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         private $mIsNew;                  // /< Whether this is a "new page" (i.e. it has only one revision)
  68         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  69         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  70         var $mOldRestrictions = false;
  71         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  72         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  73         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  74         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  75         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  76         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  77         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  78         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  79         # Don't change the following default, NS_MAIN is hardcoded in several
  80         # places.  See bug 696.
  81         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  82                                                                           # Zero except in {{transclusion}} tags
  83         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  84         var $mLength = -1;                // /< The page length, 0 for special pages
  85         var $mRedirect = null;            // /< Is the article at this title a redirect?
  86         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  87         var $mBacklinkCache = null;       // /< Cache of links to this title
  88         // @}
  89
  90
  91         /**
  92          * Constructor
  93          */
  94         /*protected*/ function __construct() { }
  95
  96         /**
  97          * Create a new Title from a prefixed DB key
  98          *
  99          * @param $key String the database key, which has underscores
 100          *      instead of spaces, possibly including namespace and
 101          *      interwiki prefixes
 102          * @return Title, or NULL on an error
 103          */
 104         public static function newFromDBkey( $key ) {
 105                 $t = new Title();
 106                 $t->mDbkeyform = $key;
 107                 if ( $t->secureAndSplit() ) {
 108                         return $t;
 109                 } else {
 110                         return null;
 111                 }
 112         }
 113
 114         /**
 115          * Create a new Title from text, such as what one would find in a link. De-
 116          * codes any HTML entities in the text.
 117          *
 118          * @param $text String the link text; spaces, prefixes, and an
 119          *   initial ':' indicating the main namespace are accepted.
 120          * @param $defaultNamespace Int the namespace to use if none is speci-
 121          *   fied by a prefix.  If you want to force a specific namespace even if
 122          *   $text might begin with a namespace prefix, use makeTitle() or
 123          *   makeTitleSafe().
 124          * @return Title, or null on an error.
 125          */
 126         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 127                 if ( is_object( $text ) ) {
 128                         throw new MWException( 'Title::newFromText given an object' );
 129                 }
 130
 131                 /**
 132                  * Wiki pages often contain multiple links to the same page.
 133                  * Title normalization and parsing can become expensive on
 134                  * pages with many links, so we can save a little time by
 135                  * caching them.
 136                  *
 137                  * In theory these are value objects and won't get changed...
 138                  */
 139                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 140                         return Title::$titleCache[$text];
 141                 }
 142
 143                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 144                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 145
 146                 $t = new Title();
 147                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 148                 $t->mDefaultNamespace = $defaultNamespace;
 149
 150                 static $cachedcount = 0 ;
 151                 if ( $t->secureAndSplit() ) {
 152                         if ( $defaultNamespace == NS_MAIN ) {
 153                                 if ( $cachedcount >= self::CACHE_MAX ) {
 154                                         # Avoid memory leaks on mass operations...
 155                                         Title::$titleCache = array();
 156                                         $cachedcount = 0;
 157                                 }
 158                                 $cachedcount++;
 159                                 Title::$titleCache[$text] =& $t;
 160                         }
 161                         return $t;
 162                 } else {
 163                         $ret = null;
 164                         return $ret;
 165                 }
 166         }
 167
 168         /**
 169          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 170          *
 171          * Example of wrong and broken code:
 172          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 173          *
 174          * Example of right code:
 175          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 176          *
 177          * Create a new Title from URL-encoded text. Ensures that
 178          * the given title's length does not exceed the maximum.
 179          *
 180          * @param $url String the title, as might be taken from a URL
 181          * @return Title the new object, or NULL on an error
 182          */
 183         public static function newFromURL( $url ) {
 184                 global $wgLegalTitleChars;
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Create a new Title from an article ID
 204          *
 205          * @param $id Int the page_id corresponding to the Title to create
 206          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 207          * @return Title the new object, or NULL on an error
 208          */
 209         public static function newFromID( $id, $flags = 0 ) {
 210                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 211                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 212                 if ( $row !== false ) {
 213                         $title = Title::newFromRow( $row );
 214                 } else {
 215                         $title = null;
 216                 }
 217                 return $title;
 218         }
 219
 220         /**
 221          * Make an array of titles from an array of IDs
 222          *
 223          * @param $ids Array of Int Array of IDs
 224          * @return Array of Titles
 225          */
 226         public static function newFromIDs( $ids ) {
 227                 if ( !count( $ids ) ) {
 228                         return array();
 229                 }
 230                 $dbr = wfGetDB( DB_SLAVE );
 231
 232                 $res = $dbr->select(
 233                         'page',
 234                         array(
 235                                 'page_namespace', 'page_title', 'page_id',
 236                                 'page_len', 'page_is_redirect', 'page_latest',
 237                         ),
 238                         array( 'page_id' => $ids ),
 239                         __METHOD__
 240                 );
 241
 242                 $titles = array();
 243                 foreach ( $res as $row ) {
 244                         $titles[] = Title::newFromRow( $row );
 245                 }
 246                 return $titles;
 247         }
 248
 249         /**
 250          * Make a Title object from a DB row
 251          *
 252          * @param $row Object database row (needs at least page_title,page_namespace)
 253          * @return Title corresponding Title
 254          */
 255         public static function newFromRow( $row ) {
 256                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 257                 $t->loadFromRow( $row );
 258                 return $t;
 259         }
 260
 261         /**
 262          * Load Title object fields from a DB row.
 263          * If false is given, the title will be treated as non-existing.
 264          *
 265          * @param $row Object|false database row
 266          * @return void
 267          */
 268         public function loadFromRow( $row ) {
 269                 if ( $row ) { // page found
 270                         if ( isset( $row->page_id ) )
 271                                 $this->mArticleID = (int)$row->page_id;
 272                         if ( isset( $row->page_len ) )
 273                                 $this->mLength = (int)$row->page_len;
 274                         if ( isset( $row->page_is_redirect ) )
 275                                 $this->mRedirect = (bool)$row->page_is_redirect;
 276                         if ( isset( $row->page_latest ) )
 277                                 $this->mLatestID = (int)$row->page_latest;
 278                         if ( isset( $row->page_counter ) )
 279                                 $this->mCounter = (int)$row->page_counter;
 280                         if ( isset( $row->page_is_new ) )
 281                                 $this->mIsNew = (bool)$row->page_is_new;
 282                 } else { // page not found
 283                         $this->mArticleID = 0;
 284                         $this->mLength = 0;
 285                         $this->mRedirect = false;
 286                         $this->mLatestID = 0;
 287                         $this->mCounter = 0;
 288                 }
 289         }
 290
 291         /**
 292          * Create a new Title from a namespace index and a DB key.
 293          * It's assumed that $ns and $title are *valid*, for instance when
 294          * they came directly from the database or a special page name.
 295          * For convenience, spaces are converted to underscores so that
 296          * eg user_text fields can be used directly.
 297          *
 298          * @param $ns Int the namespace of the article
 299          * @param $title String the unprefixed database key form
 300          * @param $fragment String the link fragment (after the "#")
 301          * @param $interwiki String the interwiki prefix
 302          * @return Title the new object
 303          */
 304         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 305                 $t = new Title();
 306                 $t->mInterwiki = $interwiki;
 307                 $t->mFragment = $fragment;
 308                 $t->mNamespace = $ns = intval( $ns );
 309                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 310                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 311                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 312                 $t->mTextform = str_replace( '_', ' ', $title );
 313                 return $t;
 314         }
 315
 316         /**
 317          * Create a new Title from a namespace index and a DB key.
 318          * The parameters will be checked for validity, which is a bit slower
 319          * than makeTitle() but safer for user-provided data.
 320          *
 321          * @param $ns Int the namespace of the article
 322          * @param $title String database key form
 323          * @param $fragment String the link fragment (after the "#")
 324          * @param $interwiki String interwiki prefix
 325          * @return Title the new object, or NULL on an error
 326          */
 327         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 328                 $t = new Title();
 329                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 330                 if ( $t->secureAndSplit() ) {
 331                         return $t;
 332                 } else {
 333                         return null;
 334                 }
 335         }
 336
 337         /**
 338          * Create a new Title for the Main Page
 339          *
 340          * @return Title the new object
 341          */
 342         public static function newMainPage() {
 343                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 344                 // Don't give fatal errors if the message is broken
 345                 if ( !$title ) {
 346                         $title = Title::newFromText( 'Main Page' );
 347                 }
 348                 return $title;
 349         }
 350
 351         /**
 352          * Extract a redirect destination from a string and return the
 353          * Title, or null if the text doesn't contain a valid redirect
 354          * This will only return the very next target, useful for
 355          * the redirect table and other checks that don't need full recursion
 356          *
 357          * @param $text String: Text with possible redirect
 358          * @return Title: The corresponding Title
 359          */
 360         public static function newFromRedirect( $text ) {
 361                 return self::newFromRedirectInternal( $text );
 362         }
 363
 364         /**
 365          * Extract a redirect destination from a string and return the
 366          * Title, or null if the text doesn't contain a valid redirect
 367          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 368          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 369          *
 370          * @param $text String Text with possible redirect
 371          * @return Title
 372          */
 373         public static function newFromRedirectRecurse( $text ) {
 374                 $titles = self::newFromRedirectArray( $text );
 375                 return $titles ? array_pop( $titles ) : null;
 376         }
 377
 378         /**
 379          * Extract a redirect destination from a string and return an
 380          * array of Titles, or null if the text doesn't contain a valid redirect
 381          * The last element in the array is the final destination after all redirects
 382          * have been resolved (up to $wgMaxRedirects times)
 383          *
 384          * @param $text String Text with possible redirect
 385          * @return Array of Titles, with the destination last
 386          */
 387         public static function newFromRedirectArray( $text ) {
 388                 global $wgMaxRedirects;
 389                 $title = self::newFromRedirectInternal( $text );
 390                 if ( is_null( $title ) ) {
 391                         return null;
 392                 }
 393                 // recursive check to follow double redirects
 394                 $recurse = $wgMaxRedirects;
 395                 $titles = array( $title );
 396                 while ( --$recurse > 0 ) {
 397                         if ( $title->isRedirect() ) {
 398                                 $page = WikiPage::factory( $title );
 399                                 $newtitle = $page->getRedirectTarget();
 400                         } else {
 401                                 break;
 402                         }
 403                         // Redirects to some special pages are not permitted
 404                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 405                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 406                                 $title = $newtitle;
 407                                 $titles[] = $newtitle;
 408                         } else {
 409                                 break;
 410                         }
 411                 }
 412                 return $titles;
 413         }
 414
 415         /**
 416          * Really extract the redirect destination
 417          * Do not call this function directly, use one of the newFromRedirect* functions above
 418          *
 419          * @param $text String Text with possible redirect
 420          * @return Title
 421          */
 422         protected static function newFromRedirectInternal( $text ) {
 423                 global $wgMaxRedirects;
 424                 if ( $wgMaxRedirects < 1 ) {
 425                         //redirects are disabled, so quit early
 426                         return null;
 427                 }
 428                 $redir = MagicWord::get( 'redirect' );
 429                 $text = trim( $text );
 430                 if ( $redir->matchStartAndRemove( $text ) ) {
 431                         // Extract the first link and see if it's usable
 432                         // Ensure that it really does come directly after #REDIRECT
 433                         // Some older redirects included a colon, so don't freak about that!
 434                         $m = array();
 435                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 436                                 // Strip preceding colon used to "escape" categories, etc.
 437                                 // and URL-decode links
 438                                 if ( strpos( $m[1], '%' ) !== false ) {
 439                                         // Match behavior of inline link parsing here;
 440                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 441                                 }
 442                                 $title = Title::newFromText( $m[1] );
 443                                 // If the title is a redirect to bad special pages or is invalid, return null
 444                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 445                                         return null;
 446                                 }
 447                                 return $title;
 448                         }
 449                 }
 450                 return null;
 451         }
 452
 453         /**
 454          * Get the prefixed DB key associated with an ID
 455          *
 456          * @param $id Int the page_id of the article
 457          * @return Title an object representing the article, or NULL if no such article was found
 458          */
 459         public static function nameOf( $id ) {
 460                 $dbr = wfGetDB( DB_SLAVE );
 461
 462                 $s = $dbr->selectRow(
 463                         'page',
 464                         array( 'page_namespace', 'page_title' ),
 465                         array( 'page_id' => $id ),
 466                         __METHOD__
 467                 );
 468                 if ( $s === false ) {
 469                         return null;
 470                 }
 471
 472                 $n = self::makeName( $s->page_namespace, $s->page_title );
 473                 return $n;
 474         }
 475
 476         /**
 477          * Get a regex character class describing the legal characters in a link
 478          *
 479          * @return String the list of characters, not delimited
 480          */
 481         public static function legalChars() {
 482                 global $wgLegalTitleChars;
 483                 return $wgLegalTitleChars;
 484         }
 485
 486         /**
 487          * Returns a simple regex that will match on characters and sequences invalid in titles.
 488          * Note that this doesn't pick up many things that could be wrong with titles, but that
 489          * replacing this regex with something valid will make many titles valid.
 490          *
 491          * @return String regex string
 492          */
 493         static function getTitleInvalidRegex() {
 494                 static $rxTc = false;
 495                 if ( !$rxTc ) {
 496                         # Matching titles will be held as illegal.
 497                         $rxTc = '/' .
 498                                 # Any character not allowed is forbidden...
 499                                 '[^' . self::legalChars() . ']' .
 500                                 # URL percent encoding sequences interfere with the ability
 501                                 # to round-trip titles -- you can't link to them consistently.
 502                                 '|%[0-9A-Fa-f]{2}' .
 503                                 # XML/HTML character references produce similar issues.
 504                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 505                                 '|&#[0-9]+;' .
 506                                 '|&#x[0-9A-Fa-f]+;' .
 507                                 '/S';
 508                 }
 509
 510                 return $rxTc;
 511         }
 512
 513         /**
 514          * Get a string representation of a title suitable for
 515          * including in a search index
 516          *
 517          * @param $ns Int a namespace index
 518          * @param $title String text-form main part
 519          * @return String a stripped-down title string ready for the search index
 520          */
 521         public static function indexTitle( $ns, $title ) {
 522                 global $wgContLang;
 523
 524                 $lc = SearchEngine::legalSearchChars() . '&#;';
 525                 $t = $wgContLang->normalizeForSearch( $title );
 526                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 527                 $t = $wgContLang->lc( $t );
 528
 529                 # Handle 's, s'
 530                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 531                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 532
 533                 $t = preg_replace( "/\\s+/", ' ', $t );
 534
 535                 if ( $ns == NS_FILE ) {
 536                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 537                 }
 538                 return trim( $t );
 539         }
 540
 541         /**
 542          * Make a prefixed DB key from a DB key and a namespace index
 543          *
 544          * @param $ns Int numerical representation of the namespace
 545          * @param $title String the DB key form the title
 546          * @param $fragment String The link fragment (after the "#")
 547          * @param $interwiki String The interwiki prefix
 548          * @return String the prefixed form of the title
 549          */
 550         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 551                 global $wgContLang;
 552
 553                 $namespace = $wgContLang->getNsText( $ns );
 554                 $name = $namespace == '' ? $title : "$namespace:$title";
 555                 if ( strval( $interwiki ) != '' ) {
 556                         $name = "$interwiki:$name";
 557                 }
 558                 if ( strval( $fragment ) != '' ) {
 559                         $name .= '#' . $fragment;
 560                 }
 561                 return $name;
 562         }
 563
 564         /**
 565          * Escape a text fragment, say from a link, for a URL
 566          *
 567          * @param $fragment string containing a URL or link fragment (after the "#")
 568          * @return String: escaped string
 569          */
 570         static function escapeFragmentForURL( $fragment ) {
 571                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 572                 # fragments appear not to work in IE (at least up to 7) or in at least
 573                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 574                 # to care if they aren't encoded.
 575                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 576         }
 577
 578         /**
 579          * Callback for usort() to do title sorts by (namespace, title)
 580          *
 581          * @param $a Title
 582          * @param $b Title
 583          *
 584          * @return Integer: result of string comparison, or namespace comparison
 585          */
 586         public static function compare( $a, $b ) {
 587                 if ( $a->getNamespace() == $b->getNamespace() ) {
 588                         return strcmp( $a->getText(), $b->getText() );
 589                 } else {
 590                         return $a->getNamespace() - $b->getNamespace();
 591                 }
 592         }
 593
 594         /**
 595          * Determine whether the object refers to a page within
 596          * this project.
 597          *
 598          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 599          */
 600         public function isLocal() {
 601                 if ( $this->mInterwiki != '' ) {
 602                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 603                 } else {
 604                         return true;
 605                 }
 606         }
 607
 608         /**
 609          * Is this Title interwiki?
 610          *
 611          * @return Bool
 612          */
 613         public function isExternal() {
 614                 return ( $this->mInterwiki != '' );
 615         }
 616
 617         /**
 618          * Get the interwiki prefix (or null string)
 619          *
 620          * @return String Interwiki prefix
 621          */
 622         public function getInterwiki() {
 623                 return $this->mInterwiki;
 624         }
 625
 626         /**
 627          * Determine whether the object refers to a page within
 628          * this project and is transcludable.
 629          *
 630          * @return Bool TRUE if this is transcludable
 631          */
 632         public function isTrans() {
 633                 if ( $this->mInterwiki == '' ) {
 634                         return false;
 635                 }
 636
 637                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 638         }
 639
 640         /**
 641          * Returns the DB name of the distant wiki which owns the object.
 642          *
 643          * @return String the DB name
 644          */
 645         public function getTransWikiID() {
 646                 if ( $this->mInterwiki == '' ) {
 647                         return false;
 648                 }
 649
 650                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 651         }
 652
 653         /**
 654          * Get the text form (spaces not underscores) of the main part
 655          *
 656          * @return String Main part of the title
 657          */
 658         public function getText() {
 659                 return $this->mTextform;
 660         }
 661
 662         /**
 663          * Get the URL-encoded form of the main part
 664          *
 665          * @return String Main part of the title, URL-encoded
 666          */
 667         public function getPartialURL() {
 668                 return $this->mUrlform;
 669         }
 670
 671         /**
 672          * Get the main part with underscores
 673          *
 674          * @return String: Main part of the title, with underscores
 675          */
 676         public function getDBkey() {
 677                 return $this->mDbkeyform;
 678         }
 679
 680         /**
 681          * Get the DB key with the initial letter case as specified by the user
 682          *
 683          * @return String DB key
 684          */
 685         function getUserCaseDBKey() {
 686                 return $this->mUserCaseDBKey;
 687         }
 688
 689         /**
 690          * Get the namespace index, i.e. one of the NS_xxxx constants.
 691          *
 692          * @return Integer: Namespace index
 693          */
 694         public function getNamespace() {
 695                 return $this->mNamespace;
 696         }
 697
 698         /**
 699          * Get the namespace text
 700          *
 701          * @return String: Namespace text
 702          */
 703         public function getNsText() {
 704                 global $wgContLang;
 705
 706                 if ( $this->mInterwiki != '' ) {
 707                         // This probably shouldn't even happen. ohh man, oh yuck.
 708                         // But for interwiki transclusion it sometimes does.
 709                         // Shit. Shit shit shit.
 710                         //
 711                         // Use the canonical namespaces if possible to try to
 712                         // resolve a foreign namespace.
 713                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 714                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 715                         }
 716                 }
 717
 718                 // Strip off subpages
 719                 $pagename = $this->getText();
 720                 if ( strpos( $pagename, '/' ) !== false ) {
 721                         list( $username , ) = explode( '/', $pagename, 2 );
 722                 } else {
 723                         $username = $pagename;
 724                 }
 725
 726                 if ( $wgContLang->needsGenderDistinction() &&
 727                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 728                         $gender = GenderCache::singleton()->getGenderOf( $username, __METHOD__ );
 729                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 730                 }
 731
 732                 return $wgContLang->getNsText( $this->mNamespace );
 733         }
 734
 735         /**
 736          * Get the namespace text of the subject (rather than talk) page
 737          *
 738          * @return String Namespace text
 739          */
 740         public function getSubjectNsText() {
 741                 global $wgContLang;
 742                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 743         }
 744
 745         /**
 746          * Get the namespace text of the talk page
 747          *
 748          * @return String Namespace text
 749          */
 750         public function getTalkNsText() {
 751                 global $wgContLang;
 752                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 753         }
 754
 755         /**
 756          * Could this title have a corresponding talk page?
 757          *
 758          * @return Bool TRUE or FALSE
 759          */
 760         public function canTalk() {
 761                 return( MWNamespace::canTalk( $this->mNamespace ) );
 762         }
 763
 764         /**
 765          * Is this in a namespace that allows actual pages?
 766          *
 767          * @return Bool
 768          * @internal note -- uses hardcoded namespace index instead of constants
 769          */
 770         public function canExist() {
 771                 return $this->mNamespace >= NS_MAIN;
 772         }
 773
 774         /**
 775          * Can this title be added to a user's watchlist?
 776          *
 777          * @return Bool TRUE or FALSE
 778          */
 779         public function isWatchable() {
 780                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 781         }
 782
 783         /**
 784          * Returns true if this is a special page.
 785          *
 786          * @return boolean
 787          */
 788         public function isSpecialPage() {
 789                 return $this->getNamespace() == NS_SPECIAL;
 790         }
 791
 792         /**
 793          * Returns true if this title resolves to the named special page
 794          *
 795          * @param $name String The special page name
 796          * @return boolean
 797          */
 798         public function isSpecial( $name ) {
 799                 if ( $this->isSpecialPage() ) {
 800                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 801                         if ( $name == $thisName ) {
 802                                 return true;
 803                         }
 804                 }
 805                 return false;
 806         }
 807
 808         /**
 809          * If the Title refers to a special page alias which is not the local default, resolve
 810          * the alias, and localise the name as necessary.  Otherwise, return $this
 811          *
 812          * @return Title
 813          */
 814         public function fixSpecialName() {
 815                 if ( $this->isSpecialPage() ) {
 816                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 817                         if ( $canonicalName ) {
 818                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 819                                 if ( $localName != $this->mDbkeyform ) {
 820                                         return Title::makeTitle( NS_SPECIAL, $localName );
 821                                 }
 822                         }
 823                 }
 824                 return $this;
 825         }
 826
 827         /**
 828          * Returns true if the title is inside the specified namespace.
 829          *
 830          * Please make use of this instead of comparing to getNamespace()
 831          * This function is much more resistant to changes we may make
 832          * to namespaces than code that makes direct comparisons.
 833          * @param $ns int The namespace
 834          * @return bool
 835          * @since 1.19
 836          */
 837         public function inNamespace( $ns ) {
 838                 return MWNamespace::equals( $this->getNamespace(), $ns );
 839         }
 840
 841         /**
 842          * Returns true if the title is inside one of the specified namespaces.
 843          *
 844          * @param ...$namespaces The namespaces to check for
 845          * @return bool
 846          * @since 1.19
 847          */
 848         public function inNamespaces( /* ... */ ) {
 849                 $namespaces = func_get_args();
 850                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 851                         $namespaces = $namespaces[0];
 852                 }
 853
 854                 foreach ( $namespaces as $ns ) {
 855                         if ( $this->inNamespace( $ns ) ) {
 856                                 return true;
 857                         }
 858                 }
 859
 860                 return false;
 861         }
 862
 863         /**
 864          * Returns true if the title has the same subject namespace as the
 865          * namespace specified.
 866          * For example this method will take NS_USER and return true if namespace
 867          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 868          * as their subject namespace.
 869          *
 870          * This is MUCH simpler than individually testing for equivilance
 871          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 872          * @since 1.19
 873          */
 874         public function hasSubjectNamespace( $ns ) {
 875                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 876         }
 877
 878         /**
 879          * Is this Title in a namespace which contains content?
 880          * In other words, is this a content page, for the purposes of calculating
 881          * statistics, etc?
 882          *
 883          * @return Boolean
 884          */
 885         public function isContentPage() {
 886                 return MWNamespace::isContent( $this->getNamespace() );
 887         }
 888
 889         /**
 890          * Would anybody with sufficient privileges be able to move this page?
 891          * Some pages just aren't movable.
 892          *
 893          * @return Bool TRUE or FALSE
 894          */
 895         public function isMovable() {
 896                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 897                         // Interwiki title or immovable namespace. Hooks don't get to override here
 898                         return false;
 899                 }
 900
 901                 $result = true;
 902                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 903                 return $result;
 904         }
 905
 906         /**
 907          * Is this the mainpage?
 908          * @note Title::newFromText seams to be sufficiently optimized by the title
 909          * cache that we don't need to over-optimize by doing direct comparisons and
 910          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 911          * ends up reporting something differently than $title->isMainPage();
 912          *
 913          * @since 1.18
 914          * @return Bool
 915          */
 916         public function isMainPage() {
 917                 return $this->equals( Title::newMainPage() );
 918         }
 919
 920         /**
 921          * Is this a subpage?
 922          *
 923          * @return Bool
 924          */
 925         public function isSubpage() {
 926                 return MWNamespace::hasSubpages( $this->mNamespace )
 927                         ? strpos( $this->getText(), '/' ) !== false
 928                         : false;
 929         }
 930
 931         /**
 932          * Is this a conversion table for the LanguageConverter?
 933          *
 934          * @return Bool
 935          */
 936         public function isConversionTable() {
 937                 return $this->getNamespace() == NS_MEDIAWIKI &&
 938                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 939         }
 940
 941         /**
 942          * Does that page contain wikitext, or it is JS, CSS or whatever?
 943          *
 944          * @return Bool
 945          */
 946         public function isWikitextPage() {
 947                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 948                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 949                 return $retval;
 950         }
 951
 952         /**
 953          * Could this page contain custom CSS or JavaScript, based
 954          * on the title?
 955          *
 956          * @return Bool
 957          */
 958         public function isCssOrJsPage() {
 959                 $retval = $this->mNamespace == NS_MEDIAWIKI
 960                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 961                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 962                 return $retval;
 963         }
 964
 965         /**
 966          * Is this a .css or .js subpage of a user page?
 967          * @return Bool
 968          */
 969         public function isCssJsSubpage() {
 970                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 971         }
 972
 973         /**
 974          * Trim down a .css or .js subpage title to get the corresponding skin name
 975          *
 976          * @return string containing skin name from .css or .js subpage title
 977          */
 978         public function getSkinFromCssJsSubpage() {
 979                 $subpage = explode( '/', $this->mTextform );
 980                 $subpage = $subpage[ count( $subpage ) - 1 ];
 981                 $lastdot = strrpos( $subpage, '.' );
 982                 if ( $lastdot === false )
 983                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 984                 return substr( $subpage, 0, $lastdot );
 985         }
 986
 987         /**
 988          * Is this a .css subpage of a user page?
 989          *
 990          * @return Bool
 991          */
 992         public function isCssSubpage() {
 993                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
 994         }
 995
 996         /**
 997          * Is this a .js subpage of a user page?
 998          *
 999          * @return Bool
1000          */
1001         public function isJsSubpage() {
1002                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1003         }
1004
1005         /**
1006          * Is this a talk page of some sort?
1007          *
1008          * @return Bool
1009          */
1010         public function isTalkPage() {
1011                 return MWNamespace::isTalk( $this->getNamespace() );
1012         }
1013
1014         /**
1015          * Get a Title object associated with the talk page of this article
1016          *
1017          * @return Title the object for the talk page
1018          */
1019         public function getTalkPage() {
1020                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1021         }
1022
1023         /**
1024          * Get a title object associated with the subject page of this
1025          * talk page
1026          *
1027          * @return Title the object for the subject page
1028          */
1029         public function getSubjectPage() {
1030                 // Is this the same title?
1031                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1032                 if ( $this->getNamespace() == $subjectNS ) {
1033                         return $this;
1034                 }
1035                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1036         }
1037
1038         /**
1039          * Get the default namespace index, for when there is no namespace
1040          *
1041          * @return Int Default namespace index
1042          */
1043         public function getDefaultNamespace() {
1044                 return $this->mDefaultNamespace;
1045         }
1046
1047         /**
1048          * Get title for search index
1049          *
1050          * @return String a stripped-down title string ready for the
1051          *  search index
1052          */
1053         public function getIndexTitle() {
1054                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1055         }
1056
1057         /**
1058          * Get the Title fragment (i.e.\ the bit after the #) in text form
1059          *
1060          * @return String Title fragment
1061          */
1062         public function getFragment() {
1063                 return $this->mFragment;
1064         }
1065
1066         /**
1067          * Get the fragment in URL form, including the "#" character if there is one
1068          * @return String Fragment in URL form
1069          */
1070         public function getFragmentForURL() {
1071                 if ( $this->mFragment == '' ) {
1072                         return '';
1073                 } else {
1074                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1075                 }
1076         }
1077
1078         /**
1079          * Set the fragment for this title. Removes the first character from the
1080          * specified fragment before setting, so it assumes you're passing it with
1081          * an initial "#".
1082          *
1083          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1084          * Still in active use privately.
1085          *
1086          * @param $fragment String text
1087          */
1088         public function setFragment( $fragment ) {
1089                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1090         }
1091
1092         /**
1093          * Prefix some arbitrary text with the namespace or interwiki prefix
1094          * of this object
1095          *
1096          * @param $name String the text
1097          * @return String the prefixed text
1098          * @private
1099          */
1100         private function prefix( $name ) {
1101                 $p = '';
1102                 if ( $this->mInterwiki != '' ) {
1103                         $p = $this->mInterwiki . ':';
1104                 }
1105
1106                 if ( 0 != $this->mNamespace ) {
1107                         $p .= $this->getNsText() . ':';
1108                 }
1109                 return $p . $name;
1110         }
1111
1112         /**
1113          * Get the prefixed database key form
1114          *
1115          * @return String the prefixed title, with underscores and
1116          *  any interwiki and namespace prefixes
1117          */
1118         public function getPrefixedDBkey() {
1119                 $s = $this->prefix( $this->mDbkeyform );
1120                 $s = str_replace( ' ', '_', $s );
1121                 return $s;
1122         }
1123
1124         /**
1125          * Get the prefixed title with spaces.
1126          * This is the form usually used for display
1127          *
1128          * @return String the prefixed title, with spaces
1129          */
1130         public function getPrefixedText() {
1131                 // @todo FIXME: Bad usage of empty() ?
1132                 if ( empty( $this->mPrefixedText ) ) {
1133                         $s = $this->prefix( $this->mTextform );
1134                         $s = str_replace( '_', ' ', $s );
1135                         $this->mPrefixedText = $s;
1136                 }
1137                 return $this->mPrefixedText;
1138         }
1139
1140         /**
1141          * Return a string representation of this title
1142          *
1143          * @return String representation of this title
1144          */
1145         public function __toString() {
1146                 return $this->getPrefixedText();
1147         }
1148
1149         /**
1150          * Get the prefixed title with spaces, plus any fragment
1151          * (part beginning with '#')
1152          *
1153          * @return String the prefixed title, with spaces and the fragment, including '#'
1154          */
1155         public function getFullText() {
1156                 $text = $this->getPrefixedText();
1157                 if ( $this->mFragment != '' ) {
1158                         $text .= '#' . $this->mFragment;
1159                 }
1160                 return $text;
1161         }
1162
1163         /**
1164          * Get the base page name, i.e. the leftmost part before any slashes
1165          *
1166          * @return String Base name
1167          */
1168         public function getBaseText() {
1169                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1170                         return $this->getText();
1171                 }
1172
1173                 $parts = explode( '/', $this->getText() );
1174                 # Don't discard the real title if there's no subpage involved
1175                 if ( count( $parts ) > 1 ) {
1176                         unset( $parts[count( $parts ) - 1] );
1177                 }
1178                 return implode( '/', $parts );
1179         }
1180
1181         /**
1182          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1183          *
1184          * @return String Subpage name
1185          */
1186         public function getSubpageText() {
1187                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1188                         return( $this->mTextform );
1189                 }
1190                 $parts = explode( '/', $this->mTextform );
1191                 return( $parts[count( $parts ) - 1] );
1192         }
1193
1194         /**
1195          * Get the HTML-escaped displayable text form.
1196          * Used for the title field in <a> tags.
1197          *
1198          * @return String the text, including any prefixes
1199          */
1200         public function getEscapedText() {
1201                 wfDeprecated( __METHOD__, '1.19' );
1202                 return htmlspecialchars( $this->getPrefixedText() );
1203         }
1204
1205         /**
1206          * Get a URL-encoded form of the subpage text
1207          *
1208          * @return String URL-encoded subpage name
1209          */
1210         public function getSubpageUrlForm() {
1211                 $text = $this->getSubpageText();
1212                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1213                 return( $text );
1214         }
1215
1216         /**
1217          * Get a URL-encoded title (not an actual URL) including interwiki
1218          *
1219          * @return String the URL-encoded form
1220          */
1221         public function getPrefixedURL() {
1222                 $s = $this->prefix( $this->mDbkeyform );
1223                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1224                 return $s;
1225         }
1226
1227         /**
1228          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1229          */
1230         private static function fixUrlQueryArgs( $query, $query2 ) {
1231                 if ( is_array( $query ) ) {
1232                         $query = wfArrayToCGI( $query );
1233                 }
1234                 if ( $query2 ) {
1235                         if ( is_string( $query2 ) ) {
1236                                 // $query2 is a string, we will consider this to be
1237                                 // a deprecated $variant argument and add it to the query
1238                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1239                         } else {
1240                                 $query2 = wfArrayToCGI( $query2 );
1241                         }
1242                         // If we have $query content add a & to it first
1243                         if ( $query ) {
1244                                 $query .= '&';
1245                         }
1246                         // Now append the queries together
1247                         $query .= $query2;
1248                 }
1249                 return $query;
1250         }
1251
1252         /**
1253          * Get a real URL referring to this title, with interwiki link and
1254          * fragment
1255          *
1256          * See getLocalURL for the arguments.
1257          *
1258          * @see self::getLocalURL
1259          * @return String the URL
1260          */
1261         public function getFullURL( $query = '', $query2 = false ) {
1262                 $query = self::fixUrlQueryArgs( $query, $query2 );
1263
1264                 # Hand off all the decisions on urls to getLocalURL
1265                 $url = $this->getLocalURL( $query );
1266
1267                 # Expand the url to make it a full url. Note that getLocalURL has the
1268                 # potential to output full urls for a variety of reasons, so we use
1269                 # wfExpandUrl instead of simply prepending $wgServer
1270                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1271
1272                 # Finally, add the fragment.
1273                 $url .= $this->getFragmentForURL();
1274
1275                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1276                 return $url;
1277         }
1278
1279         /**
1280          * Get a URL with no fragment or server name.  If this page is generated
1281          * with action=render, $wgServer is prepended.
1282          *
1283
1284          * @param $query \twotypes{\string,\array} an optional query string,
1285          *   not used for interwiki     links. Can be specified as an associative array as well,
1286          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1287          *   Some query patterns will trigger various shorturl path replacements.
1288          * @param $query2 Mixed: An optional secondary query array. This one MUST
1289          *   be an array. If a string is passed it will be interpreted as a deprecated
1290          *   variant argument and urlencoded into a variant= argument.
1291          *   This second query argument will be added to the $query
1292          * @return String the URL
1293          */
1294         public function getLocalURL( $query = '', $query2 = false ) {
1295                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1296
1297                 $query = self::fixUrlQueryArgs( $query, $query2 );
1298
1299                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1300                 if ( $interwiki ) {
1301                         $namespace = $this->getNsText();
1302                         if ( $namespace != '' ) {
1303                                 # Can this actually happen? Interwikis shouldn't be parsed.
1304                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1305                                 $namespace .= ':';
1306                         }
1307                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1308                         $url = wfAppendQuery( $url, $query );
1309                 } else {
1310                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1311                         if ( $query == '' ) {
1312                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1313                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1314                         } else {
1315                                 global $wgVariantArticlePath, $wgActionPaths;
1316                                 $url = false;
1317                                 $matches = array();
1318
1319                                 if ( !empty( $wgActionPaths ) &&
1320                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1321                                 {
1322                                         $action = urldecode( $matches[2] );
1323                                         if ( isset( $wgActionPaths[$action] ) ) {
1324                                                 $query = $matches[1];
1325                                                 if ( isset( $matches[4] ) ) {
1326                                                         $query .= $matches[4];
1327                                                 }
1328                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1329                                                 if ( $query != '' ) {
1330                                                         $url = wfAppendQuery( $url, $query );
1331                                                 }
1332                                         }
1333                                 }
1334
1335                                 if ( $url === false &&
1336                                         $wgVariantArticlePath &&
1337                                         $this->getPageLanguage()->hasVariants() &&
1338                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1339                                 {
1340                                         $variant = urldecode( $matches[1] );
1341                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1342                                                 // Only do the variant replacement if the given variant is a valid
1343                                                 // variant for the page's language.
1344                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1345                                                 $url = str_replace( '$1', $dbkey, $url );
1346                                         }
1347                                 }
1348
1349                                 if ( $url === false ) {
1350                                         if ( $query == '-' ) {
1351                                                 $query = '';
1352                                         }
1353                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1354                                 }
1355                         }
1356
1357                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1358
1359                         // @todo FIXME: This causes breakage in various places when we
1360                         // actually expected a local URL and end up with dupe prefixes.
1361                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1362                                 $url = $wgServer . $url;
1363                         }
1364                 }
1365                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1366                 return $url;
1367         }
1368
1369         /**
1370          * Get a URL that's the simplest URL that will be valid to link, locally,
1371          * to the current Title.  It includes the fragment, but does not include
1372          * the server unless action=render is used (or the link is external).  If
1373          * there's a fragment but the prefixed text is empty, we just return a link
1374          * to the fragment.
1375          *
1376          * The result obviously should not be URL-escaped, but does need to be
1377          * HTML-escaped if it's being output in HTML.
1378          *
1379          * See getLocalURL for the arguments.
1380          *
1381          * @see self::getLocalURL
1382          * @return String the URL
1383          */
1384         public function getLinkURL( $query = '', $query2 = false ) {
1385                 wfProfileIn( __METHOD__ );
1386                 if ( $this->isExternal() ) {
1387                         $ret = $this->getFullURL( $query, $query2 );
1388                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1389                         $ret = $this->getFragmentForURL();
1390                 } else {
1391                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1392                 }
1393                 wfProfileOut( __METHOD__ );
1394                 return $ret;
1395         }
1396
1397         /**
1398          * Get an HTML-escaped version of the URL form, suitable for
1399          * using in a link, without a server name or fragment
1400          *
1401          * See getLocalURL for the arguments.
1402          *
1403          * @see self::getLocalURL
1404          * @return String the URL
1405          */
1406         public function escapeLocalURL( $query = '', $query2 = false ) {
1407                 wfDeprecated( __METHOD__, '1.19' );
1408                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1409         }
1410
1411         /**
1412          * Get an HTML-escaped version of the URL form, suitable for
1413          * using in a link, including the server name and fragment
1414          *
1415          * See getLocalURL for the arguments.
1416          *
1417          * @see self::getLocalURL
1418          * @return String the URL
1419          */
1420         public function escapeFullURL( $query = '', $query2 = false ) {
1421                 wfDeprecated( __METHOD__, '1.19' );
1422                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1423         }
1424
1425         /**
1426          * Get the URL form for an internal link.
1427          * - Used in various Squid-related code, in case we have a different
1428          * internal hostname for the server from the exposed one.
1429          *
1430          * This uses $wgInternalServer to qualify the path, or $wgServer
1431          * if $wgInternalServer is not set. If the server variable used is
1432          * protocol-relative, the URL will be expanded to http://
1433          *
1434          * See getLocalURL for the arguments.
1435          *
1436          * @see self::getLocalURL
1437          * @return String the URL
1438          */
1439         public function getInternalURL( $query = '', $query2 = false ) {
1440                 global $wgInternalServer, $wgServer;
1441                 $query = self::fixUrlQueryArgs( $query, $query2 );
1442                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1443                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1444                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1445                 return $url;
1446         }
1447
1448         /**
1449          * Get the URL for a canonical link, for use in things like IRC and
1450          * e-mail notifications. Uses $wgCanonicalServer and the
1451          * GetCanonicalURL hook.
1452          *
1453          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1454          *
1455          * See getLocalURL for the arguments.
1456          *
1457          * @see self::getLocalURL
1458          * @return string The URL
1459          * @since 1.18
1460          */
1461         public function getCanonicalURL( $query = '', $query2 = false ) {
1462                 $query = self::fixUrlQueryArgs( $query, $query2 );
1463                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1464                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1465                 return $url;
1466         }
1467
1468         /**
1469          * HTML-escaped version of getCanonicalURL()
1470          *
1471          * See getLocalURL for the arguments.
1472          *
1473          * @see self::getLocalURL
1474          * @since 1.18
1475          */
1476         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1477                 wfDeprecated( __METHOD__, '1.19' );
1478                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1479         }
1480
1481         /**
1482          * Get the edit URL for this Title
1483          *
1484          * @return String the URL, or a null string if this is an
1485          *  interwiki link
1486          */
1487         public function getEditURL() {
1488                 if ( $this->mInterwiki != '' ) {
1489                         return '';
1490                 }
1491                 $s = $this->getLocalURL( 'action=edit' );
1492
1493                 return $s;
1494         }
1495
1496         /**
1497          * Is $wgUser watching this page?
1498          *
1499          * @return Bool
1500          */
1501         public function userIsWatching() {
1502                 global $wgUser;
1503
1504                 if ( is_null( $this->mWatched ) ) {
1505                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1506                                 $this->mWatched = false;
1507                         } else {
1508                                 $this->mWatched = $wgUser->isWatched( $this );
1509                         }
1510                 }
1511                 return $this->mWatched;
1512         }
1513
1514         /**
1515          * Can $wgUser read this page?
1516          *
1517          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1518          * @return Bool
1519          * @todo fold these checks into userCan()
1520          */
1521         public function userCanRead() {
1522                 wfDeprecated( __METHOD__, '1.19' );
1523                 return $this->userCan( 'read' );
1524         }
1525
1526         /**
1527          * Can $user perform $action on this page?
1528          * This skips potentially expensive cascading permission checks
1529          * as well as avoids expensive error formatting
1530          *
1531          * Suitable for use for nonessential UI controls in common cases, but
1532          * _not_ for functional access control.
1533          *
1534          * May provide false positives, but should never provide a false negative.
1535          *
1536          * @param $action String action that permission needs to be checked for
1537          * @param $user User to check (since 1.19); $wgUser will be used if not
1538          *              provided.
1539          * @return Bool
1540          */
1541         public function quickUserCan( $action, $user = null ) {
1542                 return $this->userCan( $action, $user, false );
1543         }
1544
1545         /**
1546          * Can $user perform $action on this page?
1547          *
1548          * @param $action String action that permission needs to be checked for
1549          * @param $user User to check (since 1.19); $wgUser will be used if not
1550          *   provided.
1551          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1552          *   unnecessary queries.
1553          * @return Bool
1554          */
1555         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1556                 if ( !$user instanceof User ) {
1557                         global $wgUser;
1558                         $user = $wgUser;
1559                 }
1560                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1561         }
1562
1563         /**
1564          * Can $user perform $action on this page?
1565          *
1566          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1567          *
1568          * @param $action String action that permission needs to be checked for
1569          * @param $user User to check
1570          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1571          *   queries by skipping checks for cascading protections and user blocks.
1572          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1573          *   whose corresponding errors may be ignored.
1574          * @return Array of arguments to wfMsg to explain permissions problems.
1575          */
1576         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1577                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1578
1579                 // Remove the errors being ignored.
1580                 foreach ( $errors as $index => $error ) {
1581                         $error_key = is_array( $error ) ? $error[0] : $error;
1582
1583                         if ( in_array( $error_key, $ignoreErrors ) ) {
1584                                 unset( $errors[$index] );
1585                         }
1586                 }
1587
1588                 return $errors;
1589         }
1590
1591         /**
1592          * Permissions checks that fail most often, and which are easiest to test.
1593          *
1594          * @param $action String the action to check
1595          * @param $user User user to check
1596          * @param $errors Array list of current errors
1597          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1598          * @param $short Boolean short circuit on first error
1599          *
1600          * @return Array list of errors
1601          */
1602         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1603                 if ( $action == 'create' ) {
1604                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1605                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1606                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1607                         }
1608                 } elseif ( $action == 'move' ) {
1609                         if ( !$user->isAllowed( 'move-rootuserpages' )
1610                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1611                                 // Show user page-specific message only if the user can move other pages
1612                                 $errors[] = array( 'cant-move-user-page' );
1613                         }
1614
1615                         // Check if user is allowed to move files if it's a file
1616                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1617                                 $errors[] = array( 'movenotallowedfile' );
1618                         }
1619
1620                         if ( !$user->isAllowed( 'move' ) ) {
1621                                 // User can't move anything
1622                                 global $wgGroupPermissions;
1623                                 $userCanMove = false;
1624                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1625                                         $userCanMove = $wgGroupPermissions['user']['move'];
1626                                 }
1627                                 $autoconfirmedCanMove = false;
1628                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1629                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1630                                 }
1631                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1632                                         // custom message if logged-in users without any special rights can move
1633                                         $errors[] = array( 'movenologintext' );
1634                                 } else {
1635                                         $errors[] = array( 'movenotallowed' );
1636                                 }
1637                         }
1638                 } elseif ( $action == 'move-target' ) {
1639                         if ( !$user->isAllowed( 'move' ) ) {
1640                                 // User can't move anything
1641                                 $errors[] = array( 'movenotallowed' );
1642                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1643                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1644                                 // Show user page-specific message only if the user can move other pages
1645                                 $errors[] = array( 'cant-move-to-user-page' );
1646                         }
1647                 } elseif ( !$user->isAllowed( $action ) ) {
1648                         $errors[] = $this->missingPermissionError( $action, $short );
1649                 }
1650
1651                 return $errors;
1652         }
1653
1654         /**
1655          * Add the resulting error code to the errors array
1656          *
1657          * @param $errors Array list of current errors
1658          * @param $result Mixed result of errors
1659          *
1660          * @return Array list of errors
1661          */
1662         private function resultToError( $errors, $result ) {
1663                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1664                         // A single array representing an error
1665                         $errors[] = $result;
1666                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1667                         // A nested array representing multiple errors
1668                         $errors = array_merge( $errors, $result );
1669                 } elseif ( $result !== '' && is_string( $result ) ) {
1670                         // A string representing a message-id
1671                         $errors[] = array( $result );
1672                 } elseif ( $result === false ) {
1673                         // a generic "We don't want them to do that"
1674                         $errors[] = array( 'badaccess-group0' );
1675                 }
1676                 return $errors;
1677         }
1678
1679         /**
1680          * Check various permission hooks
1681          *
1682          * @param $action String the action to check
1683          * @param $user User user to check
1684          * @param $errors Array list of current errors
1685          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1686          * @param $short Boolean short circuit on first error
1687          *
1688          * @return Array list of errors
1689          */
1690         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1691                 // Use getUserPermissionsErrors instead
1692                 $result = '';
1693                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1694                         return $result ? array() : array( array( 'badaccess-group0' ) );
1695                 }
1696                 // Check getUserPermissionsErrors hook
1697                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1698                         $errors = $this->resultToError( $errors, $result );
1699                 }
1700                 // Check getUserPermissionsErrorsExpensive hook
1701                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1702                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1703                         $errors = $this->resultToError( $errors, $result );
1704                 }
1705
1706                 return $errors;
1707         }
1708
1709         /**
1710          * Check permissions on special pages & namespaces
1711          *
1712          * @param $action String the action to check
1713          * @param $user User user to check
1714          * @param $errors Array list of current errors
1715          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1716          * @param $short Boolean short circuit on first error
1717          *
1718          * @return Array list of errors
1719          */
1720         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1721                 # Only 'createaccount' and 'execute' can be performed on
1722                 # special pages, which don't actually exist in the DB.
1723                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1724                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1725                         $errors[] = array( 'ns-specialprotected' );
1726                 }
1727
1728                 # Check $wgNamespaceProtection for restricted namespaces
1729                 if ( $this->isNamespaceProtected( $user ) ) {
1730                         $ns = $this->mNamespace == NS_MAIN ?
1731                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1732                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1733                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1734                 }
1735
1736                 return $errors;
1737         }
1738
1739         /**
1740          * Check CSS/JS sub-page permissions
1741          *
1742          * @param $action String the action to check
1743          * @param $user User user to check
1744          * @param $errors Array list of current errors
1745          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1746          * @param $short Boolean short circuit on first error
1747          *
1748          * @return Array list of errors
1749          */
1750         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1751                 # Protect css/js subpages of user pages
1752                 # XXX: this might be better using restrictions
1753                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1754                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1755                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1756                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1757                                 $errors[] = array( 'customcssprotected' );
1758                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1759                                 $errors[] = array( 'customjsprotected' );
1760                         }
1761                 }
1762
1763                 return $errors;
1764         }
1765
1766         /**
1767          * Check against page_restrictions table requirements on this
1768          * page. The user must possess all required rights for this
1769          * action.
1770          *
1771          * @param $action String the action to check
1772          * @param $user User user to check
1773          * @param $errors Array list of current errors
1774          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1775          * @param $short Boolean short circuit on first error
1776          *
1777          * @return Array list of errors
1778          */
1779         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1780                 foreach ( $this->getRestrictions( $action ) as $right ) {
1781                         // Backwards compatibility, rewrite sysop -> protect
1782                         if ( $right == 'sysop' ) {
1783                                 $right = 'protect';
1784                         }
1785                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1786                                 // Users with 'editprotected' permission can edit protected pages
1787                                 // without cascading option turned on.
1788                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1789                                         || $this->mCascadeRestriction )
1790                                 {
1791                                         $errors[] = array( 'protectedpagetext', $right );
1792                                 }
1793                         }
1794                 }
1795
1796                 return $errors;
1797         }
1798
1799         /**
1800          * Check restrictions on cascading pages.
1801          *
1802          * @param $action String the action to check
1803          * @param $user User to check
1804          * @param $errors Array list of current errors
1805          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1806          * @param $short Boolean short circuit on first error
1807          *
1808          * @return Array list of errors
1809          */
1810         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1811                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1812                         # We /could/ use the protection level on the source page, but it's
1813                         # fairly ugly as we have to establish a precedence hierarchy for pages
1814                         # included by multiple cascade-protected pages. So just restrict
1815                         # it to people with 'protect' permission, as they could remove the
1816                         # protection anyway.
1817                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1818                         # Cascading protection depends on more than this page...
1819                         # Several cascading protected pages may include this page...
1820                         # Check each cascading level
1821                         # This is only for protection restrictions, not for all actions
1822                         if ( isset( $restrictions[$action] ) ) {
1823                                 foreach ( $restrictions[$action] as $right ) {
1824                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1825                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1826                                                 $pages = '';
1827                                                 foreach ( $cascadingSources as $page )
1828                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1829                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1830                                         }
1831                                 }
1832                         }
1833                 }
1834
1835                 return $errors;
1836         }
1837
1838         /**
1839          * Check action permissions not already checked in checkQuickPermissions
1840          *
1841          * @param $action String the action to check
1842          * @param $user User to check
1843          * @param $errors Array list of current errors
1844          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1845          * @param $short Boolean short circuit on first error
1846          *
1847          * @return Array list of errors
1848          */
1849         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1850                 global $wgDeleteRevisionsLimit, $wgLang;
1851
1852                 if ( $action == 'protect' ) {
1853                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1854                                 // If they can't edit, they shouldn't protect.
1855                                 $errors[] = array( 'protect-cantedit' );
1856                         }
1857                 } elseif ( $action == 'create' ) {
1858                         $title_protection = $this->getTitleProtection();
1859                         if( $title_protection ) {
1860                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1861                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1862                                 }
1863                                 if( $title_protection['pt_create_perm'] == '' ||
1864                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1865                                 {
1866                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1867                                 }
1868                         }
1869                 } elseif ( $action == 'move' ) {
1870                         // Check for immobile pages
1871                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1872                                 // Specific message for this case
1873                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1874                         } elseif ( !$this->isMovable() ) {
1875                                 // Less specific message for rarer cases
1876                                 $errors[] = array( 'immobile-source-page' );
1877                         }
1878                 } elseif ( $action == 'move-target' ) {
1879                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1880                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1881                         } elseif ( !$this->isMovable() ) {
1882                                 $errors[] = array( 'immobile-target-page' );
1883                         }
1884                 } elseif ( $action == 'delete' ) {
1885                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1886                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1887                         {
1888                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1889                         }
1890                 }
1891                 return $errors;
1892         }
1893
1894         /**
1895          * Check that the user isn't blocked from editting.
1896          *
1897          * @param $action String the action to check
1898          * @param $user User to check
1899          * @param $errors Array list of current errors
1900          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1901          * @param $short Boolean short circuit on first error
1902          *
1903          * @return Array list of errors
1904          */
1905         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1906                 // Account creation blocks handled at userlogin.
1907                 // Unblocking handled in SpecialUnblock
1908                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1909                         return $errors;
1910                 }
1911
1912                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1913
1914                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1915                         $errors[] = array( 'confirmedittext' );
1916                 }
1917
1918                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1919                         // Don't block the user from editing their own talk page unless they've been
1920                         // explicitly blocked from that too.
1921                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1922                         $block = $user->mBlock;
1923
1924                         // This is from OutputPage::blockedPage
1925                         // Copied at r23888 by werdna
1926
1927                         $id = $user->blockedBy();
1928                         $reason = $user->blockedFor();
1929                         if ( $reason == '' ) {
1930                                 $reason = wfMsg( 'blockednoreason' );
1931                         }
1932                         $ip = $user->getRequest()->getIP();
1933
1934                         if ( is_numeric( $id ) ) {
1935                                 $name = User::whoIs( $id );
1936                         } else {
1937                                 $name = $id;
1938                         }
1939
1940                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1941                         $blockid = $block->getId();
1942                         $blockExpiry = $user->mBlock->mExpiry;
1943                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1944                         if ( $blockExpiry == 'infinity' ) {
1945                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1946                         } else {
1947                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1948                         }
1949
1950                         $intended = strval( $user->mBlock->getTarget() );
1951
1952                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1953                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1954                 }
1955
1956                 return $errors;
1957         }
1958
1959         /**
1960          * Check that the user is allowed to read this page.
1961          *
1962          * @param $action String the action to check
1963          * @param $user User to check
1964          * @param $errors Array list of current errors
1965          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1966          * @param $short Boolean short circuit on first error
1967          *
1968          * @return Array list of errors
1969          */
1970         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1971                 static $useShortcut = null;
1972
1973                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1974                 if ( is_null( $useShortcut ) ) {
1975                         global $wgGroupPermissions, $wgRevokePermissions;
1976                         $useShortcut = true;
1977                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1978                                 # Not a public wiki, so no shortcut
1979                                 $useShortcut = false;
1980                         } elseif ( !empty( $wgRevokePermissions ) ) {
1981                                 /**
1982                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1983                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1984                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1985                                  * reading is allowed.
1986                                  */
1987                                 foreach ( $wgRevokePermissions as $perms ) {
1988                                         if ( !empty( $perms['read'] ) ) {
1989                                                 # We might be removing the read right from the user, so no shortcut
1990                                                 $useShortcut = false;
1991                                                 break;
1992                                         }
1993                                 }
1994                         }
1995                 }
1996
1997                 # Shortcut for public wikis, allows skipping quite a bit of code
1998                 if ( $useShortcut ) {
1999                         return $errors;
2000                 }
2001
2002                 # If the user is allowed to read pages, he is allowed to read all pages
2003                 if ( $user->isAllowed( 'read' ) ) {
2004                         return $errors;
2005                 }
2006
2007                 # Always grant access to the login page.
2008                 # Even anons need to be able to log in.
2009                 if ( $this->isSpecial( 'Userlogin' )
2010                         || $this->isSpecial( 'ChangePassword' )
2011                         || $this->isSpecial( 'PasswordReset' )
2012                 ) {
2013                         return $errors;
2014                 }
2015
2016                 # Time to check the whitelist
2017                 global $wgWhitelistRead;
2018
2019                 # Only do these checks is there's something to check against
2020                 if ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2021                         # Check for explicit whitelisting
2022                         $name = $this->getPrefixedText();
2023                         $dbName = $this->getPrefixedDBKey();
2024
2025                         // Check with and without underscores
2026                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2027                                 return $errors;
2028                         }
2029
2030                         # Old settings might have the title prefixed with
2031                         # a colon for main-namespace pages
2032                         if ( $this->getNamespace() == NS_MAIN ) {
2033                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2034                                         return $errors;
2035                                 }
2036                         }
2037
2038                         # If it's a special page, ditch the subpage bit and check again
2039                         if ( $this->isSpecialPage() ) {
2040                                 $name = $this->getDBkey();
2041                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2042                                 if ( $name !== false ) {
2043                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2044                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2045                                                 return $errors;
2046                                         }
2047                                 }
2048                         }
2049                 }
2050
2051                 $errors[] = $this->missingPermissionError( $action, $short );
2052                 return $errors;
2053         }
2054
2055         /**
2056          * Get a description array when the user doesn't have the right to perform
2057          * $action (i.e. when User::isAllowed() returns false)
2058          *
2059          * @param $action String the action to check
2060          * @param $short Boolean short circuit on first error
2061          * @return Array list of errors
2062          */
2063         private function missingPermissionError( $action, $short ) {
2064                 // We avoid expensive display logic for quickUserCan's and such
2065                 if ( $short ) {
2066                         return array( 'badaccess-group0' );
2067                 }
2068
2069                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2070                         User::getGroupsWithPermission( $action ) );
2071
2072                 if ( count( $groups ) ) {
2073                         global $wgLang;
2074                         return array(
2075                                 'badaccess-groups',
2076                                 $wgLang->commaList( $groups ),
2077                                 count( $groups )
2078                         );
2079                 } else {
2080                         return array( 'badaccess-group0' );
2081                 }
2082         }
2083
2084         /**
2085          * Can $user perform $action on this page? This is an internal function,
2086          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2087          * checks on wfReadOnly() and blocks)
2088          *
2089          * @param $action String action that permission needs to be checked for
2090          * @param $user User to check
2091          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2092          * @param $short Bool Set this to true to stop after the first permission error.
2093          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2094          */
2095         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2096                 wfProfileIn( __METHOD__ );
2097
2098                 # Read has special handling
2099                 if ( $action == 'read' ) {
2100                         $checks = array(
2101                                 'checkPermissionHooks',
2102                                 'checkReadPermissions',
2103                         );
2104                 } else {
2105                         $checks = array(
2106                                 'checkQuickPermissions',
2107                                 'checkPermissionHooks',
2108                                 'checkSpecialsAndNSPermissions',
2109                                 'checkCSSandJSPermissions',
2110                                 'checkPageRestrictions',
2111                                 'checkCascadingSourcesRestrictions',
2112                                 'checkActionPermissions',
2113                                 'checkUserBlock'
2114                         );
2115                 }
2116
2117                 $errors = array();
2118                 while( count( $checks ) > 0 &&
2119                                 !( $short && count( $errors ) > 0 ) ) {
2120                         $method = array_shift( $checks );
2121                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2122                 }
2123
2124                 wfProfileOut( __METHOD__ );
2125                 return $errors;
2126         }
2127
2128         /**
2129          * Protect css subpages of user pages: can $wgUser edit
2130          * this page?
2131          *
2132          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2133          * @return Bool
2134          */
2135         public function userCanEditCssSubpage() {
2136                 global $wgUser;
2137                 wfDeprecated( __METHOD__, '1.19' );
2138                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2139                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2140         }
2141
2142         /**
2143          * Protect js subpages of user pages: can $wgUser edit
2144          * this page?
2145          *
2146          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2147          * @return Bool
2148          */
2149         public function userCanEditJsSubpage() {
2150                 global $wgUser;
2151                 wfDeprecated( __METHOD__, '1.19' );
2152                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2153                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2154         }
2155
2156         /**
2157          * Get a filtered list of all restriction types supported by this wiki.
2158          * @param bool $exists True to get all restriction types that apply to
2159          * titles that do exist, False for all restriction types that apply to
2160          * titles that do not exist
2161          * @return array
2162          */
2163         public static function getFilteredRestrictionTypes( $exists = true ) {
2164                 global $wgRestrictionTypes;
2165                 $types = $wgRestrictionTypes;
2166                 if ( $exists ) {
2167                         # Remove the create restriction for existing titles
2168                         $types = array_diff( $types, array( 'create' ) );
2169                 } else {
2170                         # Only the create and upload restrictions apply to non-existing titles
2171                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2172                 }
2173                 return $types;
2174         }
2175
2176         /**
2177          * Returns restriction types for the current Title
2178          *
2179          * @return array applicable restriction types
2180          */
2181         public function getRestrictionTypes() {
2182                 if ( $this->isSpecialPage() ) {
2183                         return array();
2184                 }
2185
2186                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2187
2188                 if ( $this->getNamespace() != NS_FILE ) {
2189                         # Remove the upload restriction for non-file titles
2190                         $types = array_diff( $types, array( 'upload' ) );
2191                 }
2192
2193                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2194
2195                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2196                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2197
2198                 return $types;
2199         }
2200
2201         /**
2202          * Is this title subject to title protection?
2203          * Title protection is the one applied against creation of such title.
2204          *
2205          * @return Mixed An associative array representing any existent title
2206          *   protection, or false if there's none.
2207          */
2208         private function getTitleProtection() {
2209                 // Can't protect pages in special namespaces
2210                 if ( $this->getNamespace() < 0 ) {
2211                         return false;
2212                 }
2213
2214                 // Can't protect pages that exist.
2215                 if ( $this->exists() ) {
2216                         return false;
2217                 }
2218
2219                 if ( !isset( $this->mTitleProtection ) ) {
2220                         $dbr = wfGetDB( DB_SLAVE );
2221                         $res = $dbr->select( 'protected_titles', '*',
2222                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2223                                 __METHOD__ );
2224
2225                         // fetchRow returns false if there are no rows.
2226                         $this->mTitleProtection = $dbr->fetchRow( $res );
2227                 }
2228                 return $this->mTitleProtection;
2229         }
2230
2231         /**
2232          * Update the title protection status
2233          *
2234          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2235          * @param $create_perm String Permission required for creation
2236          * @param $reason String Reason for protection
2237          * @param $expiry String Expiry timestamp
2238          * @return boolean true
2239          */
2240         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2241                 wfDeprecated( __METHOD__, '1.19' );
2242
2243                 global $wgUser;
2244
2245                 $limit = array( 'create' => $create_perm );
2246                 $expiry = array( 'create' => $expiry );
2247
2248                 $page = WikiPage::factory( $this );
2249                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2250
2251                 return $status->isOK();
2252         }
2253
2254         /**
2255          * Remove any title protection due to page existing
2256          */
2257         public function deleteTitleProtection() {
2258                 $dbw = wfGetDB( DB_MASTER );
2259
2260                 $dbw->delete(
2261                         'protected_titles',
2262                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2263                         __METHOD__
2264                 );
2265                 $this->mTitleProtection = false;
2266         }
2267
2268         /**
2269          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2270          *
2271          * @param $action String Action to check (default: edit)
2272          * @return Bool
2273          */
2274         public function isSemiProtected( $action = 'edit' ) {
2275                 if ( $this->exists() ) {
2276                         $restrictions = $this->getRestrictions( $action );
2277                         if ( count( $restrictions ) > 0 ) {
2278                                 foreach ( $restrictions as $restriction ) {
2279                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2280                                                 return false;
2281                                         }
2282                                 }
2283                         } else {
2284                                 # Not protected
2285                                 return false;
2286                         }
2287                         return true;
2288                 } else {
2289                         # If it doesn't exist, it can't be protected
2290                         return false;
2291                 }
2292         }
2293
2294         /**
2295          * Does the title correspond to a protected article?
2296          *
2297          * @param $action String the action the page is protected from,
2298          * by default checks all actions.
2299          * @return Bool
2300          */
2301         public function isProtected( $action = '' ) {
2302                 global $wgRestrictionLevels;
2303
2304                 $restrictionTypes = $this->getRestrictionTypes();
2305
2306                 # Special pages have inherent protection
2307                 if( $this->isSpecialPage() ) {
2308                         return true;
2309                 }
2310
2311                 # Check regular protection levels
2312                 foreach ( $restrictionTypes as $type ) {
2313                         if ( $action == $type || $action == '' ) {
2314                                 $r = $this->getRestrictions( $type );
2315                                 foreach ( $wgRestrictionLevels as $level ) {
2316                                         if ( in_array( $level, $r ) && $level != '' ) {
2317                                                 return true;
2318                                         }
2319                                 }
2320                         }
2321                 }
2322
2323                 return false;
2324         }
2325
2326         /**
2327          * Determines if $user is unable to edit this page because it has been protected
2328          * by $wgNamespaceProtection.
2329          *
2330          * @param $user User object to check permissions
2331          * @return Bool
2332          */
2333         public function isNamespaceProtected( User $user ) {
2334                 global $wgNamespaceProtection;
2335
2336                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2337                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2338                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2339                                         return true;
2340                                 }
2341                         }
2342                 }
2343                 return false;
2344         }
2345
2346         /**
2347          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2348          *
2349          * @return Bool If the page is subject to cascading restrictions.
2350          */
2351         public function isCascadeProtected() {
2352                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2353                 return ( $sources > 0 );
2354         }
2355
2356         /**
2357          * Cascading protection: Get the source of any cascading restrictions on this page.
2358          *
2359          * @param $getPages Bool Whether or not to retrieve the actual pages
2360          *        that the restrictions have come from.
2361          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2362          *     have come, false for none, or true if such restrictions exist, but $getPages
2363          *     was not set.  The restriction array is an array of each type, each of which
2364          *     contains a array of unique groups.
2365          */
2366         public function getCascadeProtectionSources( $getPages = true ) {
2367                 global $wgContLang;
2368                 $pagerestrictions = array();
2369
2370                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2371                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2372                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2373                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2374                 }
2375
2376                 wfProfileIn( __METHOD__ );
2377
2378                 $dbr = wfGetDB( DB_SLAVE );
2379
2380                 if ( $this->getNamespace() == NS_FILE ) {
2381                         $tables = array( 'imagelinks', 'page_restrictions' );
2382                         $where_clauses = array(
2383                                 'il_to' => $this->getDBkey(),
2384                                 'il_from=pr_page',
2385                                 'pr_cascade' => 1
2386                         );
2387                 } else {
2388                         $tables = array( 'templatelinks', 'page_restrictions' );
2389                         $where_clauses = array(
2390                                 'tl_namespace' => $this->getNamespace(),
2391                                 'tl_title' => $this->getDBkey(),
2392                                 'tl_from=pr_page',
2393                                 'pr_cascade' => 1
2394                         );
2395                 }
2396
2397                 if ( $getPages ) {
2398                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2399                                                    'pr_expiry', 'pr_type', 'pr_level' );
2400                         $where_clauses[] = 'page_id=pr_page';
2401                         $tables[] = 'page';
2402                 } else {
2403                         $cols = array( 'pr_expiry' );
2404                 }
2405
2406                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2407
2408                 $sources = $getPages ? array() : false;
2409                 $now = wfTimestampNow();
2410                 $purgeExpired = false;
2411
2412                 foreach ( $res as $row ) {
2413                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2414                         if ( $expiry > $now ) {
2415                                 if ( $getPages ) {
2416                                         $page_id = $row->pr_page;
2417                                         $page_ns = $row->page_namespace;
2418                                         $page_title = $row->page_title;
2419                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2420                                         # Add groups needed for each restriction type if its not already there
2421                                         # Make sure this restriction type still exists
2422
2423                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2424                                                 $pagerestrictions[$row->pr_type] = array();
2425                                         }
2426
2427                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2428                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2429                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2430                                         }
2431                                 } else {
2432                                         $sources = true;
2433                                 }
2434                         } else {
2435                                 // Trigger lazy purge of expired restrictions from the db
2436                                 $purgeExpired = true;
2437                         }
2438                 }
2439                 if ( $purgeExpired ) {
2440                         Title::purgeExpiredRestrictions();
2441                 }
2442
2443                 if ( $getPages ) {
2444                         $this->mCascadeSources = $sources;
2445                         $this->mCascadingRestrictions = $pagerestrictions;
2446                 } else {
2447                         $this->mHasCascadingRestrictions = $sources;
2448                 }
2449
2450                 wfProfileOut( __METHOD__ );
2451                 return array( $sources, $pagerestrictions );
2452         }
2453
2454         /**
2455          * Accessor/initialisation for mRestrictions
2456          *
2457          * @param $action String action that permission needs to be checked for
2458          * @return Array of Strings the array of groups allowed to edit this article
2459          */
2460         public function getRestrictions( $action ) {
2461                 if ( !$this->mRestrictionsLoaded ) {
2462                         $this->loadRestrictions();
2463                 }
2464                 return isset( $this->mRestrictions[$action] )
2465                                 ? $this->mRestrictions[$action]
2466                                 : array();
2467         }
2468
2469         /**
2470          * Get the expiry time for the restriction against a given action
2471          *
2472          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2473          *      or not protected at all, or false if the action is not recognised.
2474          */
2475         public function getRestrictionExpiry( $action ) {
2476                 if ( !$this->mRestrictionsLoaded ) {
2477                         $this->loadRestrictions();
2478                 }
2479                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2480         }
2481
2482         /**
2483          * Returns cascading restrictions for the current article
2484          *
2485          * @return Boolean
2486          */
2487         function areRestrictionsCascading() {
2488                 if ( !$this->mRestrictionsLoaded ) {
2489                         $this->loadRestrictions();
2490                 }
2491
2492                 return $this->mCascadeRestriction;
2493         }
2494
2495         /**
2496          * Loads a string into mRestrictions array
2497          *
2498          * @param $res Resource restrictions as an SQL result.
2499          * @param $oldFashionedRestrictions String comma-separated list of page
2500          *        restrictions from page table (pre 1.10)
2501          */
2502         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2503                 $rows = array();
2504
2505                 foreach ( $res as $row ) {
2506                         $rows[] = $row;
2507                 }
2508
2509                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2510         }
2511
2512         /**
2513          * Compiles list of active page restrictions from both page table (pre 1.10)
2514          * and page_restrictions table for this existing page.
2515          * Public for usage by LiquidThreads.
2516          *
2517          * @param $rows array of db result objects
2518          * @param $oldFashionedRestrictions string comma-separated list of page
2519          *        restrictions from page table (pre 1.10)
2520          */
2521         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2522                 global $wgContLang;
2523                 $dbr = wfGetDB( DB_SLAVE );
2524
2525                 $restrictionTypes = $this->getRestrictionTypes();
2526
2527                 foreach ( $restrictionTypes as $type ) {
2528                         $this->mRestrictions[$type] = array();
2529                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2530                 }
2531
2532                 $this->mCascadeRestriction = false;
2533
2534                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2535
2536                 if ( $oldFashionedRestrictions === null ) {
2537                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2538                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2539                 }
2540
2541                 if ( $oldFashionedRestrictions != '' ) {
2542
2543                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2544                                 $temp = explode( '=', trim( $restrict ) );
2545                                 if ( count( $temp ) == 1 ) {
2546                                         // old old format should be treated as edit/move restriction
2547                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2548                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2549                                 } else {
2550                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2551                                 }
2552                         }
2553
2554                         $this->mOldRestrictions = true;
2555
2556                 }
2557
2558                 if ( count( $rows ) ) {
2559                         # Current system - load second to make them override.
2560                         $now = wfTimestampNow();
2561                         $purgeExpired = false;
2562
2563                         # Cycle through all the restrictions.
2564                         foreach ( $rows as $row ) {
2565
2566                                 // Don't take care of restrictions types that aren't allowed
2567                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2568                                         continue;
2569
2570                                 // This code should be refactored, now that it's being used more generally,
2571                                 // But I don't really see any harm in leaving it in Block for now -werdna
2572                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2573
2574                                 // Only apply the restrictions if they haven't expired!
2575                                 if ( !$expiry || $expiry > $now ) {
2576                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2577                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2578
2579                                         $this->mCascadeRestriction |= $row->pr_cascade;
2580                                 } else {
2581                                         // Trigger a lazy purge of expired restrictions
2582                                         $purgeExpired = true;
2583                                 }
2584                         }
2585
2586                         if ( $purgeExpired ) {
2587                                 Title::purgeExpiredRestrictions();
2588                         }
2589                 }
2590
2591                 $this->mRestrictionsLoaded = true;
2592         }
2593
2594         /**
2595          * Load restrictions from the page_restrictions table
2596          *
2597          * @param $oldFashionedRestrictions String comma-separated list of page
2598          *        restrictions from page table (pre 1.10)
2599          */
2600         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2601                 global $wgContLang;
2602                 if ( !$this->mRestrictionsLoaded ) {
2603                         if ( $this->exists() ) {
2604                                 $dbr = wfGetDB( DB_SLAVE );
2605
2606                                 $res = $dbr->select(
2607                                         'page_restrictions',
2608                                         '*',
2609                                         array( 'pr_page' => $this->getArticleId() ),
2610                                         __METHOD__
2611                                 );
2612
2613                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2614                         } else {
2615                                 $title_protection = $this->getTitleProtection();
2616
2617                                 if ( $title_protection ) {
2618                                         $now = wfTimestampNow();
2619                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2620
2621                                         if ( !$expiry || $expiry > $now ) {
2622                                                 // Apply the restrictions
2623                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2624                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2625                                         } else { // Get rid of the old restrictions
2626                                                 Title::purgeExpiredRestrictions();
2627                                                 $this->mTitleProtection = false;
2628                                         }
2629                                 } else {
2630                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2631                                 }
2632                                 $this->mRestrictionsLoaded = true;
2633                         }
2634                 }
2635         }
2636
2637         /**
2638          * Flush the protection cache in this object and force reload from the database.
2639          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2640          */
2641         public function flushRestrictions() {
2642                 $this->mRestrictionsLoaded = false;
2643                 $this->mTitleProtection = null;
2644         }
2645
2646         /**
2647          * Purge expired restrictions from the page_restrictions table
2648          */
2649         static function purgeExpiredRestrictions() {
2650                 $dbw = wfGetDB( DB_MASTER );
2651                 $dbw->delete(
2652                         'page_restrictions',
2653                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2654                         __METHOD__
2655                 );
2656
2657                 $dbw->delete(
2658                         'protected_titles',
2659                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2660                         __METHOD__
2661                 );
2662         }
2663
2664         /**
2665          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2666          *
2667          * @return Bool
2668          */
2669         public function hasSubpages() {
2670                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2671                         # Duh
2672                         return false;
2673                 }
2674
2675                 # We dynamically add a member variable for the purpose of this method
2676                 # alone to cache the result.  There's no point in having it hanging
2677                 # around uninitialized in every Title object; therefore we only add it
2678                 # if needed and don't declare it statically.
2679                 if ( isset( $this->mHasSubpages ) ) {
2680                         return $this->mHasSubpages;
2681                 }
2682
2683                 $subpages = $this->getSubpages( 1 );
2684                 if ( $subpages instanceof TitleArray ) {
2685                         return $this->mHasSubpages = (bool)$subpages->count();
2686                 }
2687                 return $this->mHasSubpages = false;
2688         }
2689
2690         /**
2691          * Get all subpages of this page.
2692          *
2693          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2694          * @return mixed TitleArray, or empty array if this page's namespace
2695          *  doesn't allow subpages
2696          */
2697         public function getSubpages( $limit = -1 ) {
2698                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2699                         return array();
2700                 }
2701
2702                 $dbr = wfGetDB( DB_SLAVE );
2703                 $conds['page_namespace'] = $this->getNamespace();
2704                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2705                 $options = array();
2706                 if ( $limit > -1 ) {
2707                         $options['LIMIT'] = $limit;
2708                 }
2709                 return $this->mSubpages = TitleArray::newFromResult(
2710                         $dbr->select( 'page',
2711                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2712                                 $conds,
2713                                 __METHOD__,
2714                                 $options
2715                         )
2716                 );
2717         }
2718
2719         /**
2720          * Is there a version of this page in the deletion archive?
2721          *
2722          * @return Int the number of archived revisions
2723          */
2724         public function isDeleted() {
2725                 if ( $this->getNamespace() < 0 ) {
2726                         $n = 0;
2727                 } else {
2728                         $dbr = wfGetDB( DB_SLAVE );
2729
2730                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2731                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2732                                 __METHOD__
2733                         );
2734                         if ( $this->getNamespace() == NS_FILE ) {
2735                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2736                                         array( 'fa_name' => $this->getDBkey() ),
2737                                         __METHOD__
2738                                 );
2739                         }
2740                 }
2741                 return (int)$n;
2742         }
2743
2744         /**
2745          * Is there a version of this page in the deletion archive?
2746          *
2747          * @return Boolean
2748          */
2749         public function isDeletedQuick() {
2750                 if ( $this->getNamespace() < 0 ) {
2751                         return false;
2752                 }
2753                 $dbr = wfGetDB( DB_SLAVE );
2754                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2755                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2756                         __METHOD__
2757                 );
2758                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2759                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2760                                 array( 'fa_name' => $this->getDBkey() ),
2761                                 __METHOD__
2762                         );
2763                 }
2764                 return $deleted;
2765         }
2766
2767         /**
2768          * Get the number of views of this page
2769          *
2770          * @return int The view count for the page
2771          */
2772         public function getCount() {
2773                 if ( $this->mCounter == -1 ) {
2774                         if ( $this->exists() ) {
2775                                 $dbr = wfGetDB( DB_SLAVE );
2776                                 $this->mCounter = $dbr->selectField( 'page',
2777                                         'page_counter',
2778                                         array( 'page_id' => $this->getArticleID() ),
2779                                         __METHOD__
2780                                 );
2781                         } else {
2782                                 $this->mCounter = 0;
2783                         }
2784                 }
2785
2786                 return $this->mCounter;
2787         }
2788
2789         /**
2790          * Check if this is a new page (i.e. it has only one revision)
2791          *
2792          * @return bool
2793          */
2794         public function isNewPage() {
2795                 if ( $this->mIsNew === null ) {
2796                         if ( $this->exists() ) {
2797                                 $dbr = wfGetDB( DB_SLAVE );
2798                                 $this->mIsNew = (bool)$dbr->selectField( 'page',
2799                                         'page_is_new',
2800                                         array( 'page_id' => $this->getArticleID() ),
2801                                         __METHOD__
2802                                 );
2803                         } else {
2804                                 $this->mIsNew = false;
2805                         }
2806                 }
2807                 return $this->mIsNew;
2808         }
2809
2810         /**
2811          * Get the article ID for this Title from the link cache,
2812          * adding it if necessary
2813          *
2814          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2815          *  for update
2816          * @return Int the ID
2817          */
2818         public function getArticleID( $flags = 0 ) {
2819                 if ( $this->getNamespace() < 0 ) {
2820                         return $this->mArticleID = 0;
2821                 }
2822                 $linkCache = LinkCache::singleton();
2823                 if ( $flags & self::GAID_FOR_UPDATE ) {
2824                         $oldUpdate = $linkCache->forUpdate( true );
2825                         $linkCache->clearLink( $this );
2826                         $this->mArticleID = $linkCache->addLinkObj( $this );
2827                         $linkCache->forUpdate( $oldUpdate );
2828                 } else {
2829                         if ( -1 == $this->mArticleID ) {
2830                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2831                         }
2832                 }
2833                 return $this->mArticleID;
2834         }
2835
2836         /**
2837          * Is this an article that is a redirect page?
2838          * Uses link cache, adding it if necessary
2839          *
2840          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2841          * @return Bool
2842          */
2843         public function isRedirect( $flags = 0 ) {
2844                 if ( !is_null( $this->mRedirect ) ) {
2845                         return $this->mRedirect;
2846                 }
2847                 # Calling getArticleID() loads the field from cache as needed
2848                 if ( !$this->getArticleID( $flags ) ) {
2849                         return $this->mRedirect = false;
2850                 }
2851                 $linkCache = LinkCache::singleton();
2852                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2853
2854                 return $this->mRedirect;
2855         }
2856
2857         /**
2858          * What is the length of this page?
2859          * Uses link cache, adding it if necessary
2860          *
2861          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2862          * @return Int
2863          */
2864         public function getLength( $flags = 0 ) {
2865                 if ( $this->mLength != -1 ) {
2866                         return $this->mLength;
2867                 }
2868                 # Calling getArticleID() loads the field from cache as needed
2869                 if ( !$this->getArticleID( $flags ) ) {
2870                         return $this->mLength = 0;
2871                 }
2872                 $linkCache = LinkCache::singleton();
2873                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2874
2875                 return $this->mLength;
2876         }
2877
2878         /**
2879          * What is the page_latest field for this page?
2880          *
2881          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2882          * @return Int or 0 if the page doesn't exist
2883          */
2884         public function getLatestRevID( $flags = 0 ) {
2885                 if ( $this->mLatestID !== false ) {
2886                         return intval( $this->mLatestID );
2887                 }
2888                 # Calling getArticleID() loads the field from cache as needed
2889                 if ( !$this->getArticleID( $flags ) ) {
2890                         return $this->mLatestID = 0;
2891                 }
2892                 $linkCache = LinkCache::singleton();
2893                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2894
2895                 return $this->mLatestID;
2896         }
2897
2898         /**
2899          * This clears some fields in this object, and clears any associated
2900          * keys in the "bad links" section of the link cache.
2901          *
2902          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2903          * loading of the new page_id. It's also called from
2904          * WikiPage::doDeleteArticle()
2905          *
2906          * @param $newid Int the new Article ID
2907          */
2908         public function resetArticleID( $newid ) {
2909                 $linkCache = LinkCache::singleton();
2910                 $linkCache->clearLink( $this );
2911
2912                 if ( $newid === false ) {
2913                         $this->mArticleID = -1;
2914                 } else {
2915                         $this->mArticleID = intval( $newid );
2916                 }
2917                 $this->mRestrictionsLoaded = false;
2918                 $this->mRestrictions = array();
2919                 $this->mRedirect = null;
2920                 $this->mLength = -1;
2921                 $this->mLatestID = false;
2922                 $this->mCounter = -1;
2923                 $this->mEstimateRevisions = null;
2924         }
2925
2926         /**
2927          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2928          *
2929          * @param $text String containing title to capitalize
2930          * @param $ns int namespace index, defaults to NS_MAIN
2931          * @return String containing capitalized title
2932          */
2933         public static function capitalize( $text, $ns = NS_MAIN ) {
2934                 global $wgContLang;
2935
2936                 if ( MWNamespace::isCapitalized( $ns ) ) {
2937                         return $wgContLang->ucfirst( $text );
2938                 } else {
2939                         return $text;
2940                 }
2941         }
2942
2943         /**
2944          * Secure and split - main initialisation function for this object
2945          *
2946          * Assumes that mDbkeyform has been set, and is urldecoded
2947          * and uses underscores, but not otherwise munged.  This function
2948          * removes illegal characters, splits off the interwiki and
2949          * namespace prefixes, sets the other forms, and canonicalizes
2950          * everything.
2951          *
2952          * @return Bool true on success
2953          */
2954         private function secureAndSplit() {
2955                 global $wgContLang, $wgLocalInterwiki;
2956
2957                 # Initialisation
2958                 $this->mInterwiki = $this->mFragment = '';
2959                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2960
2961                 $dbkey = $this->mDbkeyform;
2962
2963                 # Strip Unicode bidi override characters.
2964                 # Sometimes they slip into cut-n-pasted page titles, where the
2965                 # override chars get included in list displays.
2966                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2967
2968                 # Clean up whitespace
2969                 # Note: use of the /u option on preg_replace here will cause
2970                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2971                 # conveniently disabling them.
2972                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2973                 $dbkey = trim( $dbkey, '_' );
2974
2975                 if ( $dbkey == '' ) {
2976                         return false;
2977                 }
2978
2979                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2980                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2981                         return false;
2982                 }
2983
2984                 $this->mDbkeyform = $dbkey;
2985
2986                 # Initial colon indicates main namespace rather than specified default
2987                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2988                 if ( ':' == $dbkey[0] ) {
2989                         $this->mNamespace = NS_MAIN;
2990                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2991                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2992                 }
2993
2994                 # Namespace or interwiki prefix
2995                 $firstPass = true;
2996                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2997                 do {
2998                         $m = array();
2999                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3000                                 $p = $m[1];
3001                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3002                                         # Ordinary namespace
3003                                         $dbkey = $m[2];
3004                                         $this->mNamespace = $ns;
3005                                         # For Talk:X pages, check if X has a "namespace" prefix
3006                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3007                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3008                                                         # Disallow Talk:File:x type titles...
3009                                                         return false;
3010                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3011                                                         # Disallow Talk:Interwiki:x type titles...
3012                                                         return false;
3013                                                 }
3014                                         }
3015                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3016                                         if ( !$firstPass ) {
3017                                                 # Can't make a local interwiki link to an interwiki link.
3018                                                 # That's just crazy!
3019                                                 return false;
3020                                         }
3021
3022                                         # Interwiki link
3023                                         $dbkey = $m[2];
3024                                         $this->mInterwiki = $wgContLang->lc( $p );
3025
3026                                         # Redundant interwiki prefix to the local wiki
3027                                         if ( $wgLocalInterwiki !== false
3028                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3029                                         {
3030                                                 if ( $dbkey == '' ) {
3031                                                         # Can't have an empty self-link
3032                                                         return false;
3033                                                 }
3034                                                 $this->mInterwiki = '';
3035                                                 $firstPass = false;
3036                                                 # Do another namespace split...
3037                                                 continue;
3038                                         }
3039
3040                                         # If there's an initial colon after the interwiki, that also
3041                                         # resets the default namespace
3042                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3043                                                 $this->mNamespace = NS_MAIN;
3044                                                 $dbkey = substr( $dbkey, 1 );
3045                                         }
3046                                 }
3047                                 # If there's no recognized interwiki or namespace,
3048                                 # then let the colon expression be part of the title.
3049                         }
3050                         break;
3051                 } while ( true );
3052
3053                 # We already know that some pages won't be in the database!
3054                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3055                         $this->mArticleID = 0;
3056                 }
3057                 $fragment = strstr( $dbkey, '#' );
3058                 if ( false !== $fragment ) {
3059                         $this->setFragment( $fragment );
3060                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3061                         # remove whitespace again: prevents "Foo_bar_#"
3062                         # becoming "Foo_bar_"
3063                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3064                 }
3065
3066                 # Reject illegal characters.
3067                 $rxTc = self::getTitleInvalidRegex();
3068                 if ( preg_match( $rxTc, $dbkey ) ) {
3069                         return false;
3070                 }
3071
3072                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3073                 # reachable due to the way web browsers deal with 'relative' URLs.
3074                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3075                 if ( strpos( $dbkey, '.' ) !== false &&
3076                          ( $dbkey === '.' || $dbkey === '..' ||
3077                            strpos( $dbkey, './' ) === 0  ||
3078                            strpos( $dbkey, '../' ) === 0 ||
3079                            strpos( $dbkey, '/./' ) !== false ||
3080                            strpos( $dbkey, '/../' ) !== false  ||
3081                            substr( $dbkey, -2 ) == '/.' ||
3082                            substr( $dbkey, -3 ) == '/..' ) )
3083                 {
3084                         return false;
3085                 }
3086
3087                 # Magic tilde sequences? Nu-uh!
3088                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3089                         return false;
3090                 }
3091
3092                 # Limit the size of titles to 255 bytes. This is typically the size of the
3093                 # underlying database field. We make an exception for special pages, which
3094                 # don't need to be stored in the database, and may edge over 255 bytes due
3095                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3096                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3097                   strlen( $dbkey ) > 512 )
3098                 {
3099                         return false;
3100                 }
3101
3102                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3103                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3104                 # other site might be case-sensitive.
3105                 $this->mUserCaseDBKey = $dbkey;
3106                 if ( $this->mInterwiki == '' ) {
3107                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3108                 }
3109
3110                 # Can't make a link to a namespace alone... "empty" local links can only be
3111                 # self-links with a fragment identifier.
3112                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3113                         return false;
3114                 }
3115
3116                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3117                 // IP names are not allowed for accounts, and can only be referring to
3118                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3119                 // there are numerous ways to present the same IP. Having sp:contribs scan
3120                 // them all is silly and having some show the edits and others not is
3121                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3122                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3123                         ? IP::sanitizeIP( $dbkey )
3124                         : $dbkey;
3125
3126                 // Any remaining initial :s are illegal.
3127                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3128                         return false;
3129                 }
3130
3131                 # Fill fields
3132                 $this->mDbkeyform = $dbkey;
3133                 $this->mUrlform = wfUrlencode( $dbkey );
3134
3135                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3136
3137                 return true;
3138         }
3139
3140         /**
3141          * Get an array of Title objects linking to this Title
3142          * Also stores the IDs in the link cache.
3143          *
3144          * WARNING: do not use this function on arbitrary user-supplied titles!
3145          * On heavily-used templates it will max out the memory.
3146          *
3147          * @param $options Array: may be FOR UPDATE
3148          * @param $table String: table name
3149          * @param $prefix String: fields prefix
3150          * @return Array of Title objects linking here
3151          */
3152         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3153                 if ( count( $options ) > 0 ) {
3154                         $db = wfGetDB( DB_MASTER );
3155                 } else {
3156                         $db = wfGetDB( DB_SLAVE );
3157                 }
3158
3159                 $res = $db->select(
3160                         array( 'page', $table ),
3161                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3162                         array(
3163                                 "{$prefix}_from=page_id",
3164                                 "{$prefix}_namespace" => $this->getNamespace(),
3165                                 "{$prefix}_title"     => $this->getDBkey() ),
3166                         __METHOD__,
3167                         $options
3168                 );
3169
3170                 $retVal = array();
3171                 if ( $res->numRows() ) {
3172                         $linkCache = LinkCache::singleton();
3173                         foreach ( $res as $row ) {
3174                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3175                                 if ( $titleObj ) {
3176                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3177                                         $retVal[] = $titleObj;
3178                                 }
3179                         }
3180                 }
3181                 return $retVal;
3182         }
3183
3184         /**
3185          * Get an array of Title objects using this Title as a template
3186          * Also stores the IDs in the link cache.
3187          *
3188          * WARNING: do not use this function on arbitrary user-supplied titles!
3189          * On heavily-used templates it will max out the memory.
3190          *
3191          * @param $options Array: may be FOR UPDATE
3192          * @return Array of Title the Title objects linking here
3193          */
3194         public function getTemplateLinksTo( $options = array() ) {
3195                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3196         }
3197
3198         /**
3199          * Get an array of Title objects linked from this Title
3200          * Also stores the IDs in the link cache.
3201          *
3202          * WARNING: do not use this function on arbitrary user-supplied titles!
3203          * On heavily-used templates it will max out the memory.
3204          *
3205          * @param $options Array: may be FOR UPDATE
3206          * @param $table String: table name
3207          * @param $prefix String: fields prefix
3208          * @return Array of Title objects linking here
3209          */
3210         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3211                 $id = $this->getArticleId();
3212
3213                 # If the page doesn't exist; there can't be any link from this page
3214                 if ( !$id ) {
3215                         return array();
3216                 }
3217
3218                 if ( count( $options ) > 0 ) {
3219                         $db = wfGetDB( DB_MASTER );
3220                 } else {
3221                         $db = wfGetDB( DB_SLAVE );
3222                 }
3223
3224                 $namespaceFiled = "{$prefix}_namespace";
3225                 $titleField = "{$prefix}_title";
3226
3227                 $res = $db->select(
3228                         array( $table, 'page' ),
3229                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3230                         array( "{$prefix}_from" => $id ),
3231                         __METHOD__,
3232                         $options,
3233                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3234                 );
3235
3236                 $retVal = array();
3237                 if ( $res->numRows() ) {
3238                         $linkCache = LinkCache::singleton();
3239                         foreach ( $res as $row ) {
3240                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3241                                 if ( $titleObj ) {
3242                                         if ( $row->page_id ) {
3243                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3244                                         } else {
3245                                                 $linkCache->addBadLinkObj( $titleObj );
3246                                         }
3247                                         $retVal[] = $titleObj;
3248                                 }
3249                         }
3250                 }
3251                 return $retVal;
3252         }
3253
3254         /**
3255          * Get an array of Title objects used on this Title as a template
3256          * Also stores the IDs in the link cache.
3257          *
3258          * WARNING: do not use this function on arbitrary user-supplied titles!
3259          * On heavily-used templates it will max out the memory.
3260          *
3261          * @param $options Array: may be FOR UPDATE
3262          * @return Array of Title the Title objects used here
3263          */
3264         public function getTemplateLinksFrom( $options = array() ) {
3265                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3266         }
3267
3268         /**
3269          * Get an array of Title objects referring to non-existent articles linked from this page
3270          *
3271          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3272          * @return Array of Title the Title objects
3273          */
3274         public function getBrokenLinksFrom() {
3275                 if ( $this->getArticleId() == 0 ) {
3276                         # All links from article ID 0 are false positives
3277                         return array();
3278                 }
3279
3280                 $dbr = wfGetDB( DB_SLAVE );
3281                 $res = $dbr->select(
3282                         array( 'page', 'pagelinks' ),
3283                         array( 'pl_namespace', 'pl_title' ),
3284                         array(
3285                                 'pl_from' => $this->getArticleId(),
3286                                 'page_namespace IS NULL'
3287                         ),
3288                         __METHOD__, array(),
3289                         array(
3290                                 'page' => array(
3291                                         'LEFT JOIN',
3292                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3293                                 )
3294                         )
3295                 );
3296
3297                 $retVal = array();
3298                 foreach ( $res as $row ) {
3299                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3300                 }
3301                 return $retVal;
3302         }
3303
3304
3305         /**
3306          * Get a list of URLs to purge from the Squid cache when this
3307          * page changes
3308          *
3309          * @return Array of String the URLs
3310          */
3311         public function getSquidURLs() {
3312                 global $wgContLang;
3313
3314                 $urls = array(
3315                         $this->getInternalURL(),
3316                         $this->getInternalURL( 'action=history' )
3317                 );
3318
3319                 // purge variant urls as well
3320                 if ( $wgContLang->hasVariants() ) {
3321                         $variants = $wgContLang->getVariants();
3322                         foreach ( $variants as $vCode ) {
3323                                 $urls[] = $this->getInternalURL( '', $vCode );
3324                         }
3325                 }
3326
3327                 return $urls;
3328         }
3329
3330         /**
3331          * Purge all applicable Squid URLs
3332          */
3333         public function purgeSquid() {
3334                 global $wgUseSquid;
3335                 if ( $wgUseSquid ) {
3336                         $urls = $this->getSquidURLs();
3337                         $u = new SquidUpdate( $urls );
3338                         $u->doUpdate();
3339                 }
3340         }
3341
3342         /**
3343          * Move this page without authentication
3344          *
3345          * @param $nt Title the new page Title
3346          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3347          */
3348         public function moveNoAuth( &$nt ) {
3349                 return $this->moveTo( $nt, false );
3350         }
3351
3352         /**
3353          * Check whether a given move operation would be valid.
3354          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3355          *
3356          * @param $nt Title the new title
3357          * @param $auth Bool indicates whether $wgUser's permissions
3358          *  should be checked
3359          * @param $reason String is the log summary of the move, used for spam checking
3360          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3361          */
3362         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3363                 global $wgUser;
3364
3365                 $errors = array();
3366                 if ( !$nt ) {
3367                         // Normally we'd add this to $errors, but we'll get
3368                         // lots of syntax errors if $nt is not an object
3369                         return array( array( 'badtitletext' ) );
3370                 }
3371                 if ( $this->equals( $nt ) ) {
3372                         $errors[] = array( 'selfmove' );
3373                 }
3374                 if ( !$this->isMovable() ) {
3375                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3376                 }
3377                 if ( $nt->getInterwiki() != '' ) {
3378                         $errors[] = array( 'immobile-target-namespace-iw' );
3379                 }
3380                 if ( !$nt->isMovable() ) {
3381                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3382                 }
3383
3384                 $oldid = $this->getArticleID();
3385                 $newid = $nt->getArticleID();
3386
3387                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3388                         $errors[] = array( 'articleexists' );
3389                 }
3390                 if ( ( $this->getDBkey() == '' ) ||
3391                          ( !$oldid ) ||
3392                          ( $nt->getDBkey() == '' ) ) {
3393                         $errors[] = array( 'badarticleerror' );
3394                 }
3395
3396                 // Image-specific checks
3397                 if ( $this->getNamespace() == NS_FILE ) {
3398                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3399                 }
3400
3401                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3402                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3403                 }
3404
3405                 if ( $auth ) {
3406                         $errors = wfMergeErrorArrays( $errors,
3407                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3408                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3409                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3410                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3411                 }
3412
3413                 $match = EditPage::matchSummarySpamRegex( $reason );
3414                 if ( $match !== false ) {
3415                         // This is kind of lame, won't display nice
3416                         $errors[] = array( 'spamprotectiontext' );
3417                 }
3418
3419                 $err = null;
3420                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3421                         $errors[] = array( 'hookaborted', $err );
3422                 }
3423
3424                 # The move is allowed only if (1) the target doesn't exist, or
3425                 # (2) the target is a redirect to the source, and has no history
3426                 # (so we can undo bad moves right after they're done).
3427
3428                 if ( 0 != $newid ) { # Target exists; check for validity
3429                         if ( !$this->isValidMoveTarget( $nt ) ) {
3430                                 $errors[] = array( 'articleexists' );
3431                         }
3432                 } else {
3433                         $tp = $nt->getTitleProtection();
3434                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3435                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3436                                 $errors[] = array( 'cantmove-titleprotected' );
3437                         }
3438                 }
3439                 if ( empty( $errors ) ) {
3440                         return true;
3441                 }
3442                 return $errors;
3443         }
3444
3445         /**
3446          * Check if the requested move target is a valid file move target
3447          * @param Title $nt Target title
3448          * @return array List of errors
3449          */
3450         protected function validateFileMoveOperation( $nt ) {
3451                 global $wgUser;
3452
3453                 $errors = array();
3454
3455                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3456
3457                 $file = wfLocalFile( $this );
3458                 if ( $file->exists() ) {
3459                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3460                                 $errors[] = array( 'imageinvalidfilename' );
3461                         }
3462                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3463                                 $errors[] = array( 'imagetypemismatch' );
3464                         }
3465                 }
3466
3467                 if ( $nt->getNamespace() != NS_FILE ) {
3468                         $errors[] = array( 'imagenocrossnamespace' );
3469                         // From here we want to do checks on a file object, so if we can't
3470                         // create one, we must return.
3471                         return $errors;
3472                 }
3473
3474                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3475
3476                 $destFile = wfLocalFile( $nt );
3477                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3478                         $errors[] = array( 'file-exists-sharedrepo' );
3479                 }
3480
3481                 return $errors;
3482         }
3483
3484         /**
3485          * Move a title to a new location
3486          *
3487          * @param $nt Title the new title
3488          * @param $auth Bool indicates whether $wgUser's permissions
3489          *  should be checked
3490          * @param $reason String the reason for the move
3491          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3492          *  Ignored if the user doesn't have the suppressredirect right.
3493          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3494          */
3495         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3496                 global $wgUser;
3497                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3498                 if ( is_array( $err ) ) {
3499                         // Auto-block user's IP if the account was "hard" blocked
3500                         $wgUser->spreadAnyEditBlock();
3501                         return $err;
3502                 }
3503
3504                 // If it is a file, move it first.
3505                 // It is done before all other moving stuff is done because it's hard to revert.
3506                 $dbw = wfGetDB( DB_MASTER );
3507                 if ( $this->getNamespace() == NS_FILE ) {
3508                         $file = wfLocalFile( $this );
3509                         if ( $file->exists() ) {
3510                                 $status = $file->move( $nt );
3511                                 if ( !$status->isOk() ) {
3512                                         return $status->getErrorsArray();
3513                                 }
3514                         }
3515                         // Clear RepoGroup process cache
3516                         RepoGroup::singleton()->clearCache( $this );
3517                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3518                 }
3519
3520                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3521                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3522                 $protected = $this->isProtected();
3523
3524                 // Do the actual move
3525                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3526                 if ( is_array( $err ) ) {
3527                         # @todo FIXME: What about the File we have already moved?
3528                         $dbw->rollback();
3529                         return $err;
3530                 }
3531
3532                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3533                 // cl_timestamp, which may disturb time-based lists on some sites.
3534                 $prefixes = $dbw->select(
3535                         'categorylinks',
3536                         array( 'cl_sortkey_prefix', 'cl_to' ),
3537                         array( 'cl_from' => $pageid ),
3538                         __METHOD__
3539                 );
3540                 foreach ( $prefixes as $prefixRow ) {
3541                         $prefix = $prefixRow->cl_sortkey_prefix;
3542                         $catTo = $prefixRow->cl_to;
3543                         $dbw->update( 'categorylinks',
3544                                 array(
3545                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3546                                                 $nt->getCategorySortkey( $prefix ) ),
3547                                         'cl_timestamp=cl_timestamp' ),
3548                                 array(
3549                                         'cl_from' => $pageid,
3550                                         'cl_to' => $catTo ),
3551                                 __METHOD__
3552                         );
3553                 }
3554
3555                 $redirid = $this->getArticleID();
3556
3557                 if ( $protected ) {
3558                         # Protect the redirect title as the title used to be...
3559                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3560                                 array(
3561                                         'pr_page'    => $redirid,
3562                                         'pr_type'    => 'pr_type',
3563                                         'pr_level'   => 'pr_level',
3564                                         'pr_cascade' => 'pr_cascade',
3565                                         'pr_user'    => 'pr_user',
3566                                         'pr_expiry'  => 'pr_expiry'
3567                                 ),
3568                                 array( 'pr_page' => $pageid ),
3569                                 __METHOD__,
3570                                 array( 'IGNORE' )
3571                         );
3572                         # Update the protection log
3573                         $log = new LogPage( 'protect' );
3574                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3575                         if ( $reason ) {
3576                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3577                         }
3578                         // @todo FIXME: $params?
3579                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3580                 }
3581
3582                 # Update watchlists
3583                 $oldnamespace = $this->getNamespace() & ~1;
3584                 $newnamespace = $nt->getNamespace() & ~1;
3585                 $oldtitle = $this->getDBkey();
3586                 $newtitle = $nt->getDBkey();
3587
3588                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3589                         WatchedItem::duplicateEntries( $this, $nt );
3590                 }
3591
3592                 $dbw->commit();
3593
3594                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3595                 return true;
3596         }
3597
3598         /**
3599          * Move page to a title which is either a redirect to the
3600          * source page or nonexistent
3601          *
3602          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3603          * @param $reason String The reason for the move
3604          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3605          *   if the user doesn't have the suppressredirect right
3606          */
3607         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3608                 global $wgUser, $wgContLang;
3609
3610                 if ( $nt->exists() ) {
3611                         $moveOverRedirect = true;
3612                         $logType = 'move_redir';
3613                 } else {
3614                         $moveOverRedirect = false;
3615                         $logType = 'move';
3616                 }
3617
3618                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3619
3620                 $logEntry = new ManualLogEntry( 'move', $logType );
3621                 $logEntry->setPerformer( $wgUser );
3622                 $logEntry->setTarget( $this );
3623                 $logEntry->setComment( $reason );
3624                 $logEntry->setParameters( array(
3625                         '4::target' => $nt->getPrefixedText(),
3626                         '5::noredir' => $redirectSuppressed ? '1': '0',
3627                 ) );
3628
3629                 $formatter = LogFormatter::newFromEntry( $logEntry );
3630                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3631                 $comment = $formatter->getPlainActionText();
3632                 if ( $reason ) {
3633                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3634                 }
3635                 # Truncate for whole multibyte characters.
3636                 $comment = $wgContLang->truncate( $comment, 255 );
3637
3638                 $oldid = $this->getArticleID();
3639                 $latest = $this->getLatestRevID();
3640
3641                 $dbw = wfGetDB( DB_MASTER );
3642
3643                 $newpage = WikiPage::factory( $nt );
3644
3645                 if ( $moveOverRedirect ) {
3646                         $newid = $nt->getArticleID();
3647
3648                         # Delete the old redirect. We don't save it to history since
3649                         # by definition if we've got here it's rather uninteresting.
3650                         # We have to remove it so that the next step doesn't trigger
3651                         # a conflict on the unique namespace+title index...
3652                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3653
3654                         $newpage->doDeleteUpdates( $newid );
3655                 }
3656
3657                 # Save a null revision in the page's history notifying of the move
3658                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3659                 if ( !is_object( $nullRevision ) ) {
3660                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3661                 }
3662                 $nullRevId = $nullRevision->insertOn( $dbw );
3663
3664                 # Change the name of the target page:
3665                 $dbw->update( 'page',
3666                         /* SET */ array(
3667                                 'page_namespace' => $nt->getNamespace(),
3668                                 'page_title'     => $nt->getDBkey(),
3669                         ),
3670                         /* WHERE */ array( 'page_id' => $oldid ),
3671                         __METHOD__
3672                 );
3673
3674                 $this->resetArticleID( 0 );
3675                 $nt->resetArticleID( $oldid );
3676
3677                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3678
3679                 wfRunHooks( 'NewRevisionFromEditComplete',
3680                         array( $newpage, $nullRevision, $latest, $wgUser ) );
3681
3682                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3683
3684                 # Recreate the redirect, this time in the other direction.
3685                 if ( $redirectSuppressed ) {
3686                         WikiPage::onArticleDelete( $this );
3687                 } else {
3688                         $mwRedir = MagicWord::get( 'redirect' );
3689                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3690                         $redirectArticle = WikiPage::factory( $this );
3691                         $newid = $redirectArticle->insertOn( $dbw );
3692                         if ( $newid ) { // sanity
3693                                 $redirectRevision = new Revision( array(
3694                                         'page'    => $newid,
3695                                         'comment' => $comment,
3696                                         'text'    => $redirectText ) );
3697                                 $redirectRevision->insertOn( $dbw );
3698                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3699
3700                                 wfRunHooks( 'NewRevisionFromEditComplete',
3701                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3702
3703                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3704                         }
3705                 }
3706
3707                 # Log the move
3708                 $logid = $logEntry->insert();
3709                 $logEntry->publish( $logid );
3710         }
3711
3712         /**
3713          * Move this page's subpages to be subpages of $nt
3714          *
3715          * @param $nt Title Move target
3716          * @param $auth bool Whether $wgUser's permissions should be checked
3717          * @param $reason string The reason for the move
3718          * @param $createRedirect bool Whether to create redirects from the old subpages to
3719          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3720          * @return mixed array with old page titles as keys, and strings (new page titles) or
3721          *     arrays (errors) as values, or an error array with numeric indices if no pages
3722          *     were moved
3723          */
3724         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3725                 global $wgMaximumMovedPages;
3726                 // Check permissions
3727                 if ( !$this->userCan( 'move-subpages' ) ) {
3728                         return array( 'cant-move-subpages' );
3729                 }
3730                 // Do the source and target namespaces support subpages?
3731                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3732                         return array( 'namespace-nosubpages',
3733                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3734                 }
3735                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3736                         return array( 'namespace-nosubpages',
3737                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3738                 }
3739
3740                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3741                 $retval = array();
3742                 $count = 0;
3743                 foreach ( $subpages as $oldSubpage ) {
3744                         $count++;
3745                         if ( $count > $wgMaximumMovedPages ) {
3746                                 $retval[$oldSubpage->getPrefixedTitle()] =
3747                                                 array( 'movepage-max-pages',
3748                                                         $wgMaximumMovedPages );
3749                                 break;
3750                         }
3751
3752                         // We don't know whether this function was called before
3753                         // or after moving the root page, so check both
3754                         // $this and $nt
3755                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3756                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3757                         {
3758                                 // When moving a page to a subpage of itself,
3759                                 // don't move it twice
3760                                 continue;
3761                         }
3762                         $newPageName = preg_replace(
3763                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3764                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3765                                         $oldSubpage->getDBkey() );
3766                         if ( $oldSubpage->isTalkPage() ) {
3767                                 $newNs = $nt->getTalkPage()->getNamespace();
3768                         } else {
3769                                 $newNs = $nt->getSubjectPage()->getNamespace();
3770                         }
3771                         # Bug 14385: we need makeTitleSafe because the new page names may
3772                         # be longer than 255 characters.
3773                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3774
3775                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3776                         if ( $success === true ) {
3777                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3778                         } else {
3779                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3780                         }
3781                 }
3782                 return $retval;
3783         }
3784
3785         /**
3786          * Checks if this page is just a one-rev redirect.
3787          * Adds lock, so don't use just for light purposes.
3788          *
3789          * @return Bool
3790          */
3791         public function isSingleRevRedirect() {
3792                 $dbw = wfGetDB( DB_MASTER );
3793                 # Is it a redirect?
3794                 $row = $dbw->selectRow( 'page',
3795                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3796                         $this->pageCond(),
3797                         __METHOD__,
3798                         array( 'FOR UPDATE' )
3799                 );
3800                 # Cache some fields we may want
3801                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3802                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3803                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3804                 if ( !$this->mRedirect ) {
3805                         return false;
3806                 }
3807                 # Does the article have a history?
3808                 $row = $dbw->selectField( array( 'page', 'revision' ),
3809                         'rev_id',
3810                         array( 'page_namespace' => $this->getNamespace(),
3811                                 'page_title' => $this->getDBkey(),
3812                                 'page_id=rev_page',
3813                                 'page_latest != rev_id'
3814                         ),
3815                         __METHOD__,
3816                         array( 'FOR UPDATE' )
3817                 );
3818                 # Return true if there was no history
3819                 return ( $row === false );
3820         }
3821
3822         /**
3823          * Checks if $this can be moved to a given Title
3824          * - Selects for update, so don't call it unless you mean business
3825          *
3826          * @param $nt Title the new title to check
3827          * @return Bool
3828          */
3829         public function isValidMoveTarget( $nt ) {
3830                 # Is it an existing file?
3831                 if ( $nt->getNamespace() == NS_FILE ) {
3832                         $file = wfLocalFile( $nt );
3833                         if ( $file->exists() ) {
3834                                 wfDebug( __METHOD__ . ": file exists\n" );
3835                                 return false;
3836                         }
3837                 }
3838                 # Is it a redirect with no history?
3839                 if ( !$nt->isSingleRevRedirect() ) {
3840                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3841                         return false;
3842                 }
3843                 # Get the article text
3844                 $rev = Revision::newFromTitle( $nt );
3845                 if( !is_object( $rev ) ){
3846                         return false;
3847                 }
3848                 $text = $rev->getText();
3849                 # Does the redirect point to the source?
3850                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3851                 $m = array();
3852                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3853                         $redirTitle = Title::newFromText( $m[1] );
3854                         if ( !is_object( $redirTitle ) ||
3855                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3856                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3857                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3858                                 return false;
3859                         }
3860                 } else {
3861                         # Fail safe
3862                         wfDebug( __METHOD__ . ": failsafe\n" );
3863                         return false;
3864                 }
3865                 return true;
3866         }
3867
3868         /**
3869          * Get categories to which this Title belongs and return an array of
3870          * categories' names.
3871          *
3872          * @return Array of parents in the form:
3873          *        $parent => $currentarticle
3874          */
3875         public function getParentCategories() {
3876                 global $wgContLang;
3877
3878                 $data = array();
3879
3880                 $titleKey = $this->getArticleId();
3881
3882                 if ( $titleKey === 0 ) {
3883                         return $data;
3884                 }
3885
3886                 $dbr = wfGetDB( DB_SLAVE );
3887
3888                 $res = $dbr->select( 'categorylinks', '*',
3889                         array(
3890                                 'cl_from' => $titleKey,
3891                         ),
3892                         __METHOD__,
3893                         array()
3894                 );
3895
3896                 if ( $dbr->numRows( $res ) > 0 ) {
3897                         foreach ( $res as $row ) {
3898                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3899                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3900                         }
3901                 }
3902                 return $data;
3903         }
3904
3905         /**
3906          * Get a tree of parent categories
3907          *
3908          * @param $children Array with the children in the keys, to check for circular refs
3909          * @return Array Tree of parent categories
3910          */
3911         public function getParentCategoryTree( $children = array() ) {
3912                 $stack = array();
3913                 $parents = $this->getParentCategories();
3914
3915                 if ( $parents ) {
3916                         foreach ( $parents as $parent => $current ) {
3917                                 if ( array_key_exists( $parent, $children ) ) {
3918                                         # Circular reference
3919                                         $stack[$parent] = array();
3920                                 } else {
3921                                         $nt = Title::newFromText( $parent );
3922                                         if ( $nt ) {
3923                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3924                                         }
3925                                 }
3926                         }
3927                 }
3928
3929                 return $stack;
3930         }
3931
3932         /**
3933          * Get an associative array for selecting this title from
3934          * the "page" table
3935          *
3936          * @return Array suitable for the $where parameter of DB::select()
3937          */
3938         public function pageCond() {
3939                 if ( $this->mArticleID > 0 ) {
3940                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3941                         return array( 'page_id' => $this->mArticleID );
3942                 } else {
3943                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3944                 }
3945         }
3946
3947         /**
3948          * Get the revision ID of the previous revision
3949          *
3950          * @param $revId Int Revision ID. Get the revision that was before this one.
3951          * @param $flags Int Title::GAID_FOR_UPDATE
3952          * @return Int|Bool Old revision ID, or FALSE if none exists
3953          */
3954         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3955                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3956                 return $db->selectField( 'revision', 'rev_id',
3957                         array(
3958                                 'rev_page' => $this->getArticleId( $flags ),
3959                                 'rev_id < ' . intval( $revId )
3960                         ),
3961                         __METHOD__,
3962                         array( 'ORDER BY' => 'rev_id DESC' )
3963                 );
3964         }
3965
3966         /**
3967          * Get the revision ID of the next revision
3968          *
3969          * @param $revId Int Revision ID. Get the revision that was after this one.
3970          * @param $flags Int Title::GAID_FOR_UPDATE
3971          * @return Int|Bool Next revision ID, or FALSE if none exists
3972          */
3973         public function getNextRevisionID( $revId, $flags = 0 ) {
3974                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3975                 return $db->selectField( 'revision', 'rev_id',
3976                         array(
3977                                 'rev_page' => $this->getArticleId( $flags ),
3978                                 'rev_id > ' . intval( $revId )
3979                         ),
3980                         __METHOD__,
3981                         array( 'ORDER BY' => 'rev_id' )
3982                 );
3983         }
3984
3985         /**
3986          * Get the first revision of the page
3987          *
3988          * @param $flags Int Title::GAID_FOR_UPDATE
3989          * @return Revision|Null if page doesn't exist
3990          */
3991         public function getFirstRevision( $flags = 0 ) {
3992                 $pageId = $this->getArticleId( $flags );
3993                 if ( $pageId ) {
3994                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3995                         $row = $db->selectRow( 'revision', '*',
3996                                 array( 'rev_page' => $pageId ),
3997                                 __METHOD__,
3998                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3999                         );
4000                         if ( $row ) {
4001                                 return new Revision( $row );
4002                         }
4003                 }
4004                 return null;
4005         }
4006
4007         /**
4008          * Get the oldest revision timestamp of this page
4009          *
4010          * @param $flags Int Title::GAID_FOR_UPDATE
4011          * @return String: MW timestamp
4012          */
4013         public function getEarliestRevTime( $flags = 0 ) {
4014                 $rev = $this->getFirstRevision( $flags );
4015                 return $rev ? $rev->getTimestamp() : null;
4016         }
4017
4018         /**
4019          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4020          *
4021          * @return bool
4022          */
4023         public function isBigDeletion() {
4024                 global $wgDeleteRevisionsLimit;
4025
4026                 if ( !$wgDeleteRevisionsLimit ) {
4027                         return false;
4028                 }
4029
4030                 $revCount = $this->estimateRevisionCount();
4031                 return $revCount > $wgDeleteRevisionsLimit;
4032         }
4033
4034         /**
4035          * Get the  approximate revision count of this page.
4036          *
4037          * @return int
4038          */
4039         public function estimateRevisionCount() {
4040                 if ( !$this->exists() ) {
4041                         return 0;
4042                 }
4043
4044                 if ( $this->mEstimateRevisions === null ) {
4045                         $dbr = wfGetDB( DB_SLAVE );
4046                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4047                                 array( 'rev_page' => $this->getArticleId() ), __METHOD__ );
4048                 }
4049
4050                 return $this->mEstimateRevisions;
4051         }
4052
4053         /**
4054          * Get the number of revisions between the given revision.
4055          * Used for diffs and other things that really need it.
4056          *
4057          * @param $old int|Revision Old revision or rev ID (first before range)
4058          * @param $new int|Revision New revision or rev ID (first after range)
4059          * @return Int Number of revisions between these revisions.
4060          */
4061         public function countRevisionsBetween( $old, $new ) {
4062                 if ( !( $old instanceof Revision ) ) {
4063                         $old = Revision::newFromTitle( $this, (int)$old );
4064                 }
4065                 if ( !( $new instanceof Revision ) ) {
4066                         $new = Revision::newFromTitle( $this, (int)$new );
4067                 }
4068                 if ( !$old || !$new ) {
4069                         return 0; // nothing to compare
4070                 }
4071                 $dbr = wfGetDB( DB_SLAVE );
4072                 return (int)$dbr->selectField( 'revision', 'count(*)',
4073                         array(
4074                                 'rev_page' => $this->getArticleId(),
4075                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4076                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4077                         ),
4078                         __METHOD__
4079                 );
4080         }
4081
4082         /**
4083          * Get the number of authors between the given revision IDs.
4084          * Used for diffs and other things that really need it.
4085          *
4086          * @param $old int|Revision Old revision or rev ID (first before range)
4087          * @param $new int|Revision New revision or rev ID (first after range)
4088          * @param $limit Int Maximum number of authors
4089          * @return Int Number of revision authors between these revisions.
4090          */
4091         public function countAuthorsBetween( $old, $new, $limit ) {
4092                 if ( !( $old instanceof Revision ) ) {
4093                         $old = Revision::newFromTitle( $this, (int)$old );
4094                 }
4095                 if ( !( $new instanceof Revision ) ) {
4096                         $new = Revision::newFromTitle( $this, (int)$new );
4097                 }
4098                 if ( !$old || !$new ) {
4099                         return 0; // nothing to compare
4100                 }
4101                 $dbr = wfGetDB( DB_SLAVE );
4102                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4103                         array(
4104                                 'rev_page' => $this->getArticleID(),
4105                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4106                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4107                         ), __METHOD__,
4108                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4109                 );
4110                 return (int)$dbr->numRows( $res );
4111         }
4112
4113         /**
4114          * Compare with another title.
4115          *
4116          * @param $title Title
4117          * @return Bool
4118          */
4119         public function equals( Title $title ) {
4120                 // Note: === is necessary for proper matching of number-like titles.
4121                 return $this->getInterwiki() === $title->getInterwiki()
4122                         && $this->getNamespace() == $title->getNamespace()
4123                         && $this->getDBkey() === $title->getDBkey();
4124         }
4125
4126         /**
4127          * Check if this title is a subpage of another title
4128          *
4129          * @param $title Title
4130          * @return Bool
4131          */
4132         public function isSubpageOf( Title $title ) {
4133                 return $this->getInterwiki() === $title->getInterwiki()
4134                         && $this->getNamespace() == $title->getNamespace()
4135                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4136         }
4137
4138         /**
4139          * Check if page exists.  For historical reasons, this function simply
4140          * checks for the existence of the title in the page table, and will
4141          * thus return false for interwiki links, special pages and the like.
4142          * If you want to know if a title can be meaningfully viewed, you should
4143          * probably call the isKnown() method instead.
4144          *
4145          * @return Bool
4146          */
4147         public function exists() {
4148                 return $this->getArticleId() != 0;
4149         }
4150
4151         /**
4152          * Should links to this title be shown as potentially viewable (i.e. as
4153          * "bluelinks"), even if there's no record by this title in the page
4154          * table?
4155          *
4156          * This function is semi-deprecated for public use, as well as somewhat
4157          * misleadingly named.  You probably just want to call isKnown(), which
4158          * calls this function internally.
4159          *
4160          * (ISSUE: Most of these checks are cheap, but the file existence check
4161          * can potentially be quite expensive.  Including it here fixes a lot of
4162          * existing code, but we might want to add an optional parameter to skip
4163          * it and any other expensive checks.)
4164          *
4165          * @return Bool
4166          */
4167         public function isAlwaysKnown() {
4168                 if ( $this->mInterwiki != '' ) {
4169                         return true;  // any interwiki link might be viewable, for all we know
4170                 }
4171                 switch( $this->mNamespace ) {
4172                         case NS_MEDIA:
4173                         case NS_FILE:
4174                                 // file exists, possibly in a foreign repo
4175                                 return (bool)wfFindFile( $this );
4176                         case NS_SPECIAL:
4177                                 // valid special page
4178                                 return SpecialPageFactory::exists( $this->getDBkey() );
4179                         case NS_MAIN:
4180                                 // selflink, possibly with fragment
4181                                 return $this->mDbkeyform == '';
4182                         case NS_MEDIAWIKI:
4183                                 // known system message
4184                                 return $this->hasSourceText() !== false;
4185                         default:
4186                                 return false;
4187                 }
4188         }
4189
4190         /**
4191          * Does this title refer to a page that can (or might) be meaningfully
4192          * viewed?  In particular, this function may be used to determine if
4193          * links to the title should be rendered as "bluelinks" (as opposed to
4194          * "redlinks" to non-existent pages).
4195          *
4196          * @return Bool
4197          */
4198         public function isKnown() {
4199                 return $this->isAlwaysKnown() || $this->exists();
4200         }
4201
4202         /**
4203          * Does this page have source text?
4204          *
4205          * @return Boolean
4206          */
4207         public function hasSourceText() {
4208                 if ( $this->exists() ) {
4209                         return true;
4210                 }
4211
4212                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4213                         // If the page doesn't exist but is a known system message, default
4214                         // message content will be displayed, same for language subpages-
4215                         // Use always content language to avoid loading hundreds of languages
4216                         // to get the link color.
4217                         global $wgContLang;
4218                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4219                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4220                         return $message->exists();
4221                 }
4222
4223                 return false;
4224         }
4225
4226         /**
4227          * Get the default message text or false if the message doesn't exist
4228          *
4229          * @return String or false
4230          */
4231         public function getDefaultMessageText() {
4232                 global $wgContLang;
4233
4234                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4235                         return false;
4236                 }
4237
4238                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4239                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4240
4241                 if ( $message->exists() ) {
4242                         return $message->plain();
4243                 } else {
4244                         return false;
4245                 }
4246         }
4247
4248         /**
4249          * Updates page_touched for this page; called from LinksUpdate.php
4250          *
4251          * @return Bool true if the update succeded
4252          */
4253         public function invalidateCache() {
4254                 if ( wfReadOnly() ) {
4255                         return false;
4256                 }
4257                 $dbw = wfGetDB( DB_MASTER );
4258                 $success = $dbw->update(
4259                         'page',
4260                         array( 'page_touched' => $dbw->timestamp() ),
4261                         $this->pageCond(),
4262                         __METHOD__
4263                 );
4264                 HTMLFileCache::clearFileCache( $this );
4265                 return $success;
4266         }
4267
4268         /**
4269          * Update page_touched timestamps and send squid purge messages for
4270          * pages linking to this title. May be sent to the job queue depending
4271          * on the number of links. Typically called on create and delete.
4272          */
4273         public function touchLinks() {
4274                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4275                 $u->doUpdate();
4276
4277                 if ( $this->getNamespace() == NS_CATEGORY ) {
4278                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4279                         $u->doUpdate();
4280                 }
4281         }
4282
4283         /**
4284          * Get the last touched timestamp
4285          *
4286          * @param $db DatabaseBase: optional db
4287          * @return String last-touched timestamp
4288          */
4289         public function getTouched( $db = null ) {
4290                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4291                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4292                 return $touched;
4293         }
4294
4295         /**
4296          * Get the timestamp when this page was updated since the user last saw it.
4297          *
4298          * @param $user User
4299          * @return String|Null
4300          */
4301         public function getNotificationTimestamp( $user = null ) {
4302                 global $wgUser, $wgShowUpdatedMarker;
4303                 // Assume current user if none given
4304                 if ( !$user ) {
4305                         $user = $wgUser;
4306                 }
4307                 // Check cache first
4308                 $uid = $user->getId();
4309                 // avoid isset here, as it'll return false for null entries
4310                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4311                         return $this->mNotificationTimestamp[$uid];
4312                 }
4313                 if ( !$uid || !$wgShowUpdatedMarker ) {
4314                         return $this->mNotificationTimestamp[$uid] = false;
4315                 }
4316                 // Don't cache too much!
4317                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4318                         $this->mNotificationTimestamp = array();
4319                 }
4320                 $dbr = wfGetDB( DB_SLAVE );
4321                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4322                         'wl_notificationtimestamp',
4323                         array( 'wl_namespace' => $this->getNamespace(),
4324                                 'wl_title' => $this->getDBkey(),
4325                                 'wl_user' => $user->getId()
4326                         ),
4327                         __METHOD__
4328                 );
4329                 return $this->mNotificationTimestamp[$uid];
4330         }
4331
4332         /**
4333          * Generate strings used for xml 'id' names in monobook tabs
4334          *
4335          * @param $prepend string defaults to 'nstab-'
4336          * @return String XML 'id' name
4337          */
4338         public function getNamespaceKey( $prepend = 'nstab-' ) {
4339                 global $wgContLang;
4340                 // Gets the subject namespace if this title
4341                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4342                 // Checks if cononical namespace name exists for namespace
4343                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4344                         // Uses canonical namespace name
4345                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4346                 } else {
4347                         // Uses text of namespace
4348                         $namespaceKey = $this->getSubjectNsText();
4349                 }
4350                 // Makes namespace key lowercase
4351                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4352                 // Uses main
4353                 if ( $namespaceKey == '' ) {
4354                         $namespaceKey = 'main';
4355                 }
4356                 // Changes file to image for backwards compatibility
4357                 if ( $namespaceKey == 'file' ) {
4358                         $namespaceKey = 'image';
4359                 }
4360                 return $prepend . $namespaceKey;
4361         }
4362
4363         /**
4364          * Get all extant redirects to this Title
4365          *
4366          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4367          * @return Array of Title redirects to this title
4368          */
4369         public function getRedirectsHere( $ns = null ) {
4370                 $redirs = array();
4371
4372                 $dbr = wfGetDB( DB_SLAVE );
4373                 $where = array(
4374                         'rd_namespace' => $this->getNamespace(),
4375                         'rd_title' => $this->getDBkey(),
4376                         'rd_from = page_id'
4377                 );
4378                 if ( !is_null( $ns ) ) {
4379                         $where['page_namespace'] = $ns;
4380                 }
4381
4382                 $res = $dbr->select(
4383                         array( 'redirect', 'page' ),
4384                         array( 'page_namespace', 'page_title' ),
4385                         $where,
4386                         __METHOD__
4387                 );
4388
4389                 foreach ( $res as $row ) {
4390                         $redirs[] = self::newFromRow( $row );
4391                 }
4392                 return $redirs;
4393         }
4394
4395         /**
4396          * Check if this Title is a valid redirect target
4397          *
4398          * @return Bool
4399          */
4400         public function isValidRedirectTarget() {
4401                 global $wgInvalidRedirectTargets;
4402
4403                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4404                 if ( $this->isSpecial( 'Userlogout' ) ) {
4405                         return false;
4406                 }
4407
4408                 foreach ( $wgInvalidRedirectTargets as $target ) {
4409                         if ( $this->isSpecial( $target ) ) {
4410                                 return false;
4411                         }
4412                 }
4413
4414                 return true;
4415         }
4416
4417         /**
4418          * Get a backlink cache object
4419          *
4420          * @return BacklinkCache
4421          */
4422         function getBacklinkCache() {
4423                 if ( is_null( $this->mBacklinkCache ) ) {
4424                         $this->mBacklinkCache = new BacklinkCache( $this );
4425                 }
4426                 return $this->mBacklinkCache;
4427         }
4428
4429         /**
4430          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4431          *
4432          * @return Boolean
4433          */
4434         public function canUseNoindex() {
4435                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4436
4437                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4438                         ? $wgContentNamespaces
4439                         : $wgExemptFromUserRobotsControl;
4440
4441                 return !in_array( $this->mNamespace, $bannedNamespaces );
4442
4443         }
4444
4445         /**
4446          * Returns the raw sort key to be used for categories, with the specified
4447          * prefix.  This will be fed to Collation::getSortKey() to get a
4448          * binary sortkey that can be used for actual sorting.
4449          *
4450          * @param $prefix string The prefix to be used, specified using
4451          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4452          *   prefix.
4453          * @return string
4454          */
4455         public function getCategorySortkey( $prefix = '' ) {
4456                 $unprefixed = $this->getText();
4457
4458                 // Anything that uses this hook should only depend
4459                 // on the Title object passed in, and should probably
4460                 // tell the users to run updateCollations.php --force
4461                 // in order to re-sort existing category relations.
4462                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4463                 if ( $prefix !== '' ) {
4464                         # Separate with a line feed, so the unprefixed part is only used as
4465                         # a tiebreaker when two pages have the exact same prefix.
4466                         # In UCA, tab is the only character that can sort above LF
4467                         # so we strip both of them from the original prefix.
4468                         $prefix = strtr( $prefix, "\n\t", '  ' );
4469                         return "$prefix\n$unprefixed";
4470                 }
4471                 return $unprefixed;
4472         }
4473
4474         /**
4475          * Get the language in which the content of this page is written.
4476          * Defaults to $wgContLang, but in certain cases it can be e.g.
4477          * $wgLang (such as special pages, which are in the user language).
4478          *
4479          * @since 1.18
4480          * @return object Language
4481          */
4482         public function getPageLanguage() {
4483                 global $wgLang;
4484                 if ( $this->isSpecialPage() ) {
4485                         // special pages are in the user language
4486                         return $wgLang;
4487                 } elseif ( $this->isCssOrJsPage() ) {
4488                         // css/js should always be LTR and is, in fact, English
4489                         return wfGetLangObj( 'en' );
4490                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4491                         // Parse mediawiki messages with correct target language
4492                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4493                         return wfGetLangObj( $lang );
4494                 }
4495                 global $wgContLang;
4496                 // If nothing special, it should be in the wiki content language
4497                 $pageLang = $wgContLang;
4498                 // Hook at the end because we don't want to override the above stuff
4499                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4500                 return wfGetLangObj( $pageLang );
4501         }
4502 }