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          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mCounter = -1;               // /< Number of times this page has been viewed (-1 means "not loaded")
  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                         if ( isset( $row->page_counter ) )
 277                                 $this->mCounter = (int)$row->page_counter;
 278                 } else { // page not found
 279                         $this->mArticleID = 0;
 280                         $this->mLength = 0;
 281                         $this->mRedirect = false;
 282                         $this->mLatestID = 0;
 283                         $this->mCounter = 0;
 284                 }
 285         }
 286
 287         /**
 288          * Create a new Title from a namespace index and a DB key.
 289          * It's assumed that $ns and $title are *valid*, for instance when
 290          * they came directly from the database or a special page name.
 291          * For convenience, spaces are converted to underscores so that
 292          * eg user_text fields can be used directly.
 293          *
 294          * @param $ns Int the namespace of the article
 295          * @param $title String the unprefixed database key form
 296          * @param $fragment String the link fragment (after the "#")
 297          * @param $interwiki String the interwiki prefix
 298          * @return Title the new object
 299          */
 300         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 301                 $t = new Title();
 302                 $t->mInterwiki = $interwiki;
 303                 $t->mFragment = $fragment;
 304                 $t->mNamespace = $ns = intval( $ns );
 305                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 306                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 307                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 308                 $t->mTextform = str_replace( '_', ' ', $title );
 309                 return $t;
 310         }
 311
 312         /**
 313          * Create a new Title from a namespace index and a DB key.
 314          * The parameters will be checked for validity, which is a bit slower
 315          * than makeTitle() but safer for user-provided data.
 316          *
 317          * @param $ns Int the namespace of the article
 318          * @param $title String database key form
 319          * @param $fragment String the link fragment (after the "#")
 320          * @param $interwiki String interwiki prefix
 321          * @return Title the new object, or NULL on an error
 322          */
 323         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 324                 $t = new Title();
 325                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * Create a new Title for the Main Page
 335          *
 336          * @return Title the new object
 337          */
 338         public static function newMainPage() {
 339                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 340                 // Don't give fatal errors if the message is broken
 341                 if ( !$title ) {
 342                         $title = Title::newFromText( 'Main Page' );
 343                 }
 344                 return $title;
 345         }
 346
 347         /**
 348          * Extract a redirect destination from a string and return the
 349          * Title, or null if the text doesn't contain a valid redirect
 350          * This will only return the very next target, useful for
 351          * the redirect table and other checks that don't need full recursion
 352          *
 353          * @param $text String: Text with possible redirect
 354          * @return Title: The corresponding Title
 355          */
 356         public static function newFromRedirect( $text ) {
 357                 return self::newFromRedirectInternal( $text );
 358         }
 359
 360         /**
 361          * Extract a redirect destination from a string and return the
 362          * Title, or null if the text doesn't contain a valid redirect
 363          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 364          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 365          *
 366          * @param $text String Text with possible redirect
 367          * @return Title
 368          */
 369         public static function newFromRedirectRecurse( $text ) {
 370                 $titles = self::newFromRedirectArray( $text );
 371                 return $titles ? array_pop( $titles ) : null;
 372         }
 373
 374         /**
 375          * Extract a redirect destination from a string and return an
 376          * array of Titles, or null if the text doesn't contain a valid redirect
 377          * The last element in the array is the final destination after all redirects
 378          * have been resolved (up to $wgMaxRedirects times)
 379          *
 380          * @param $text String Text with possible redirect
 381          * @return Array of Titles, with the destination last
 382          */
 383         public static function newFromRedirectArray( $text ) {
 384                 global $wgMaxRedirects;
 385                 $title = self::newFromRedirectInternal( $text );
 386                 if ( is_null( $title ) ) {
 387                         return null;
 388                 }
 389                 // recursive check to follow double redirects
 390                 $recurse = $wgMaxRedirects;
 391                 $titles = array( $title );
 392                 while ( --$recurse > 0 ) {
 393                         if ( $title->isRedirect() ) {
 394                                 $page = WikiPage::factory( $title );
 395                                 $newtitle = $page->getRedirectTarget();
 396                         } else {
 397                                 break;
 398                         }
 399                         // Redirects to some special pages are not permitted
 400                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 401                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 402                                 $title = $newtitle;
 403                                 $titles[] = $newtitle;
 404                         } else {
 405                                 break;
 406                         }
 407                 }
 408                 return $titles;
 409         }
 410
 411         /**
 412          * Really extract the redirect destination
 413          * Do not call this function directly, use one of the newFromRedirect* functions above
 414          *
 415          * @param $text String Text with possible redirect
 416          * @return Title
 417          */
 418         protected static function newFromRedirectInternal( $text ) {
 419                 global $wgMaxRedirects;
 420                 if ( $wgMaxRedirects < 1 ) {
 421                         //redirects are disabled, so quit early
 422                         return null;
 423                 }
 424                 $redir = MagicWord::get( 'redirect' );
 425                 $text = trim( $text );
 426                 if ( $redir->matchStartAndRemove( $text ) ) {
 427                         // Extract the first link and see if it's usable
 428                         // Ensure that it really does come directly after #REDIRECT
 429                         // Some older redirects included a colon, so don't freak about that!
 430                         $m = array();
 431                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 432                                 // Strip preceding colon used to "escape" categories, etc.
 433                                 // and URL-decode links
 434                                 if ( strpos( $m[1], '%' ) !== false ) {
 435                                         // Match behavior of inline link parsing here;
 436                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 437                                 }
 438                                 $title = Title::newFromText( $m[1] );
 439                                 // If the title is a redirect to bad special pages or is invalid, return null
 440                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 441                                         return null;
 442                                 }
 443                                 return $title;
 444                         }
 445                 }
 446                 return null;
 447         }
 448
 449         /**
 450          * Get the prefixed DB key associated with an ID
 451          *
 452          * @param $id Int the page_id of the article
 453          * @return Title an object representing the article, or NULL if no such article was found
 454          */
 455         public static function nameOf( $id ) {
 456                 $dbr = wfGetDB( DB_SLAVE );
 457
 458                 $s = $dbr->selectRow(
 459                         'page',
 460                         array( 'page_namespace', 'page_title' ),
 461                         array( 'page_id' => $id ),
 462                         __METHOD__
 463                 );
 464                 if ( $s === false ) {
 465                         return null;
 466                 }
 467
 468                 $n = self::makeName( $s->page_namespace, $s->page_title );
 469                 return $n;
 470         }
 471
 472         /**
 473          * Get a regex character class describing the legal characters in a link
 474          *
 475          * @return String the list of characters, not delimited
 476          */
 477         public static function legalChars() {
 478                 global $wgLegalTitleChars;
 479                 return $wgLegalTitleChars;
 480         }
 481
 482         /**
 483          * Returns a simple regex that will match on characters and sequences invalid in titles.
 484          * Note that this doesn't pick up many things that could be wrong with titles, but that
 485          * replacing this regex with something valid will make many titles valid.
 486          *
 487          * @return String regex string
 488          */
 489         static function getTitleInvalidRegex() {
 490                 static $rxTc = false;
 491                 if ( !$rxTc ) {
 492                         # Matching titles will be held as illegal.
 493                         $rxTc = '/' .
 494                                 # Any character not allowed is forbidden...
 495                                 '[^' . self::legalChars() . ']' .
 496                                 # URL percent encoding sequences interfere with the ability
 497                                 # to round-trip titles -- you can't link to them consistently.
 498                                 '|%[0-9A-Fa-f]{2}' .
 499                                 # XML/HTML character references produce similar issues.
 500                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 501                                 '|&#[0-9]+;' .
 502                                 '|&#x[0-9A-Fa-f]+;' .
 503                                 '/S';
 504                 }
 505
 506                 return $rxTc;
 507         }
 508
 509         /**
 510          * Get a string representation of a title suitable for
 511          * including in a search index
 512          *
 513          * @param $ns Int a namespace index
 514          * @param $title String text-form main part
 515          * @return String a stripped-down title string ready for the search index
 516          */
 517         public static function indexTitle( $ns, $title ) {
 518                 global $wgContLang;
 519
 520                 $lc = SearchEngine::legalSearchChars() . '&#;';
 521                 $t = $wgContLang->normalizeForSearch( $title );
 522                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 523                 $t = $wgContLang->lc( $t );
 524
 525                 # Handle 's, s'
 526                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 527                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 528
 529                 $t = preg_replace( "/\\s+/", ' ', $t );
 530
 531                 if ( $ns == NS_FILE ) {
 532                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 533                 }
 534                 return trim( $t );
 535         }
 536
 537         /**
 538          * Make a prefixed DB key from a DB key and a namespace index
 539          *
 540          * @param $ns Int numerical representation of the namespace
 541          * @param $title String the DB key form the title
 542          * @param $fragment String The link fragment (after the "#")
 543          * @param $interwiki String The interwiki prefix
 544          * @return String the prefixed form of the title
 545          */
 546         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 547                 global $wgContLang;
 548
 549                 $namespace = $wgContLang->getNsText( $ns );
 550                 $name = $namespace == '' ? $title : "$namespace:$title";
 551                 if ( strval( $interwiki ) != '' ) {
 552                         $name = "$interwiki:$name";
 553                 }
 554                 if ( strval( $fragment ) != '' ) {
 555                         $name .= '#' . $fragment;
 556                 }
 557                 return $name;
 558         }
 559
 560         /**
 561          * Escape a text fragment, say from a link, for a URL
 562          *
 563          * @param $fragment string containing a URL or link fragment (after the "#")
 564          * @return String: escaped string
 565          */
 566         static function escapeFragmentForURL( $fragment ) {
 567                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 568                 # fragments appear not to work in IE (at least up to 7) or in at least
 569                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 570                 # to care if they aren't encoded.
 571                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 572         }
 573
 574         /**
 575          * Callback for usort() to do title sorts by (namespace, title)
 576          *
 577          * @param $a Title
 578          * @param $b Title
 579          *
 580          * @return Integer: result of string comparison, or namespace comparison
 581          */
 582         public static function compare( $a, $b ) {
 583                 if ( $a->getNamespace() == $b->getNamespace() ) {
 584                         return strcmp( $a->getText(), $b->getText() );
 585                 } else {
 586                         return $a->getNamespace() - $b->getNamespace();
 587                 }
 588         }
 589
 590         /**
 591          * Determine whether the object refers to a page within
 592          * this project.
 593          *
 594          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 595          */
 596         public function isLocal() {
 597                 if ( $this->mInterwiki != '' ) {
 598                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 599                 } else {
 600                         return true;
 601                 }
 602         }
 603
 604         /**
 605          * Is this Title interwiki?
 606          *
 607          * @return Bool
 608          */
 609         public function isExternal() {
 610                 return ( $this->mInterwiki != '' );
 611         }
 612
 613         /**
 614          * Get the interwiki prefix (or null string)
 615          *
 616          * @return String Interwiki prefix
 617          */
 618         public function getInterwiki() {
 619                 return $this->mInterwiki;
 620         }
 621
 622         /**
 623          * Determine whether the object refers to a page within
 624          * this project and is transcludable.
 625          *
 626          * @return Bool TRUE if this is transcludable
 627          */
 628         public function isTrans() {
 629                 if ( $this->mInterwiki == '' ) {
 630                         return false;
 631                 }
 632
 633                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 634         }
 635
 636         /**
 637          * Returns the DB name of the distant wiki which owns the object.
 638          *
 639          * @return String the DB name
 640          */
 641         public function getTransWikiID() {
 642                 if ( $this->mInterwiki == '' ) {
 643                         return false;
 644                 }
 645
 646                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 647         }
 648
 649         /**
 650          * Get the text form (spaces not underscores) of the main part
 651          *
 652          * @return String Main part of the title
 653          */
 654         public function getText() {
 655                 return $this->mTextform;
 656         }
 657
 658         /**
 659          * Get the URL-encoded form of the main part
 660          *
 661          * @return String Main part of the title, URL-encoded
 662          */
 663         public function getPartialURL() {
 664                 return $this->mUrlform;
 665         }
 666
 667         /**
 668          * Get the main part with underscores
 669          *
 670          * @return String: Main part of the title, with underscores
 671          */
 672         public function getDBkey() {
 673                 return $this->mDbkeyform;
 674         }
 675
 676         /**
 677          * Get the DB key with the initial letter case as specified by the user
 678          *
 679          * @return String DB key
 680          */
 681         function getUserCaseDBKey() {
 682                 return $this->mUserCaseDBKey;
 683         }
 684
 685         /**
 686          * Get the namespace index, i.e. one of the NS_xxxx constants.
 687          *
 688          * @return Integer: Namespace index
 689          */
 690         public function getNamespace() {
 691                 return $this->mNamespace;
 692         }
 693
 694         /**
 695          * Get the namespace text
 696          *
 697          * @return String: Namespace text
 698          */
 699         public function getNsText() {
 700                 global $wgContLang;
 701
 702                 if ( $this->mInterwiki != '' ) {
 703                         // This probably shouldn't even happen. ohh man, oh yuck.
 704                         // But for interwiki transclusion it sometimes does.
 705                         // Shit. Shit shit shit.
 706                         //
 707                         // Use the canonical namespaces if possible to try to
 708                         // resolve a foreign namespace.
 709                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 710                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 711                         }
 712                 }
 713
 714                 // Strip off subpages
 715                 $pagename = $this->getText();
 716                 if ( strpos( $pagename, '/' ) !== false ) {
 717                         list( $username , ) = explode( '/', $pagename, 2 );
 718                 } else {
 719                         $username = $pagename;
 720                 }
 721
 722                 if ( $wgContLang->needsGenderDistinction() &&
 723                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 724                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 725                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 726                 }
 727
 728                 return $wgContLang->getNsText( $this->mNamespace );
 729         }
 730
 731         /**
 732          * Get the namespace text of the subject (rather than talk) page
 733          *
 734          * @return String Namespace text
 735          */
 736         public function getSubjectNsText() {
 737                 global $wgContLang;
 738                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 739         }
 740
 741         /**
 742          * Get the namespace text of the talk page
 743          *
 744          * @return String Namespace text
 745          */
 746         public function getTalkNsText() {
 747                 global $wgContLang;
 748                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 749         }
 750
 751         /**
 752          * Could this title have a corresponding talk page?
 753          *
 754          * @return Bool TRUE or FALSE
 755          */
 756         public function canTalk() {
 757                 return( MWNamespace::canTalk( $this->mNamespace ) );
 758         }
 759
 760         /**
 761          * Is this in a namespace that allows actual pages?
 762          *
 763          * @return Bool
 764          * @internal note -- uses hardcoded namespace index instead of constants
 765          */
 766         public function canExist() {
 767                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
 768         }
 769
 770         /**
 771          * Can this title be added to a user's watchlist?
 772          *
 773          * @return Bool TRUE or FALSE
 774          */
 775         public function isWatchable() {
 776                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 777         }
 778
 779         /**
 780          * Returns true if this is a special page.
 781          *
 782          * @return boolean
 783          */
 784         public function isSpecialPage() {
 785                 return $this->getNamespace() == NS_SPECIAL;
 786         }
 787
 788         /**
 789          * Returns true if this title resolves to the named special page
 790          *
 791          * @param $name String The special page name
 792          * @return boolean
 793          */
 794         public function isSpecial( $name ) {
 795                 if ( $this->isSpecialPage() ) {
 796                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 797                         if ( $name == $thisName ) {
 798                                 return true;
 799                         }
 800                 }
 801                 return false;
 802         }
 803
 804         /**
 805          * If the Title refers to a special page alias which is not the local default, resolve
 806          * the alias, and localise the name as necessary.  Otherwise, return $this
 807          *
 808          * @return Title
 809          */
 810         public function fixSpecialName() {
 811                 if ( $this->isSpecialPage() ) {
 812                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 813                         if ( $canonicalName ) {
 814                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 815                                 if ( $localName != $this->mDbkeyform ) {
 816                                         return Title::makeTitle( NS_SPECIAL, $localName );
 817                                 }
 818                         }
 819                 }
 820                 return $this;
 821         }
 822
 823         /**
 824          * Returns true if the title is inside the specified namespace.
 825          *
 826          * Please make use of this instead of comparing to getNamespace()
 827          * This function is much more resistant to changes we may make
 828          * to namespaces than code that makes direct comparisons.
 829          * @param $ns int The namespace
 830          * @return bool
 831          * @since 1.19
 832          */
 833         public function inNamespace( $ns ) {
 834                 return MWNamespace::equals( $this->getNamespace(), $ns );
 835         }
 836
 837         /**
 838          * Returns true if the title is inside one of the specified namespaces.
 839          *
 840          * @param ...$namespaces The namespaces to check for
 841          * @return bool
 842          * @since 1.19
 843          */
 844         public function inNamespaces( /* ... */ ) {
 845                 $namespaces = func_get_args();
 846                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 847                         $namespaces = $namespaces[0];
 848                 }
 849
 850                 foreach ( $namespaces as $ns ) {
 851                         if ( $this->inNamespace( $ns ) ) {
 852                                 return true;
 853                         }
 854                 }
 855
 856                 return false;
 857         }
 858
 859         /**
 860          * Returns true if the title has the same subject namespace as the
 861          * namespace specified.
 862          * For example this method will take NS_USER and return true if namespace
 863          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 864          * as their subject namespace.
 865          *
 866          * This is MUCH simpler than individually testing for equivilance
 867          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 868          * @since 1.19
 869          */
 870         public function hasSubjectNamespace( $ns ) {
 871                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 872         }
 873
 874         /**
 875          * Is this Title in a namespace which contains content?
 876          * In other words, is this a content page, for the purposes of calculating
 877          * statistics, etc?
 878          *
 879          * @return Boolean
 880          */
 881         public function isContentPage() {
 882                 return MWNamespace::isContent( $this->getNamespace() );
 883         }
 884
 885         /**
 886          * Would anybody with sufficient privileges be able to move this page?
 887          * Some pages just aren't movable.
 888          *
 889          * @return Bool TRUE or FALSE
 890          */
 891         public function isMovable() {
 892                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 893                         // Interwiki title or immovable namespace. Hooks don't get to override here
 894                         return false;
 895                 }
 896
 897                 $result = true;
 898                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 899                 return $result;
 900         }
 901
 902         /**
 903          * Is this the mainpage?
 904          * @note Title::newFromText seams to be sufficiently optimized by the title
 905          * cache that we don't need to over-optimize by doing direct comparisons and
 906          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 907          * ends up reporting something differently than $title->isMainPage();
 908          *
 909          * @since 1.18
 910          * @return Bool
 911          */
 912         public function isMainPage() {
 913                 return $this->equals( Title::newMainPage() );
 914         }
 915
 916         /**
 917          * Is this a subpage?
 918          *
 919          * @return Bool
 920          */
 921         public function isSubpage() {
 922                 return MWNamespace::hasSubpages( $this->mNamespace )
 923                         ? strpos( $this->getText(), '/' ) !== false
 924                         : false;
 925         }
 926
 927         /**
 928          * Is this a conversion table for the LanguageConverter?
 929          *
 930          * @return Bool
 931          */
 932         public function isConversionTable() {
 933                 return $this->getNamespace() == NS_MEDIAWIKI &&
 934                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 935         }
 936
 937         /**
 938          * Does that page contain wikitext, or it is JS, CSS or whatever?
 939          *
 940          * @return Bool
 941          */
 942         public function isWikitextPage() {
 943                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 944                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 945                 return $retval;
 946         }
 947
 948         /**
 949          * Could this page contain custom CSS or JavaScript, based
 950          * on the title?
 951          *
 952          * @return Bool
 953          */
 954         public function isCssOrJsPage() {
 955                 $retval = $this->mNamespace == NS_MEDIAWIKI
 956                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 957                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 958                 return $retval;
 959         }
 960
 961         /**
 962          * Is this a .css or .js subpage of a user page?
 963          * @return Bool
 964          */
 965         public function isCssJsSubpage() {
 966                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 967         }
 968
 969         /**
 970          * Is this a *valid* .css or .js subpage of a user page?
 971          *
 972          * @return Bool
 973          * @deprecated since 1.17
 974          */
 975         public function isValidCssJsSubpage() {
 976                 return $this->isCssJsSubpage();
 977         }
 978
 979         /**
 980          * Trim down a .css or .js subpage title to get the corresponding skin name
 981          *
 982          * @return string containing skin name from .css or .js subpage title
 983          */
 984         public function getSkinFromCssJsSubpage() {
 985                 $subpage = explode( '/', $this->mTextform );
 986                 $subpage = $subpage[ count( $subpage ) - 1 ];
 987                 $lastdot = strrpos( $subpage, '.' );
 988                 if ( $lastdot === false )
 989                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 990                 return substr( $subpage, 0, $lastdot );
 991         }
 992
 993         /**
 994          * Is this a .css subpage of a user page?
 995          *
 996          * @return Bool
 997          */
 998         public function isCssSubpage() {
 999                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1000         }
1001
1002         /**
1003          * Is this a .js subpage of a user page?
1004          *
1005          * @return Bool
1006          */
1007         public function isJsSubpage() {
1008                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1009         }
1010
1011         /**
1012          * Is this a talk page of some sort?
1013          *
1014          * @return Bool
1015          */
1016         public function isTalkPage() {
1017                 return MWNamespace::isTalk( $this->getNamespace() );
1018         }
1019
1020         /**
1021          * Get a Title object associated with the talk page of this article
1022          *
1023          * @return Title the object for the talk page
1024          */
1025         public function getTalkPage() {
1026                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1027         }
1028
1029         /**
1030          * Get a title object associated with the subject page of this
1031          * talk page
1032          *
1033          * @return Title the object for the subject page
1034          */
1035         public function getSubjectPage() {
1036                 // Is this the same title?
1037                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1038                 if ( $this->getNamespace() == $subjectNS ) {
1039                         return $this;
1040                 }
1041                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1042         }
1043
1044         /**
1045          * Get the default namespace index, for when there is no namespace
1046          *
1047          * @return Int Default namespace index
1048          */
1049         public function getDefaultNamespace() {
1050                 return $this->mDefaultNamespace;
1051         }
1052
1053         /**
1054          * Get title for search index
1055          *
1056          * @return String a stripped-down title string ready for the
1057          *  search index
1058          */
1059         public function getIndexTitle() {
1060                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1061         }
1062
1063         /**
1064          * Get the Title fragment (i.e.\ the bit after the #) in text form
1065          *
1066          * @return String Title fragment
1067          */
1068         public function getFragment() {
1069                 return $this->mFragment;
1070         }
1071
1072         /**
1073          * Get the fragment in URL form, including the "#" character if there is one
1074          * @return String Fragment in URL form
1075          */
1076         public function getFragmentForURL() {
1077                 if ( $this->mFragment == '' ) {
1078                         return '';
1079                 } else {
1080                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1081                 }
1082         }
1083
1084         /**
1085          * Set the fragment for this title. Removes the first character from the
1086          * specified fragment before setting, so it assumes you're passing it with
1087          * an initial "#".
1088          *
1089          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1090          * Still in active use privately.
1091          *
1092          * @param $fragment String text
1093          */
1094         public function setFragment( $fragment ) {
1095                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1096         }
1097
1098         /**
1099          * Prefix some arbitrary text with the namespace or interwiki prefix
1100          * of this object
1101          *
1102          * @param $name String the text
1103          * @return String the prefixed text
1104          * @private
1105          */
1106         private function prefix( $name ) {
1107                 $p = '';
1108                 if ( $this->mInterwiki != '' ) {
1109                         $p = $this->mInterwiki . ':';
1110                 }
1111
1112                 if ( 0 != $this->mNamespace ) {
1113                         $p .= $this->getNsText() . ':';
1114                 }
1115                 return $p . $name;
1116         }
1117
1118         /**
1119          * Get the prefixed database key form
1120          *
1121          * @return String the prefixed title, with underscores and
1122          *  any interwiki and namespace prefixes
1123          */
1124         public function getPrefixedDBkey() {
1125                 $s = $this->prefix( $this->mDbkeyform );
1126                 $s = str_replace( ' ', '_', $s );
1127                 return $s;
1128         }
1129
1130         /**
1131          * Get the prefixed title with spaces.
1132          * This is the form usually used for display
1133          *
1134          * @return String the prefixed title, with spaces
1135          */
1136         public function getPrefixedText() {
1137                 // @todo FIXME: Bad usage of empty() ?
1138                 if ( empty( $this->mPrefixedText ) ) {
1139                         $s = $this->prefix( $this->mTextform );
1140                         $s = str_replace( '_', ' ', $s );
1141                         $this->mPrefixedText = $s;
1142                 }
1143                 return $this->mPrefixedText;
1144         }
1145
1146         /**
1147          * Return a string representation of this title
1148          *
1149          * @return String representation of this title
1150          */
1151         public function __toString() {
1152                 return $this->getPrefixedText();
1153         }
1154
1155         /**
1156          * Get the prefixed title with spaces, plus any fragment
1157          * (part beginning with '#')
1158          *
1159          * @return String the prefixed title, with spaces and the fragment, including '#'
1160          */
1161         public function getFullText() {
1162                 $text = $this->getPrefixedText();
1163                 if ( $this->mFragment != '' ) {
1164                         $text .= '#' . $this->mFragment;
1165                 }
1166                 return $text;
1167         }
1168
1169         /**
1170          * Get the base page name, i.e. the leftmost part before any slashes
1171          *
1172          * @return String Base name
1173          */
1174         public function getBaseText() {
1175                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1176                         return $this->getText();
1177                 }
1178
1179                 $parts = explode( '/', $this->getText() );
1180                 # Don't discard the real title if there's no subpage involved
1181                 if ( count( $parts ) > 1 ) {
1182                         unset( $parts[count( $parts ) - 1] );
1183                 }
1184                 return implode( '/', $parts );
1185         }
1186
1187         /**
1188          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1189          *
1190          * @return String Subpage name
1191          */
1192         public function getSubpageText() {
1193                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1194                         return( $this->mTextform );
1195                 }
1196                 $parts = explode( '/', $this->mTextform );
1197                 return( $parts[count( $parts ) - 1] );
1198         }
1199
1200         /**
1201          * Get the HTML-escaped displayable text form.
1202          * Used for the title field in <a> tags.
1203          *
1204          * @return String the text, including any prefixes
1205          */
1206         public function getEscapedText() {
1207                 return htmlspecialchars( $this->getPrefixedText() );
1208         }
1209
1210         /**
1211          * Get a URL-encoded form of the subpage text
1212          *
1213          * @return String URL-encoded subpage name
1214          */
1215         public function getSubpageUrlForm() {
1216                 $text = $this->getSubpageText();
1217                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1218                 return( $text );
1219         }
1220
1221         /**
1222          * Get a URL-encoded title (not an actual URL) including interwiki
1223          *
1224          * @return String the URL-encoded form
1225          */
1226         public function getPrefixedURL() {
1227                 $s = $this->prefix( $this->mDbkeyform );
1228                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1229                 return $s;
1230         }
1231
1232         /**
1233          * Get a real URL referring to this title, with interwiki link and
1234          * fragment
1235          *
1236          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
1237          *   links. Can be specified as an associative array as well, e.g.,
1238          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1239          * @param $variant String language variant of url (for sr, zh..)
1240          * @return String the URL
1241          */
1242         public function getFullURL( $query = '', $variant = false ) {
1243                 # Hand off all the decisions on urls to getLocalURL
1244                 $url = $this->getLocalURL( $query, $variant );
1245
1246                 # Expand the url to make it a full url. Note that getLocalURL has the
1247                 # potential to output full urls for a variety of reasons, so we use
1248                 # wfExpandUrl instead of simply prepending $wgServer
1249                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1250
1251                 # Finally, add the fragment.
1252                 $url .= $this->getFragmentForURL();
1253
1254                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query, $variant ) );
1255                 return $url;
1256         }
1257
1258         /**
1259          * Get a URL with no fragment or server name.  If this page is generated
1260          * with action=render, $wgServer is prepended.
1261          *
1262          * @param $query Mixed: an optional query string; if not specified,
1263          *   $wgArticlePath will be used.  Can be specified as an associative array
1264          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
1265          *   URL-escaped).
1266          * @param $variant String language variant of url (for sr, zh..)
1267          * @return String the URL
1268          */
1269         public function getLocalURL( $query = '', $variant = false ) {
1270                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1271                 global $wgVariantArticlePath;
1272
1273                 if ( is_array( $query ) ) {
1274                         $query = wfArrayToCGI( $query );
1275                 }
1276
1277                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1278                 if ( $interwiki ) {
1279                         $namespace = $this->getNsText();
1280                         if ( $namespace != '' ) {
1281                                 # Can this actually happen? Interwikis shouldn't be parsed.
1282                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1283                                 $namespace .= ':';
1284                         }
1285                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1286                         $url = wfAppendQuery( $url, $query );
1287                 } else {
1288                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1289                         if ( $query == '' ) {
1290                                 if ( $variant != false && $this->getPageLanguage()->hasVariants() ) {
1291                                         if ( !$wgVariantArticlePath ) {
1292                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
1293                                         } else {
1294                                                 $variantArticlePath = $wgVariantArticlePath;
1295                                         }
1296                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
1297                                         $url = str_replace( '$1', $dbkey, $url  );
1298                                 } else {
1299                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
1300                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1301                                 }
1302                         } else {
1303                                 global $wgActionPaths;
1304                                 $url = false;
1305                                 $matches = array();
1306                                 if ( !empty( $wgActionPaths ) &&
1307                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1308                                 {
1309                                         $action = urldecode( $matches[2] );
1310                                         if ( isset( $wgActionPaths[$action] ) ) {
1311                                                 $query = $matches[1];
1312                                                 if ( isset( $matches[4] ) ) {
1313                                                         $query .= $matches[4];
1314                                                 }
1315                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1316                                                 if ( $query != '' ) {
1317                                                         $url = wfAppendQuery( $url, $query );
1318                                                 }
1319                                         }
1320                                 }
1321
1322                                 if ( $url === false ) {
1323                                         if ( $query == '-' ) {
1324                                                 $query = '';
1325                                         }
1326                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1327                                 }
1328                         }
1329
1330                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
1331
1332                         // @todo FIXME: This causes breakage in various places when we
1333                         // actually expected a local URL and end up with dupe prefixes.
1334                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1335                                 $url = $wgServer . $url;
1336                         }
1337                 }
1338                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
1339                 return $url;
1340         }
1341
1342         /**
1343          * Get a URL that's the simplest URL that will be valid to link, locally,
1344          * to the current Title.  It includes the fragment, but does not include
1345          * the server unless action=render is used (or the link is external).  If
1346          * there's a fragment but the prefixed text is empty, we just return a link
1347          * to the fragment.
1348          *
1349          * The result obviously should not be URL-escaped, but does need to be
1350          * HTML-escaped if it's being output in HTML.
1351          *
1352          * @param $query Array of Strings An associative array of key => value pairs for the
1353          *   query string.  Keys and values will be escaped.
1354          * @param $variant String language variant of URL (for sr, zh..).  Ignored
1355          *   for external links.  Default is "false" (same variant as current page,
1356          *   for anonymous users).
1357          * @return String the URL
1358          */
1359         public function getLinkURL( $query = array(), $variant = false ) {
1360                 wfProfileIn( __METHOD__ );
1361                 if ( $this->isExternal() ) {
1362                         $ret = $this->getFullURL( $query );
1363                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1364                         $ret = $this->getFragmentForURL();
1365                 } else {
1366                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
1367                 }
1368                 wfProfileOut( __METHOD__ );
1369                 return $ret;
1370         }
1371
1372         /**
1373          * Get an HTML-escaped version of the URL form, suitable for
1374          * using in a link, without a server name or fragment
1375          *
1376          * @param $query String an optional query string
1377          * @return String the URL
1378          */
1379         public function escapeLocalURL( $query = '' ) {
1380                 return htmlspecialchars( $this->getLocalURL( $query ) );
1381         }
1382
1383         /**
1384          * Get an HTML-escaped version of the URL form, suitable for
1385          * using in a link, including the server name and fragment
1386          *
1387          * @param $query String an optional query string
1388          * @return String the URL
1389          */
1390         public function escapeFullURL( $query = '' ) {
1391                 return htmlspecialchars( $this->getFullURL( $query ) );
1392         }
1393
1394         /**
1395          * Get the URL form for an internal link.
1396          * - Used in various Squid-related code, in case we have a different
1397          * internal hostname for the server from the exposed one.
1398          *
1399          * This uses $wgInternalServer to qualify the path, or $wgServer
1400          * if $wgInternalServer is not set. If the server variable used is
1401          * protocol-relative, the URL will be expanded to http://
1402          *
1403          * @param $query String an optional query string
1404          * @param $variant String language variant of url (for sr, zh..)
1405          * @return String the URL
1406          */
1407         public function getInternalURL( $query = '', $variant = false ) {
1408                 global $wgInternalServer, $wgServer;
1409                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1410                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1411                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query, $variant ) );
1412                 return $url;
1413         }
1414
1415         /**
1416          * Get the URL for a canonical link, for use in things like IRC and
1417          * e-mail notifications. Uses $wgCanonicalServer and the
1418          * GetCanonicalURL hook.
1419          *
1420          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1421          *
1422          * @param $query string An optional query string
1423          * @param $variant string Language variant of URL (for sr, zh, ...)
1424          * @return string The URL
1425          * @since 1.18
1426          */
1427         public function getCanonicalURL( $query = '', $variant = false ) {
1428                 $url = wfExpandUrl( $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1429                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query, $variant ) );
1430                 return $url;
1431         }
1432
1433         /**
1434          * HTML-escaped version of getCanonicalURL()
1435          * @since 1.18
1436          */
1437         public function escapeCanonicalURL( $query = '', $variant = false ) {
1438                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1439         }
1440
1441         /**
1442          * Get the edit URL for this Title
1443          *
1444          * @return String the URL, or a null string if this is an
1445          *  interwiki link
1446          */
1447         public function getEditURL() {
1448                 if ( $this->mInterwiki != '' ) {
1449                         return '';
1450                 }
1451                 $s = $this->getLocalURL( 'action=edit' );
1452
1453                 return $s;
1454         }
1455
1456         /**
1457          * Is $wgUser watching this page?
1458          *
1459          * @return Bool
1460          */
1461         public function userIsWatching() {
1462                 global $wgUser;
1463
1464                 if ( is_null( $this->mWatched ) ) {
1465                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1466                                 $this->mWatched = false;
1467                         } else {
1468                                 $this->mWatched = $wgUser->isWatched( $this );
1469                         }
1470                 }
1471                 return $this->mWatched;
1472         }
1473
1474         /**
1475          * Can $wgUser read this page?
1476          *
1477          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1478          * @return Bool
1479          * @todo fold these checks into userCan()
1480          */
1481         public function userCanRead() {
1482                 return $this->userCan( 'read' );
1483         }
1484
1485         /**
1486          * Can $user perform $action on this page?
1487          * This skips potentially expensive cascading permission checks
1488          * as well as avoids expensive error formatting
1489          *
1490          * Suitable for use for nonessential UI controls in common cases, but
1491          * _not_ for functional access control.
1492          *
1493          * May provide false positives, but should never provide a false negative.
1494          *
1495          * @param $action String action that permission needs to be checked for
1496          * @param $user User to check (since 1.19); $wgUser will be used if not
1497          *              provided.
1498          * @return Bool
1499          */
1500         public function quickUserCan( $action, $user = null ) {
1501                 return $this->userCan( $action, $user, false );
1502         }
1503
1504         /**
1505          * Can $user perform $action on this page?
1506          *
1507          * @param $action String action that permission needs to be checked for
1508          * @param $user User to check (since 1.19); $wgUser will be used if not
1509          *   provided.
1510          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1511          *   unnecessary queries.
1512          * @return Bool
1513          */
1514         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1515                 if ( !$user instanceof User ) {
1516                         global $wgUser;
1517                         $user = $wgUser;
1518                 }
1519                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1520         }
1521
1522         /**
1523          * Can $user perform $action on this page?
1524          *
1525          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1526          *
1527          * @param $action String action that permission needs to be checked for
1528          * @param $user User to check
1529          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1530          *   queries by skipping checks for cascading protections and user blocks.
1531          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1532          *   whose corresponding errors may be ignored.
1533          * @return Array of arguments to wfMsg to explain permissions problems.
1534          */
1535         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1536                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1537
1538                 // Remove the errors being ignored.
1539                 foreach ( $errors as $index => $error ) {
1540                         $error_key = is_array( $error ) ? $error[0] : $error;
1541
1542                         if ( in_array( $error_key, $ignoreErrors ) ) {
1543                                 unset( $errors[$index] );
1544                         }
1545                 }
1546
1547                 return $errors;
1548         }
1549
1550         /**
1551          * Permissions checks that fail most often, and which are easiest to test.
1552          *
1553          * @param $action String the action to check
1554          * @param $user User user to check
1555          * @param $errors Array list of current errors
1556          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1557          * @param $short Boolean short circuit on first error
1558          *
1559          * @return Array list of errors
1560          */
1561         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1562                 if ( $action == 'create' ) {
1563                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1564                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1565                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1566                         }
1567                 } elseif ( $action == 'move' ) {
1568                         if ( !$user->isAllowed( 'move-rootuserpages' )
1569                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1570                                 // Show user page-specific message only if the user can move other pages
1571                                 $errors[] = array( 'cant-move-user-page' );
1572                         }
1573
1574                         // Check if user is allowed to move files if it's a file
1575                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1576                                 $errors[] = array( 'movenotallowedfile' );
1577                         }
1578
1579                         if ( !$user->isAllowed( 'move' ) ) {
1580                                 // User can't move anything
1581                                 global $wgGroupPermissions;
1582                                 $userCanMove = false;
1583                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1584                                         $userCanMove = $wgGroupPermissions['user']['move'];
1585                                 }
1586                                 $autoconfirmedCanMove = false;
1587                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1588                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1589                                 }
1590                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1591                                         // custom message if logged-in users without any special rights can move
1592                                         $errors[] = array( 'movenologintext' );
1593                                 } else {
1594                                         $errors[] = array( 'movenotallowed' );
1595                                 }
1596                         }
1597                 } elseif ( $action == 'move-target' ) {
1598                         if ( !$user->isAllowed( 'move' ) ) {
1599                                 // User can't move anything
1600                                 $errors[] = array( 'movenotallowed' );
1601                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1602                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1603                                 // Show user page-specific message only if the user can move other pages
1604                                 $errors[] = array( 'cant-move-to-user-page' );
1605                         }
1606                 } elseif ( !$user->isAllowed( $action ) ) {
1607                         $errors[] = $this->missingPermissionError( $action, $short );
1608                 }
1609
1610                 return $errors;
1611         }
1612
1613         /**
1614          * Add the resulting error code to the errors array
1615          *
1616          * @param $errors Array list of current errors
1617          * @param $result Mixed result of errors
1618          *
1619          * @return Array list of errors
1620          */
1621         private function resultToError( $errors, $result ) {
1622                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1623                         // A single array representing an error
1624                         $errors[] = $result;
1625                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1626                         // A nested array representing multiple errors
1627                         $errors = array_merge( $errors, $result );
1628                 } elseif ( $result !== '' && is_string( $result ) ) {
1629                         // A string representing a message-id
1630                         $errors[] = array( $result );
1631                 } elseif ( $result === false ) {
1632                         // a generic "We don't want them to do that"
1633                         $errors[] = array( 'badaccess-group0' );
1634                 }
1635                 return $errors;
1636         }
1637
1638         /**
1639          * Check various permission hooks
1640          *
1641          * @param $action String the action to check
1642          * @param $user User user to check
1643          * @param $errors Array list of current errors
1644          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1645          * @param $short Boolean short circuit on first error
1646          *
1647          * @return Array list of errors
1648          */
1649         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1650                 // Use getUserPermissionsErrors instead
1651                 $result = '';
1652                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1653                         return $result ? array() : array( array( 'badaccess-group0' ) );
1654                 }
1655                 // Check getUserPermissionsErrors hook
1656                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1657                         $errors = $this->resultToError( $errors, $result );
1658                 }
1659                 // Check getUserPermissionsErrorsExpensive hook
1660                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1661                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1662                         $errors = $this->resultToError( $errors, $result );
1663                 }
1664
1665                 return $errors;
1666         }
1667
1668         /**
1669          * Check permissions on special pages & namespaces
1670          *
1671          * @param $action String the action to check
1672          * @param $user User user to check
1673          * @param $errors Array list of current errors
1674          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1675          * @param $short Boolean short circuit on first error
1676          *
1677          * @return Array list of errors
1678          */
1679         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1680                 # Only 'createaccount' and 'execute' can be performed on
1681                 # special pages, which don't actually exist in the DB.
1682                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1683                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1684                         $errors[] = array( 'ns-specialprotected' );
1685                 }
1686
1687                 # Check $wgNamespaceProtection for restricted namespaces
1688                 if ( $this->isNamespaceProtected( $user ) ) {
1689                         $ns = $this->mNamespace == NS_MAIN ?
1690                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1691                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1692                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1693                 }
1694
1695                 return $errors;
1696         }
1697
1698         /**
1699          * Check CSS/JS sub-page permissions
1700          *
1701          * @param $action String the action to check
1702          * @param $user User user to check
1703          * @param $errors Array list of current errors
1704          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1705          * @param $short Boolean short circuit on first error
1706          *
1707          * @return Array list of errors
1708          */
1709         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1710                 # Protect css/js subpages of user pages
1711                 # XXX: this might be better using restrictions
1712                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1713                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1714                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1715                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1716                                 $errors[] = array( 'customcssprotected' );
1717                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1718                                 $errors[] = array( 'customjsprotected' );
1719                         }
1720                 }
1721
1722                 return $errors;
1723         }
1724
1725         /**
1726          * Check against page_restrictions table requirements on this
1727          * page. The user must possess all required rights for this
1728          * action.
1729          *
1730          * @param $action String the action to check
1731          * @param $user User user to check
1732          * @param $errors Array list of current errors
1733          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1734          * @param $short Boolean short circuit on first error
1735          *
1736          * @return Array list of errors
1737          */
1738         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1739                 foreach ( $this->getRestrictions( $action ) as $right ) {
1740                         // Backwards compatibility, rewrite sysop -> protect
1741                         if ( $right == 'sysop' ) {
1742                                 $right = 'protect';
1743                         }
1744                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1745                                 // Users with 'editprotected' permission can edit protected pages
1746                                 // without cascading option turned on.
1747                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1748                                         || $this->mCascadeRestriction )
1749                                 {
1750                                         $errors[] = array( 'protectedpagetext', $right );
1751                                 }
1752                         }
1753                 }
1754
1755                 return $errors;
1756         }
1757
1758         /**
1759          * Check restrictions on cascading pages.
1760          *
1761          * @param $action String the action to check
1762          * @param $user User to check
1763          * @param $errors Array list of current errors
1764          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1765          * @param $short Boolean short circuit on first error
1766          *
1767          * @return Array list of errors
1768          */
1769         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1770                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1771                         # We /could/ use the protection level on the source page, but it's
1772                         # fairly ugly as we have to establish a precedence hierarchy for pages
1773                         # included by multiple cascade-protected pages. So just restrict
1774                         # it to people with 'protect' permission, as they could remove the
1775                         # protection anyway.
1776                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1777                         # Cascading protection depends on more than this page...
1778                         # Several cascading protected pages may include this page...
1779                         # Check each cascading level
1780                         # This is only for protection restrictions, not for all actions
1781                         if ( isset( $restrictions[$action] ) ) {
1782                                 foreach ( $restrictions[$action] as $right ) {
1783                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1784                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1785                                                 $pages = '';
1786                                                 foreach ( $cascadingSources as $page )
1787                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1788                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1789                                         }
1790                                 }
1791                         }
1792                 }
1793
1794                 return $errors;
1795         }
1796
1797         /**
1798          * Check action permissions not already checked in checkQuickPermissions
1799          *
1800          * @param $action String the action to check
1801          * @param $user User to check
1802          * @param $errors Array list of current errors
1803          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1804          * @param $short Boolean short circuit on first error
1805          *
1806          * @return Array list of errors
1807          */
1808         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1809                 if ( $action == 'protect' ) {
1810                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1811                                 // If they can't edit, they shouldn't protect.
1812                                 $errors[] = array( 'protect-cantedit' );
1813                         }
1814                 } elseif ( $action == 'create' ) {
1815                         $title_protection = $this->getTitleProtection();
1816                         if( $title_protection ) {
1817                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1818                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1819                                 }
1820                                 if( $title_protection['pt_create_perm'] == '' ||
1821                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1822                                 {
1823                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1824                                 }
1825                         }
1826                 } elseif ( $action == 'move' ) {
1827                         // Check for immobile pages
1828                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1829                                 // Specific message for this case
1830                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1831                         } elseif ( !$this->isMovable() ) {
1832                                 // Less specific message for rarer cases
1833                                 $errors[] = array( 'immobile-source-page' );
1834                         }
1835                 } elseif ( $action == 'move-target' ) {
1836                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1837                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1838                         } elseif ( !$this->isMovable() ) {
1839                                 $errors[] = array( 'immobile-target-page' );
1840                         }
1841                 }
1842                 return $errors;
1843         }
1844
1845         /**
1846          * Check that the user isn't blocked from editting.
1847          *
1848          * @param $action String the action to check
1849          * @param $user User to check
1850          * @param $errors Array list of current errors
1851          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1852          * @param $short Boolean short circuit on first error
1853          *
1854          * @return Array list of errors
1855          */
1856         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1857                 // Account creation blocks handled at userlogin.
1858                 // Unblocking handled in SpecialUnblock
1859                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1860                         return $errors;
1861                 }
1862
1863                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1864
1865                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1866                         $errors[] = array( 'confirmedittext' );
1867                 }
1868
1869                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1870                         // Don't block the user from editing their own talk page unless they've been
1871                         // explicitly blocked from that too.
1872                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1873                         $block = $user->mBlock;
1874
1875                         // This is from OutputPage::blockedPage
1876                         // Copied at r23888 by werdna
1877
1878                         $id = $user->blockedBy();
1879                         $reason = $user->blockedFor();
1880                         if ( $reason == '' ) {
1881                                 $reason = wfMsg( 'blockednoreason' );
1882                         }
1883                         $ip = $user->getRequest()->getIP();
1884
1885                         if ( is_numeric( $id ) ) {
1886                                 $name = User::whoIs( $id );
1887                         } else {
1888                                 $name = $id;
1889                         }
1890
1891                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1892                         $blockid = $block->getId();
1893                         $blockExpiry = $user->mBlock->mExpiry;
1894                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1895                         if ( $blockExpiry == 'infinity' ) {
1896                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1897                         } else {
1898                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1899                         }
1900
1901                         $intended = strval( $user->mBlock->getTarget() );
1902
1903                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1904                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1905                 }
1906
1907                 return $errors;
1908         }
1909
1910         /**
1911          * Check that the user is allowed to read this page.
1912          *
1913          * @param $action String the action to check
1914          * @param $user User to check
1915          * @param $errors Array list of current errors
1916          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1917          * @param $short Boolean short circuit on first error
1918          *
1919          * @return Array list of errors
1920          */
1921         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1922                 static $useShortcut = null;
1923
1924                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1925                 if ( is_null( $useShortcut ) ) {
1926                         global $wgGroupPermissions, $wgRevokePermissions;
1927                         $useShortcut = true;
1928                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1929                                 # Not a public wiki, so no shortcut
1930                                 $useShortcut = false;
1931                         } elseif ( !empty( $wgRevokePermissions ) ) {
1932                                 /**
1933                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1934                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1935                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1936                                  * reading is allowed.
1937                                  */
1938                                 foreach ( $wgRevokePermissions as $perms ) {
1939                                         if ( !empty( $perms['read'] ) ) {
1940                                                 # We might be removing the read right from the user, so no shortcut
1941                                                 $useShortcut = false;
1942                                                 break;
1943                                         }
1944                                 }
1945                         }
1946                 }
1947
1948                 # Shortcut for public wikis, allows skipping quite a bit of code
1949                 if ( $useShortcut ) {
1950                         return $errors;
1951                 }
1952
1953                 # If the user is allowed to read pages, he is allowed to read all pages
1954                 if ( $user->isAllowed( 'read' ) ) {
1955                         return $errors;
1956                 }
1957
1958                 # Always grant access to the login page.
1959                 # Even anons need to be able to log in.
1960                 if ( $this->isSpecial( 'Userlogin' )
1961                         || $this->isSpecial( 'ChangePassword' )
1962                         || $this->isSpecial( 'PasswordReset' )
1963                 ) {
1964                         return $errors;
1965                 }
1966
1967                 # Time to check the whitelist
1968                 global $wgWhitelistRead;
1969
1970                 # Only to these checks is there's something to check against
1971                 if ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
1972                         # Check for explicit whitelisting
1973                         $name = $this->getPrefixedText();
1974                         $dbName = $this->getPrefixedDBKey();
1975
1976                         // Check with and without underscores
1977                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
1978                                 return $errors;
1979                         }
1980
1981                         # Old settings might have the title prefixed with
1982                         # a colon for main-namespace pages
1983                         if ( $this->getNamespace() == NS_MAIN ) {
1984                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1985                                         return $errors;
1986                                 }
1987                         }
1988
1989                         # If it's a special page, ditch the subpage bit and check again
1990                         if ( $this->isSpecialPage() ) {
1991                                 $name = $this->getDBkey();
1992                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1993                                 if ( $name !== false ) {
1994                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1995                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1996                                                 return $errors;
1997                                         }
1998                                 }
1999                         }
2000                 }
2001
2002                 $errors[] = $this->missingPermissionError( $action, $short );
2003                 return $errors;
2004         }
2005
2006         /**
2007          * Get a description array when the user doesn't have the right to perform
2008          * $action (i.e. when User::isAllowed() returns false)
2009          *
2010          * @param $action String the action to check
2011          * @param $short Boolean short circuit on first error
2012          * @return Array list of errors
2013          */
2014         private function missingPermissionError( $action, $short ) {
2015                 // We avoid expensive display logic for quickUserCan's and such
2016                 if ( $short ) {
2017                         return array( 'badaccess-group0' );
2018                 }
2019
2020                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2021                         User::getGroupsWithPermission( $action ) );
2022
2023                 if ( count( $groups ) ) {
2024                         global $wgLang;
2025                         return array(
2026                                 'badaccess-groups',
2027                                 $wgLang->commaList( $groups ),
2028                                 count( $groups )
2029                         );
2030                 } else {
2031                         return array( 'badaccess-group0' );
2032                 }
2033         }
2034
2035         /**
2036          * Can $user perform $action on this page? This is an internal function,
2037          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2038          * checks on wfReadOnly() and blocks)
2039          *
2040          * @param $action String action that permission needs to be checked for
2041          * @param $user User to check
2042          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2043          * @param $short Bool Set this to true to stop after the first permission error.
2044          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2045          */
2046         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2047                 wfProfileIn( __METHOD__ );
2048
2049                 # Read has special handling
2050                 if ( $action == 'read' ) {
2051                         $checks = array(
2052                                 'checkPermissionHooks',
2053                                 'checkReadPermissions',
2054                         );
2055                 } else {
2056                         $checks = array(
2057                                 'checkQuickPermissions',
2058                                 'checkPermissionHooks',
2059                                 'checkSpecialsAndNSPermissions',
2060                                 'checkCSSandJSPermissions',
2061                                 'checkPageRestrictions',
2062                                 'checkCascadingSourcesRestrictions',
2063                                 'checkActionPermissions',
2064                                 'checkUserBlock'
2065                         );
2066                 }
2067
2068                 $errors = array();
2069                 while( count( $checks ) > 0 &&
2070                                 !( $short && count( $errors ) > 0 ) ) {
2071                         $method = array_shift( $checks );
2072                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2073                 }
2074
2075                 wfProfileOut( __METHOD__ );
2076                 return $errors;
2077         }
2078
2079         /**
2080          * Protect css subpages of user pages: can $wgUser edit
2081          * this page?
2082          *
2083          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2084          * @return Bool
2085          */
2086         public function userCanEditCssSubpage() {
2087                 global $wgUser;
2088                 wfDeprecated( __METHOD__ );
2089                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2090                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2091         }
2092
2093         /**
2094          * Protect js subpages of user pages: can $wgUser edit
2095          * this page?
2096          *
2097          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2098          * @return Bool
2099          */
2100         public function userCanEditJsSubpage() {
2101                 global $wgUser;
2102                 wfDeprecated( __METHOD__ );
2103                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2104                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2105         }
2106
2107         /**
2108          * Get a filtered list of all restriction types supported by this wiki.
2109          * @param bool $exists True to get all restriction types that apply to
2110          * titles that do exist, False for all restriction types that apply to
2111          * titles that do not exist
2112          * @return array
2113          */
2114         public static function getFilteredRestrictionTypes( $exists = true ) {
2115                 global $wgRestrictionTypes;
2116                 $types = $wgRestrictionTypes;
2117                 if ( $exists ) {
2118                         # Remove the create restriction for existing titles
2119                         $types = array_diff( $types, array( 'create' ) );
2120                 } else {
2121                         # Only the create and upload restrictions apply to non-existing titles
2122                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2123                 }
2124                 return $types;
2125         }
2126
2127         /**
2128          * Returns restriction types for the current Title
2129          *
2130          * @return array applicable restriction types
2131          */
2132         public function getRestrictionTypes() {
2133                 if ( $this->isSpecialPage() ) {
2134                         return array();
2135                 }
2136
2137                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2138
2139                 if ( $this->getNamespace() != NS_FILE ) {
2140                         # Remove the upload restriction for non-file titles
2141                         $types = array_diff( $types, array( 'upload' ) );
2142                 }
2143
2144                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2145
2146                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2147                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2148
2149                 return $types;
2150         }
2151
2152         /**
2153          * Is this title subject to title protection?
2154          * Title protection is the one applied against creation of such title.
2155          *
2156          * @return Mixed An associative array representing any existent title
2157          *   protection, or false if there's none.
2158          */
2159         private function getTitleProtection() {
2160                 // Can't protect pages in special namespaces
2161                 if ( $this->getNamespace() < 0 ) {
2162                         return false;
2163                 }
2164
2165                 // Can't protect pages that exist.
2166                 if ( $this->exists() ) {
2167                         return false;
2168                 }
2169
2170                 if ( !isset( $this->mTitleProtection ) ) {
2171                         $dbr = wfGetDB( DB_SLAVE );
2172                         $res = $dbr->select( 'protected_titles', '*',
2173                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2174                                 __METHOD__ );
2175
2176                         // fetchRow returns false if there are no rows.
2177                         $this->mTitleProtection = $dbr->fetchRow( $res );
2178                 }
2179                 return $this->mTitleProtection;
2180         }
2181
2182         /**
2183          * Update the title protection status
2184          *
2185          * @param $create_perm String Permission required for creation
2186          * @param $reason String Reason for protection
2187          * @param $expiry String Expiry timestamp
2188          * @return boolean true
2189          */
2190         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2191                 global $wgUser, $wgContLang;
2192
2193                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
2194                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
2195                         // No change
2196                         return true;
2197                 }
2198
2199                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
2200
2201                 $dbw = wfGetDB( DB_MASTER );
2202
2203                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
2204
2205                 $expiry_description = '';
2206                 if ( $encodedExpiry != $dbw->getInfinity() ) {
2207                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
2208                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
2209                 } else {
2210                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
2211                 }
2212
2213                 # Update protection table
2214                 if ( $create_perm != '' ) {
2215                         $this->mTitleProtection = array(
2216                                         'pt_namespace' => $namespace,
2217                                         'pt_title' => $title,
2218                                         'pt_create_perm' => $create_perm,
2219                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
2220                                         'pt_expiry' => $encodedExpiry,
2221                                         'pt_user' => $wgUser->getId(),
2222                                         'pt_reason' => $reason,
2223                                 );
2224                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
2225                                 $this->mTitleProtection, __METHOD__     );
2226                 } else {
2227                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
2228                                 'pt_title' => $title ), __METHOD__ );
2229                         $this->mTitleProtection = false;
2230                 }
2231
2232                 # Update the protection log
2233                 if ( $dbw->affectedRows() ) {
2234                         $log = new LogPage( 'protect' );
2235
2236                         if ( $create_perm ) {
2237                                 $params = array( "[create=$create_perm] $expiry_description", '' );
2238                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
2239                         } else {
2240                                 $log->addEntry( 'unprotect', $this, $reason );
2241                         }
2242                 }
2243
2244                 return true;
2245         }
2246
2247         /**
2248          * Remove any title protection due to page existing
2249          */
2250         public function deleteTitleProtection() {
2251                 $dbw = wfGetDB( DB_MASTER );
2252
2253                 $dbw->delete(
2254                         'protected_titles',
2255                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2256                         __METHOD__
2257                 );
2258                 $this->mTitleProtection = false;
2259         }
2260
2261         /**
2262          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2263          *
2264          * @param $action String Action to check (default: edit)
2265          * @return Bool
2266          */
2267         public function isSemiProtected( $action = 'edit' ) {
2268                 if ( $this->exists() ) {
2269                         $restrictions = $this->getRestrictions( $action );
2270                         if ( count( $restrictions ) > 0 ) {
2271                                 foreach ( $restrictions as $restriction ) {
2272                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2273                                                 return false;
2274                                         }
2275                                 }
2276                         } else {
2277                                 # Not protected
2278                                 return false;
2279                         }
2280                         return true;
2281                 } else {
2282                         # If it doesn't exist, it can't be protected
2283                         return false;
2284                 }
2285         }
2286
2287         /**
2288          * Does the title correspond to a protected article?
2289          *
2290          * @param $action String the action the page is protected from,
2291          * by default checks all actions.
2292          * @return Bool
2293          */
2294         public function isProtected( $action = '' ) {
2295                 global $wgRestrictionLevels;
2296
2297                 $restrictionTypes = $this->getRestrictionTypes();
2298
2299                 # Special pages have inherent protection
2300                 if( $this->isSpecialPage() ) {
2301                         return true;
2302                 }
2303
2304                 # Check regular protection levels
2305                 foreach ( $restrictionTypes as $type ) {
2306                         if ( $action == $type || $action == '' ) {
2307                                 $r = $this->getRestrictions( $type );
2308                                 foreach ( $wgRestrictionLevels as $level ) {
2309                                         if ( in_array( $level, $r ) && $level != '' ) {
2310                                                 return true;
2311                                         }
2312                                 }
2313                         }
2314                 }
2315
2316                 return false;
2317         }
2318
2319         /**
2320          * Determines if $user is unable to edit this page because it has been protected
2321          * by $wgNamespaceProtection.
2322          *
2323          * @param $user User object to check permissions
2324          * @return Bool
2325          */
2326         public function isNamespaceProtected( User $user ) {
2327                 global $wgNamespaceProtection;
2328
2329                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2330                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2331                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2332                                         return true;
2333                                 }
2334                         }
2335                 }
2336                 return false;
2337         }
2338
2339         /**
2340          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2341          *
2342          * @return Bool If the page is subject to cascading restrictions.
2343          */
2344         public function isCascadeProtected() {
2345                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2346                 return ( $sources > 0 );
2347         }
2348
2349         /**
2350          * Cascading protection: Get the source of any cascading restrictions on this page.
2351          *
2352          * @param $getPages Bool Whether or not to retrieve the actual pages
2353          *        that the restrictions have come from.
2354          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2355          *     have come, false for none, or true if such restrictions exist, but $getPages
2356          *     was not set.  The restriction array is an array of each type, each of which
2357          *     contains a array of unique groups.
2358          */
2359         public function getCascadeProtectionSources( $getPages = true ) {
2360                 global $wgContLang;
2361                 $pagerestrictions = array();
2362
2363                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2364                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2365                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2366                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2367                 }
2368
2369                 wfProfileIn( __METHOD__ );
2370
2371                 $dbr = wfGetDB( DB_SLAVE );
2372
2373                 if ( $this->getNamespace() == NS_FILE ) {
2374                         $tables = array( 'imagelinks', 'page_restrictions' );
2375                         $where_clauses = array(
2376                                 'il_to' => $this->getDBkey(),
2377                                 'il_from=pr_page',
2378                                 'pr_cascade' => 1
2379                         );
2380                 } else {
2381                         $tables = array( 'templatelinks', 'page_restrictions' );
2382                         $where_clauses = array(
2383                                 'tl_namespace' => $this->getNamespace(),
2384                                 'tl_title' => $this->getDBkey(),
2385                                 'tl_from=pr_page',
2386                                 'pr_cascade' => 1
2387                         );
2388                 }
2389
2390                 if ( $getPages ) {
2391                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2392                                                    'pr_expiry', 'pr_type', 'pr_level' );
2393                         $where_clauses[] = 'page_id=pr_page';
2394                         $tables[] = 'page';
2395                 } else {
2396                         $cols = array( 'pr_expiry' );
2397                 }
2398
2399                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2400
2401                 $sources = $getPages ? array() : false;
2402                 $now = wfTimestampNow();
2403                 $purgeExpired = false;
2404
2405                 foreach ( $res as $row ) {
2406                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2407                         if ( $expiry > $now ) {
2408                                 if ( $getPages ) {
2409                                         $page_id = $row->pr_page;
2410                                         $page_ns = $row->page_namespace;
2411                                         $page_title = $row->page_title;
2412                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2413                                         # Add groups needed for each restriction type if its not already there
2414                                         # Make sure this restriction type still exists
2415
2416                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2417                                                 $pagerestrictions[$row->pr_type] = array();
2418                                         }
2419
2420                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2421                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2422                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2423                                         }
2424                                 } else {
2425                                         $sources = true;
2426                                 }
2427                         } else {
2428                                 // Trigger lazy purge of expired restrictions from the db
2429                                 $purgeExpired = true;
2430                         }
2431                 }
2432                 if ( $purgeExpired ) {
2433                         Title::purgeExpiredRestrictions();
2434                 }
2435
2436                 if ( $getPages ) {
2437                         $this->mCascadeSources = $sources;
2438                         $this->mCascadingRestrictions = $pagerestrictions;
2439                 } else {
2440                         $this->mHasCascadingRestrictions = $sources;
2441                 }
2442
2443                 wfProfileOut( __METHOD__ );
2444                 return array( $sources, $pagerestrictions );
2445         }
2446
2447         /**
2448          * Accessor/initialisation for mRestrictions
2449          *
2450          * @param $action String action that permission needs to be checked for
2451          * @return Array of Strings the array of groups allowed to edit this article
2452          */
2453         public function getRestrictions( $action ) {
2454                 if ( !$this->mRestrictionsLoaded ) {
2455                         $this->loadRestrictions();
2456                 }
2457                 return isset( $this->mRestrictions[$action] )
2458                                 ? $this->mRestrictions[$action]
2459                                 : array();
2460         }
2461
2462         /**
2463          * Get the expiry time for the restriction against a given action
2464          *
2465          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2466          *      or not protected at all, or false if the action is not recognised.
2467          */
2468         public function getRestrictionExpiry( $action ) {
2469                 if ( !$this->mRestrictionsLoaded ) {
2470                         $this->loadRestrictions();
2471                 }
2472                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2473         }
2474
2475         /**
2476          * Returns cascading restrictions for the current article
2477          *
2478          * @return Boolean
2479          */
2480         function areRestrictionsCascading() {
2481                 if ( !$this->mRestrictionsLoaded ) {
2482                         $this->loadRestrictions();
2483                 }
2484
2485                 return $this->mCascadeRestriction;
2486         }
2487
2488         /**
2489          * Loads a string into mRestrictions array
2490          *
2491          * @param $res Resource restrictions as an SQL result.
2492          * @param $oldFashionedRestrictions String comma-separated list of page
2493          *        restrictions from page table (pre 1.10)
2494          */
2495         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2496                 $rows = array();
2497
2498                 foreach ( $res as $row ) {
2499                         $rows[] = $row;
2500                 }
2501
2502                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2503         }
2504
2505         /**
2506          * Compiles list of active page restrictions from both page table (pre 1.10)
2507          * and page_restrictions table for this existing page.
2508          * Public for usage by LiquidThreads.
2509          *
2510          * @param $rows array of db result objects
2511          * @param $oldFashionedRestrictions string comma-separated list of page
2512          *        restrictions from page table (pre 1.10)
2513          */
2514         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2515                 global $wgContLang;
2516                 $dbr = wfGetDB( DB_SLAVE );
2517
2518                 $restrictionTypes = $this->getRestrictionTypes();
2519
2520                 foreach ( $restrictionTypes as $type ) {
2521                         $this->mRestrictions[$type] = array();
2522                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2523                 }
2524
2525                 $this->mCascadeRestriction = false;
2526
2527                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2528
2529                 if ( $oldFashionedRestrictions === null ) {
2530                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2531                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2532                 }
2533
2534                 if ( $oldFashionedRestrictions != '' ) {
2535
2536                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2537                                 $temp = explode( '=', trim( $restrict ) );
2538                                 if ( count( $temp ) == 1 ) {
2539                                         // old old format should be treated as edit/move restriction
2540                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2541                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2542                                 } else {
2543                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2544                                 }
2545                         }
2546
2547                         $this->mOldRestrictions = true;
2548
2549                 }
2550
2551                 if ( count( $rows ) ) {
2552                         # Current system - load second to make them override.
2553                         $now = wfTimestampNow();
2554                         $purgeExpired = false;
2555
2556                         # Cycle through all the restrictions.
2557                         foreach ( $rows as $row ) {
2558
2559                                 // Don't take care of restrictions types that aren't allowed
2560                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2561                                         continue;
2562
2563                                 // This code should be refactored, now that it's being used more generally,
2564                                 // But I don't really see any harm in leaving it in Block for now -werdna
2565                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2566
2567                                 // Only apply the restrictions if they haven't expired!
2568                                 if ( !$expiry || $expiry > $now ) {
2569                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2570                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2571
2572                                         $this->mCascadeRestriction |= $row->pr_cascade;
2573                                 } else {
2574                                         // Trigger a lazy purge of expired restrictions
2575                                         $purgeExpired = true;
2576                                 }
2577                         }
2578
2579                         if ( $purgeExpired ) {
2580                                 Title::purgeExpiredRestrictions();
2581                         }
2582                 }
2583
2584                 $this->mRestrictionsLoaded = true;
2585         }
2586
2587         /**
2588          * Load restrictions from the page_restrictions table
2589          *
2590          * @param $oldFashionedRestrictions String comma-separated list of page
2591          *        restrictions from page table (pre 1.10)
2592          */
2593         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2594                 global $wgContLang;
2595                 if ( !$this->mRestrictionsLoaded ) {
2596                         if ( $this->exists() ) {
2597                                 $dbr = wfGetDB( DB_SLAVE );
2598
2599                                 $res = $dbr->select(
2600                                         'page_restrictions',
2601                                         '*',
2602                                         array( 'pr_page' => $this->getArticleId() ),
2603                                         __METHOD__
2604                                 );
2605
2606                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2607                         } else {
2608                                 $title_protection = $this->getTitleProtection();
2609
2610                                 if ( $title_protection ) {
2611                                         $now = wfTimestampNow();
2612                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2613
2614                                         if ( !$expiry || $expiry > $now ) {
2615                                                 // Apply the restrictions
2616                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2617                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2618                                         } else { // Get rid of the old restrictions
2619                                                 Title::purgeExpiredRestrictions();
2620                                                 $this->mTitleProtection = false;
2621                                         }
2622                                 } else {
2623                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2624                                 }
2625                                 $this->mRestrictionsLoaded = true;
2626                         }
2627                 }
2628         }
2629
2630         /**
2631          * Purge expired restrictions from the page_restrictions table
2632          */
2633         static function purgeExpiredRestrictions() {
2634                 $dbw = wfGetDB( DB_MASTER );
2635                 $dbw->delete(
2636                         'page_restrictions',
2637                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2638                         __METHOD__
2639                 );
2640
2641                 $dbw->delete(
2642                         'protected_titles',
2643                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2644                         __METHOD__
2645                 );
2646         }
2647
2648         /**
2649          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2650          *
2651          * @return Bool
2652          */
2653         public function hasSubpages() {
2654                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2655                         # Duh
2656                         return false;
2657                 }
2658
2659                 # We dynamically add a member variable for the purpose of this method
2660                 # alone to cache the result.  There's no point in having it hanging
2661                 # around uninitialized in every Title object; therefore we only add it
2662                 # if needed and don't declare it statically.
2663                 if ( isset( $this->mHasSubpages ) ) {
2664                         return $this->mHasSubpages;
2665                 }
2666
2667                 $subpages = $this->getSubpages( 1 );
2668                 if ( $subpages instanceof TitleArray ) {
2669                         return $this->mHasSubpages = (bool)$subpages->count();
2670                 }
2671                 return $this->mHasSubpages = false;
2672         }
2673
2674         /**
2675          * Get all subpages of this page.
2676          *
2677          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2678          * @return mixed TitleArray, or empty array if this page's namespace
2679          *  doesn't allow subpages
2680          */
2681         public function getSubpages( $limit = -1 ) {
2682                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2683                         return array();
2684                 }
2685
2686                 $dbr = wfGetDB( DB_SLAVE );
2687                 $conds['page_namespace'] = $this->getNamespace();
2688                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2689                 $options = array();
2690                 if ( $limit > -1 ) {
2691                         $options['LIMIT'] = $limit;
2692                 }
2693                 return $this->mSubpages = TitleArray::newFromResult(
2694                         $dbr->select( 'page',
2695                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2696                                 $conds,
2697                                 __METHOD__,
2698                                 $options
2699                         )
2700                 );
2701         }
2702
2703         /**
2704          * Is there a version of this page in the deletion archive?
2705          *
2706          * @return Int the number of archived revisions
2707          */
2708         public function isDeleted() {
2709                 if ( $this->getNamespace() < 0 ) {
2710                         $n = 0;
2711                 } else {
2712                         $dbr = wfGetDB( DB_SLAVE );
2713
2714                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2715                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2716                                 __METHOD__
2717                         );
2718                         if ( $this->getNamespace() == NS_FILE ) {
2719                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2720                                         array( 'fa_name' => $this->getDBkey() ),
2721                                         __METHOD__
2722                                 );
2723                         }
2724                 }
2725                 return (int)$n;
2726         }
2727
2728         /**
2729          * Is there a version of this page in the deletion archive?
2730          *
2731          * @return Boolean
2732          */
2733         public function isDeletedQuick() {
2734                 if ( $this->getNamespace() < 0 ) {
2735                         return false;
2736                 }
2737                 $dbr = wfGetDB( DB_SLAVE );
2738                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2739                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2740                         __METHOD__
2741                 );
2742                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2743                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2744                                 array( 'fa_name' => $this->getDBkey() ),
2745                                 __METHOD__
2746                         );
2747                 }
2748                 return $deleted;
2749         }
2750
2751         /**
2752          * Get the number of views of this page
2753          *
2754          * @return int The view count for the page
2755          */
2756         public function getCount() {
2757                 if ( $this->mCounter == -1 ) {
2758                         if ( $this->exists() ) {
2759                                 $dbr = wfGetDB( DB_SLAVE );
2760                                 $this->mCounter = $dbr->selectField( 'page',
2761                                         'page_counter',
2762                                         array( 'page_id' => $this->getArticleID() ),
2763                                         __METHOD__
2764                                 );
2765                         } else {
2766                                 $this->mCounter = 0;
2767                         }
2768                 }
2769
2770                 return $this->mCounter;
2771         }
2772
2773         /**
2774          * Get the article ID for this Title from the link cache,
2775          * adding it if necessary
2776          *
2777          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2778          *  for update
2779          * @return Int the ID
2780          */
2781         public function getArticleID( $flags = 0 ) {
2782                 if ( $this->getNamespace() < 0 ) {
2783                         return $this->mArticleID = 0;
2784                 }
2785                 $linkCache = LinkCache::singleton();
2786                 if ( $flags & self::GAID_FOR_UPDATE ) {
2787                         $oldUpdate = $linkCache->forUpdate( true );
2788                         $linkCache->clearLink( $this );
2789                         $this->mArticleID = $linkCache->addLinkObj( $this );
2790                         $linkCache->forUpdate( $oldUpdate );
2791                 } else {
2792                         if ( -1 == $this->mArticleID ) {
2793                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2794                         }
2795                 }
2796                 return $this->mArticleID;
2797         }
2798
2799         /**
2800          * Is this an article that is a redirect page?
2801          * Uses link cache, adding it if necessary
2802          *
2803          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2804          * @return Bool
2805          */
2806         public function isRedirect( $flags = 0 ) {
2807                 if ( !is_null( $this->mRedirect ) ) {
2808                         return $this->mRedirect;
2809                 }
2810                 # Calling getArticleID() loads the field from cache as needed
2811                 if ( !$this->getArticleID( $flags ) ) {
2812                         return $this->mRedirect = false;
2813                 }
2814                 $linkCache = LinkCache::singleton();
2815                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2816
2817                 return $this->mRedirect;
2818         }
2819
2820         /**
2821          * What is the length of this page?
2822          * Uses link cache, adding it if necessary
2823          *
2824          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2825          * @return Int
2826          */
2827         public function getLength( $flags = 0 ) {
2828                 if ( $this->mLength != -1 ) {
2829                         return $this->mLength;
2830                 }
2831                 # Calling getArticleID() loads the field from cache as needed
2832                 if ( !$this->getArticleID( $flags ) ) {
2833                         return $this->mLength = 0;
2834                 }
2835                 $linkCache = LinkCache::singleton();
2836                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2837
2838                 return $this->mLength;
2839         }
2840
2841         /**
2842          * What is the page_latest field for this page?
2843          *
2844          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2845          * @return Int or 0 if the page doesn't exist
2846          */
2847         public function getLatestRevID( $flags = 0 ) {
2848                 if ( $this->mLatestID !== false ) {
2849                         return intval( $this->mLatestID );
2850                 }
2851                 # Calling getArticleID() loads the field from cache as needed
2852                 if ( !$this->getArticleID( $flags ) ) {
2853                         return $this->mLatestID = 0;
2854                 }
2855                 $linkCache = LinkCache::singleton();
2856                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2857
2858                 return $this->mLatestID;
2859         }
2860
2861         /**
2862          * This clears some fields in this object, and clears any associated
2863          * keys in the "bad links" section of the link cache.
2864          *
2865          * - This is called from Article::doEdit() and Article::insertOn() to allow
2866          * loading of the new page_id. It's also called from
2867          * Article::doDeleteArticle()
2868          *
2869          * @param $newid Int the new Article ID
2870          */
2871         public function resetArticleID( $newid ) {
2872                 $linkCache = LinkCache::singleton();
2873                 $linkCache->clearLink( $this );
2874
2875                 if ( $newid === false ) {
2876                         $this->mArticleID = -1;
2877                 } else {
2878                         $this->mArticleID = intval( $newid );
2879                 }
2880                 $this->mRestrictionsLoaded = false;
2881                 $this->mRestrictions = array();
2882                 $this->mRedirect = null;
2883                 $this->mLength = -1;
2884                 $this->mLatestID = false;
2885                 $this->mCounter = -1;
2886         }
2887
2888         /**
2889          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2890          *
2891          * @param $text String containing title to capitalize
2892          * @param $ns int namespace index, defaults to NS_MAIN
2893          * @return String containing capitalized title
2894          */
2895         public static function capitalize( $text, $ns = NS_MAIN ) {
2896                 global $wgContLang;
2897
2898                 if ( MWNamespace::isCapitalized( $ns ) ) {
2899                         return $wgContLang->ucfirst( $text );
2900                 } else {
2901                         return $text;
2902                 }
2903         }
2904
2905         /**
2906          * Secure and split - main initialisation function for this object
2907          *
2908          * Assumes that mDbkeyform has been set, and is urldecoded
2909          * and uses underscores, but not otherwise munged.  This function
2910          * removes illegal characters, splits off the interwiki and
2911          * namespace prefixes, sets the other forms, and canonicalizes
2912          * everything.
2913          *
2914          * @return Bool true on success
2915          */
2916         private function secureAndSplit() {
2917                 global $wgContLang, $wgLocalInterwiki;
2918
2919                 # Initialisation
2920                 $this->mInterwiki = $this->mFragment = '';
2921                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2922
2923                 $dbkey = $this->mDbkeyform;
2924
2925                 # Strip Unicode bidi override characters.
2926                 # Sometimes they slip into cut-n-pasted page titles, where the
2927                 # override chars get included in list displays.
2928                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2929
2930                 # Clean up whitespace
2931                 # Note: use of the /u option on preg_replace here will cause
2932                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2933                 # conveniently disabling them.
2934                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2935                 $dbkey = trim( $dbkey, '_' );
2936
2937                 if ( $dbkey == '' ) {
2938                         return false;
2939                 }
2940
2941                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2942                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2943                         return false;
2944                 }
2945
2946                 $this->mDbkeyform = $dbkey;
2947
2948                 # Initial colon indicates main namespace rather than specified default
2949                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2950                 if ( ':' == $dbkey[0] ) {
2951                         $this->mNamespace = NS_MAIN;
2952                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2953                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2954                 }
2955
2956                 # Namespace or interwiki prefix
2957                 $firstPass = true;
2958                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2959                 do {
2960                         $m = array();
2961                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2962                                 $p = $m[1];
2963                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2964                                         # Ordinary namespace
2965                                         $dbkey = $m[2];
2966                                         $this->mNamespace = $ns;
2967                                         # For Talk:X pages, check if X has a "namespace" prefix
2968                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2969                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2970                                                         # Disallow Talk:File:x type titles...
2971                                                         return false;
2972                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2973                                                         # Disallow Talk:Interwiki:x type titles...
2974                                                         return false;
2975                                                 }
2976                                         }
2977                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2978                                         if ( !$firstPass ) {
2979                                                 # Can't make a local interwiki link to an interwiki link.
2980                                                 # That's just crazy!
2981                                                 return false;
2982                                         }
2983
2984                                         # Interwiki link
2985                                         $dbkey = $m[2];
2986                                         $this->mInterwiki = $wgContLang->lc( $p );
2987
2988                                         # Redundant interwiki prefix to the local wiki
2989                                         if ( $wgLocalInterwiki !== false
2990                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2991                                         {
2992                                                 if ( $dbkey == '' ) {
2993                                                         # Can't have an empty self-link
2994                                                         return false;
2995                                                 }
2996                                                 $this->mInterwiki = '';
2997                                                 $firstPass = false;
2998                                                 # Do another namespace split...
2999                                                 continue;
3000                                         }
3001
3002                                         # If there's an initial colon after the interwiki, that also
3003                                         # resets the default namespace
3004                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3005                                                 $this->mNamespace = NS_MAIN;
3006                                                 $dbkey = substr( $dbkey, 1 );
3007                                         }
3008                                 }
3009                                 # If there's no recognized interwiki or namespace,
3010                                 # then let the colon expression be part of the title.
3011                         }
3012                         break;
3013                 } while ( true );
3014
3015                 # We already know that some pages won't be in the database!
3016                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3017                         $this->mArticleID = 0;
3018                 }
3019                 $fragment = strstr( $dbkey, '#' );
3020                 if ( false !== $fragment ) {
3021                         $this->setFragment( $fragment );
3022                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3023                         # remove whitespace again: prevents "Foo_bar_#"
3024                         # becoming "Foo_bar_"
3025                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3026                 }
3027
3028                 # Reject illegal characters.
3029                 $rxTc = self::getTitleInvalidRegex();
3030                 if ( preg_match( $rxTc, $dbkey ) ) {
3031                         return false;
3032                 }
3033
3034                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3035                 # reachable due to the way web browsers deal with 'relative' URLs.
3036                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3037                 if ( strpos( $dbkey, '.' ) !== false &&
3038                          ( $dbkey === '.' || $dbkey === '..' ||
3039                            strpos( $dbkey, './' ) === 0  ||
3040                            strpos( $dbkey, '../' ) === 0 ||
3041                            strpos( $dbkey, '/./' ) !== false ||
3042                            strpos( $dbkey, '/../' ) !== false  ||
3043                            substr( $dbkey, -2 ) == '/.' ||
3044                            substr( $dbkey, -3 ) == '/..' ) )
3045                 {
3046                         return false;
3047                 }
3048
3049                 # Magic tilde sequences? Nu-uh!
3050                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3051                         return false;
3052                 }
3053
3054                 # Limit the size of titles to 255 bytes. This is typically the size of the
3055                 # underlying database field. We make an exception for special pages, which
3056                 # don't need to be stored in the database, and may edge over 255 bytes due
3057                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3058                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3059                   strlen( $dbkey ) > 512 )
3060                 {
3061                         return false;
3062                 }
3063
3064                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3065                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3066                 # other site might be case-sensitive.
3067                 $this->mUserCaseDBKey = $dbkey;
3068                 if ( $this->mInterwiki == '' ) {
3069                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3070                 }
3071
3072                 # Can't make a link to a namespace alone... "empty" local links can only be
3073                 # self-links with a fragment identifier.
3074                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3075                         return false;
3076                 }
3077
3078                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3079                 // IP names are not allowed for accounts, and can only be referring to
3080                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3081                 // there are numerous ways to present the same IP. Having sp:contribs scan
3082                 // them all is silly and having some show the edits and others not is
3083                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3084                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3085                         ? IP::sanitizeIP( $dbkey )
3086                         : $dbkey;
3087
3088                 // Any remaining initial :s are illegal.
3089                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3090                         return false;
3091                 }
3092
3093                 # Fill fields
3094                 $this->mDbkeyform = $dbkey;
3095                 $this->mUrlform = wfUrlencode( $dbkey );
3096
3097                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3098
3099                 return true;
3100         }
3101
3102         /**
3103          * Get an array of Title objects linking to this Title
3104          * Also stores the IDs in the link cache.
3105          *
3106          * WARNING: do not use this function on arbitrary user-supplied titles!
3107          * On heavily-used templates it will max out the memory.
3108          *
3109          * @param $options Array: may be FOR UPDATE
3110          * @param $table String: table name
3111          * @param $prefix String: fields prefix
3112          * @return Array of Title objects linking here
3113          */
3114         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3115                 $linkCache = LinkCache::singleton();
3116
3117                 if ( count( $options ) > 0 ) {
3118                         $db = wfGetDB( DB_MASTER );
3119                 } else {
3120                         $db = wfGetDB( DB_SLAVE );
3121                 }
3122
3123                 $res = $db->select(
3124                         array( 'page', $table ),
3125                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3126                         array(
3127                                 "{$prefix}_from=page_id",
3128                                 "{$prefix}_namespace" => $this->getNamespace(),
3129                                 "{$prefix}_title"     => $this->getDBkey() ),
3130                         __METHOD__,
3131                         $options
3132                 );
3133
3134                 $retVal = array();
3135                 if ( $db->numRows( $res ) ) {
3136                         foreach ( $res as $row ) {
3137                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3138                                 if ( $titleObj ) {
3139                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3140                                         $retVal[] = $titleObj;
3141                                 }
3142                         }
3143                 }
3144                 return $retVal;
3145         }
3146
3147         /**
3148          * Get an array of Title objects using this Title as a template
3149          * Also stores the IDs in the link cache.
3150          *
3151          * WARNING: do not use this function on arbitrary user-supplied titles!
3152          * On heavily-used templates it will max out the memory.
3153          *
3154          * @param $options Array: may be FOR UPDATE
3155          * @return Array of Title the Title objects linking here
3156          */
3157         public function getTemplateLinksTo( $options = array() ) {
3158                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3159         }
3160
3161         /**
3162          * Get an array of Title objects referring to non-existent articles linked from this page
3163          *
3164          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3165          * @return Array of Title the Title objects
3166          */
3167         public function getBrokenLinksFrom() {
3168                 if ( $this->getArticleId() == 0 ) {
3169                         # All links from article ID 0 are false positives
3170                         return array();
3171                 }
3172
3173                 $dbr = wfGetDB( DB_SLAVE );
3174                 $res = $dbr->select(
3175                         array( 'page', 'pagelinks' ),
3176                         array( 'pl_namespace', 'pl_title' ),
3177                         array(
3178                                 'pl_from' => $this->getArticleId(),
3179                                 'page_namespace IS NULL'
3180                         ),
3181                         __METHOD__, array(),
3182                         array(
3183                                 'page' => array(
3184                                         'LEFT JOIN',
3185                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3186                                 )
3187                         )
3188                 );
3189
3190                 $retVal = array();
3191                 foreach ( $res as $row ) {
3192                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3193                 }
3194                 return $retVal;
3195         }
3196
3197
3198         /**
3199          * Get a list of URLs to purge from the Squid cache when this
3200          * page changes
3201          *
3202          * @return Array of String the URLs
3203          */
3204         public function getSquidURLs() {
3205                 global $wgContLang;
3206
3207                 $urls = array(
3208                         $this->getInternalURL(),
3209                         $this->getInternalURL( 'action=history' )
3210                 );
3211
3212                 // purge variant urls as well
3213                 if ( $wgContLang->hasVariants() ) {
3214                         $variants = $wgContLang->getVariants();
3215                         foreach ( $variants as $vCode ) {
3216                                 $urls[] = $this->getInternalURL( '', $vCode );
3217                         }
3218                 }
3219
3220                 return $urls;
3221         }
3222
3223         /**
3224          * Purge all applicable Squid URLs
3225          */
3226         public function purgeSquid() {
3227                 global $wgUseSquid;
3228                 if ( $wgUseSquid ) {
3229                         $urls = $this->getSquidURLs();
3230                         $u = new SquidUpdate( $urls );
3231                         $u->doUpdate();
3232                 }
3233         }
3234
3235         /**
3236          * Move this page without authentication
3237          *
3238          * @param $nt Title the new page Title
3239          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3240          */
3241         public function moveNoAuth( &$nt ) {
3242                 return $this->moveTo( $nt, false );
3243         }
3244
3245         /**
3246          * Check whether a given move operation would be valid.
3247          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3248          *
3249          * @param $nt Title the new title
3250          * @param $auth Bool indicates whether $wgUser's permissions
3251          *  should be checked
3252          * @param $reason String is the log summary of the move, used for spam checking
3253          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3254          */
3255         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3256                 global $wgUser;
3257
3258                 $errors = array();
3259                 if ( !$nt ) {
3260                         // Normally we'd add this to $errors, but we'll get
3261                         // lots of syntax errors if $nt is not an object
3262                         return array( array( 'badtitletext' ) );
3263                 }
3264                 if ( $this->equals( $nt ) ) {
3265                         $errors[] = array( 'selfmove' );
3266                 }
3267                 if ( !$this->isMovable() ) {
3268                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3269                 }
3270                 if ( $nt->getInterwiki() != '' ) {
3271                         $errors[] = array( 'immobile-target-namespace-iw' );
3272                 }
3273                 if ( !$nt->isMovable() ) {
3274                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3275                 }
3276
3277                 $oldid = $this->getArticleID();
3278                 $newid = $nt->getArticleID();
3279
3280                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3281                         $errors[] = array( 'articleexists' );
3282                 }
3283                 if ( ( $this->getDBkey() == '' ) ||
3284                          ( !$oldid ) ||
3285                          ( $nt->getDBkey() == '' ) ) {
3286                         $errors[] = array( 'badarticleerror' );
3287                 }
3288
3289                 // Image-specific checks
3290                 if ( $this->getNamespace() == NS_FILE ) {
3291                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3292                 }
3293
3294                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3295                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3296                 }
3297
3298                 if ( $auth ) {
3299                         $errors = wfMergeErrorArrays( $errors,
3300                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3301                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3302                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3303                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3304                 }
3305
3306                 $match = EditPage::matchSummarySpamRegex( $reason );
3307                 if ( $match !== false ) {
3308                         // This is kind of lame, won't display nice
3309                         $errors[] = array( 'spamprotectiontext' );
3310                 }
3311
3312                 $err = null;
3313                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3314                         $errors[] = array( 'hookaborted', $err );
3315                 }
3316
3317                 # The move is allowed only if (1) the target doesn't exist, or
3318                 # (2) the target is a redirect to the source, and has no history
3319                 # (so we can undo bad moves right after they're done).
3320
3321                 if ( 0 != $newid ) { # Target exists; check for validity
3322                         if ( !$this->isValidMoveTarget( $nt ) ) {
3323                                 $errors[] = array( 'articleexists' );
3324                         }
3325                 } else {
3326                         $tp = $nt->getTitleProtection();
3327                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3328                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3329                                 $errors[] = array( 'cantmove-titleprotected' );
3330                         }
3331                 }
3332                 if ( empty( $errors ) ) {
3333                         return true;
3334                 }
3335                 return $errors;
3336         }
3337
3338         /**
3339          * Check if the requested move target is a valid file move target
3340          * @param Title $nt Target title
3341          * @return array List of errors
3342          */
3343         protected function validateFileMoveOperation( $nt ) {
3344                 global $wgUser;
3345
3346                 $errors = array();
3347
3348                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3349
3350                 $file = wfLocalFile( $this );
3351                 if ( $file->exists() ) {
3352                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3353                                 $errors[] = array( 'imageinvalidfilename' );
3354                         }
3355                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3356                                 $errors[] = array( 'imagetypemismatch' );
3357                         }
3358                 }
3359
3360                 if ( $nt->getNamespace() != NS_FILE ) {
3361                         $errors[] = array( 'imagenocrossnamespace' );
3362                         // From here we want to do checks on a file object, so if we can't
3363                         // create one, we must return.
3364                         return $errors;
3365                 }
3366
3367                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3368
3369                 $destFile = wfLocalFile( $nt );
3370                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3371                         $errors[] = array( 'file-exists-sharedrepo' );
3372                 }
3373
3374                 return $errors;
3375         }
3376
3377         /**
3378          * Move a title to a new location
3379          *
3380          * @param $nt Title the new title
3381          * @param $auth Bool indicates whether $wgUser's permissions
3382          *  should be checked
3383          * @param $reason String the reason for the move
3384          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3385          *  Ignored if the user doesn't have the suppressredirect right.
3386          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3387          */
3388         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3389                 global $wgUser;
3390                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3391                 if ( is_array( $err ) ) {
3392                         // Auto-block user's IP if the account was "hard" blocked
3393                         $wgUser->spreadAnyEditBlock();
3394                         return $err;
3395                 }
3396
3397                 // If it is a file, move it first.
3398                 // It is done before all other moving stuff is done because it's hard to revert.
3399                 $dbw = wfGetDB( DB_MASTER );
3400                 if ( $this->getNamespace() == NS_FILE ) {
3401                         $file = wfLocalFile( $this );
3402                         if ( $file->exists() ) {
3403                                 $status = $file->move( $nt );
3404                                 if ( !$status->isOk() ) {
3405                                         return $status->getErrorsArray();
3406                                 }
3407                         }
3408                 }
3409                 // Clear RepoGroup process cache
3410                 RepoGroup::singleton()->clearCache( $this );
3411                 RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3412
3413                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3414                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3415                 $protected = $this->isProtected();
3416                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3417
3418                 // Do the actual move
3419                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3420                 if ( is_array( $err ) ) {
3421                         # @todo FIXME: What about the File we have already moved?
3422                         $dbw->rollback();
3423                         return $err;
3424                 }
3425
3426                 $redirid = $this->getArticleID();
3427
3428                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3429                 // cl_timestamp, which may disturb time-based lists on some sites.
3430                 $prefixes = $dbw->select(
3431                         'categorylinks',
3432                         array( 'cl_sortkey_prefix', 'cl_to' ),
3433                         array( 'cl_from' => $pageid ),
3434                         __METHOD__
3435                 );
3436                 foreach ( $prefixes as $prefixRow ) {
3437                         $prefix = $prefixRow->cl_sortkey_prefix;
3438                         $catTo = $prefixRow->cl_to;
3439                         $dbw->update( 'categorylinks',
3440                                 array(
3441                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3442                                                 $nt->getCategorySortkey( $prefix ) ),
3443                                         'cl_timestamp=cl_timestamp' ),
3444                                 array(
3445                                         'cl_from' => $pageid,
3446                                         'cl_to' => $catTo ),
3447                                 __METHOD__
3448                         );
3449                 }
3450
3451                 if ( $protected ) {
3452                         # Protect the redirect title as the title used to be...
3453                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3454                                 array(
3455                                         'pr_page'    => $redirid,
3456                                         'pr_type'    => 'pr_type',
3457                                         'pr_level'   => 'pr_level',
3458                                         'pr_cascade' => 'pr_cascade',
3459                                         'pr_user'    => 'pr_user',
3460                                         'pr_expiry'  => 'pr_expiry'
3461                                 ),
3462                                 array( 'pr_page' => $pageid ),
3463                                 __METHOD__,
3464                                 array( 'IGNORE' )
3465                         );
3466                         # Update the protection log
3467                         $log = new LogPage( 'protect' );
3468                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3469                         if ( $reason ) {
3470                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3471                         }
3472                         // @todo FIXME: $params?
3473                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3474                 }
3475
3476                 # Update watchlists
3477                 $oldnamespace = $this->getNamespace() & ~1;
3478                 $newnamespace = $nt->getNamespace() & ~1;
3479                 $oldtitle = $this->getDBkey();
3480                 $newtitle = $nt->getDBkey();
3481
3482                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3483                         WatchedItem::duplicateEntries( $this, $nt );
3484                 }
3485
3486                 # Update search engine
3487                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3488                 $u->doUpdate();
3489                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3490                 $u->doUpdate();
3491
3492                 $dbw->commit();
3493
3494                 # Update site_stats
3495                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3496                         # No longer a content page
3497                         # Not viewed, edited, removing
3498                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3499                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3500                         # Now a content page
3501                         # Not viewed, edited, adding
3502                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3503                 } elseif ( $pageCountChange ) {
3504                         # Redirect added
3505                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3506                 } else {
3507                         # Nothing special
3508                         $u = false;
3509                 }
3510                 if ( $u ) {
3511                         $u->doUpdate();
3512                 }
3513
3514                 # Update message cache for interface messages
3515                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3516                         # @bug 17860: old article can be deleted, if this the case,
3517                         # delete it from message cache
3518                         if ( $this->getArticleID() === 0 ) {
3519                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3520                         } else {
3521                                 $rev = Revision::newFromTitle( $this );
3522                                 MessageCache::singleton()->replace( $this->getDBkey(), $rev->getText() );
3523                         }
3524                 }
3525                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3526                         $rev = Revision::newFromTitle( $nt );
3527                         MessageCache::singleton()->replace( $nt->getDBkey(), $rev->getText() );
3528                 }
3529
3530                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3531                 return true;
3532         }
3533
3534         /**
3535          * Move page to a title which is either a redirect to the
3536          * source page or nonexistent
3537          *
3538          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3539          * @param $reason String The reason for the move
3540          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3541          *   if the user doesn't have the suppressredirect right
3542          */
3543         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3544                 global $wgUser, $wgContLang;
3545
3546                 if ( $nt->exists() ) {
3547                         $moveOverRedirect = true;
3548                         $logType = 'move_redir';
3549                 } else {
3550                         $moveOverRedirect = false;
3551                         $logType = 'move';
3552                 }
3553
3554                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3555
3556                 $logEntry = new ManualLogEntry( 'move', $logType );
3557                 $logEntry->setPerformer( $wgUser );
3558                 $logEntry->setTarget( $this );
3559                 $logEntry->setComment( $reason );
3560                 $logEntry->setParameters( array(
3561                         '4::target' => $nt->getPrefixedText(),
3562                         '5::noredir' => $redirectSuppressed ? '1': '0',
3563                 ) );
3564
3565                 $formatter = LogFormatter::newFromEntry( $logEntry );
3566                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3567                 $comment = $formatter->getPlainActionText();
3568                 if ( $reason ) {
3569                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3570                 }
3571                 # Truncate for whole multibyte characters.
3572                 $comment = $wgContLang->truncate( $comment, 255 );
3573
3574                 $oldid = $this->getArticleID();
3575                 $latest = $this->getLatestRevID();
3576
3577                 $dbw = wfGetDB( DB_MASTER );
3578
3579                 if ( $moveOverRedirect ) {
3580                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3581
3582                         $newid = $nt->getArticleID();
3583                         $newns = $nt->getNamespace();
3584                         $newdbk = $nt->getDBkey();
3585
3586                         # Delete the old redirect. We don't save it to history since
3587                         # by definition if we've got here it's rather uninteresting.
3588                         # We have to remove it so that the next step doesn't trigger
3589                         # a conflict on the unique namespace+title index...
3590                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3591                         if ( !$dbw->cascadingDeletes() ) {
3592                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3593
3594                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3595                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3596                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3597                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3598                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3599                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3600                                 $dbw->delete( 'iwlinks', array( 'iwl_from' => $newid ), __METHOD__ );
3601                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3602                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3603                         }
3604                         // If the target page was recently created, it may have an entry in recentchanges still
3605                         $dbw->delete( 'recentchanges',
3606                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3607                                 __METHOD__
3608                         );
3609                 }
3610
3611                 # Save a null revision in the page's history notifying of the move
3612                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3613                 if ( !is_object( $nullRevision ) ) {
3614                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3615                 }
3616                 $nullRevId = $nullRevision->insertOn( $dbw );
3617
3618                 $now = wfTimestampNow();
3619                 # Change the name of the target page:
3620                 $dbw->update( 'page',
3621                         /* SET */ array(
3622                                 'page_touched'   => $dbw->timestamp( $now ),
3623                                 'page_namespace' => $nt->getNamespace(),
3624                                 'page_title'     => $nt->getDBkey(),
3625                                 'page_latest'    => $nullRevId,
3626                         ),
3627                         /* WHERE */ array( 'page_id' => $oldid ),
3628                         __METHOD__
3629                 );
3630                 $nt->resetArticleID( $oldid );
3631
3632                 $article = WikiPage::factory( $nt );
3633                 wfRunHooks( 'NewRevisionFromEditComplete',
3634                         array( $article, $nullRevision, $latest, $wgUser ) );
3635                 $article->setCachedLastEditTime( $now );
3636
3637                 # Recreate the redirect, this time in the other direction.
3638                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3639                         $mwRedir = MagicWord::get( 'redirect' );
3640                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3641                         $redirectArticle = WikiPage::factory( $this );
3642                         $newid = $redirectArticle->insertOn( $dbw );
3643                         if ( $newid ) { // sanity
3644                                 $redirectRevision = new Revision( array(
3645                                         'page'    => $newid,
3646                                         'comment' => $comment,
3647                                         'text'    => $redirectText ) );
3648                                 $redirectRevision->insertOn( $dbw );
3649                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3650
3651                                 wfRunHooks( 'NewRevisionFromEditComplete',
3652                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3653
3654                                 # Now, we record the link from the redirect to the new title.
3655                                 # It should have no other outgoing links...
3656                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3657                                 $dbw->insert( 'pagelinks',
3658                                         array(
3659                                                 'pl_from'      => $newid,
3660                                                 'pl_namespace' => $nt->getNamespace(),
3661                                                 'pl_title'     => $nt->getDBkey() ),
3662                                         __METHOD__ );
3663                         }
3664                 } else {
3665                         $this->resetArticleID( 0 );
3666                 }
3667
3668                 # Log the move
3669                 $logid = $logEntry->insert();
3670                 $logEntry->publish( $logid );
3671
3672                 # Purge caches for old and new titles
3673                 if ( $moveOverRedirect ) {
3674                         # A simple purge is enough when moving over a redirect
3675                         $nt->purgeSquid();
3676                 } else {
3677                         # Purge caches as per article creation, including any pages that link to this title
3678                         Article::onArticleCreate( $nt );
3679                 }
3680                 $this->purgeSquid();
3681         }
3682
3683         /**
3684          * Move this page's subpages to be subpages of $nt
3685          *
3686          * @param $nt Title Move target
3687          * @param $auth bool Whether $wgUser's permissions should be checked
3688          * @param $reason string The reason for the move
3689          * @param $createRedirect bool Whether to create redirects from the old subpages to
3690          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3691          * @return mixed array with old page titles as keys, and strings (new page titles) or
3692          *     arrays (errors) as values, or an error array with numeric indices if no pages
3693          *     were moved
3694          */
3695         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3696                 global $wgMaximumMovedPages;
3697                 // Check permissions
3698                 if ( !$this->userCan( 'move-subpages' ) ) {
3699                         return array( 'cant-move-subpages' );
3700                 }
3701                 // Do the source and target namespaces support subpages?
3702                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3703                         return array( 'namespace-nosubpages',
3704                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3705                 }
3706                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3707                         return array( 'namespace-nosubpages',
3708                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3709                 }
3710
3711                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3712                 $retval = array();
3713                 $count = 0;
3714                 foreach ( $subpages as $oldSubpage ) {
3715                         $count++;
3716                         if ( $count > $wgMaximumMovedPages ) {
3717                                 $retval[$oldSubpage->getPrefixedTitle()] =
3718                                                 array( 'movepage-max-pages',
3719                                                         $wgMaximumMovedPages );
3720                                 break;
3721                         }
3722
3723                         // We don't know whether this function was called before
3724                         // or after moving the root page, so check both
3725                         // $this and $nt
3726                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3727                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3728                         {
3729                                 // When moving a page to a subpage of itself,
3730                                 // don't move it twice
3731                                 continue;
3732                         }
3733                         $newPageName = preg_replace(
3734                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3735                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3736                                         $oldSubpage->getDBkey() );
3737                         if ( $oldSubpage->isTalkPage() ) {
3738                                 $newNs = $nt->getTalkPage()->getNamespace();
3739                         } else {
3740                                 $newNs = $nt->getSubjectPage()->getNamespace();
3741                         }
3742                         # Bug 14385: we need makeTitleSafe because the new page names may
3743                         # be longer than 255 characters.
3744                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3745
3746                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3747                         if ( $success === true ) {
3748                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3749                         } else {
3750                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3751                         }
3752                 }
3753                 return $retval;
3754         }
3755
3756         /**
3757          * Checks if this page is just a one-rev redirect.
3758          * Adds lock, so don't use just for light purposes.
3759          *
3760          * @return Bool
3761          */
3762         public function isSingleRevRedirect() {
3763                 $dbw = wfGetDB( DB_MASTER );
3764                 # Is it a redirect?
3765                 $row = $dbw->selectRow( 'page',
3766                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3767                         $this->pageCond(),
3768                         __METHOD__,
3769                         array( 'FOR UPDATE' )
3770                 );
3771                 # Cache some fields we may want
3772                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3773                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3774                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3775                 if ( !$this->mRedirect ) {
3776                         return false;
3777                 }
3778                 # Does the article have a history?
3779                 $row = $dbw->selectField( array( 'page', 'revision' ),
3780                         'rev_id',
3781                         array( 'page_namespace' => $this->getNamespace(),
3782                                 'page_title' => $this->getDBkey(),
3783                                 'page_id=rev_page',
3784                                 'page_latest != rev_id'
3785                         ),
3786                         __METHOD__,
3787                         array( 'FOR UPDATE' )
3788                 );
3789                 # Return true if there was no history
3790                 return ( $row === false );
3791         }
3792
3793         /**
3794          * Checks if $this can be moved to a given Title
3795          * - Selects for update, so don't call it unless you mean business
3796          *
3797          * @param $nt Title the new title to check
3798          * @return Bool
3799          */
3800         public function isValidMoveTarget( $nt ) {
3801                 # Is it an existing file?
3802                 if ( $nt->getNamespace() == NS_FILE ) {
3803                         $file = wfLocalFile( $nt );
3804                         if ( $file->exists() ) {
3805                                 wfDebug( __METHOD__ . ": file exists\n" );
3806                                 return false;
3807                         }
3808                 }
3809                 # Is it a redirect with no history?
3810                 if ( !$nt->isSingleRevRedirect() ) {
3811                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3812                         return false;
3813                 }
3814                 # Get the article text
3815                 $rev = Revision::newFromTitle( $nt );
3816                 if( !is_object( $rev ) ){
3817                         return false;
3818                 }
3819                 $text = $rev->getText();
3820                 # Does the redirect point to the source?
3821                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3822                 $m = array();
3823                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3824                         $redirTitle = Title::newFromText( $m[1] );
3825                         if ( !is_object( $redirTitle ) ||
3826                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3827                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3828                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3829                                 return false;
3830                         }
3831                 } else {
3832                         # Fail safe
3833                         wfDebug( __METHOD__ . ": failsafe\n" );
3834                         return false;
3835                 }
3836                 return true;
3837         }
3838
3839         /**
3840          * Get categories to which this Title belongs and return an array of
3841          * categories' names.
3842          *
3843          * @return Array of parents in the form:
3844          *        $parent => $currentarticle
3845          */
3846         public function getParentCategories() {
3847                 global $wgContLang;
3848
3849                 $data = array();
3850
3851                 $titleKey = $this->getArticleId();
3852
3853                 if ( $titleKey === 0 ) {
3854                         return $data;
3855                 }
3856
3857                 $dbr = wfGetDB( DB_SLAVE );
3858
3859                 $res = $dbr->select( 'categorylinks', '*',
3860                         array(
3861                                 'cl_from' => $titleKey,
3862                         ),
3863                         __METHOD__,
3864                         array()
3865                 );
3866
3867                 if ( $dbr->numRows( $res ) > 0 ) {
3868                         foreach ( $res as $row ) {
3869                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3870                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3871                         }
3872                 }
3873                 return $data;
3874         }
3875
3876         /**
3877          * Get a tree of parent categories
3878          *
3879          * @param $children Array with the children in the keys, to check for circular refs
3880          * @return Array Tree of parent categories
3881          */
3882         public function getParentCategoryTree( $children = array() ) {
3883                 $stack = array();
3884                 $parents = $this->getParentCategories();
3885
3886                 if ( $parents ) {
3887                         foreach ( $parents as $parent => $current ) {
3888                                 if ( array_key_exists( $parent, $children ) ) {
3889                                         # Circular reference
3890                                         $stack[$parent] = array();
3891                                 } else {
3892                                         $nt = Title::newFromText( $parent );
3893                                         if ( $nt ) {
3894                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3895                                         }
3896                                 }
3897                         }
3898                 }
3899
3900                 return $stack;
3901         }
3902
3903         /**
3904          * Get an associative array for selecting this title from
3905          * the "page" table
3906          *
3907          * @return Array suitable for the $where parameter of DB::select()
3908          */
3909         public function pageCond() {
3910                 if ( $this->mArticleID > 0 ) {
3911                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3912                         return array( 'page_id' => $this->mArticleID );
3913                 } else {
3914                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3915                 }
3916         }
3917
3918         /**
3919          * Get the revision ID of the previous revision
3920          *
3921          * @param $revId Int Revision ID. Get the revision that was before this one.
3922          * @param $flags Int Title::GAID_FOR_UPDATE
3923          * @return Int|Bool Old revision ID, or FALSE if none exists
3924          */
3925         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3926                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3927                 return $db->selectField( 'revision', 'rev_id',
3928                         array(
3929                                 'rev_page' => $this->getArticleId( $flags ),
3930                                 'rev_id < ' . intval( $revId )
3931                         ),
3932                         __METHOD__,
3933                         array( 'ORDER BY' => 'rev_id DESC' )
3934                 );
3935         }
3936
3937         /**
3938          * Get the revision ID of the next revision
3939          *
3940          * @param $revId Int Revision ID. Get the revision that was after this one.
3941          * @param $flags Int Title::GAID_FOR_UPDATE
3942          * @return Int|Bool Next revision ID, or FALSE if none exists
3943          */
3944         public function getNextRevisionID( $revId, $flags = 0 ) {
3945                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3946                 return $db->selectField( 'revision', 'rev_id',
3947                         array(
3948                                 'rev_page' => $this->getArticleId( $flags ),
3949                                 'rev_id > ' . intval( $revId )
3950                         ),
3951                         __METHOD__,
3952                         array( 'ORDER BY' => 'rev_id' )
3953                 );
3954         }
3955
3956         /**
3957          * Get the first revision of the page
3958          *
3959          * @param $flags Int Title::GAID_FOR_UPDATE
3960          * @return Revision|Null if page doesn't exist
3961          */
3962         public function getFirstRevision( $flags = 0 ) {
3963                 $pageId = $this->getArticleId( $flags );
3964                 if ( $pageId ) {
3965                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3966                         $row = $db->selectRow( 'revision', '*',
3967                                 array( 'rev_page' => $pageId ),
3968                                 __METHOD__,
3969                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3970                         );
3971                         if ( $row ) {
3972                                 return new Revision( $row );
3973                         }
3974                 }
3975                 return null;
3976         }
3977
3978         /**
3979          * Get the oldest revision timestamp of this page
3980          *
3981          * @param $flags Int Title::GAID_FOR_UPDATE
3982          * @return String: MW timestamp
3983          */
3984         public function getEarliestRevTime( $flags = 0 ) {
3985                 $rev = $this->getFirstRevision( $flags );
3986                 return $rev ? $rev->getTimestamp() : null;
3987         }
3988
3989         /**
3990          * Check if this is a new page
3991          *
3992          * @return bool
3993          */
3994         public function isNewPage() {
3995                 $dbr = wfGetDB( DB_SLAVE );
3996                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3997         }
3998
3999         /**
4000          * Get the number of revisions between the given revision.
4001          * Used for diffs and other things that really need it.
4002          *
4003          * @param $old int|Revision Old revision or rev ID (first before range)
4004          * @param $new int|Revision New revision or rev ID (first after range)
4005          * @return Int Number of revisions between these revisions.
4006          */
4007         public function countRevisionsBetween( $old, $new ) {
4008                 if ( !( $old instanceof Revision ) ) {
4009                         $old = Revision::newFromTitle( $this, (int)$old );
4010                 }
4011                 if ( !( $new instanceof Revision ) ) {
4012                         $new = Revision::newFromTitle( $this, (int)$new );
4013                 }
4014                 if ( !$old || !$new ) {
4015                         return 0; // nothing to compare
4016                 }
4017                 $dbr = wfGetDB( DB_SLAVE );
4018                 return (int)$dbr->selectField( 'revision', 'count(*)',
4019                         array(
4020                                 'rev_page' => $this->getArticleId(),
4021                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4022                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4023                         ),
4024                         __METHOD__
4025                 );
4026         }
4027
4028         /**
4029          * Get the number of authors between the given revision IDs.
4030          * Used for diffs and other things that really need it.
4031          *
4032          * @param $old int|Revision Old revision or rev ID (first before range)
4033          * @param $new int|Revision New revision or rev ID (first after range)
4034          * @param $limit Int Maximum number of authors
4035          * @return Int Number of revision authors between these revisions.
4036          */
4037         public function countAuthorsBetween( $old, $new, $limit ) {
4038                 if ( !( $old instanceof Revision ) ) {
4039                         $old = Revision::newFromTitle( $this, (int)$old );
4040                 }
4041                 if ( !( $new instanceof Revision ) ) {
4042                         $new = Revision::newFromTitle( $this, (int)$new );
4043                 }
4044                 if ( !$old || !$new ) {
4045                         return 0; // nothing to compare
4046                 }
4047                 $dbr = wfGetDB( DB_SLAVE );
4048                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4049                         array(
4050                                 'rev_page' => $this->getArticleID(),
4051                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4052                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4053                         ), __METHOD__,
4054                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4055                 );
4056                 return (int)$dbr->numRows( $res );
4057         }
4058
4059         /**
4060          * Compare with another title.
4061          *
4062          * @param $title Title
4063          * @return Bool
4064          */
4065         public function equals( Title $title ) {
4066                 // Note: === is necessary for proper matching of number-like titles.
4067                 return $this->getInterwiki() === $title->getInterwiki()
4068                         && $this->getNamespace() == $title->getNamespace()
4069                         && $this->getDBkey() === $title->getDBkey();
4070         }
4071
4072         /**
4073          * Check if this title is a subpage of another title
4074          *
4075          * @param $title Title
4076          * @return Bool
4077          */
4078         public function isSubpageOf( Title $title ) {
4079                 return $this->getInterwiki() === $title->getInterwiki()
4080                         && $this->getNamespace() == $title->getNamespace()
4081                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4082         }
4083
4084         /**
4085          * Check if page exists.  For historical reasons, this function simply
4086          * checks for the existence of the title in the page table, and will
4087          * thus return false for interwiki links, special pages and the like.
4088          * If you want to know if a title can be meaningfully viewed, you should
4089          * probably call the isKnown() method instead.
4090          *
4091          * @return Bool
4092          */
4093         public function exists() {
4094                 return $this->getArticleId() != 0;
4095         }
4096
4097         /**
4098          * Should links to this title be shown as potentially viewable (i.e. as
4099          * "bluelinks"), even if there's no record by this title in the page
4100          * table?
4101          *
4102          * This function is semi-deprecated for public use, as well as somewhat
4103          * misleadingly named.  You probably just want to call isKnown(), which
4104          * calls this function internally.
4105          *
4106          * (ISSUE: Most of these checks are cheap, but the file existence check
4107          * can potentially be quite expensive.  Including it here fixes a lot of
4108          * existing code, but we might want to add an optional parameter to skip
4109          * it and any other expensive checks.)
4110          *
4111          * @return Bool
4112          */
4113         public function isAlwaysKnown() {
4114                 if ( $this->mInterwiki != '' ) {
4115                         return true;  // any interwiki link might be viewable, for all we know
4116                 }
4117                 switch( $this->mNamespace ) {
4118                         case NS_MEDIA:
4119                         case NS_FILE:
4120                                 // file exists, possibly in a foreign repo
4121                                 return (bool)wfFindFile( $this );
4122                         case NS_SPECIAL:
4123                                 // valid special page
4124                                 return SpecialPageFactory::exists( $this->getDBkey() );
4125                         case NS_MAIN:
4126                                 // selflink, possibly with fragment
4127                                 return $this->mDbkeyform == '';
4128                         case NS_MEDIAWIKI:
4129                                 // known system message
4130                                 return $this->hasSourceText() !== false;
4131                         default:
4132                                 return false;
4133                 }
4134         }
4135
4136         /**
4137          * Does this title refer to a page that can (or might) be meaningfully
4138          * viewed?  In particular, this function may be used to determine if
4139          * links to the title should be rendered as "bluelinks" (as opposed to
4140          * "redlinks" to non-existent pages).
4141          *
4142          * @return Bool
4143          */
4144         public function isKnown() {
4145                 return $this->isAlwaysKnown() || $this->exists();
4146         }
4147
4148         /**
4149          * Does this page have source text?
4150          *
4151          * @return Boolean
4152          */
4153         public function hasSourceText() {
4154                 if ( $this->exists() ) {
4155                         return true;
4156                 }
4157
4158                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4159                         // If the page doesn't exist but is a known system message, default
4160                         // message content will be displayed, same for language subpages-
4161                         // Use always content language to avoid loading hundreds of languages
4162                         // to get the link color.
4163                         global $wgContLang;
4164                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4165                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4166                         return $message->exists();
4167                 }
4168
4169                 return false;
4170         }
4171
4172         /**
4173          * Get the default message text or false if the message doesn't exist
4174          *
4175          * @return String or false
4176          */
4177         public function getDefaultMessageText() {
4178                 global $wgContLang;
4179
4180                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4181                         return false;
4182                 }
4183
4184                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4185                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4186
4187                 if ( $message->exists() ) {
4188                         return $message->plain();
4189                 } else {
4190                         return false;
4191                 }
4192         }
4193
4194         /**
4195          * Updates page_touched for this page; called from LinksUpdate.php
4196          *
4197          * @return Bool true if the update succeded
4198          */
4199         public function invalidateCache() {
4200                 if ( wfReadOnly() ) {
4201                         return false;
4202                 }
4203                 $dbw = wfGetDB( DB_MASTER );
4204                 $success = $dbw->update(
4205                         'page',
4206                         array( 'page_touched' => $dbw->timestamp() ),
4207                         $this->pageCond(),
4208                         __METHOD__
4209                 );
4210                 HTMLFileCache::clearFileCache( $this );
4211                 return $success;
4212         }
4213
4214         /**
4215          * Update page_touched timestamps and send squid purge messages for
4216          * pages linking to this title. May be sent to the job queue depending
4217          * on the number of links. Typically called on create and delete.
4218          */
4219         public function touchLinks() {
4220                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4221                 $u->doUpdate();
4222
4223                 if ( $this->getNamespace() == NS_CATEGORY ) {
4224                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4225                         $u->doUpdate();
4226                 }
4227         }
4228
4229         /**
4230          * Get the last touched timestamp
4231          *
4232          * @param $db DatabaseBase: optional db
4233          * @return String last-touched timestamp
4234          */
4235         public function getTouched( $db = null ) {
4236                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4237                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4238                 return $touched;
4239         }
4240
4241         /**
4242          * Get the timestamp when this page was updated since the user last saw it.
4243          *
4244          * @param $user User
4245          * @return String|Null
4246          */
4247         public function getNotificationTimestamp( $user = null ) {
4248                 global $wgUser, $wgShowUpdatedMarker;
4249                 // Assume current user if none given
4250                 if ( !$user ) {
4251                         $user = $wgUser;
4252                 }
4253                 // Check cache first
4254                 $uid = $user->getId();
4255                 // avoid isset here, as it'll return false for null entries
4256                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4257                         return $this->mNotificationTimestamp[$uid];
4258                 }
4259                 if ( !$uid || !$wgShowUpdatedMarker ) {
4260                         return $this->mNotificationTimestamp[$uid] = false;
4261                 }
4262                 // Don't cache too much!
4263                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4264                         $this->mNotificationTimestamp = array();
4265                 }
4266                 $dbr = wfGetDB( DB_SLAVE );
4267                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4268                         'wl_notificationtimestamp',
4269                         array( 'wl_namespace' => $this->getNamespace(),
4270                                 'wl_title' => $this->getDBkey(),
4271                                 'wl_user' => $user->getId()
4272                         ),
4273                         __METHOD__
4274                 );
4275                 return $this->mNotificationTimestamp[$uid];
4276         }
4277
4278         /**
4279          * Generate strings used for xml 'id' names in monobook tabs
4280          *
4281          * @param $prepend string defaults to 'nstab-'
4282          * @return String XML 'id' name
4283          */
4284         public function getNamespaceKey( $prepend = 'nstab-' ) {
4285                 global $wgContLang;
4286                 // Gets the subject namespace if this title
4287                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4288                 // Checks if cononical namespace name exists for namespace
4289                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4290                         // Uses canonical namespace name
4291                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4292                 } else {
4293                         // Uses text of namespace
4294                         $namespaceKey = $this->getSubjectNsText();
4295                 }
4296                 // Makes namespace key lowercase
4297                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4298                 // Uses main
4299                 if ( $namespaceKey == '' ) {
4300                         $namespaceKey = 'main';
4301                 }
4302                 // Changes file to image for backwards compatibility
4303                 if ( $namespaceKey == 'file' ) {
4304                         $namespaceKey = 'image';
4305                 }
4306                 return $prepend . $namespaceKey;
4307         }
4308
4309         /**
4310          * Get all extant redirects to this Title
4311          *
4312          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4313          * @return Array of Title redirects to this title
4314          */
4315         public function getRedirectsHere( $ns = null ) {
4316                 $redirs = array();
4317
4318                 $dbr = wfGetDB( DB_SLAVE );
4319                 $where = array(
4320                         'rd_namespace' => $this->getNamespace(),
4321                         'rd_title' => $this->getDBkey(),
4322                         'rd_from = page_id'
4323                 );
4324                 if ( !is_null( $ns ) ) {
4325                         $where['page_namespace'] = $ns;
4326                 }
4327
4328                 $res = $dbr->select(
4329                         array( 'redirect', 'page' ),
4330                         array( 'page_namespace', 'page_title' ),
4331                         $where,
4332                         __METHOD__
4333                 );
4334
4335                 foreach ( $res as $row ) {
4336                         $redirs[] = self::newFromRow( $row );
4337                 }
4338                 return $redirs;
4339         }
4340
4341         /**
4342          * Check if this Title is a valid redirect target
4343          *
4344          * @return Bool
4345          */
4346         public function isValidRedirectTarget() {
4347                 global $wgInvalidRedirectTargets;
4348
4349                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4350                 if ( $this->isSpecial( 'Userlogout' ) ) {
4351                         return false;
4352                 }
4353
4354                 foreach ( $wgInvalidRedirectTargets as $target ) {
4355                         if ( $this->isSpecial( $target ) ) {
4356                                 return false;
4357                         }
4358                 }
4359
4360                 return true;
4361         }
4362
4363         /**
4364          * Get a backlink cache object
4365          *
4366          * @return BacklinkCache
4367          */
4368         function getBacklinkCache() {
4369                 if ( is_null( $this->mBacklinkCache ) ) {
4370                         $this->mBacklinkCache = new BacklinkCache( $this );
4371                 }
4372                 return $this->mBacklinkCache;
4373         }
4374
4375         /**
4376          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4377          *
4378          * @return Boolean
4379          */
4380         public function canUseNoindex() {
4381                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4382
4383                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4384                         ? $wgContentNamespaces
4385                         : $wgExemptFromUserRobotsControl;
4386
4387                 return !in_array( $this->mNamespace, $bannedNamespaces );
4388
4389         }
4390
4391         /**
4392          * Returns the raw sort key to be used for categories, with the specified
4393          * prefix.  This will be fed to Collation::getSortKey() to get a
4394          * binary sortkey that can be used for actual sorting.
4395          *
4396          * @param $prefix string The prefix to be used, specified using
4397          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4398          *   prefix.
4399          * @return string
4400          */
4401         public function getCategorySortkey( $prefix = '' ) {
4402                 $unprefixed = $this->getText();
4403
4404                 // Anything that uses this hook should only depend
4405                 // on the Title object passed in, and should probably
4406                 // tell the users to run updateCollations.php --force
4407                 // in order to re-sort existing category relations.
4408                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4409                 if ( $prefix !== '' ) {
4410                         # Separate with a line feed, so the unprefixed part is only used as
4411                         # a tiebreaker when two pages have the exact same prefix.
4412                         # In UCA, tab is the only character that can sort above LF
4413                         # so we strip both of them from the original prefix.
4414                         $prefix = strtr( $prefix, "\n\t", '  ' );
4415                         return "$prefix\n$unprefixed";
4416                 }
4417                 return $unprefixed;
4418         }
4419
4420         /**
4421          * Get the language in which the content of this page is written.
4422          * Defaults to $wgContLang, but in certain cases it can be e.g.
4423          * $wgLang (such as special pages, which are in the user language).
4424          *
4425          * @since 1.18
4426          * @return object Language
4427          */
4428         public function getPageLanguage() {
4429                 global $wgLang;
4430                 if ( $this->isSpecialPage() ) {
4431                         // special pages are in the user language
4432                         return $wgLang;
4433                 } elseif ( $this->isCssOrJsPage() ) {
4434                         // css/js should always be LTR and is, in fact, English
4435                         return wfGetLangObj( 'en' );
4436                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4437                         // Parse mediawiki messages with correct target language
4438                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4439                         return wfGetLangObj( $lang );
4440                 }
4441                 global $wgContLang;
4442                 // If nothing special, it should be in the wiki content language
4443                 $pageLang = $wgContLang;
4444                 // Hook at the end because we don't want to override the above stuff
4445                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4446                 return wfGetLangObj( $pageLang );
4447         }
4448 }