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