title->getNamespace()
3874                         && $this->getDBkey() === $title->getDBkey();
3875         }
3876
3877         /**
3878          * Check if this title is a subpage of another title
3879          *
3880          * @param $title Title
3881          * @return Bool
3882          */
3883         public function isSubpageOf( Title $title ) {
3884                 return $this->getInterwiki() === $title->getInterwiki()
3885                         && $this->getNamespace() == $title->getNamespace()
3886                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
3887         }
3888
3889         /**
3890          * Callback for usort() to do title sorts by (namespace, title)
3891          *
3892          * @param $a Title
3893          * @param $b Title
3894          *
3895          * @return Integer: result of string comparison, or namespace comparison
3896          */
3897         public static function compare( $a, $b ) {
3898                 if ( $a->getNamespace() == $b->getNamespace() ) {
3899                         return strcmp( $a->getText(), $b->getText() );
3900                 } else {
3901                         return $a->getNamespace() - $b->getNamespace();
3902                 }
3903         }
3904
3905         /**
3906          * Return a string representation of this title
3907          *
3908          * @return String representation of this title
3909          */
3910         public function __toString() {
3911                 return $this->getPrefixedText();
3912         }
3913
3914         /**
3915          * Check if page exists.  For historical reasons, this function simply
3916          * checks for the existence of the title in the page table, and will
3917          * thus return false for interwiki links, special pages and the like.
3918          * If you want to know if a title can be meaningfully viewed, you should
3919          * probably call the isKnown() method instead.
3920          *
3921          * @return Bool
3922          */
3923         public function exists() {
3924                 return $this->getArticleId() != 0;
3925         }
3926
3927         /**
3928          * Should links to this title be shown as potentially viewable (i.e. as
3929          * "bluelinks"), even if there's no record by this title in the page
3930          * table?
3931          *
3932          * This function is semi-deprecated for public use, as well as somewhat
3933          * misleadingly named.  You probably just want to call isKnown(), which
3934          * calls this function internally.
3935          *
3936          * (ISSUE: Most of these checks are cheap, but the file existence check
3937          * can potentially be quite expensive.  Including it here fixes a lot of
3938          * existing code, but we might want to add an optional parameter to skip
3939          * it and any other expensive checks.)
3940          *
3941          * @return Bool
3942          */
3943         public function isAlwaysKnown() {
3944                 if ( $this->mInterwiki != '' ) {
3945                         return true;  // any interwiki link might be viewable, for all we know
3946                 }
3947                 switch( $this->mNamespace ) {
3948                         case NS_MEDIA:
3949                         case NS_FILE:
3950                                 // file exists, possibly in a foreign repo
3951                                 return (bool)wfFindFile( $this );
3952                         case NS_SPECIAL:
3953                                 // valid special page
3954                                 return SpecialPageFactory::exists( $this->getDBkey() );
3955                         case NS_MAIN:
3956                                 // selflink, possibly with fragment
3957                                 return $this->mDbkeyform == '';
3958                         case NS_MEDIAWIKI:
3959                                 // known system message
3960                                 return $this->getDefaultMessageText() !== false;
3961                         default:
3962                                 return false;
3963                 }
3964         }
3965
3966         /**
3967          * Does this title refer to a page that can (or might) be meaningfully
3968          * viewed?  In particular, this function may be used to determine if
3969          * links to the title should be rendered as "bluelinks" (as opposed to
3970          * "redlinks" to non-existent pages).
3971          *
3972          * @return Bool
3973          */
3974         public function isKnown() {
3975                 return $this->isAlwaysKnown() || $this->exists();
3976         }
3977
3978         /**
3979          * Does this page have source text?
3980          *
3981          * @return Boolean
3982          */
3983         public function hasSourceText() {
3984                 if ( $this->exists() ) {
3985                         return true;
3986                 }
3987
3988                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3989                         // If the page doesn't exist but is a known system message, default
3990                         // message content will be displayed, same for language subpages
3991                         return $this->getDefaultMessageText() !== false;
3992                 }
3993
3994                 return false;
3995         }
3996
3997         /**
3998          * Get the default message text or false if the message doesn't exist
3999          *
4000          * @return String or false
4001          */
4002         public function getDefaultMessageText() {
4003                 global $wgContLang;
4004
4005                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4006                         return false;
4007                 }
4008
4009                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4010                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4011
4012                 if ( $message->exists() ) {
4013                         return $message->plain();
4014                 } else {
4015                         return false;
4016                 }
4017         }
4018
4019         /**
4020          * Is this in a namespace that allows actual pages?
4021          *
4022          * @return Bool
4023          * @internal note -- uses hardcoded namespace index instead of constants
4024          */
4025         public function canExist() {
4026                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
4027         }
4028
4029         /**
4030          * Update page_touched timestamps and send squid purge messages for
4031          * pages linking to this title. May be sent to the job queue depending
4032          * on the number of links. Typically called on create and delete.
4033          */
4034         public function touchLinks() {
4035                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4036                 $u->doUpdate();
4037
4038                 if ( $this->getNamespace() == NS_CATEGORY ) {
4039                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4040                         $u->doUpdate();
4041                 }
4042         }
4043
4044         /**
4045          * Get the last touched timestamp
4046          *
4047          * @param $db DatabaseBase: optional db
4048          * @return String last-touched timestamp
4049          */
4050         public function getTouched( $db = null ) {
4051                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4052                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4053                 return $touched;
4054         }
4055
4056         /**
4057          * Get the timestamp when this page was updated since the user last saw it.
4058          *
4059          * @param $user User
4060          * @return String|Null
4061          */
4062         public function getNotificationTimestamp( $user = null ) {
4063                 global $wgUser, $wgShowUpdatedMarker;
4064                 // Assume current user if none given
4065                 if ( !$user ) {
4066                         $user = $wgUser;
4067                 }
4068                 // Check cache first
4069                 $uid = $user->getId();
4070                 // avoid isset here, as it'll return false for null entries
4071                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4072                         return $this->mNotificationTimestamp[$uid];
4073                 }
4074                 if ( !$uid || !$wgShowUpdatedMarker ) {
4075                         return $this->mNotificationTimestamp[$uid] = false;
4076                 }
4077                 // Don't cache too much!
4078                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4079                         $this->mNotificationTimestamp = array();
4080                 }
4081                 $dbr = wfGetDB( DB_SLAVE );
4082                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4083                         'wl_notificationtimestamp',
4084                         array( 'wl_namespace' => $this->getNamespace(),
4085                                 'wl_title' => $this->getDBkey(),
4086                                 'wl_user' => $user->getId()
4087                         ),
4088                         __METHOD__
4089                 );
4090                 return $this->mNotificationTimestamp[$uid];
4091         }
4092
4093         /**
4094          * Get the trackback URL for this page
4095          *
4096          * @return String Trackback URL
4097          */
4098         public function trackbackURL() {
4099                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4100
4101                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4102                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4103         }
4104
4105         /**
4106          * Get the trackback RDF for this page
4107          *
4108          * @return String Trackback RDF
4109          */
4110         public function trackbackRDF() {
4111                 $url = htmlspecialchars( $this->getFullURL() );
4112                 $title = htmlspecialchars( $this->getText() );
4113                 $tburl = $this->trackbackURL();
4114
4115                 // Autodiscovery RDF is placed in comments so HTML validator
4116                 // won't barf. This is a rather icky workaround, but seems
4117                 // frequently used by this kind of RDF thingy.
4118                 //
4119                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4120                 return "<!--
4121 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4122                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4123                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4124 <rdf:Description
4125    rdf:about=\"$url\"
4126    dc:identifier=\"$url\"
4127    dc:title=\"$title\"
4128    trackback:ping=\"$tburl\" />
4129 </rdf:RDF>
4130 -->";
4131         }
4132
4133         /**
4134          * Generate strings used for xml 'id' names in monobook tabs
4135          *
4136          * @param $prepend string defaults to 'nstab-'
4137          * @return String XML 'id' name
4138          */
4139         public function getNamespaceKey( $prepend = 'nstab-' ) {
4140                 global $wgContLang;
4141                 // Gets the subject namespace if this title
4142                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4143                 // Checks if cononical namespace name exists for namespace
4144                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4145                         // Uses canonical namespace name
4146                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4147                 } else {
4148                         // Uses text of namespace
4149                         $namespaceKey = $this->getSubjectNsText();
4150                 }
4151                 // Makes namespace key lowercase
4152                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4153                 // Uses main
4154                 if ( $namespaceKey == '' ) {
4155                         $namespaceKey = 'main';
4156                 }
4157                 // Changes file to image for backwards compatibility
4158                 if ( $namespaceKey == 'file' ) {
4159                         $namespaceKey = 'image';
4160                 }
4161                 return $prepend . $namespaceKey;
4162         }
4163
4164         /**
4165          * Returns true if this is a special page.
4166          *
4167          * @return boolean
4168          */
4169         public function isSpecialPage() {
4170                 return $this->getNamespace() == NS_SPECIAL;
4171         }
4172
4173         /**
4174          * Returns true if this title resolves to the named special page
4175          *
4176          * @param $name String The special page name
4177          * @return boolean
4178          */
4179         public function isSpecial( $name ) {
4180                 if ( $this->getNamespace() == NS_SPECIAL ) {
4181                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4182                         if ( $name == $thisName ) {
4183                                 return true;
4184                         }
4185                 }
4186                 return false;
4187         }
4188
4189         /**
4190          * If the Title refers to a special page alias which is not the local default, resolve
4191          * the alias, and localise the name as necessary.  Otherwise, return $this
4192          *
4193          * @return Title
4194          */
4195         public function fixSpecialName() {
4196                 if ( $this->getNamespace() == NS_SPECIAL ) {
4197                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4198                         if ( $canonicalName ) {
4199                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4200                                 if ( $localName != $this->mDbkeyform ) {
4201                                         return Title::makeTitle( NS_SPECIAL, $localName );
4202                                 }
4203                         }
4204                 }
4205                 return $this;
4206         }
4207
4208         /**
4209          * Is this Title in a namespace which contains content?
4210          * In other words, is this a content page, for the purposes of calculating
4211          * statistics, etc?
4212          *
4213          * @return Boolean
4214          */
4215         public function isContentPage() {
4216                 return MWNamespace::isContent( $this->getNamespace() );
4217         }
4218
4219         /**
4220          * Get all extant redirects to this Title
4221          *
4222          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4223          * @return Array of Title redirects to this title
4224          */
4225         public function getRedirectsHere( $ns = null ) {
4226                 $redirs = array();
4227
4228                 $dbr = wfGetDB( DB_SLAVE );
4229                 $where = array(
4230                         'rd_namespace' => $this->getNamespace(),
4231                         'rd_title' => $this->getDBkey(),
4232                         'rd_from = page_id'
4233                 );
4234                 if ( !is_null( $ns ) ) {
4235                         $where['page_namespace'] = $ns;
4236                 }
4237
4238                 $res = $dbr->select(
4239                         array( 'redirect', 'page' ),
4240                         array( 'page_namespace', 'page_title' ),
4241                         $where,
4242                         __METHOD__
4243                 );
4244
4245                 foreach ( $res as $row ) {
4246                         $redirs[] = self::newFromRow( $row );
4247                 }
4248                 return $redirs;
4249         }
4250
4251         /**
4252          * Check if this Title is a valid redirect target
4253          *
4254          * @return Bool
4255          */
4256         public function isValidRedirectTarget() {
4257                 global $wgInvalidRedirectTargets;
4258
4259                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4260                 if ( $this->isSpecial( 'Userlogout' ) ) {
4261                         return false;
4262                 }
4263
4264                 foreach ( $wgInvalidRedirectTargets as $target ) {
4265                         if ( $this->isSpecial( $target ) ) {
4266                                 return false;
4267                         }
4268                 }
4269
4270                 return true;
4271         }
4272
4273         /**
4274          * Get a backlink cache object
4275          *
4276          * @return object BacklinkCache
4277          */
4278         function getBacklinkCache() {
4279                 if ( is_null( $this->mBacklinkCache ) ) {
4280                         $this->mBacklinkCache = new BacklinkCache( $this );
4281                 }
4282                 return $this->mBacklinkCache;
4283         }
4284
4285         /**
4286          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4287          *
4288          * @return Boolean
4289          */
4290         public function canUseNoindex() {
4291                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4292
4293                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4294                         ? $wgContentNamespaces
4295                         : $wgExemptFromUserRobotsControl;
4296
4297                 return !in_array( $this->mNamespace, $bannedNamespaces );
4298
4299         }
4300
4301         /**
4302          * Returns restriction types for the current Title
4303          *
4304          * @return array applicable restriction types
4305          */
4306         public function getRestrictionTypes() {
4307                 if ( $this->getNamespace() == NS_SPECIAL ) {
4308                         return array();
4309                 }
4310
4311                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4312
4313                 if ( $this->getNamespace() != NS_FILE ) {
4314                         # Remove the upload restriction for non-file titles
4315                         $types = array_diff( $types, array( 'upload' ) );
4316                 }
4317
4318                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4319
4320                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4321                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4322
4323                 return $types;
4324         }
4325         /**
4326          * Get a filtered list of all restriction types supported by this wiki.
4327          * @param bool $exists True to get all restriction types that apply to
4328          * titles that do exist, False for all restriction types that apply to
4329          * titles that do not exist
4330          * @return array
4331          */
4332         public static function getFilteredRestrictionTypes( $exists = true ) {
4333                 global $wgRestrictionTypes;
4334                 $types = $wgRestrictionTypes;
4335                 if ( $exists ) {
4336                         # Remove the create restriction for existing titles
4337                         $types = array_diff( $types, array( 'create' ) );
4338                 } else {
4339                         # Only the create and upload restrictions apply to non-existing titles
4340                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4341                 }
4342                 return $types;
4343         }
4344
4345         /**
4346          * Returns the raw sort key to be used for categories, with the specified
4347          * prefix.  This will be fed to Collation::getSortKey() to get a
4348          * binary sortkey that can be used for actual sorting.
4349          *
4350          * @param $prefix string The prefix to be used, specified using
4351          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4352          *   prefix.
4353          * @return string
4354          */
4355         public function getCategorySortkey( $prefix = '' ) {
4356                 $unprefixed = $this->getText();
4357
4358                 // Anything that uses this hook should only depend
4359                 // on the Title object passed in, and should probably
4360                 // tell the users to run updateCollations.php --force
4361                 // in order to re-sort existing category relations.
4362                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4363                 if ( $prefix !== '' ) {
4364                         # Separate with a line feed, so the unprefixed part is only used as
4365                         # a tiebreaker when two pages have the exact same prefix.
4366                         # In UCA, tab is the only character that can sort above LF
4367                         # so we strip both of them from the original prefix.
4368                         $prefix = strtr( $prefix, "\n\t", '  ' );
4369                         return "$prefix\n$unprefixed";
4370                 }
4371                 return $unprefixed;
4372         }
4373
4374         /**
4375          * Get the language in which the content of this page is written.
4376          * Defaults to $wgContLang, but in certain cases it can be e.g.
4377          * $wgLang (such as special pages, which are in the user language).
4378          *
4379          * @since 1.18
4380          * @return object Language
4381          */
4382         public function getPageLanguage() {
4383                 global $wgLang;
4384                 if ( $this->getNamespace() == NS_SPECIAL ) {
4385                         // special pages are in the user language
4386                         return $wgLang;
4387                 } elseif ( $this->isRedirect() ) {
4388                         // the arrow on a redirect page is aligned according to the user language
4389                         return $wgLang;
4390                 } elseif ( $this->isCssOrJsPage() ) {
4391                         // css/js should always be LTR and is, in fact, English
4392                         return wfGetLangObj( 'en' );
4393                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4394                         // Parse mediawiki messages with correct target language
4395                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4396                         return wfGetLangObj( $lang );
4397                 }
4398                 global $wgContLang;
4399                 // If nothing special, it should be in the wiki content language
4400                 $pageLang = $wgContLang;
4401                 // Hook at the end because we don't want to override the above stuff
4402                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4403                 return wfGetLangObj( $pageLang );
4404         }
4405 }