includes/Title.php

   1 <?php
   2 /**
   3  * Representation a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @name Static cache variables */
  35         // @{
  36         static private $titleCache = array();
  37         // @}
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  65         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  69         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  70         var $mOldRestrictions = false;
  71         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  72         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  73         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  74         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  75         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  76         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  77         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  78         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  79         # Don't change the following default, NS_MAIN is hardcoded in several
  80         # places.  See bug 696.
  81         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  82                                                                           # Zero except in {{transclusion}} tags
  83         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  84         var $mLength = -1;                // /< The page length, 0 for special pages
  85         var $mRedirect = null;            // /< Is the article at this title a redirect?
  86         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  87         var $mHasSubpage;                 // /< Whether a page has any subpages
  88         // @}
  89
  90
  91         /**
  92          * Constructor
  93          */
  94         /*protected*/ function __construct() { }
  95
  96         /**
  97          * Create a new Title from a prefixed DB key
  98          *
  99          * @param $key String the database key, which has underscores
 100          *      instead of spaces, possibly including namespace and
 101          *      interwiki prefixes
 102          * @return Title, or NULL on an error
 103          */
 104         public static function newFromDBkey( $key ) {
 105                 $t = new Title();
 106                 $t->mDbkeyform = $key;
 107                 if ( $t->secureAndSplit() ) {
 108                         return $t;
 109                 } else {
 110                         return null;
 111                 }
 112         }
 113
 114         /**
 115          * Create a new Title from text, such as what one would find in a link. De-
 116          * codes any HTML entities in the text.
 117          *
 118          * @param $text String the link text; spaces, prefixes, and an
 119          *   initial ':' indicating the main namespace are accepted.
 120          * @param $defaultNamespace Int the namespace to use if none is speci-
 121          *   fied by a prefix.  If you want to force a specific namespace even if
 122          *   $text might begin with a namespace prefix, use makeTitle() or
 123          *   makeTitleSafe().
 124          * @throws MWException
 125          * @return Title|null - Title or null on an error.
 126          */
 127         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 128                 if ( is_object( $text ) ) {
 129                         throw new MWException( 'Title::newFromText given an object' );
 130                 }
 131
 132                 /**
 133                  * Wiki pages often contain multiple links to the same page.
 134                  * Title normalization and parsing can become expensive on
 135                  * pages with many links, so we can save a little time by
 136                  * caching them.
 137                  *
 138                  * In theory these are value objects and won't get changed...
 139                  */
 140                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 141                         return Title::$titleCache[$text];
 142                 }
 143
 144                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 145                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 146
 147                 $t = new Title();
 148                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 149                 $t->mDefaultNamespace = $defaultNamespace;
 150
 151                 static $cachedcount = 0 ;
 152                 if ( $t->secureAndSplit() ) {
 153                         if ( $defaultNamespace == NS_MAIN ) {
 154                                 if ( $cachedcount >= self::CACHE_MAX ) {
 155                                         # Avoid memory leaks on mass operations...
 156                                         Title::$titleCache = array();
 157                                         $cachedcount = 0;
 158                                 }
 159                                 $cachedcount++;
 160                                 Title::$titleCache[$text] =& $t;
 161                         }
 162                         return $t;
 163                 } else {
 164                         $ret = null;
 165                         return $ret;
 166                 }
 167         }
 168
 169         /**
 170          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 171          *
 172          * Example of wrong and broken code:
 173          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Example of right code:
 176          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 177          *
 178          * Create a new Title from URL-encoded text. Ensures that
 179          * the given title's length does not exceed the maximum.
 180          *
 181          * @param $url String the title, as might be taken from a URL
 182          * @return Title the new object, or NULL on an error
 183          */
 184         public static function newFromURL( $url ) {
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( self::legalChars(), '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Create a new Title from an article ID
 204          *
 205          * @param $id Int the page_id corresponding to the Title to create
 206          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 207          * @return Title the new object, or NULL on an error
 208          */
 209         public static function newFromID( $id, $flags = 0 ) {
 210                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 211                 $row = $db->selectRow(
 212                         'page',
 213                         array(
 214                                 'page_namespace', 'page_title', 'page_id',
 215                                 'page_len', 'page_is_redirect', 'page_latest',
 216                         ),
 217                         array( 'page_id' => $id ),
 218                         __METHOD__
 219                 );
 220                 if ( $row !== false ) {
 221                         $title = Title::newFromRow( $row );
 222                 } else {
 223                         $title = null;
 224                 }
 225                 return $title;
 226         }
 227
 228         /**
 229          * Make an array of titles from an array of IDs
 230          *
 231          * @param $ids Array of Int Array of IDs
 232          * @return Array of Titles
 233          */
 234         public static function newFromIDs( $ids ) {
 235                 if ( !count( $ids ) ) {
 236                         return array();
 237                 }
 238                 $dbr = wfGetDB( DB_SLAVE );
 239
 240                 $res = $dbr->select(
 241                         'page',
 242                         array(
 243                                 'page_namespace', 'page_title', 'page_id',
 244                                 'page_len', 'page_is_redirect', 'page_latest',
 245                         ),
 246                         array( 'page_id' => $ids ),
 247                         __METHOD__
 248                 );
 249
 250                 $titles = array();
 251                 foreach ( $res as $row ) {
 252                         $titles[] = Title::newFromRow( $row );
 253                 }
 254                 return $titles;
 255         }
 256
 257         /**
 258          * Make a Title object from a DB row
 259          *
 260          * @param $row Object database row (needs at least page_title,page_namespace)
 261          * @return Title corresponding Title
 262          */
 263         public static function newFromRow( $row ) {
 264                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 265                 $t->loadFromRow( $row );
 266                 return $t;
 267         }
 268
 269         /**
 270          * Load Title object fields from a DB row.
 271          * If false is given, the title will be treated as non-existing.
 272          *
 273          * @param $row Object|bool database row
 274          */
 275         public function loadFromRow( $row ) {
 276                 if ( $row ) { // page found
 277                         if ( isset( $row->page_id ) )
 278                                 $this->mArticleID = (int)$row->page_id;
 279                         if ( isset( $row->page_len ) )
 280                                 $this->mLength = (int)$row->page_len;
 281                         if ( isset( $row->page_is_redirect ) )
 282                                 $this->mRedirect = (bool)$row->page_is_redirect;
 283                         if ( isset( $row->page_latest ) )
 284                                 $this->mLatestID = (int)$row->page_latest;
 285                 } else { // page not found
 286                         $this->mArticleID = 0;
 287                         $this->mLength = 0;
 288                         $this->mRedirect = false;
 289                         $this->mLatestID = 0;
 290                 }
 291         }
 292
 293         /**
 294          * Create a new Title from a namespace index and a DB key.
 295          * It's assumed that $ns and $title are *valid*, for instance when
 296          * they came directly from the database or a special page name.
 297          * For convenience, spaces are converted to underscores so that
 298          * eg user_text fields can be used directly.
 299          *
 300          * @param $ns Int the namespace of the article
 301          * @param $title String the unprefixed database key form
 302          * @param $fragment String the link fragment (after the "#")
 303          * @param $interwiki String the interwiki prefix
 304          * @return Title the new object
 305          */
 306         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 307                 $t = new Title();
 308                 $t->mInterwiki = $interwiki;
 309                 $t->mFragment = $fragment;
 310                 $t->mNamespace = $ns = intval( $ns );
 311                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 312                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 313                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 314                 $t->mTextform = str_replace( '_', ' ', $title );
 315                 return $t;
 316         }
 317
 318         /**
 319          * Create a new Title from a namespace index and a DB key.
 320          * The parameters will be checked for validity, which is a bit slower
 321          * than makeTitle() but safer for user-provided data.
 322          *
 323          * @param $ns Int the namespace of the article
 324          * @param $title String database key form
 325          * @param $fragment String the link fragment (after the "#")
 326          * @param $interwiki String interwiki prefix
 327          * @return Title the new object, or NULL on an error
 328          */
 329         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 330                 if ( !MWNamespace::exists( $ns ) ) {
 331                         return null;
 332                 }
 333
 334                 $t = new Title();
 335                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 336                 if ( $t->secureAndSplit() ) {
 337                         return $t;
 338                 } else {
 339                         return null;
 340                 }
 341         }
 342
 343         /**
 344          * Create a new Title for the Main Page
 345          *
 346          * @return Title the new object
 347          */
 348         public static function newMainPage() {
 349                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 350                 // Don't give fatal errors if the message is broken
 351                 if ( !$title ) {
 352                         $title = Title::newFromText( 'Main Page' );
 353                 }
 354                 return $title;
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will only return the very next target, useful for
 361          * the redirect table and other checks that don't need full recursion
 362          *
 363          * @param $text String: Text with possible redirect
 364          * @return Title: The corresponding Title
 365          */
 366         public static function newFromRedirect( $text ) {
 367                 return self::newFromRedirectInternal( $text );
 368         }
 369
 370         /**
 371          * Extract a redirect destination from a string and return the
 372          * Title, or null if the text doesn't contain a valid redirect
 373          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 374          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Title
 378          */
 379         public static function newFromRedirectRecurse( $text ) {
 380                 $titles = self::newFromRedirectArray( $text );
 381                 return $titles ? array_pop( $titles ) : null;
 382         }
 383
 384         /**
 385          * Extract a redirect destination from a string and return an
 386          * array of Titles, or null if the text doesn't contain a valid redirect
 387          * The last element in the array is the final destination after all redirects
 388          * have been resolved (up to $wgMaxRedirects times)
 389          *
 390          * @param $text String Text with possible redirect
 391          * @return Array of Titles, with the destination last
 392          */
 393         public static function newFromRedirectArray( $text ) {
 394                 global $wgMaxRedirects;
 395                 $title = self::newFromRedirectInternal( $text );
 396                 if ( is_null( $title ) ) {
 397                         return null;
 398                 }
 399                 // recursive check to follow double redirects
 400                 $recurse = $wgMaxRedirects;
 401                 $titles = array( $title );
 402                 while ( --$recurse > 0 ) {
 403                         if ( $title->isRedirect() ) {
 404                                 $page = WikiPage::factory( $title );
 405                                 $newtitle = $page->getRedirectTarget();
 406                         } else {
 407                                 break;
 408                         }
 409                         // Redirects to some special pages are not permitted
 410                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 411                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 412                                 $title = $newtitle;
 413                                 $titles[] = $newtitle;
 414                         } else {
 415                                 break;
 416                         }
 417                 }
 418                 return $titles;
 419         }
 420
 421         /**
 422          * Really extract the redirect destination
 423          * Do not call this function directly, use one of the newFromRedirect* functions above
 424          *
 425          * @param $text String Text with possible redirect
 426          * @return Title
 427          */
 428         protected static function newFromRedirectInternal( $text ) {
 429                 global $wgMaxRedirects;
 430                 if ( $wgMaxRedirects < 1 ) {
 431                         //redirects are disabled, so quit early
 432                         return null;
 433                 }
 434                 $redir = MagicWord::get( 'redirect' );
 435                 $text = trim( $text );
 436                 if ( $redir->matchStartAndRemove( $text ) ) {
 437                         // Extract the first link and see if it's usable
 438                         // Ensure that it really does come directly after #REDIRECT
 439                         // Some older redirects included a colon, so don't freak about that!
 440                         $m = array();
 441                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 442                                 // Strip preceding colon used to "escape" categories, etc.
 443                                 // and URL-decode links
 444                                 if ( strpos( $m[1], '%' ) !== false ) {
 445                                         // Match behavior of inline link parsing here;
 446                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 447                                 }
 448                                 $title = Title::newFromText( $m[1] );
 449                                 // If the title is a redirect to bad special pages or is invalid, return null
 450                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 451                                         return null;
 452                                 }
 453                                 return $title;
 454                         }
 455                 }
 456                 return null;
 457         }
 458
 459         /**
 460          * Get the prefixed DB key associated with an ID
 461          *
 462          * @param $id Int the page_id of the article
 463          * @return Title an object representing the article, or NULL if no such article was found
 464          */
 465         public static function nameOf( $id ) {
 466                 $dbr = wfGetDB( DB_SLAVE );
 467
 468                 $s = $dbr->selectRow(
 469                         'page',
 470                         array( 'page_namespace', 'page_title' ),
 471                         array( 'page_id' => $id ),
 472                         __METHOD__
 473                 );
 474                 if ( $s === false ) {
 475                         return null;
 476                 }
 477
 478                 $n = self::makeName( $s->page_namespace, $s->page_title );
 479                 return $n;
 480         }
 481
 482         /**
 483          * Get a regex character class describing the legal characters in a link
 484          *
 485          * @return String the list of characters, not delimited
 486          */
 487         public static function legalChars() {
 488                 global $wgLegalTitleChars;
 489                 return $wgLegalTitleChars;
 490         }
 491
 492         /**
 493          * Returns a simple regex that will match on characters and sequences invalid in titles.
 494          * Note that this doesn't pick up many things that could be wrong with titles, but that
 495          * replacing this regex with something valid will make many titles valid.
 496          *
 497          * @return String regex string
 498          */
 499         static function getTitleInvalidRegex() {
 500                 static $rxTc = false;
 501                 if ( !$rxTc ) {
 502                         # Matching titles will be held as illegal.
 503                         $rxTc = '/' .
 504                                 # Any character not allowed is forbidden...
 505                                 '[^' . self::legalChars() . ']' .
 506                                 # URL percent encoding sequences interfere with the ability
 507                                 # to round-trip titles -- you can't link to them consistently.
 508                                 '|%[0-9A-Fa-f]{2}' .
 509                                 # XML/HTML character references produce similar issues.
 510                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 511                                 '|&#[0-9]+;' .
 512                                 '|&#x[0-9A-Fa-f]+;' .
 513                                 '/S';
 514                 }
 515
 516                 return $rxTc;
 517         }
 518
 519         /**
 520          * Get a string representation of a title suitable for
 521          * including in a search index
 522          *
 523          * @param $ns Int a namespace index
 524          * @param $title String text-form main part
 525          * @return String a stripped-down title string ready for the search index
 526          */
 527         public static function indexTitle( $ns, $title ) {
 528                 global $wgContLang;
 529
 530                 $lc = SearchEngine::legalSearchChars() . '&#;';
 531                 $t = $wgContLang->normalizeForSearch( $title );
 532                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 533                 $t = $wgContLang->lc( $t );
 534
 535                 # Handle 's, s'
 536                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 537                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 538
 539                 $t = preg_replace( "/\\s+/", ' ', $t );
 540
 541                 if ( $ns == NS_FILE ) {
 542                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 543                 }
 544                 return trim( $t );
 545         }
 546
 547         /**
 548          * Make a prefixed DB key from a DB key and a namespace index
 549          *
 550          * @param $ns Int numerical representation of the namespace
 551          * @param $title String the DB key form the title
 552          * @param $fragment String The link fragment (after the "#")
 553          * @param $interwiki String The interwiki prefix
 554          * @return String the prefixed form of the title
 555          */
 556         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 557                 global $wgContLang;
 558
 559                 $namespace = $wgContLang->getNsText( $ns );
 560                 $name = $namespace == '' ? $title : "$namespace:$title";
 561                 if ( strval( $interwiki ) != '' ) {
 562                         $name = "$interwiki:$name";
 563                 }
 564                 if ( strval( $fragment ) != '' ) {
 565                         $name .= '#' . $fragment;
 566                 }
 567                 return $name;
 568         }
 569
 570         /**
 571          * Escape a text fragment, say from a link, for a URL
 572          *
 573          * @param $fragment string containing a URL or link fragment (after the "#")
 574          * @return String: escaped string
 575          */
 576         static function escapeFragmentForURL( $fragment ) {
 577                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 578                 # fragments appear not to work in IE (at least up to 7) or in at least
 579                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 580                 # to care if they aren't encoded.
 581                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 582         }
 583
 584         /**
 585          * Callback for usort() to do title sorts by (namespace, title)
 586          *
 587          * @param $a Title
 588          * @param $b Title
 589          *
 590          * @return Integer: result of string comparison, or namespace comparison
 591          */
 592         public static function compare( $a, $b ) {
 593                 if ( $a->getNamespace() == $b->getNamespace() ) {
 594                         return strcmp( $a->getText(), $b->getText() );
 595                 } else {
 596                         return $a->getNamespace() - $b->getNamespace();
 597                 }
 598         }
 599
 600         /**
 601          * Determine whether the object refers to a page within
 602          * this project.
 603          *
 604          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 605          */
 606         public function isLocal() {
 607                 if ( $this->mInterwiki != '' ) {
 608                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 609                 } else {
 610                         return true;
 611                 }
 612         }
 613
 614         /**
 615          * Is this Title interwiki?
 616          *
 617          * @return Bool
 618          */
 619         public function isExternal() {
 620                 return ( $this->mInterwiki != '' );
 621         }
 622
 623         /**
 624          * Get the interwiki prefix (or null string)
 625          *
 626          * @return String Interwiki prefix
 627          */
 628         public function getInterwiki() {
 629                 return $this->mInterwiki;
 630         }
 631
 632         /**
 633          * Determine whether the object refers to a page within
 634          * this project and is transcludable.
 635          *
 636          * @return Bool TRUE if this is transcludable
 637          */
 638         public function isTrans() {
 639                 if ( $this->mInterwiki == '' ) {
 640                         return false;
 641                 }
 642
 643                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 644         }
 645
 646         /**
 647          * Returns the DB name of the distant wiki which owns the object.
 648          *
 649          * @return String the DB name
 650          */
 651         public function getTransWikiID() {
 652                 if ( $this->mInterwiki == '' ) {
 653                         return false;
 654                 }
 655
 656                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 657         }
 658
 659         /**
 660          * Get the text form (spaces not underscores) of the main part
 661          *
 662          * @return String Main part of the title
 663          */
 664         public function getText() {
 665                 return $this->mTextform;
 666         }
 667
 668         /**
 669          * Get the URL-encoded form of the main part
 670          *
 671          * @return String Main part of the title, URL-encoded
 672          */
 673         public function getPartialURL() {
 674                 return $this->mUrlform;
 675         }
 676
 677         /**
 678          * Get the main part with underscores
 679          *
 680          * @return String: Main part of the title, with underscores
 681          */
 682         public function getDBkey() {
 683                 return $this->mDbkeyform;
 684         }
 685
 686         /**
 687          * Get the DB key with the initial letter case as specified by the user
 688          *
 689          * @return String DB key
 690          */
 691         function getUserCaseDBKey() {
 692                 return $this->mUserCaseDBKey;
 693         }
 694
 695         /**
 696          * Get the namespace index, i.e. one of the NS_xxxx constants.
 697          *
 698          * @return Integer: Namespace index
 699          */
 700         public function getNamespace() {
 701                 return $this->mNamespace;
 702         }
 703
 704         /**
 705          * Get the namespace text
 706          *
 707          * @return String: Namespace text
 708          */
 709         public function getNsText() {
 710                 global $wgContLang;
 711
 712                 if ( $this->mInterwiki != '' ) {
 713                         // This probably shouldn't even happen. ohh man, oh yuck.
 714                         // But for interwiki transclusion it sometimes does.
 715                         // Shit. Shit shit shit.
 716                         //
 717                         // Use the canonical namespaces if possible to try to
 718                         // resolve a foreign namespace.
 719                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 720                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 721                         }
 722                 }
 723
 724                 if ( $wgContLang->needsGenderDistinction() &&
 725                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 726                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 727                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 728                 }
 729
 730                 return $wgContLang->getNsText( $this->mNamespace );
 731         }
 732
 733         /**
 734          * Get the namespace text of the subject (rather than talk) page
 735          *
 736          * @return String Namespace text
 737          */
 738         public function getSubjectNsText() {
 739                 global $wgContLang;
 740                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 741         }
 742
 743         /**
 744          * Get the namespace text of the talk page
 745          *
 746          * @return String Namespace text
 747          */
 748         public function getTalkNsText() {
 749                 global $wgContLang;
 750                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 751         }
 752
 753         /**
 754          * Could this title have a corresponding talk page?
 755          *
 756          * @return Bool TRUE or FALSE
 757          */
 758         public function canTalk() {
 759                 return( MWNamespace::canTalk( $this->mNamespace ) );
 760         }
 761
 762         /**
 763          * Is this in a namespace that allows actual pages?
 764          *
 765          * @return Bool
 766          * @internal note -- uses hardcoded namespace index instead of constants
 767          */
 768         public function canExist() {
 769                 return $this->mNamespace >= NS_MAIN;
 770         }
 771
 772         /**
 773          * Can this title be added to a user's watchlist?
 774          *
 775          * @return Bool TRUE or FALSE
 776          */
 777         public function isWatchable() {
 778                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 779         }
 780
 781         /**
 782          * Returns true if this is a special page.
 783          *
 784          * @return boolean
 785          */
 786         public function isSpecialPage() {
 787                 return $this->getNamespace() == NS_SPECIAL;
 788         }
 789
 790         /**
 791          * Returns true if this title resolves to the named special page
 792          *
 793          * @param $name String The special page name
 794          * @return boolean
 795          */
 796         public function isSpecial( $name ) {
 797                 if ( $this->isSpecialPage() ) {
 798                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 799                         if ( $name == $thisName ) {
 800                                 return true;
 801                         }
 802                 }
 803                 return false;
 804         }
 805
 806         /**
 807          * If the Title refers to a special page alias which is not the local default, resolve
 808          * the alias, and localise the name as necessary.  Otherwise, return $this
 809          *
 810          * @return Title
 811          */
 812         public function fixSpecialName() {
 813                 if ( $this->isSpecialPage() ) {
 814                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 815                         if ( $canonicalName ) {
 816                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 817                                 if ( $localName != $this->mDbkeyform ) {
 818                                         return Title::makeTitle( NS_SPECIAL, $localName );
 819                                 }
 820                         }
 821                 }
 822                 return $this;
 823         }
 824
 825         /**
 826          * Returns true if the title is inside the specified namespace.
 827          *
 828          * Please make use of this instead of comparing to getNamespace()
 829          * This function is much more resistant to changes we may make
 830          * to namespaces than code that makes direct comparisons.
 831          * @param $ns int The namespace
 832          * @return bool
 833          * @since 1.19
 834          */
 835         public function inNamespace( $ns ) {
 836                 return MWNamespace::equals( $this->getNamespace(), $ns );
 837         }
 838
 839         /**
 840          * Returns true if the title is inside one of the specified namespaces.
 841          *
 842          * @param ...$namespaces The namespaces to check for
 843          * @return bool
 844          * @since 1.19
 845          */
 846         public function inNamespaces( /* ... */ ) {
 847                 $namespaces = func_get_args();
 848                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 849                         $namespaces = $namespaces[0];
 850                 }
 851
 852                 foreach ( $namespaces as $ns ) {
 853                         if ( $this->inNamespace( $ns ) ) {
 854                                 return true;
 855                         }
 856                 }
 857
 858                 return false;
 859         }
 860
 861         /**
 862          * Returns true if the title has the same subject namespace as the
 863          * namespace specified.
 864          * For example this method will take NS_USER and return true if namespace
 865          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 866          * as their subject namespace.
 867          *
 868          * This is MUCH simpler than individually testing for equivilance
 869          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 870          * @since 1.19
 871          * @param $ns int
 872          * @return bool
 873          */
 874         public function hasSubjectNamespace( $ns ) {
 875                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 876         }
 877
 878         /**
 879          * Is this Title in a namespace which contains content?
 880          * In other words, is this a content page, for the purposes of calculating
 881          * statistics, etc?
 882          *
 883          * @return Boolean
 884          */
 885         public function isContentPage() {
 886                 return MWNamespace::isContent( $this->getNamespace() );
 887         }
 888
 889         /**
 890          * Would anybody with sufficient privileges be able to move this page?
 891          * Some pages just aren't movable.
 892          *
 893          * @return Bool TRUE or FALSE
 894          */
 895         public function isMovable() {
 896                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 897                         // Interwiki title or immovable namespace. Hooks don't get to override here
 898                         return false;
 899                 }
 900
 901                 $result = true;
 902                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 903                 return $result;
 904         }
 905
 906         /**
 907          * Is this the mainpage?
 908          * @note Title::newFromText seams to be sufficiently optimized by the title
 909          * cache that we don't need to over-optimize by doing direct comparisons and
 910          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 911          * ends up reporting something differently than $title->isMainPage();
 912          *
 913          * @since 1.18
 914          * @return Bool
 915          */
 916         public function isMainPage() {
 917                 return $this->equals( Title::newMainPage() );
 918         }
 919
 920         /**
 921          * Is this a subpage?
 922          *
 923          * @return Bool
 924          */
 925         public function isSubpage() {
 926                 return MWNamespace::hasSubpages( $this->mNamespace )
 927                         ? strpos( $this->getText(), '/' ) !== false
 928                         : false;
 929         }
 930
 931         /**
 932          * Is this a conversion table for the LanguageConverter?
 933          *
 934          * @return Bool
 935          */
 936         public function isConversionTable() {
 937                 return $this->getNamespace() == NS_MEDIAWIKI &&
 938                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 939         }
 940
 941         /**
 942          * Does that page contain wikitext, or it is JS, CSS or whatever?
 943          *
 944          * @return Bool
 945          */
 946         public function isWikitextPage() {
 947                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 948                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 949                 return $retval;
 950         }
 951
 952         /**
 953          * Could this page contain custom CSS or JavaScript, based
 954          * on the title?
 955          *
 956          * @return Bool
 957          */
 958         public function isCssOrJsPage() {
 959                 $retval = $this->mNamespace == NS_MEDIAWIKI
 960                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 961                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 962                 return $retval;
 963         }
 964
 965         /**
 966          * Is this a .css or .js subpage of a user page?
 967          * @return Bool
 968          */
 969         public function isCssJsSubpage() {
 970                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 971         }
 972
 973         /**
 974          * Trim down a .css or .js subpage title to get the corresponding skin name
 975          *
 976          * @return string containing skin name from .css or .js subpage title
 977          */
 978         public function getSkinFromCssJsSubpage() {
 979                 $subpage = explode( '/', $this->mTextform );
 980                 $subpage = $subpage[ count( $subpage ) - 1 ];
 981                 $lastdot = strrpos( $subpage, '.' );
 982                 if ( $lastdot === false )
 983                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 984                 return substr( $subpage, 0, $lastdot );
 985         }
 986
 987         /**
 988          * Is this a .css subpage of a user page?
 989          *
 990          * @return Bool
 991          */
 992         public function isCssSubpage() {
 993                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
 994         }
 995
 996         /**
 997          * Is this a .js subpage of a user page?
 998          *
 999          * @return Bool
1000          */
1001         public function isJsSubpage() {
1002                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1003         }
1004
1005         /**
1006          * Is this a talk page of some sort?
1007          *
1008          * @return Bool
1009          */
1010         public function isTalkPage() {
1011                 return MWNamespace::isTalk( $this->getNamespace() );
1012         }
1013
1014         /**
1015          * Get a Title object associated with the talk page of this article
1016          *
1017          * @return Title the object for the talk page
1018          */
1019         public function getTalkPage() {
1020                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1021         }
1022
1023         /**
1024          * Get a title object associated with the subject page of this
1025          * talk page
1026          *
1027          * @return Title the object for the subject page
1028          */
1029         public function getSubjectPage() {
1030                 // Is this the same title?
1031                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1032                 if ( $this->getNamespace() == $subjectNS ) {
1033                         return $this;
1034                 }
1035                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1036         }
1037
1038         /**
1039          * Get the default namespace index, for when there is no namespace
1040          *
1041          * @return Int Default namespace index
1042          */
1043         public function getDefaultNamespace() {
1044                 return $this->mDefaultNamespace;
1045         }
1046
1047         /**
1048          * Get title for search index
1049          *
1050          * @return String a stripped-down title string ready for the
1051          *  search index
1052          */
1053         public function getIndexTitle() {
1054                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1055         }
1056
1057         /**
1058          * Get the Title fragment (i.e.\ the bit after the #) in text form
1059          *
1060          * @return String Title fragment
1061          */
1062         public function getFragment() {
1063                 return $this->mFragment;
1064         }
1065
1066         /**
1067          * Get the fragment in URL form, including the "#" character if there is one
1068          * @return String Fragment in URL form
1069          */
1070         public function getFragmentForURL() {
1071                 if ( $this->mFragment == '' ) {
1072                         return '';
1073                 } else {
1074                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1075                 }
1076         }
1077
1078         /**
1079          * Set the fragment for this title. Removes the first character from the
1080          * specified fragment before setting, so it assumes you're passing it with
1081          * an initial "#".
1082          *
1083          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1084          * Still in active use privately.
1085          *
1086          * @param $fragment String text
1087          */
1088         public function setFragment( $fragment ) {
1089                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1090         }
1091
1092         /**
1093          * Prefix some arbitrary text with the namespace or interwiki prefix
1094          * of this object
1095          *
1096          * @param $name String the text
1097          * @return String the prefixed text
1098          * @private
1099          */
1100         private function prefix( $name ) {
1101                 $p = '';
1102                 if ( $this->mInterwiki != '' ) {
1103                         $p = $this->mInterwiki . ':';
1104                 }
1105
1106                 if ( 0 != $this->mNamespace ) {
1107                         $p .= $this->getNsText() . ':';
1108                 }
1109                 return $p . $name;
1110         }
1111
1112         /**
1113          * Get the prefixed database key form
1114          *
1115          * @return String the prefixed title, with underscores and
1116          *  any interwiki and namespace prefixes
1117          */
1118         public function getPrefixedDBkey() {
1119                 $s = $this->prefix( $this->mDbkeyform );
1120                 $s = str_replace( ' ', '_', $s );
1121                 return $s;
1122         }
1123
1124         /**
1125          * Get the prefixed title with spaces.
1126          * This is the form usually used for display
1127          *
1128          * @return String the prefixed title, with spaces
1129          */
1130         public function getPrefixedText() {
1131                 // @todo FIXME: Bad usage of empty() ?
1132                 if ( empty( $this->mPrefixedText ) ) {
1133                         $s = $this->prefix( $this->mTextform );
1134                         $s = str_replace( '_', ' ', $s );
1135                         $this->mPrefixedText = $s;
1136                 }
1137                 return $this->mPrefixedText;
1138         }
1139
1140         /**
1141          * Return a string representation of this title
1142          *
1143          * @return String representation of this title
1144          */
1145         public function __toString() {
1146                 return $this->getPrefixedText();
1147         }
1148
1149         /**
1150          * Get the prefixed title with spaces, plus any fragment
1151          * (part beginning with '#')
1152          *
1153          * @return String the prefixed title, with spaces and the fragment, including '#'
1154          */
1155         public function getFullText() {
1156                 $text = $this->getPrefixedText();
1157                 if ( $this->mFragment != '' ) {
1158                         $text .= '#' . $this->mFragment;
1159                 }
1160                 return $text;
1161         }
1162
1163         /**
1164          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1165          *
1166          * @par Example:
1167          * @code
1168          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1169          * # returns: 'Foo'
1170          * @endcode
1171          *
1172          * @return String Root name
1173          * @since 1.20
1174          */
1175         public function getRootText() {
1176                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1177                         return $this->getText();
1178                 }
1179
1180                 return strtok( $this->getText(), '/' );
1181         }
1182
1183         /**
1184          * Get the root page name title, i.e. the leftmost part before any slashes
1185          *
1186          * @par Example:
1187          * @code
1188          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1189          * # returns: Title{User:Foo}
1190          * @endcode
1191          *
1192          * @return Title Root title
1193          * @since 1.20
1194          */
1195         public function getRootTitle() {
1196                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1197         }
1198
1199         /**
1200          * Get the base page name without a namespace, i.e. the part before the subpage name
1201          *
1202          * @par Example:
1203          * @code
1204          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1205          * # returns: 'Foo/Bar'
1206          * @endcode
1207          *
1208          * @return String Base name
1209          */
1210         public function getBaseText() {
1211                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1212                         return $this->getText();
1213                 }
1214
1215                 $parts = explode( '/', $this->getText() );
1216                 # Don't discard the real title if there's no subpage involved
1217                 if ( count( $parts ) > 1 ) {
1218                         unset( $parts[count( $parts ) - 1] );
1219                 }
1220                 return implode( '/', $parts );
1221         }
1222
1223         /**
1224          * Get the base page name title, i.e. the part before the subpage name
1225          *
1226          * @par Example:
1227          * @code
1228          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1229          * # returns: Title{User:Foo/Bar}
1230          * @endcode
1231          *
1232          * @return Title Base title
1233          * @since 1.20
1234          */
1235         public function getBaseTitle() {
1236                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1237         }
1238
1239         /**
1240          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1241          *
1242          * @par Example:
1243          * @code
1244          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1245          * # returns: "Baz"
1246          * @endcode
1247          *
1248          * @return String Subpage name
1249          */
1250         public function getSubpageText() {
1251                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1252                         return( $this->mTextform );
1253                 }
1254                 $parts = explode( '/', $this->mTextform );
1255                 return( $parts[count( $parts ) - 1] );
1256         }
1257
1258         /**
1259          * Get the title for a subpage of the current page
1260          *
1261          * @par Example:
1262          * @code
1263          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1264          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1265          * @endcode
1266          *
1267          * @param $text String The subpage name to add to the title
1268          * @return Title Subpage title
1269          * @since 1.20
1270          */
1271         public function getSubpage( $text ) {
1272                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1273         }
1274
1275         /**
1276          * Get the HTML-escaped displayable text form.
1277          * Used for the title field in <a> tags.
1278          *
1279          * @return String the text, including any prefixes
1280          */
1281         public function getEscapedText() {
1282                 wfDeprecated( __METHOD__, '1.19' );
1283                 return htmlspecialchars( $this->getPrefixedText() );
1284         }
1285
1286         /**
1287          * Get a URL-encoded form of the subpage text
1288          *
1289          * @return String URL-encoded subpage name
1290          */
1291         public function getSubpageUrlForm() {
1292                 $text = $this->getSubpageText();
1293                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1294                 return( $text );
1295         }
1296
1297         /**
1298          * Get a URL-encoded title (not an actual URL) including interwiki
1299          *
1300          * @return String the URL-encoded form
1301          */
1302         public function getPrefixedURL() {
1303                 $s = $this->prefix( $this->mDbkeyform );
1304                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1305                 return $s;
1306         }
1307
1308         /**
1309          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1310          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1311          * second argument named variant. This was deprecated in favor
1312          * of passing an array of option with a "variant" key
1313          * Once $query2 is removed for good, this helper can be dropped
1314          * andthe wfArrayToCGI moved to getLocalURL();
1315          *
1316          * @since 1.19 (r105919)
1317          * @param $query
1318          * @param $query2 bool
1319          * @return String
1320          */
1321         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1322                 if( $query2 !== false ) {
1323                         wfDeprecated( "Title::get{Canonical,Full,Link,Local} method called with a second parameter is deprecated. Add your parameter to an array passed as the first parameter.", "1.19" );
1324                 }
1325                 if ( is_array( $query ) ) {
1326                         $query = wfArrayToCGI( $query );
1327                 }
1328                 if ( $query2 ) {
1329                         if ( is_string( $query2 ) ) {
1330                                 // $query2 is a string, we will consider this to be
1331                                 // a deprecated $variant argument and add it to the query
1332                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1333                         } else {
1334                                 $query2 = wfArrayToCGI( $query2 );
1335                         }
1336                         // If we have $query content add a & to it first
1337                         if ( $query ) {
1338                                 $query .= '&';
1339                         }
1340                         // Now append the queries together
1341                         $query .= $query2;
1342                 }
1343                 return $query;
1344         }
1345
1346         /**
1347          * Get a real URL referring to this title, with interwiki link and
1348          * fragment
1349          *
1350          * See getLocalURL for the arguments.
1351          *
1352          * @see self::getLocalURL
1353          * @see wfExpandUrl
1354          * @param $proto Protocol type to use in URL
1355          * @return String the URL
1356          */
1357         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1358                 $query = self::fixUrlQueryArgs( $query, $query2 );
1359
1360                 # Hand off all the decisions on urls to getLocalURL
1361                 $url = $this->getLocalURL( $query );
1362
1363                 # Expand the url to make it a full url. Note that getLocalURL has the
1364                 # potential to output full urls for a variety of reasons, so we use
1365                 # wfExpandUrl instead of simply prepending $wgServer
1366                 $url = wfExpandUrl( $url, $proto );
1367
1368                 # Finally, add the fragment.
1369                 $url .= $this->getFragmentForURL();
1370
1371                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1372                 return $url;
1373         }
1374
1375         /**
1376          * Get a URL with no fragment or server name.  If this page is generated
1377          * with action=render, $wgServer is prepended.
1378          *
1379
1380          * @param $query string|array an optional query string,
1381          *   not used for interwiki     links. Can be specified as an associative array as well,
1382          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1383          *   Some query patterns will trigger various shorturl path replacements.
1384          * @param $query2 Mixed: An optional secondary query array. This one MUST
1385          *   be an array. If a string is passed it will be interpreted as a deprecated
1386          *   variant argument and urlencoded into a variant= argument.
1387          *   This second query argument will be added to the $query
1388          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1389          *   pair in the first parameter array instead.
1390          *
1391          * @return String the URL
1392          */
1393         public function getLocalURL( $query = '', $query2 = false ) {
1394                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1395
1396                 $query = self::fixUrlQueryArgs( $query, $query2 );
1397
1398                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1399                 if ( $interwiki ) {
1400                         $namespace = $this->getNsText();
1401                         if ( $namespace != '' ) {
1402                                 # Can this actually happen? Interwikis shouldn't be parsed.
1403                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1404                                 $namespace .= ':';
1405                         }
1406                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1407                         $url = wfAppendQuery( $url, $query );
1408                 } else {
1409                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1410                         if ( $query == '' ) {
1411                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1412                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1413                         } else {
1414                                 global $wgVariantArticlePath, $wgActionPaths;
1415                                 $url = false;
1416                                 $matches = array();
1417
1418                                 if ( !empty( $wgActionPaths ) &&
1419                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1420                                 {
1421                                         $action = urldecode( $matches[2] );
1422                                         if ( isset( $wgActionPaths[$action] ) ) {
1423                                                 $query = $matches[1];
1424                                                 if ( isset( $matches[4] ) ) {
1425                                                         $query .= $matches[4];
1426                                                 }
1427                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1428                                                 if ( $query != '' ) {
1429                                                         $url = wfAppendQuery( $url, $query );
1430                                                 }
1431                                         }
1432                                 }
1433
1434                                 if ( $url === false &&
1435                                         $wgVariantArticlePath &&
1436                                         $this->getPageLanguage()->hasVariants() &&
1437                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1438                                 {
1439                                         $variant = urldecode( $matches[1] );
1440                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1441                                                 // Only do the variant replacement if the given variant is a valid
1442                                                 // variant for the page's language.
1443                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1444                                                 $url = str_replace( '$1', $dbkey, $url );
1445                                         }
1446                                 }
1447
1448                                 if ( $url === false ) {
1449                                         if ( $query == '-' ) {
1450                                                 $query = '';
1451                                         }
1452                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1453                                 }
1454                         }
1455
1456                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1457
1458                         // @todo FIXME: This causes breakage in various places when we
1459                         // actually expected a local URL and end up with dupe prefixes.
1460                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1461                                 $url = $wgServer . $url;
1462                         }
1463                 }
1464                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1465                 return $url;
1466         }
1467
1468         /**
1469          * Get a URL that's the simplest URL that will be valid to link, locally,
1470          * to the current Title.  It includes the fragment, but does not include
1471          * the server unless action=render is used (or the link is external).  If
1472          * there's a fragment but the prefixed text is empty, we just return a link
1473          * to the fragment.
1474          *
1475          * The result obviously should not be URL-escaped, but does need to be
1476          * HTML-escaped if it's being output in HTML.
1477          *
1478          * See getLocalURL for the arguments.
1479          *
1480          * @param $proto Protocol to use; setting this will cause a full URL to be used
1481          * @see self::getLocalURL
1482          * @return String the URL
1483          */
1484         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1485                 wfProfileIn( __METHOD__ );
1486                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1487                         $ret = $this->getFullURL( $query, $query2, $proto );
1488                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1489                         $ret = $this->getFragmentForURL();
1490                 } else {
1491                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1492                 }
1493                 wfProfileOut( __METHOD__ );
1494                 return $ret;
1495         }
1496
1497         /**
1498          * Get an HTML-escaped version of the URL form, suitable for
1499          * using in a link, without a server name or fragment
1500          *
1501          * See getLocalURL for the arguments.
1502          *
1503          * @see self::getLocalURL
1504          * @param $query string
1505          * @param $query2 bool|string
1506          * @return String the URL
1507          */
1508         public function escapeLocalURL( $query = '', $query2 = false ) {
1509                 wfDeprecated( __METHOD__, '1.19' );
1510                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1511         }
1512
1513         /**
1514          * Get an HTML-escaped version of the URL form, suitable for
1515          * using in a link, including the server name and fragment
1516          *
1517          * See getLocalURL for the arguments.
1518          *
1519          * @see self::getLocalURL
1520          * @return String the URL
1521          */
1522         public function escapeFullURL( $query = '', $query2 = false ) {
1523                 wfDeprecated( __METHOD__, '1.19' );
1524                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1525         }
1526
1527         /**
1528          * Get the URL form for an internal link.
1529          * - Used in various Squid-related code, in case we have a different
1530          * internal hostname for the server from the exposed one.
1531          *
1532          * This uses $wgInternalServer to qualify the path, or $wgServer
1533          * if $wgInternalServer is not set. If the server variable used is
1534          * protocol-relative, the URL will be expanded to http://
1535          *
1536          * See getLocalURL for the arguments.
1537          *
1538          * @see self::getLocalURL
1539          * @return String the URL
1540          */
1541         public function getInternalURL( $query = '', $query2 = false ) {
1542                 global $wgInternalServer, $wgServer;
1543                 $query = self::fixUrlQueryArgs( $query, $query2 );
1544                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1545                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1546                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1547                 return $url;
1548         }
1549
1550         /**
1551          * Get the URL for a canonical link, for use in things like IRC and
1552          * e-mail notifications. Uses $wgCanonicalServer and the
1553          * GetCanonicalURL hook.
1554          *
1555          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1556          *
1557          * See getLocalURL for the arguments.
1558          *
1559          * @see self::getLocalURL
1560          * @return string The URL
1561          * @since 1.18
1562          */
1563         public function getCanonicalURL( $query = '', $query2 = false ) {
1564                 $query = self::fixUrlQueryArgs( $query, $query2 );
1565                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1566                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1567                 return $url;
1568         }
1569
1570         /**
1571          * HTML-escaped version of getCanonicalURL()
1572          *
1573          * See getLocalURL for the arguments.
1574          *
1575          * @see self::getLocalURL
1576          * @since 1.18
1577          * @return string
1578          */
1579         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1580                 wfDeprecated( __METHOD__, '1.19' );
1581                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1582         }
1583
1584         /**
1585          * Get the edit URL for this Title
1586          *
1587          * @return String the URL, or a null string if this is an
1588          *  interwiki link
1589          */
1590         public function getEditURL() {
1591                 if ( $this->mInterwiki != '' ) {
1592                         return '';
1593                 }
1594                 $s = $this->getLocalURL( 'action=edit' );
1595
1596                 return $s;
1597         }
1598
1599         /**
1600          * Is $wgUser watching this page?
1601          *
1602          * @deprecated in 1.20; use User::isWatched() instead.
1603          * @return Bool
1604          */
1605         public function userIsWatching() {
1606                 global $wgUser;
1607
1608                 if ( is_null( $this->mWatched ) ) {
1609                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1610                                 $this->mWatched = false;
1611                         } else {
1612                                 $this->mWatched = $wgUser->isWatched( $this );
1613                         }
1614                 }
1615                 return $this->mWatched;
1616         }
1617
1618         /**
1619          * Can $wgUser read this page?
1620          *
1621          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1622          * @return Bool
1623          * @todo fold these checks into userCan()
1624          */
1625         public function userCanRead() {
1626                 wfDeprecated( __METHOD__, '1.19' );
1627                 return $this->userCan( 'read' );
1628         }
1629
1630         /**
1631          * Can $user perform $action on this page?
1632          * This skips potentially expensive cascading permission checks
1633          * as well as avoids expensive error formatting
1634          *
1635          * Suitable for use for nonessential UI controls in common cases, but
1636          * _not_ for functional access control.
1637          *
1638          * May provide false positives, but should never provide a false negative.
1639          *
1640          * @param $action String action that permission needs to be checked for
1641          * @param $user User to check (since 1.19); $wgUser will be used if not
1642          *              provided.
1643          * @return Bool
1644          */
1645         public function quickUserCan( $action, $user = null ) {
1646                 return $this->userCan( $action, $user, false );
1647         }
1648
1649         /**
1650          * Can $user perform $action on this page?
1651          *
1652          * @param $action String action that permission needs to be checked for
1653          * @param $user User to check (since 1.19); $wgUser will be used if not
1654          *   provided.
1655          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1656          *   unnecessary queries.
1657          * @return Bool
1658          */
1659         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1660                 if ( !$user instanceof User ) {
1661                         global $wgUser;
1662                         $user = $wgUser;
1663                 }
1664                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1665         }
1666
1667         /**
1668          * Can $user perform $action on this page?
1669          *
1670          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1671          *
1672          * @param $action String action that permission needs to be checked for
1673          * @param $user User to check
1674          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1675          *   queries by skipping checks for cascading protections and user blocks.
1676          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1677          *   whose corresponding errors may be ignored.
1678          * @return Array of arguments to wfMessage to explain permissions problems.
1679          */
1680         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1681                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1682
1683                 // Remove the errors being ignored.
1684                 foreach ( $errors as $index => $error ) {
1685                         $error_key = is_array( $error ) ? $error[0] : $error;
1686
1687                         if ( in_array( $error_key, $ignoreErrors ) ) {
1688                                 unset( $errors[$index] );
1689                         }
1690                 }
1691
1692                 return $errors;
1693         }
1694
1695         /**
1696          * Permissions checks that fail most often, and which are easiest to test.
1697          *
1698          * @param $action String the action to check
1699          * @param $user User user to check
1700          * @param $errors Array list of current errors
1701          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1702          * @param $short Boolean short circuit on first error
1703          *
1704          * @return Array list of errors
1705          */
1706         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1707                 if ( $action == 'create' ) {
1708                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1709                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1710                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1711                         }
1712                 } elseif ( $action == 'move' ) {
1713                         if ( !$user->isAllowed( 'move-rootuserpages' )
1714                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1715                                 // Show user page-specific message only if the user can move other pages
1716                                 $errors[] = array( 'cant-move-user-page' );
1717                         }
1718
1719                         // Check if user is allowed to move files if it's a file
1720                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1721                                 $errors[] = array( 'movenotallowedfile' );
1722                         }
1723
1724                         if ( !$user->isAllowed( 'move' ) ) {
1725                                 // User can't move anything
1726                                 global $wgGroupPermissions;
1727                                 $userCanMove = false;
1728                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1729                                         $userCanMove = $wgGroupPermissions['user']['move'];
1730                                 }
1731                                 $autoconfirmedCanMove = false;
1732                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1733                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1734                                 }
1735                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1736                                         // custom message if logged-in users without any special rights can move
1737                                         $errors[] = array( 'movenologintext' );
1738                                 } else {
1739                                         $errors[] = array( 'movenotallowed' );
1740                                 }
1741                         }
1742                 } elseif ( $action == 'move-target' ) {
1743                         if ( !$user->isAllowed( 'move' ) ) {
1744                                 // User can't move anything
1745                                 $errors[] = array( 'movenotallowed' );
1746                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1747                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1748                                 // Show user page-specific message only if the user can move other pages
1749                                 $errors[] = array( 'cant-move-to-user-page' );
1750                         }
1751                 } elseif ( !$user->isAllowed( $action ) ) {
1752                         $errors[] = $this->missingPermissionError( $action, $short );
1753                 }
1754
1755                 return $errors;
1756         }
1757
1758         /**
1759          * Add the resulting error code to the errors array
1760          *
1761          * @param $errors Array list of current errors
1762          * @param $result Mixed result of errors
1763          *
1764          * @return Array list of errors
1765          */
1766         private function resultToError( $errors, $result ) {
1767                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1768                         // A single array representing an error
1769                         $errors[] = $result;
1770                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1771                         // A nested array representing multiple errors
1772                         $errors = array_merge( $errors, $result );
1773                 } elseif ( $result !== '' && is_string( $result ) ) {
1774                         // A string representing a message-id
1775                         $errors[] = array( $result );
1776                 } elseif ( $result === false ) {
1777                         // a generic "We don't want them to do that"
1778                         $errors[] = array( 'badaccess-group0' );
1779                 }
1780                 return $errors;
1781         }
1782
1783         /**
1784          * Check various permission hooks
1785          *
1786          * @param $action String the action to check
1787          * @param $user User user to check
1788          * @param $errors Array list of current errors
1789          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1790          * @param $short Boolean short circuit on first error
1791          *
1792          * @return Array list of errors
1793          */
1794         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1795                 // Use getUserPermissionsErrors instead
1796                 $result = '';
1797                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1798                         return $result ? array() : array( array( 'badaccess-group0' ) );
1799                 }
1800                 // Check getUserPermissionsErrors hook
1801                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1802                         $errors = $this->resultToError( $errors, $result );
1803                 }
1804                 // Check getUserPermissionsErrorsExpensive hook
1805                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1806                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1807                         $errors = $this->resultToError( $errors, $result );
1808                 }
1809
1810                 return $errors;
1811         }
1812
1813         /**
1814          * Check permissions on special pages & namespaces
1815          *
1816          * @param $action String the action to check
1817          * @param $user User user to check
1818          * @param $errors Array list of current errors
1819          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1820          * @param $short Boolean short circuit on first error
1821          *
1822          * @return Array list of errors
1823          */
1824         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1825                 # Only 'createaccount' and 'execute' can be performed on
1826                 # special pages, which don't actually exist in the DB.
1827                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1828                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1829                         $errors[] = array( 'ns-specialprotected' );
1830                 }
1831
1832                 # Check $wgNamespaceProtection for restricted namespaces
1833                 if ( $this->isNamespaceProtected( $user ) ) {
1834                         $ns = $this->mNamespace == NS_MAIN ?
1835                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1836                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1837                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1838                 }
1839
1840                 return $errors;
1841         }
1842
1843         /**
1844          * Check CSS/JS sub-page permissions
1845          *
1846          * @param $action String the action to check
1847          * @param $user User user to check
1848          * @param $errors Array list of current errors
1849          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1850          * @param $short Boolean short circuit on first error
1851          *
1852          * @return Array list of errors
1853          */
1854         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1855                 # Protect css/js subpages of user pages
1856                 # XXX: this might be better using restrictions
1857                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1858                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1859                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1860                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1861                                 $errors[] = array( 'customcssprotected' );
1862                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1863                                 $errors[] = array( 'customjsprotected' );
1864                         }
1865                 }
1866
1867                 return $errors;
1868         }
1869
1870         /**
1871          * Check against page_restrictions table requirements on this
1872          * page. The user must possess all required rights for this
1873          * action.
1874          *
1875          * @param $action String the action to check
1876          * @param $user User user to check
1877          * @param $errors Array list of current errors
1878          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1879          * @param $short Boolean short circuit on first error
1880          *
1881          * @return Array list of errors
1882          */
1883         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1884                 foreach ( $this->getRestrictions( $action ) as $right ) {
1885                         // Backwards compatibility, rewrite sysop -> protect
1886                         if ( $right == 'sysop' ) {
1887                                 $right = 'protect';
1888                         }
1889                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1890                                 // Users with 'editprotected' permission can edit protected pages
1891                                 // without cascading option turned on.
1892                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1893                                         || $this->mCascadeRestriction )
1894                                 {
1895                                         $errors[] = array( 'protectedpagetext', $right );
1896                                 }
1897                         }
1898                 }
1899
1900                 return $errors;
1901         }
1902
1903         /**
1904          * Check restrictions on cascading pages.
1905          *
1906          * @param $action String the action to check
1907          * @param $user User to check
1908          * @param $errors Array list of current errors
1909          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1910          * @param $short Boolean short circuit on first error
1911          *
1912          * @return Array list of errors
1913          */
1914         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1915                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1916                         # We /could/ use the protection level on the source page, but it's
1917                         # fairly ugly as we have to establish a precedence hierarchy for pages
1918                         # included by multiple cascade-protected pages. So just restrict
1919                         # it to people with 'protect' permission, as they could remove the
1920                         # protection anyway.
1921                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1922                         # Cascading protection depends on more than this page...
1923                         # Several cascading protected pages may include this page...
1924                         # Check each cascading level
1925                         # This is only for protection restrictions, not for all actions
1926                         if ( isset( $restrictions[$action] ) ) {
1927                                 foreach ( $restrictions[$action] as $right ) {
1928                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1929                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1930                                                 $pages = '';
1931                                                 foreach ( $cascadingSources as $page )
1932                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1933                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1934                                         }
1935                                 }
1936                         }
1937                 }
1938
1939                 return $errors;
1940         }
1941
1942         /**
1943          * Check action permissions not already checked in checkQuickPermissions
1944          *
1945          * @param $action String the action to check
1946          * @param $user User to check
1947          * @param $errors Array list of current errors
1948          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1949          * @param $short Boolean short circuit on first error
1950          *
1951          * @return Array list of errors
1952          */
1953         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1954                 global $wgDeleteRevisionsLimit, $wgLang;
1955
1956                 if ( $action == 'protect' ) {
1957                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1958                                 // If they can't edit, they shouldn't protect.
1959                                 $errors[] = array( 'protect-cantedit' );
1960                         }
1961                 } elseif ( $action == 'create' ) {
1962                         $title_protection = $this->getTitleProtection();
1963                         if( $title_protection ) {
1964                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1965                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1966                                 }
1967                                 if( $title_protection['pt_create_perm'] == '' ||
1968                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1969                                 {
1970                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1971                                 }
1972                         }
1973                 } elseif ( $action == 'move' ) {
1974                         // Check for immobile pages
1975                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1976                                 // Specific message for this case
1977                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1978                         } elseif ( !$this->isMovable() ) {
1979                                 // Less specific message for rarer cases
1980                                 $errors[] = array( 'immobile-source-page' );
1981                         }
1982                 } elseif ( $action == 'move-target' ) {
1983                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1984                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1985                         } elseif ( !$this->isMovable() ) {
1986                                 $errors[] = array( 'immobile-target-page' );
1987                         }
1988                 } elseif ( $action == 'delete' ) {
1989                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1990                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1991                         {
1992                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1993                         }
1994                 }
1995                 return $errors;
1996         }
1997
1998         /**
1999          * Check that the user isn't blocked from editting.
2000          *
2001          * @param $action String the action to check
2002          * @param $user User to check
2003          * @param $errors Array list of current errors
2004          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2005          * @param $short Boolean short circuit on first error
2006          *
2007          * @return Array list of errors
2008          */
2009         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2010                 // Account creation blocks handled at userlogin.
2011                 // Unblocking handled in SpecialUnblock
2012                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2013                         return $errors;
2014                 }
2015
2016                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
2017
2018                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2019                         $errors[] = array( 'confirmedittext' );
2020                 }
2021
2022                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2023                         // Don't block the user from editing their own talk page unless they've been
2024                         // explicitly blocked from that too.
2025                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2026                         $block = $user->getBlock();
2027
2028                         // This is from OutputPage::blockedPage
2029                         // Copied at r23888 by werdna
2030
2031                         $id = $user->blockedBy();
2032                         $reason = $user->blockedFor();
2033                         if ( $reason == '' ) {
2034                                 $reason = wfMessage( 'blockednoreason' )->text();
2035                         }
2036                         $ip = $user->getRequest()->getIP();
2037
2038                         if ( is_numeric( $id ) ) {
2039                                 $name = User::whoIs( $id );
2040                         } else {
2041                                 $name = $id;
2042                         }
2043
2044                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
2045                         $blockid = $block->getId();
2046                         $blockExpiry = $block->getExpiry();
2047                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2048                         if ( $blockExpiry == 'infinity' ) {
2049                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2050                         } else {
2051                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2052                         }
2053
2054                         $intended = strval( $block->getTarget() );
2055
2056                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2057                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2058                 }
2059
2060                 return $errors;
2061         }
2062
2063         /**
2064          * Check that the user is allowed to read this page.
2065          *
2066          * @param $action String the action to check
2067          * @param $user User to check
2068          * @param $errors Array list of current errors
2069          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2070          * @param $short Boolean short circuit on first error
2071          *
2072          * @return Array list of errors
2073          */
2074         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2075                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2076                 static $useShortcut = null;
2077
2078                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2079                 if ( is_null( $useShortcut ) ) {
2080                         $useShortcut = true;
2081                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2082                                 # Not a public wiki, so no shortcut
2083                                 $useShortcut = false;
2084                         } elseif ( !empty( $wgRevokePermissions ) ) {
2085                                 /**
2086                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2087                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2088                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2089                                  * reading is allowed.
2090                                  */
2091                                 foreach ( $wgRevokePermissions as $perms ) {
2092                                         if ( !empty( $perms['read'] ) ) {
2093                                                 # We might be removing the read right from the user, so no shortcut
2094                                                 $useShortcut = false;
2095                                                 break;
2096                                         }
2097                                 }
2098                         }
2099                 }
2100
2101                 $whitelisted = false;
2102                 if ( $useShortcut ) {
2103                         # Shortcut for public wikis, allows skipping quite a bit of code
2104                         $whitelisted = true;
2105                 } elseif ( $user->isAllowed( 'read' ) ) {
2106                         # If the user is allowed to read pages, he is allowed to read all pages
2107                         $whitelisted = true;
2108                 } elseif ( $this->isSpecial( 'Userlogin' )
2109                         || $this->isSpecial( 'ChangePassword' )
2110                         || $this->isSpecial( 'PasswordReset' )
2111                 ) {
2112                         # Always grant access to the login page.
2113                         # Even anons need to be able to log in.
2114                         $whitelisted = true;
2115                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2116                         # Time to check the whitelist
2117                         # Only do these checks is there's something to check against
2118                         $name = $this->getPrefixedText();
2119                         $dbName = $this->getPrefixedDBKey();
2120
2121                         // Check for explicit whitelisting with and without underscores
2122                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2123                                 $whitelisted = true;
2124                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2125                                 # Old settings might have the title prefixed with
2126                                 # a colon for main-namespace pages
2127                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2128                                         $whitelisted = true;
2129                                 }
2130                         } elseif ( $this->isSpecialPage() ) {
2131                                 # If it's a special page, ditch the subpage bit and check again
2132                                 $name = $this->getDBkey();
2133                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2134                                 if ( $name !== false ) {
2135                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2136                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2137                                                 $whitelisted = true;
2138                                         }
2139                                 }
2140                         }
2141                 }
2142
2143                 if ( !$whitelisted ) {
2144                         # If the title is not whitelisted, give extensions a chance to do so...
2145                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2146                         if ( !$whitelisted ) {
2147                                 $errors[] = $this->missingPermissionError( $action, $short );
2148                         }
2149                 }
2150
2151                 return $errors;
2152         }
2153
2154         /**
2155          * Get a description array when the user doesn't have the right to perform
2156          * $action (i.e. when User::isAllowed() returns false)
2157          *
2158          * @param $action String the action to check
2159          * @param $short Boolean short circuit on first error
2160          * @return Array list of errors
2161          */
2162         private function missingPermissionError( $action, $short ) {
2163                 // We avoid expensive display logic for quickUserCan's and such
2164                 if ( $short ) {
2165                         return array( 'badaccess-group0' );
2166                 }
2167
2168                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2169                         User::getGroupsWithPermission( $action ) );
2170
2171                 if ( count( $groups ) ) {
2172                         global $wgLang;
2173                         return array(
2174                                 'badaccess-groups',
2175                                 $wgLang->commaList( $groups ),
2176                                 count( $groups )
2177                         );
2178                 } else {
2179                         return array( 'badaccess-group0' );
2180                 }
2181         }
2182
2183         /**
2184          * Can $user perform $action on this page? This is an internal function,
2185          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2186          * checks on wfReadOnly() and blocks)
2187          *
2188          * @param $action String action that permission needs to be checked for
2189          * @param $user User to check
2190          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2191          * @param $short Bool Set this to true to stop after the first permission error.
2192          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2193          */
2194         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2195                 wfProfileIn( __METHOD__ );
2196
2197                 # Read has special handling
2198                 if ( $action == 'read' ) {
2199                         $checks = array(
2200                                 'checkPermissionHooks',
2201                                 'checkReadPermissions',
2202                         );
2203                 } else {
2204                         $checks = array(
2205                                 'checkQuickPermissions',
2206                                 'checkPermissionHooks',
2207                                 'checkSpecialsAndNSPermissions',
2208                                 'checkCSSandJSPermissions',
2209                                 'checkPageRestrictions',
2210                                 'checkCascadingSourcesRestrictions',
2211                                 'checkActionPermissions',
2212                                 'checkUserBlock'
2213                         );
2214                 }
2215
2216                 $errors = array();
2217                 while( count( $checks ) > 0 &&
2218                                 !( $short && count( $errors ) > 0 ) ) {
2219                         $method = array_shift( $checks );
2220                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2221                 }
2222
2223                 wfProfileOut( __METHOD__ );
2224                 return $errors;
2225         }
2226
2227         /**
2228          * Protect css subpages of user pages: can $wgUser edit
2229          * this page?
2230          *
2231          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2232          * @return Bool
2233          */
2234         public function userCanEditCssSubpage() {
2235                 global $wgUser;
2236                 wfDeprecated( __METHOD__, '1.19' );
2237                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2238                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2239         }
2240
2241         /**
2242          * Protect js subpages of user pages: can $wgUser edit
2243          * this page?
2244          *
2245          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2246          * @return Bool
2247          */
2248         public function userCanEditJsSubpage() {
2249                 global $wgUser;
2250                 wfDeprecated( __METHOD__, '1.19' );
2251                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2252                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2253         }
2254
2255         /**
2256          * Get a filtered list of all restriction types supported by this wiki.
2257          * @param bool $exists True to get all restriction types that apply to
2258          * titles that do exist, False for all restriction types that apply to
2259          * titles that do not exist
2260          * @return array
2261          */
2262         public static function getFilteredRestrictionTypes( $exists = true ) {
2263                 global $wgRestrictionTypes;
2264                 $types = $wgRestrictionTypes;
2265                 if ( $exists ) {
2266                         # Remove the create restriction for existing titles
2267                         $types = array_diff( $types, array( 'create' ) );
2268                 } else {
2269                         # Only the create and upload restrictions apply to non-existing titles
2270                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2271                 }
2272                 return $types;
2273         }
2274
2275         /**
2276          * Returns restriction types for the current Title
2277          *
2278          * @return array applicable restriction types
2279          */
2280         public function getRestrictionTypes() {
2281                 if ( $this->isSpecialPage() ) {
2282                         return array();
2283                 }
2284
2285                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2286
2287                 if ( $this->getNamespace() != NS_FILE ) {
2288                         # Remove the upload restriction for non-file titles
2289                         $types = array_diff( $types, array( 'upload' ) );
2290                 }
2291
2292                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2293
2294                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2295                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2296
2297                 return $types;
2298         }
2299
2300         /**
2301          * Is this title subject to title protection?
2302          * Title protection is the one applied against creation of such title.
2303          *
2304          * @return Mixed An associative array representing any existent title
2305          *   protection, or false if there's none.
2306          */
2307         private function getTitleProtection() {
2308                 // Can't protect pages in special namespaces
2309                 if ( $this->getNamespace() < 0 ) {
2310                         return false;
2311                 }
2312
2313                 // Can't protect pages that exist.
2314                 if ( $this->exists() ) {
2315                         return false;
2316                 }
2317
2318                 if ( !isset( $this->mTitleProtection ) ) {
2319                         $dbr = wfGetDB( DB_SLAVE );
2320                         $res = $dbr->select( 'protected_titles', '*',
2321                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2322                                 __METHOD__ );
2323
2324                         // fetchRow returns false if there are no rows.
2325                         $this->mTitleProtection = $dbr->fetchRow( $res );
2326                 }
2327                 return $this->mTitleProtection;
2328         }
2329
2330         /**
2331          * Update the title protection status
2332          *
2333          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2334          * @param $create_perm String Permission required for creation
2335          * @param $reason String Reason for protection
2336          * @param $expiry String Expiry timestamp
2337          * @return boolean true
2338          */
2339         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2340                 wfDeprecated( __METHOD__, '1.19' );
2341
2342                 global $wgUser;
2343
2344                 $limit = array( 'create' => $create_perm );
2345                 $expiry = array( 'create' => $expiry );
2346
2347                 $page = WikiPage::factory( $this );
2348                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2349
2350                 return $status->isOK();
2351         }
2352
2353         /**
2354          * Remove any title protection due to page existing
2355          */
2356         public function deleteTitleProtection() {
2357                 $dbw = wfGetDB( DB_MASTER );
2358
2359                 $dbw->delete(
2360                         'protected_titles',
2361                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2362                         __METHOD__
2363                 );
2364                 $this->mTitleProtection = false;
2365         }
2366
2367         /**
2368          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2369          *
2370          * @param $action String Action to check (default: edit)
2371          * @return Bool
2372          */
2373         public function isSemiProtected( $action = 'edit' ) {
2374                 if ( $this->exists() ) {
2375                         $restrictions = $this->getRestrictions( $action );
2376                         if ( count( $restrictions ) > 0 ) {
2377                                 foreach ( $restrictions as $restriction ) {
2378                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2379                                                 return false;
2380                                         }
2381                                 }
2382                         } else {
2383                                 # Not protected
2384                                 return false;
2385                         }
2386                         return true;
2387                 } else {
2388                         # If it doesn't exist, it can't be protected
2389                         return false;
2390                 }
2391         }
2392
2393         /**
2394          * Does the title correspond to a protected article?
2395          *
2396          * @param $action String the action the page is protected from,
2397          * by default checks all actions.
2398          * @return Bool
2399          */
2400         public function isProtected( $action = '' ) {
2401                 global $wgRestrictionLevels;
2402
2403                 $restrictionTypes = $this->getRestrictionTypes();
2404
2405                 # Special pages have inherent protection
2406                 if( $this->isSpecialPage() ) {
2407                         return true;
2408                 }
2409
2410                 # Check regular protection levels
2411                 foreach ( $restrictionTypes as $type ) {
2412                         if ( $action == $type || $action == '' ) {
2413                                 $r = $this->getRestrictions( $type );
2414                                 foreach ( $wgRestrictionLevels as $level ) {
2415                                         if ( in_array( $level, $r ) && $level != '' ) {
2416                                                 return true;
2417                                         }
2418                                 }
2419                         }
2420                 }
2421
2422                 return false;
2423         }
2424
2425         /**
2426          * Determines if $user is unable to edit this page because it has been protected
2427          * by $wgNamespaceProtection.
2428          *
2429          * @param $user User object to check permissions
2430          * @return Bool
2431          */
2432         public function isNamespaceProtected( User $user ) {
2433                 global $wgNamespaceProtection;
2434
2435                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2436                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2437                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2438                                         return true;
2439                                 }
2440                         }
2441                 }
2442                 return false;
2443         }
2444
2445         /**
2446          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2447          *
2448          * @return Bool If the page is subject to cascading restrictions.
2449          */
2450         public function isCascadeProtected() {
2451                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2452                 return ( $sources > 0 );
2453         }
2454
2455         /**
2456          * Cascading protection: Get the source of any cascading restrictions on this page.
2457          *
2458          * @param $getPages Bool Whether or not to retrieve the actual pages
2459          *        that the restrictions have come from.
2460          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2461          *     have come, false for none, or true if such restrictions exist, but $getPages
2462          *     was not set.  The restriction array is an array of each type, each of which
2463          *     contains a array of unique groups.
2464          */
2465         public function getCascadeProtectionSources( $getPages = true ) {
2466                 global $wgContLang;
2467                 $pagerestrictions = array();
2468
2469                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2470                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2471                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2472                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2473                 }
2474
2475                 wfProfileIn( __METHOD__ );
2476
2477                 $dbr = wfGetDB( DB_SLAVE );
2478
2479                 if ( $this->getNamespace() == NS_FILE ) {
2480                         $tables = array( 'imagelinks', 'page_restrictions' );
2481                         $where_clauses = array(
2482                                 'il_to' => $this->getDBkey(),
2483                                 'il_from=pr_page',
2484                                 'pr_cascade' => 1
2485                         );
2486                 } else {
2487                         $tables = array( 'templatelinks', 'page_restrictions' );
2488                         $where_clauses = array(
2489                                 'tl_namespace' => $this->getNamespace(),
2490                                 'tl_title' => $this->getDBkey(),
2491                                 'tl_from=pr_page',
2492                                 'pr_cascade' => 1
2493                         );
2494                 }
2495
2496                 if ( $getPages ) {
2497                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2498                                                    'pr_expiry', 'pr_type', 'pr_level' );
2499                         $where_clauses[] = 'page_id=pr_page';
2500                         $tables[] = 'page';
2501                 } else {
2502                         $cols = array( 'pr_expiry' );
2503                 }
2504
2505                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2506
2507                 $sources = $getPages ? array() : false;
2508                 $now = wfTimestampNow();
2509                 $purgeExpired = false;
2510
2511                 foreach ( $res as $row ) {
2512                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2513                         if ( $expiry > $now ) {
2514                                 if ( $getPages ) {
2515                                         $page_id = $row->pr_page;
2516                                         $page_ns = $row->page_namespace;
2517                                         $page_title = $row->page_title;
2518                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2519                                         # Add groups needed for each restriction type if its not already there
2520                                         # Make sure this restriction type still exists
2521
2522                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2523                                                 $pagerestrictions[$row->pr_type] = array();
2524                                         }
2525
2526                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2527                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2528                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2529                                         }
2530                                 } else {
2531                                         $sources = true;
2532                                 }
2533                         } else {
2534                                 // Trigger lazy purge of expired restrictions from the db
2535                                 $purgeExpired = true;
2536                         }
2537                 }
2538                 if ( $purgeExpired ) {
2539                         Title::purgeExpiredRestrictions();
2540                 }
2541
2542                 if ( $getPages ) {
2543                         $this->mCascadeSources = $sources;
2544                         $this->mCascadingRestrictions = $pagerestrictions;
2545                 } else {
2546                         $this->mHasCascadingRestrictions = $sources;
2547                 }
2548
2549                 wfProfileOut( __METHOD__ );
2550                 return array( $sources, $pagerestrictions );
2551         }
2552
2553         /**
2554          * Accessor/initialisation for mRestrictions
2555          *
2556          * @param $action String action that permission needs to be checked for
2557          * @return Array of Strings the array of groups allowed to edit this article
2558          */
2559         public function getRestrictions( $action ) {
2560                 if ( !$this->mRestrictionsLoaded ) {
2561                         $this->loadRestrictions();
2562                 }
2563                 return isset( $this->mRestrictions[$action] )
2564                                 ? $this->mRestrictions[$action]
2565                                 : array();
2566         }
2567
2568         /**
2569          * Get the expiry time for the restriction against a given action
2570          *
2571          * @param $action
2572          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2573          *     or not protected at all, or false if the action is not recognised.
2574          */
2575         public function getRestrictionExpiry( $action ) {
2576                 if ( !$this->mRestrictionsLoaded ) {
2577                         $this->loadRestrictions();
2578                 }
2579                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2580         }
2581
2582         /**
2583          * Returns cascading restrictions for the current article
2584          *
2585          * @return Boolean
2586          */
2587         function areRestrictionsCascading() {
2588                 if ( !$this->mRestrictionsLoaded ) {
2589                         $this->loadRestrictions();
2590                 }
2591
2592                 return $this->mCascadeRestriction;
2593         }
2594
2595         /**
2596          * Loads a string into mRestrictions array
2597          *
2598          * @param $res Resource restrictions as an SQL result.
2599          * @param $oldFashionedRestrictions String comma-separated list of page
2600          *        restrictions from page table (pre 1.10)
2601          */
2602         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2603                 $rows = array();
2604
2605                 foreach ( $res as $row ) {
2606                         $rows[] = $row;
2607                 }
2608
2609                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2610         }
2611
2612         /**
2613          * Compiles list of active page restrictions from both page table (pre 1.10)
2614          * and page_restrictions table for this existing page.
2615          * Public for usage by LiquidThreads.
2616          *
2617          * @param $rows array of db result objects
2618          * @param $oldFashionedRestrictions string comma-separated list of page
2619          *        restrictions from page table (pre 1.10)
2620          */
2621         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2622                 global $wgContLang;
2623                 $dbr = wfGetDB( DB_SLAVE );
2624
2625                 $restrictionTypes = $this->getRestrictionTypes();
2626
2627                 foreach ( $restrictionTypes as $type ) {
2628                         $this->mRestrictions[$type] = array();
2629                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2630                 }
2631
2632                 $this->mCascadeRestriction = false;
2633
2634                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2635
2636                 if ( $oldFashionedRestrictions === null ) {
2637                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2638                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2639                 }
2640
2641                 if ( $oldFashionedRestrictions != '' ) {
2642
2643                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2644                                 $temp = explode( '=', trim( $restrict ) );
2645                                 if ( count( $temp ) == 1 ) {
2646                                         // old old format should be treated as edit/move restriction
2647                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2648                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2649                                 } else {
2650                                         $restriction = trim( $temp[1] );
2651                                         if( $restriction != '' ) { //some old entries are empty
2652                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2653                                         }
2654                                 }
2655                         }
2656
2657                         $this->mOldRestrictions = true;
2658
2659                 }
2660
2661                 if ( count( $rows ) ) {
2662                         # Current system - load second to make them override.
2663                         $now = wfTimestampNow();
2664                         $purgeExpired = false;
2665
2666                         # Cycle through all the restrictions.
2667                         foreach ( $rows as $row ) {
2668
2669                                 // Don't take care of restrictions types that aren't allowed
2670                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2671                                         continue;
2672
2673                                 // This code should be refactored, now that it's being used more generally,
2674                                 // But I don't really see any harm in leaving it in Block for now -werdna
2675                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2676
2677                                 // Only apply the restrictions if they haven't expired!
2678                                 if ( !$expiry || $expiry > $now ) {
2679                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2680                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2681
2682                                         $this->mCascadeRestriction |= $row->pr_cascade;
2683                                 } else {
2684                                         // Trigger a lazy purge of expired restrictions
2685                                         $purgeExpired = true;
2686                                 }
2687                         }
2688
2689                         if ( $purgeExpired ) {
2690                                 Title::purgeExpiredRestrictions();
2691                         }
2692                 }
2693
2694                 $this->mRestrictionsLoaded = true;
2695         }
2696
2697         /**
2698          * Load restrictions from the page_restrictions table
2699          *
2700          * @param $oldFashionedRestrictions String comma-separated list of page
2701          *        restrictions from page table (pre 1.10)
2702          */
2703         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2704                 global $wgContLang;
2705                 if ( !$this->mRestrictionsLoaded ) {
2706                         if ( $this->exists() ) {
2707                                 $dbr = wfGetDB( DB_SLAVE );
2708
2709                                 $res = $dbr->select(
2710                                         'page_restrictions',
2711                                         '*',
2712                                         array( 'pr_page' => $this->getArticleID() ),
2713                                         __METHOD__
2714                                 );
2715
2716                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2717                         } else {
2718                                 $title_protection = $this->getTitleProtection();
2719
2720                                 if ( $title_protection ) {
2721                                         $now = wfTimestampNow();
2722                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2723
2724                                         if ( !$expiry || $expiry > $now ) {
2725                                                 // Apply the restrictions
2726                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2727                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2728                                         } else { // Get rid of the old restrictions
2729                                                 Title::purgeExpiredRestrictions();
2730                                                 $this->mTitleProtection = false;
2731                                         }
2732                                 } else {
2733                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2734                                 }
2735                                 $this->mRestrictionsLoaded = true;
2736                         }
2737                 }
2738         }
2739
2740         /**
2741          * Flush the protection cache in this object and force reload from the database.
2742          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2743          */
2744         public function flushRestrictions() {
2745                 $this->mRestrictionsLoaded = false;
2746                 $this->mTitleProtection = null;
2747         }
2748
2749         /**
2750          * Purge expired restrictions from the page_restrictions table
2751          */
2752         static function purgeExpiredRestrictions() {
2753                 $dbw = wfGetDB( DB_MASTER );
2754                 $dbw->delete(
2755                         'page_restrictions',
2756                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2757                         __METHOD__
2758                 );
2759
2760                 $dbw->delete(
2761                         'protected_titles',
2762                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2763                         __METHOD__
2764                 );
2765         }
2766
2767         /**
2768          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2769          *
2770          * @return Bool
2771          */
2772         public function hasSubpages() {
2773                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2774                         # Duh
2775                         return false;
2776                 }
2777
2778                 # We dynamically add a member variable for the purpose of this method
2779                 # alone to cache the result.  There's no point in having it hanging
2780                 # around uninitialized in every Title object; therefore we only add it
2781                 # if needed and don't declare it statically.
2782                 if ( isset( $this->mHasSubpages ) ) {
2783                         return $this->mHasSubpages;
2784                 }
2785
2786                 $subpages = $this->getSubpages( 1 );
2787                 if ( $subpages instanceof TitleArray ) {
2788                         return $this->mHasSubpages = (bool)$subpages->count();
2789                 }
2790                 return $this->mHasSubpages = false;
2791         }
2792
2793         /**
2794          * Get all subpages of this page.
2795          *
2796          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2797          * @return mixed TitleArray, or empty array if this page's namespace
2798          *  doesn't allow subpages
2799          */
2800         public function getSubpages( $limit = -1 ) {
2801                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2802                         return array();
2803                 }
2804
2805                 $dbr = wfGetDB( DB_SLAVE );
2806                 $conds['page_namespace'] = $this->getNamespace();
2807                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2808                 $options = array();
2809                 if ( $limit > -1 ) {
2810                         $options['LIMIT'] = $limit;
2811                 }
2812                 return $this->mSubpages = TitleArray::newFromResult(
2813                         $dbr->select( 'page',
2814                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2815                                 $conds,
2816                                 __METHOD__,
2817                                 $options
2818                         )
2819                 );
2820         }
2821
2822         /**
2823          * Is there a version of this page in the deletion archive?
2824          *
2825          * @return Int the number of archived revisions
2826          */
2827         public function isDeleted() {
2828                 if ( $this->getNamespace() < 0 ) {
2829                         $n = 0;
2830                 } else {
2831                         $dbr = wfGetDB( DB_SLAVE );
2832
2833                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2834                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2835                                 __METHOD__
2836                         );
2837                         if ( $this->getNamespace() == NS_FILE ) {
2838                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2839                                         array( 'fa_name' => $this->getDBkey() ),
2840                                         __METHOD__
2841                                 );
2842                         }
2843                 }
2844                 return (int)$n;
2845         }
2846
2847         /**
2848          * Is there a version of this page in the deletion archive?
2849          *
2850          * @return Boolean
2851          */
2852         public function isDeletedQuick() {
2853                 if ( $this->getNamespace() < 0 ) {
2854                         return false;
2855                 }
2856                 $dbr = wfGetDB( DB_SLAVE );
2857                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2858                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2859                         __METHOD__
2860                 );
2861                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2862                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2863                                 array( 'fa_name' => $this->getDBkey() ),
2864                                 __METHOD__
2865                         );
2866                 }
2867                 return $deleted;
2868         }
2869
2870         /**
2871          * Get the article ID for this Title from the link cache,
2872          * adding it if necessary
2873          *
2874          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2875          *  for update
2876          * @return Int the ID
2877          */
2878         public function getArticleID( $flags = 0 ) {
2879                 if ( $this->getNamespace() < 0 ) {
2880                         return $this->mArticleID = 0;
2881                 }
2882                 $linkCache = LinkCache::singleton();
2883                 if ( $flags & self::GAID_FOR_UPDATE ) {
2884                         $oldUpdate = $linkCache->forUpdate( true );
2885                         $linkCache->clearLink( $this );
2886                         $this->mArticleID = $linkCache->addLinkObj( $this );
2887                         $linkCache->forUpdate( $oldUpdate );
2888                 } else {
2889                         if ( -1 == $this->mArticleID ) {
2890                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2891                         }
2892                 }
2893                 return $this->mArticleID;
2894         }
2895
2896         /**
2897          * Is this an article that is a redirect page?
2898          * Uses link cache, adding it if necessary
2899          *
2900          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2901          * @return Bool
2902          */
2903         public function isRedirect( $flags = 0 ) {
2904                 if ( !is_null( $this->mRedirect ) ) {
2905                         return $this->mRedirect;
2906                 }
2907                 # Calling getArticleID() loads the field from cache as needed
2908                 if ( !$this->getArticleID( $flags ) ) {
2909                         return $this->mRedirect = false;
2910                 }
2911                 $linkCache = LinkCache::singleton();
2912                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2913
2914                 return $this->mRedirect;
2915         }
2916
2917         /**
2918          * What is the length of this page?
2919          * Uses link cache, adding it if necessary
2920          *
2921          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2922          * @return Int
2923          */
2924         public function getLength( $flags = 0 ) {
2925                 if ( $this->mLength != -1 ) {
2926                         return $this->mLength;
2927                 }
2928                 # Calling getArticleID() loads the field from cache as needed
2929                 if ( !$this->getArticleID( $flags ) ) {
2930                         return $this->mLength = 0;
2931                 }
2932                 $linkCache = LinkCache::singleton();
2933                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2934
2935                 return $this->mLength;
2936         }
2937
2938         /**
2939          * What is the page_latest field for this page?
2940          *
2941          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2942          * @return Int or 0 if the page doesn't exist
2943          */
2944         public function getLatestRevID( $flags = 0 ) {
2945                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
2946                         return intval( $this->mLatestID );
2947                 }
2948                 # Calling getArticleID() loads the field from cache as needed
2949                 if ( !$this->getArticleID( $flags ) ) {
2950                         return $this->mLatestID = 0;
2951                 }
2952                 $linkCache = LinkCache::singleton();
2953                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2954
2955                 return $this->mLatestID;
2956         }
2957
2958         /**
2959          * This clears some fields in this object, and clears any associated
2960          * keys in the "bad links" section of the link cache.
2961          *
2962          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2963          * loading of the new page_id. It's also called from
2964          * WikiPage::doDeleteArticleReal()
2965          *
2966          * @param $newid Int the new Article ID
2967          */
2968         public function resetArticleID( $newid ) {
2969                 $linkCache = LinkCache::singleton();
2970                 $linkCache->clearLink( $this );
2971
2972                 if ( $newid === false ) {
2973                         $this->mArticleID = -1;
2974                 } else {
2975                         $this->mArticleID = intval( $newid );
2976                 }
2977                 $this->mRestrictionsLoaded = false;
2978                 $this->mRestrictions = array();
2979                 $this->mRedirect = null;
2980                 $this->mLength = -1;
2981                 $this->mLatestID = false;
2982                 $this->mEstimateRevisions = null;
2983         }
2984
2985         /**
2986          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2987          *
2988          * @param $text String containing title to capitalize
2989          * @param $ns int namespace index, defaults to NS_MAIN
2990          * @return String containing capitalized title
2991          */
2992         public static function capitalize( $text, $ns = NS_MAIN ) {
2993                 global $wgContLang;
2994
2995                 if ( MWNamespace::isCapitalized( $ns ) ) {
2996                         return $wgContLang->ucfirst( $text );
2997                 } else {
2998                         return $text;
2999                 }
3000         }
3001
3002         /**
3003          * Secure and split - main initialisation function for this object
3004          *
3005          * Assumes that mDbkeyform has been set, and is urldecoded
3006          * and uses underscores, but not otherwise munged.  This function
3007          * removes illegal characters, splits off the interwiki and
3008          * namespace prefixes, sets the other forms, and canonicalizes
3009          * everything.
3010          *
3011          * @return Bool true on success
3012          */
3013         private function secureAndSplit() {
3014                 global $wgContLang, $wgLocalInterwiki;
3015
3016                 # Initialisation
3017                 $this->mInterwiki = $this->mFragment = '';
3018                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3019
3020                 $dbkey = $this->mDbkeyform;
3021
3022                 # Strip Unicode bidi override characters.
3023                 # Sometimes they slip into cut-n-pasted page titles, where the
3024                 # override chars get included in list displays.
3025                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3026
3027                 # Clean up whitespace
3028                 # Note: use of the /u option on preg_replace here will cause
3029                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3030                 # conveniently disabling them.
3031                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3032                 $dbkey = trim( $dbkey, '_' );
3033
3034                 if ( $dbkey == '' ) {
3035                         return false;
3036                 }
3037
3038                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
3039                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3040                         return false;
3041                 }
3042
3043                 $this->mDbkeyform = $dbkey;
3044
3045                 # Initial colon indicates main namespace rather than specified default
3046                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3047                 if ( ':' == $dbkey[0] ) {
3048                         $this->mNamespace = NS_MAIN;
3049                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3050                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3051                 }
3052
3053                 # Namespace or interwiki prefix
3054                 $firstPass = true;
3055                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3056                 do {
3057                         $m = array();
3058                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3059                                 $p = $m[1];
3060                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3061                                         # Ordinary namespace
3062                                         $dbkey = $m[2];
3063                                         $this->mNamespace = $ns;
3064                                         # For Talk:X pages, check if X has a "namespace" prefix
3065                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3066                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3067                                                         # Disallow Talk:File:x type titles...
3068                                                         return false;
3069                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3070                                                         # Disallow Talk:Interwiki:x type titles...
3071                                                         return false;
3072                                                 }
3073                                         }
3074                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3075                                         if ( !$firstPass ) {
3076                                                 # Can't make a local interwiki link to an interwiki link.
3077                                                 # That's just crazy!
3078                                                 return false;
3079                                         }
3080
3081                                         # Interwiki link
3082                                         $dbkey = $m[2];
3083                                         $this->mInterwiki = $wgContLang->lc( $p );
3084
3085                                         # Redundant interwiki prefix to the local wiki
3086                                         if ( $wgLocalInterwiki !== false
3087                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3088                                         {
3089                                                 if ( $dbkey == '' ) {
3090                                                         # Can't have an empty self-link
3091                                                         return false;
3092                                                 }
3093                                                 $this->mInterwiki = '';
3094                                                 $firstPass = false;
3095                                                 # Do another namespace split...
3096                                                 continue;
3097                                         }
3098
3099                                         # If there's an initial colon after the interwiki, that also
3100                                         # resets the default namespace
3101                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3102                                                 $this->mNamespace = NS_MAIN;
3103                                                 $dbkey = substr( $dbkey, 1 );
3104                                         }
3105                                 }
3106                                 # If there's no recognized interwiki or namespace,
3107                                 # then let the colon expression be part of the title.
3108                         }
3109                         break;
3110                 } while ( true );
3111
3112                 # We already know that some pages won't be in the database!
3113                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3114                         $this->mArticleID = 0;
3115                 }
3116                 $fragment = strstr( $dbkey, '#' );
3117                 if ( false !== $fragment ) {
3118                         $this->setFragment( $fragment );
3119                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3120                         # remove whitespace again: prevents "Foo_bar_#"
3121                         # becoming "Foo_bar_"
3122                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3123                 }
3124
3125                 # Reject illegal characters.
3126                 $rxTc = self::getTitleInvalidRegex();
3127                 if ( preg_match( $rxTc, $dbkey ) ) {
3128                         return false;
3129                 }
3130
3131                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3132                 # reachable due to the way web browsers deal with 'relative' URLs.
3133                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3134                 if ( strpos( $dbkey, '.' ) !== false &&
3135                          ( $dbkey === '.' || $dbkey === '..' ||
3136                            strpos( $dbkey, './' ) === 0  ||
3137                            strpos( $dbkey, '../' ) === 0 ||
3138                            strpos( $dbkey, '/./' ) !== false ||
3139                            strpos( $dbkey, '/../' ) !== false  ||
3140                            substr( $dbkey, -2 ) == '/.' ||
3141                            substr( $dbkey, -3 ) == '/..' ) )
3142                 {
3143                         return false;
3144                 }
3145
3146                 # Magic tilde sequences? Nu-uh!
3147                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3148                         return false;
3149                 }
3150
3151                 # Limit the size of titles to 255 bytes. This is typically the size of the
3152                 # underlying database field. We make an exception for special pages, which
3153                 # don't need to be stored in the database, and may edge over 255 bytes due
3154                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3155                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3156                   strlen( $dbkey ) > 512 )
3157                 {
3158                         return false;
3159                 }
3160
3161                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3162                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3163                 # other site might be case-sensitive.
3164                 $this->mUserCaseDBKey = $dbkey;
3165                 if ( $this->mInterwiki == '' ) {
3166                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3167                 }
3168
3169                 # Can't make a link to a namespace alone... "empty" local links can only be
3170                 # self-links with a fragment identifier.
3171                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3172                         return false;
3173                 }
3174
3175                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3176                 // IP names are not allowed for accounts, and can only be referring to
3177                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3178                 // there are numerous ways to present the same IP. Having sp:contribs scan
3179                 // them all is silly and having some show the edits and others not is
3180                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3181                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3182                         ? IP::sanitizeIP( $dbkey )
3183                         : $dbkey;
3184
3185                 // Any remaining initial :s are illegal.
3186                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3187                         return false;
3188                 }
3189
3190                 # Fill fields
3191                 $this->mDbkeyform = $dbkey;
3192                 $this->mUrlform = wfUrlencode( $dbkey );
3193
3194                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3195
3196                 return true;
3197         }
3198
3199         /**
3200          * Get an array of Title objects linking to this Title
3201          * Also stores the IDs in the link cache.
3202          *
3203          * WARNING: do not use this function on arbitrary user-supplied titles!
3204          * On heavily-used templates it will max out the memory.
3205          *
3206          * @param $options Array: may be FOR UPDATE
3207          * @param $table String: table name
3208          * @param $prefix String: fields prefix
3209          * @return Array of Title objects linking here
3210          */
3211         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3212                 if ( count( $options ) > 0 ) {
3213                         $db = wfGetDB( DB_MASTER );
3214                 } else {
3215                         $db = wfGetDB( DB_SLAVE );
3216                 }
3217
3218                 $res = $db->select(
3219                         array( 'page', $table ),
3220                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3221                         array(
3222                                 "{$prefix}_from=page_id",
3223                                 "{$prefix}_namespace" => $this->getNamespace(),
3224                                 "{$prefix}_title"     => $this->getDBkey() ),
3225                         __METHOD__,
3226                         $options
3227                 );
3228
3229                 $retVal = array();
3230                 if ( $res->numRows() ) {
3231                         $linkCache = LinkCache::singleton();
3232                         foreach ( $res as $row ) {
3233                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3234                                 if ( $titleObj ) {
3235                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3236                                         $retVal[] = $titleObj;
3237                                 }
3238                         }
3239                 }
3240                 return $retVal;
3241         }
3242
3243         /**
3244          * Get an array of Title objects using this Title as a template
3245          * Also stores the IDs in the link cache.
3246          *
3247          * WARNING: do not use this function on arbitrary user-supplied titles!
3248          * On heavily-used templates it will max out the memory.
3249          *
3250          * @param $options Array: may be FOR UPDATE
3251          * @return Array of Title the Title objects linking here
3252          */
3253         public function getTemplateLinksTo( $options = array() ) {
3254                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3255         }
3256
3257         /**
3258          * Get an array of Title objects linked from this Title
3259          * Also stores the IDs in the link cache.
3260          *
3261          * WARNING: do not use this function on arbitrary user-supplied titles!
3262          * On heavily-used templates it will max out the memory.
3263          *
3264          * @param $options Array: may be FOR UPDATE
3265          * @param $table String: table name
3266          * @param $prefix String: fields prefix
3267          * @return Array of Title objects linking here
3268          */
3269         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3270                 $id = $this->getArticleID();
3271
3272                 # If the page doesn't exist; there can't be any link from this page
3273                 if ( !$id ) {
3274                         return array();
3275                 }
3276
3277                 if ( count( $options ) > 0 ) {
3278                         $db = wfGetDB( DB_MASTER );
3279                 } else {
3280                         $db = wfGetDB( DB_SLAVE );
3281                 }
3282
3283                 $namespaceFiled = "{$prefix}_namespace";
3284                 $titleField = "{$prefix}_title";
3285
3286                 $res = $db->select(
3287                         array( $table, 'page' ),
3288                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3289                         array( "{$prefix}_from" => $id ),
3290                         __METHOD__,
3291                         $options,
3292                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3293                 );
3294
3295                 $retVal = array();
3296                 if ( $res->numRows() ) {
3297                         $linkCache = LinkCache::singleton();
3298                         foreach ( $res as $row ) {
3299                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3300                                 if ( $titleObj ) {
3301                                         if ( $row->page_id ) {
3302                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3303                                         } else {
3304                                                 $linkCache->addBadLinkObj( $titleObj );
3305                                         }
3306                                         $retVal[] = $titleObj;
3307                                 }
3308                         }
3309                 }
3310                 return $retVal;
3311         }
3312
3313         /**
3314          * Get an array of Title objects used on this Title as a template
3315          * Also stores the IDs in the link cache.
3316          *
3317          * WARNING: do not use this function on arbitrary user-supplied titles!
3318          * On heavily-used templates it will max out the memory.
3319          *
3320          * @param $options Array: may be FOR UPDATE
3321          * @return Array of Title the Title objects used here
3322          */
3323         public function getTemplateLinksFrom( $options = array() ) {
3324                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3325         }
3326
3327         /**
3328          * Get an array of Title objects referring to non-existent articles linked from this page
3329          *
3330          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3331          * @return Array of Title the Title objects
3332          */
3333         public function getBrokenLinksFrom() {
3334                 if ( $this->getArticleID() == 0 ) {
3335                         # All links from article ID 0 are false positives
3336                         return array();
3337                 }
3338
3339                 $dbr = wfGetDB( DB_SLAVE );
3340                 $res = $dbr->select(
3341                         array( 'page', 'pagelinks' ),
3342                         array( 'pl_namespace', 'pl_title' ),
3343                         array(
3344                                 'pl_from' => $this->getArticleID(),
3345                                 'page_namespace IS NULL'
3346                         ),
3347                         __METHOD__, array(),
3348                         array(
3349                                 'page' => array(
3350                                         'LEFT JOIN',
3351                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3352                                 )
3353                         )
3354                 );
3355
3356                 $retVal = array();
3357                 foreach ( $res as $row ) {
3358                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3359                 }
3360                 return $retVal;
3361         }
3362
3363
3364         /**
3365          * Get a list of URLs to purge from the Squid cache when this
3366          * page changes
3367          *
3368          * @return Array of String the URLs
3369          */
3370         public function getSquidURLs() {
3371                 $urls = array(
3372                         $this->getInternalURL(),
3373                         $this->getInternalURL( 'action=history' )
3374                 );
3375
3376                 $pageLang = $this->getPageLanguage();
3377                 if ( $pageLang->hasVariants() ) {
3378                         $variants = $pageLang->getVariants();
3379                         foreach ( $variants as $vCode ) {
3380                                 $urls[] = $this->getInternalURL( '', $vCode );
3381                         }
3382                 }
3383
3384                 return $urls;
3385         }
3386
3387         /**
3388          * Purge all applicable Squid URLs
3389          */
3390         public function purgeSquid() {
3391                 global $wgUseSquid;
3392                 if ( $wgUseSquid ) {
3393                         $urls = $this->getSquidURLs();
3394                         $u = new SquidUpdate( $urls );
3395                         $u->doUpdate();
3396                 }
3397         }
3398
3399         /**
3400          * Move this page without authentication
3401          *
3402          * @param $nt Title the new page Title
3403          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3404          */
3405         public function moveNoAuth( &$nt ) {
3406                 return $this->moveTo( $nt, false );
3407         }
3408
3409         /**
3410          * Check whether a given move operation would be valid.
3411          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3412          *
3413          * @param $nt Title the new title
3414          * @param $auth Bool indicates whether $wgUser's permissions
3415          *  should be checked
3416          * @param $reason String is the log summary of the move, used for spam checking
3417          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3418          */
3419         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3420                 global $wgUser;
3421
3422                 $errors = array();
3423                 if ( !$nt ) {
3424                         // Normally we'd add this to $errors, but we'll get
3425                         // lots of syntax errors if $nt is not an object
3426                         return array( array( 'badtitletext' ) );
3427                 }
3428                 if ( $this->equals( $nt ) ) {
3429                         $errors[] = array( 'selfmove' );
3430                 }
3431                 if ( !$this->isMovable() ) {
3432                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3433                 }
3434                 if ( $nt->getInterwiki() != '' ) {
3435                         $errors[] = array( 'immobile-target-namespace-iw' );
3436                 }
3437                 if ( !$nt->isMovable() ) {
3438                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3439                 }
3440
3441                 $oldid = $this->getArticleID();
3442                 $newid = $nt->getArticleID();
3443
3444                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3445                         $errors[] = array( 'articleexists' );
3446                 }
3447                 if ( ( $this->getDBkey() == '' ) ||
3448                          ( !$oldid ) ||
3449                          ( $nt->getDBkey() == '' ) ) {
3450                         $errors[] = array( 'badarticleerror' );
3451                 }
3452
3453                 // Image-specific checks
3454                 if ( $this->getNamespace() == NS_FILE ) {
3455                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3456                 }
3457
3458                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3459                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3460                 }
3461
3462                 if ( $auth ) {
3463                         $errors = wfMergeErrorArrays( $errors,
3464                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3465                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3466                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3467                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3468                 }
3469
3470                 $match = EditPage::matchSummarySpamRegex( $reason );
3471                 if ( $match !== false ) {
3472                         // This is kind of lame, won't display nice
3473                         $errors[] = array( 'spamprotectiontext' );
3474                 }
3475
3476                 $err = null;
3477                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3478                         $errors[] = array( 'hookaborted', $err );
3479                 }
3480
3481                 # The move is allowed only if (1) the target doesn't exist, or
3482                 # (2) the target is a redirect to the source, and has no history
3483                 # (so we can undo bad moves right after they're done).
3484
3485                 if ( 0 != $newid ) { # Target exists; check for validity
3486                         if ( !$this->isValidMoveTarget( $nt ) ) {
3487                                 $errors[] = array( 'articleexists' );
3488                         }
3489                 } else {
3490                         $tp = $nt->getTitleProtection();
3491                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3492                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3493                                 $errors[] = array( 'cantmove-titleprotected' );
3494                         }
3495                 }
3496                 if ( empty( $errors ) ) {
3497                         return true;
3498                 }
3499                 return $errors;
3500         }
3501
3502         /**
3503          * Check if the requested move target is a valid file move target
3504          * @param Title $nt Target title
3505          * @return array List of errors
3506          */
3507         protected function validateFileMoveOperation( $nt ) {
3508                 global $wgUser;
3509
3510                 $errors = array();
3511
3512                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3513
3514                 $file = wfLocalFile( $this );
3515                 if ( $file->exists() ) {
3516                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3517                                 $errors[] = array( 'imageinvalidfilename' );
3518                         }
3519                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3520                                 $errors[] = array( 'imagetypemismatch' );
3521                         }
3522                 }
3523
3524                 if ( $nt->getNamespace() != NS_FILE ) {
3525                         $errors[] = array( 'imagenocrossnamespace' );
3526                         // From here we want to do checks on a file object, so if we can't
3527                         // create one, we must return.
3528                         return $errors;
3529                 }
3530
3531                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3532
3533                 $destFile = wfLocalFile( $nt );
3534                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3535                         $errors[] = array( 'file-exists-sharedrepo' );
3536                 }
3537
3538                 return $errors;
3539         }
3540
3541         /**
3542          * Move a title to a new location
3543          *
3544          * @param $nt Title the new title
3545          * @param $auth Bool indicates whether $wgUser's permissions
3546          *  should be checked
3547          * @param $reason String the reason for the move
3548          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3549          *  Ignored if the user doesn't have the suppressredirect right.
3550          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3551          */
3552         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3553                 global $wgUser;
3554                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3555                 if ( is_array( $err ) ) {
3556                         // Auto-block user's IP if the account was "hard" blocked
3557                         $wgUser->spreadAnyEditBlock();
3558                         return $err;
3559                 }
3560                 // Check suppressredirect permission
3561                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3562                         $createRedirect = true;
3563                 }
3564
3565                 // If it is a file, move it first.
3566                 // It is done before all other moving stuff is done because it's hard to revert.
3567                 $dbw = wfGetDB( DB_MASTER );
3568                 if ( $this->getNamespace() == NS_FILE ) {
3569                         $file = wfLocalFile( $this );
3570                         if ( $file->exists() ) {
3571                                 $status = $file->move( $nt );
3572                                 if ( !$status->isOk() ) {
3573                                         return $status->getErrorsArray();
3574                                 }
3575                         }
3576                         // Clear RepoGroup process cache
3577                         RepoGroup::singleton()->clearCache( $this );
3578                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3579                 }
3580
3581                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3582                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3583                 $protected = $this->isProtected();
3584
3585                 // Do the actual move
3586                 $this->moveToInternal( $nt, $reason, $createRedirect );
3587
3588                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3589                 // cl_timestamp, which may disturb time-based lists on some sites.
3590                 $prefixes = $dbw->select(
3591                         'categorylinks',
3592                         array( 'cl_sortkey_prefix', 'cl_to' ),
3593                         array( 'cl_from' => $pageid ),
3594                         __METHOD__
3595                 );
3596                 foreach ( $prefixes as $prefixRow ) {
3597                         $prefix = $prefixRow->cl_sortkey_prefix;
3598                         $catTo = $prefixRow->cl_to;
3599                         $dbw->update( 'categorylinks',
3600                                 array(
3601                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3602                                                 $nt->getCategorySortkey( $prefix ) ),
3603                                         'cl_timestamp=cl_timestamp' ),
3604                                 array(
3605                                         'cl_from' => $pageid,
3606                                         'cl_to' => $catTo ),
3607                                 __METHOD__
3608                         );
3609                 }
3610
3611                 $redirid = $this->getArticleID();
3612
3613                 if ( $protected ) {
3614                         # Protect the redirect title as the title used to be...
3615                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3616                                 array(
3617                                         'pr_page'    => $redirid,
3618                                         'pr_type'    => 'pr_type',
3619                                         'pr_level'   => 'pr_level',
3620                                         'pr_cascade' => 'pr_cascade',
3621                                         'pr_user'    => 'pr_user',
3622                                         'pr_expiry'  => 'pr_expiry'
3623                                 ),
3624                                 array( 'pr_page' => $pageid ),
3625                                 __METHOD__,
3626                                 array( 'IGNORE' )
3627                         );
3628                         # Update the protection log
3629                         $log = new LogPage( 'protect' );
3630                         $comment = wfMessage(
3631                                 'prot_1movedto2',
3632                                 $this->getPrefixedText(),
3633                                 $nt->getPrefixedText()
3634                         )->inContentLanguage()->text();
3635                         if ( $reason ) {
3636                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3637                         }
3638                         // @todo FIXME: $params?
3639                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3640                 }
3641
3642                 # Update watchlists
3643                 $oldnamespace = $this->getNamespace() & ~1;
3644                 $newnamespace = $nt->getNamespace() & ~1;
3645                 $oldtitle = $this->getDBkey();
3646                 $newtitle = $nt->getDBkey();
3647
3648                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3649                         WatchedItem::duplicateEntries( $this, $nt );
3650                 }
3651
3652                 $dbw->commit( __METHOD__ );
3653
3654                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3655                 return true;
3656         }
3657
3658         /**
3659          * Move page to a title which is either a redirect to the
3660          * source page or nonexistent
3661          *
3662          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3663          * @param $reason String The reason for the move
3664          * @param $createRedirect Bool Whether to leave a redirect at the old title. Does not check
3665          *   if the user has the suppressredirect right
3666          * @throws MWException
3667          */
3668         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3669                 global $wgUser, $wgContLang;
3670
3671                 if ( $nt->exists() ) {
3672                         $moveOverRedirect = true;
3673                         $logType = 'move_redir';
3674                 } else {
3675                         $moveOverRedirect = false;
3676                         $logType = 'move';
3677                 }
3678
3679                 $redirectSuppressed = !$createRedirect;
3680
3681                 $logEntry = new ManualLogEntry( 'move', $logType );
3682                 $logEntry->setPerformer( $wgUser );
3683                 $logEntry->setTarget( $this );
3684                 $logEntry->setComment( $reason );
3685                 $logEntry->setParameters( array(
3686                         '4::target' => $nt->getPrefixedText(),
3687                         '5::noredir' => $redirectSuppressed ? '1': '0',
3688                 ) );
3689
3690                 $formatter = LogFormatter::newFromEntry( $logEntry );
3691                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3692                 $comment = $formatter->getPlainActionText();
3693                 if ( $reason ) {
3694                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3695                 }
3696                 # Truncate for whole multibyte characters.
3697                 $comment = $wgContLang->truncate( $comment, 255 );
3698
3699                 $oldid = $this->getArticleID();
3700
3701                 $dbw = wfGetDB( DB_MASTER );
3702
3703                 $newpage = WikiPage::factory( $nt );
3704
3705                 if ( $moveOverRedirect ) {
3706                         $newid = $nt->getArticleID();
3707
3708                         # Delete the old redirect. We don't save it to history since
3709                         # by definition if we've got here it's rather uninteresting.
3710                         # We have to remove it so that the next step doesn't trigger
3711                         # a conflict on the unique namespace+title index...
3712                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3713
3714                         $newpage->doDeleteUpdates( $newid );
3715                 }
3716
3717                 # Save a null revision in the page's history notifying of the move
3718                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3719                 if ( !is_object( $nullRevision ) ) {
3720                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3721                 }
3722                 $nullRevId = $nullRevision->insertOn( $dbw );
3723
3724                 # Change the name of the target page:
3725                 $dbw->update( 'page',
3726                         /* SET */ array(
3727                                 'page_namespace' => $nt->getNamespace(),
3728                                 'page_title'     => $nt->getDBkey(),
3729                         ),
3730                         /* WHERE */ array( 'page_id' => $oldid ),
3731                         __METHOD__
3732                 );
3733
3734                 $this->resetArticleID( 0 );
3735                 $nt->resetArticleID( $oldid );
3736
3737                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3738
3739                 wfRunHooks( 'NewRevisionFromEditComplete',
3740                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3741
3742                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3743
3744                 if ( !$moveOverRedirect ) {
3745                         WikiPage::onArticleCreate( $nt );
3746                 }
3747
3748                 # Recreate the redirect, this time in the other direction.
3749                 if ( $redirectSuppressed ) {
3750                         WikiPage::onArticleDelete( $this );
3751                 } else {
3752                         $mwRedir = MagicWord::get( 'redirect' );
3753                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3754                         $redirectArticle = WikiPage::factory( $this );
3755                         $newid = $redirectArticle->insertOn( $dbw );
3756                         if ( $newid ) { // sanity
3757                                 $redirectRevision = new Revision( array(
3758                                         'page'    => $newid,
3759                                         'comment' => $comment,
3760                                         'text'    => $redirectText ) );
3761                                 $redirectRevision->insertOn( $dbw );
3762                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3763
3764                                 wfRunHooks( 'NewRevisionFromEditComplete',
3765                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3766
3767                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3768                         }
3769                 }
3770
3771                 # Log the move
3772                 $logid = $logEntry->insert();
3773                 $logEntry->publish( $logid );
3774         }
3775
3776         /**
3777          * Move this page's subpages to be subpages of $nt
3778          *
3779          * @param $nt Title Move target
3780          * @param $auth bool Whether $wgUser's permissions should be checked
3781          * @param $reason string The reason for the move
3782          * @param $createRedirect bool Whether to create redirects from the old subpages to
3783          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3784          * @return mixed array with old page titles as keys, and strings (new page titles) or
3785          *     arrays (errors) as values, or an error array with numeric indices if no pages
3786          *     were moved
3787          */
3788         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3789                 global $wgMaximumMovedPages;
3790                 // Check permissions
3791                 if ( !$this->userCan( 'move-subpages' ) ) {
3792                         return array( 'cant-move-subpages' );
3793                 }
3794                 // Do the source and target namespaces support subpages?
3795                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3796                         return array( 'namespace-nosubpages',
3797                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3798                 }
3799                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3800                         return array( 'namespace-nosubpages',
3801                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3802                 }
3803
3804                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3805                 $retval = array();
3806                 $count = 0;
3807                 foreach ( $subpages as $oldSubpage ) {
3808                         $count++;
3809                         if ( $count > $wgMaximumMovedPages ) {
3810                                 $retval[$oldSubpage->getPrefixedTitle()] =
3811                                                 array( 'movepage-max-pages',
3812                                                         $wgMaximumMovedPages );
3813                                 break;
3814                         }
3815
3816                         // We don't know whether this function was called before
3817                         // or after moving the root page, so check both
3818                         // $this and $nt
3819                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3820                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3821                         {
3822                                 // When moving a page to a subpage of itself,
3823                                 // don't move it twice
3824                                 continue;
3825                         }
3826                         $newPageName = preg_replace(
3827                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3828                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3829                                         $oldSubpage->getDBkey() );
3830                         if ( $oldSubpage->isTalkPage() ) {
3831                                 $newNs = $nt->getTalkPage()->getNamespace();
3832                         } else {
3833                                 $newNs = $nt->getSubjectPage()->getNamespace();
3834                         }
3835                         # Bug 14385: we need makeTitleSafe because the new page names may
3836                         # be longer than 255 characters.
3837                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3838
3839                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3840                         if ( $success === true ) {
3841                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3842                         } else {
3843                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3844                         }
3845                 }
3846                 return $retval;
3847         }
3848
3849         /**
3850          * Checks if this page is just a one-rev redirect.
3851          * Adds lock, so don't use just for light purposes.
3852          *
3853          * @return Bool
3854          */
3855         public function isSingleRevRedirect() {
3856                 $dbw = wfGetDB( DB_MASTER );
3857                 # Is it a redirect?
3858                 $row = $dbw->selectRow( 'page',
3859                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3860                         $this->pageCond(),
3861                         __METHOD__,
3862                         array( 'FOR UPDATE' )
3863                 );
3864                 # Cache some fields we may want
3865                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3866                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3867                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3868                 if ( !$this->mRedirect ) {
3869                         return false;
3870                 }
3871                 # Does the article have a history?
3872                 $row = $dbw->selectField( array( 'page', 'revision' ),
3873                         'rev_id',
3874                         array( 'page_namespace' => $this->getNamespace(),
3875                                 'page_title' => $this->getDBkey(),
3876                                 'page_id=rev_page',
3877                                 'page_latest != rev_id'
3878                         ),
3879                         __METHOD__,
3880                         array( 'FOR UPDATE' )
3881                 );
3882                 # Return true if there was no history
3883                 return ( $row === false );
3884         }
3885
3886         /**
3887          * Checks if $this can be moved to a given Title
3888          * - Selects for update, so don't call it unless you mean business
3889          *
3890          * @param $nt Title the new title to check
3891          * @return Bool
3892          */
3893         public function isValidMoveTarget( $nt ) {
3894                 # Is it an existing file?
3895                 if ( $nt->getNamespace() == NS_FILE ) {
3896                         $file = wfLocalFile( $nt );
3897                         if ( $file->exists() ) {
3898                                 wfDebug( __METHOD__ . ": file exists\n" );
3899                                 return false;
3900                         }
3901                 }
3902                 # Is it a redirect with no history?
3903                 if ( !$nt->isSingleRevRedirect() ) {
3904                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3905                         return false;
3906                 }
3907                 # Get the article text
3908                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3909                 if( !is_object( $rev ) ){
3910                         return false;
3911                 }
3912                 $text = $rev->getText();
3913                 # Does the redirect point to the source?
3914                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3915                 $m = array();
3916                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3917                         $redirTitle = Title::newFromText( $m[1] );
3918                         if ( !is_object( $redirTitle ) ||
3919                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3920                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3921                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3922                                 return false;
3923                         }
3924                 } else {
3925                         # Fail safe
3926                         wfDebug( __METHOD__ . ": failsafe\n" );
3927                         return false;
3928                 }
3929                 return true;
3930         }
3931
3932         /**
3933          * Get categories to which this Title belongs and return an array of
3934          * categories' names.
3935          *
3936          * @return Array of parents in the form:
3937          *        $parent => $currentarticle
3938          */
3939         public function getParentCategories() {
3940                 global $wgContLang;
3941
3942                 $data = array();
3943
3944                 $titleKey = $this->getArticleID();
3945
3946                 if ( $titleKey === 0 ) {
3947                         return $data;
3948                 }
3949
3950                 $dbr = wfGetDB( DB_SLAVE );
3951
3952                 $res = $dbr->select( 'categorylinks', '*',
3953                         array(
3954                                 'cl_from' => $titleKey,
3955                         ),
3956                         __METHOD__,
3957                         array()
3958                 );
3959
3960                 if ( $dbr->numRows( $res ) > 0 ) {
3961                         foreach ( $res as $row ) {
3962                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3963                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3964                         }
3965                 }
3966                 return $data;
3967         }
3968
3969         /**
3970          * Get a tree of parent categories
3971          *
3972          * @param $children Array with the children in the keys, to check for circular refs
3973          * @return Array Tree of parent categories
3974          */
3975         public function getParentCategoryTree( $children = array() ) {
3976                 $stack = array();
3977                 $parents = $this->getParentCategories();
3978
3979                 if ( $parents ) {
3980                         foreach ( $parents as $parent => $current ) {
3981                                 if ( array_key_exists( $parent, $children ) ) {
3982                                         # Circular reference
3983                                         $stack[$parent] = array();
3984                                 } else {
3985                                         $nt = Title::newFromText( $parent );
3986                                         if ( $nt ) {
3987                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3988                                         }
3989                                 }
3990                         }
3991                 }
3992
3993                 return $stack;
3994         }
3995
3996         /**
3997          * Get an associative array for selecting this title from
3998          * the "page" table
3999          *
4000          * @return Array suitable for the $where parameter of DB::select()
4001          */
4002         public function pageCond() {
4003                 if ( $this->mArticleID > 0 ) {
4004                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4005                         return array( 'page_id' => $this->mArticleID );
4006                 } else {
4007                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4008                 }
4009         }
4010
4011         /**
4012          * Get the revision ID of the previous revision
4013          *
4014          * @param $revId Int Revision ID. Get the revision that was before this one.
4015          * @param $flags Int Title::GAID_FOR_UPDATE
4016          * @return Int|Bool Old revision ID, or FALSE if none exists
4017          */
4018         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4019                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4020                 $revId = $db->selectField( 'revision', 'rev_id',
4021                         array(
4022                                 'rev_page' => $this->getArticleID( $flags ),
4023                                 'rev_id < ' . intval( $revId )
4024                         ),
4025                         __METHOD__,
4026                         array( 'ORDER BY' => 'rev_id DESC' )
4027                 );
4028
4029                 if ( $revId === false ) {
4030                         return false;
4031                 } else {
4032                         return intval( $revId );
4033                 }
4034         }
4035
4036         /**
4037          * Get the revision ID of the next revision
4038          *
4039          * @param $revId Int Revision ID. Get the revision that was after this one.
4040          * @param $flags Int Title::GAID_FOR_UPDATE
4041          * @return Int|Bool Next revision ID, or FALSE if none exists
4042          */
4043         public function getNextRevisionID( $revId, $flags = 0 ) {
4044                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4045                 $revId = $db->selectField( 'revision', 'rev_id',
4046                         array(
4047                                 'rev_page' => $this->getArticleID( $flags ),
4048                                 'rev_id > ' . intval( $revId )
4049                         ),
4050                         __METHOD__,
4051                         array( 'ORDER BY' => 'rev_id' )
4052                 );
4053
4054                 if ( $revId === false ) {
4055                         return false;
4056                 } else {
4057                         return intval( $revId );
4058                 }
4059         }
4060
4061         /**
4062          * Get the first revision of the page
4063          *
4064          * @param $flags Int Title::GAID_FOR_UPDATE
4065          * @return Revision|Null if page doesn't exist
4066          */
4067         public function getFirstRevision( $flags = 0 ) {
4068                 $pageId = $this->getArticleID( $flags );
4069                 if ( $pageId ) {
4070                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4071                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4072                                 array( 'rev_page' => $pageId ),
4073                                 __METHOD__,
4074                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4075                         );
4076                         if ( $row ) {
4077                                 return new Revision( $row );
4078                         }
4079                 }
4080                 return null;
4081         }
4082
4083         /**
4084          * Get the oldest revision timestamp of this page
4085          *
4086          * @param $flags Int Title::GAID_FOR_UPDATE
4087          * @return String: MW timestamp
4088          */
4089         public function getEarliestRevTime( $flags = 0 ) {
4090                 $rev = $this->getFirstRevision( $flags );
4091                 return $rev ? $rev->getTimestamp() : null;
4092         }
4093
4094         /**
4095          * Check if this is a new page
4096          *
4097          * @return bool
4098          */
4099         public function isNewPage() {
4100                 $dbr = wfGetDB( DB_SLAVE );
4101                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4102         }
4103
4104         /**
4105          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4106          *
4107          * @return bool
4108          */
4109         public function isBigDeletion() {
4110                 global $wgDeleteRevisionsLimit;
4111
4112                 if ( !$wgDeleteRevisionsLimit ) {
4113                         return false;
4114                 }
4115
4116                 $revCount = $this->estimateRevisionCount();
4117                 return $revCount > $wgDeleteRevisionsLimit;
4118         }
4119
4120         /**
4121          * Get the  approximate revision count of this page.
4122          *
4123          * @return int
4124          */
4125         public function estimateRevisionCount() {
4126                 if ( !$this->exists() ) {
4127                         return 0;
4128                 }
4129
4130                 if ( $this->mEstimateRevisions === null ) {
4131                         $dbr = wfGetDB( DB_SLAVE );
4132                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4133                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4134                 }
4135
4136                 return $this->mEstimateRevisions;
4137         }
4138
4139         /**
4140          * Get the number of revisions between the given revision.
4141          * Used for diffs and other things that really need it.
4142          *
4143          * @param $old int|Revision Old revision or rev ID (first before range)
4144          * @param $new int|Revision New revision or rev ID (first after range)
4145          * @return Int Number of revisions between these revisions.
4146          */
4147         public function countRevisionsBetween( $old, $new ) {
4148                 if ( !( $old instanceof Revision ) ) {
4149                         $old = Revision::newFromTitle( $this, (int)$old );
4150                 }
4151                 if ( !( $new instanceof Revision ) ) {
4152                         $new = Revision::newFromTitle( $this, (int)$new );
4153                 }
4154                 if ( !$old || !$new ) {
4155                         return 0; // nothing to compare
4156                 }
4157                 $dbr = wfGetDB( DB_SLAVE );
4158                 return (int)$dbr->selectField( 'revision', 'count(*)',
4159                         array(
4160                                 'rev_page' => $this->getArticleID(),
4161                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4162                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4163                         ),
4164                         __METHOD__
4165                 );
4166         }
4167
4168         /**
4169          * Get the number of authors between the given revisions or revision IDs.
4170          * Used for diffs and other things that really need it.
4171          *
4172          * @param $old int|Revision Old revision or rev ID (first before range by default)
4173          * @param $new int|Revision New revision or rev ID (first after range by default)
4174          * @param $limit int Maximum number of authors
4175          * @param $options string|array (Optional): Single option, or an array of options:
4176          *     'include_old' Include $old in the range; $new is excluded.
4177          *     'include_new' Include $new in the range; $old is excluded.
4178          *     'include_both' Include both $old and $new in the range.
4179          *     Unknown option values are ignored.
4180          * @return int Number of revision authors in the range; zero if not both revisions exist
4181          */
4182         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4183                 if ( !( $old instanceof Revision ) ) {
4184                         $old = Revision::newFromTitle( $this, (int)$old );
4185                 }
4186                 if ( !( $new instanceof Revision ) ) {
4187                         $new = Revision::newFromTitle( $this, (int)$new );
4188                 }
4189                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4190                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4191                 // in the sanity check below?
4192                 if ( !$old || !$new ) {
4193                         return 0; // nothing to compare
4194                 }
4195                 $old_cmp = '>';
4196                 $new_cmp = '<';
4197                 $options = (array) $options;
4198                 if ( in_array( 'include_old', $options ) ) {
4199                         $old_cmp = '>=';
4200                 }
4201                 if ( in_array( 'include_new', $options ) ) {
4202                         $new_cmp = '<=';
4203                 }
4204                 if ( in_array( 'include_both', $options ) ) {
4205                         $old_cmp = '>=';
4206                         $new_cmp = '<=';
4207                 }
4208                 // No DB query needed if $old and $new are the same or successive revisions:
4209                 if ( $old->getId() === $new->getId() ) {
4210                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4211                 } else if ( $old->getId() === $new->getParentId() ) {
4212                         if ( $old_cmp === '>' || $new_cmp === '<' ) {
4213                                 return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4214                         }
4215                         return ( $old->getRawUserText() === $new->getRawUserText() ) ? 1 : 2;
4216                 }
4217                 $dbr = wfGetDB( DB_SLAVE );
4218                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4219                         array(
4220                                 'rev_page' => $this->getArticleID(),
4221                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4222                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4223                         ), __METHOD__,
4224                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4225                 );
4226                 return (int)$dbr->numRows( $res );
4227         }
4228
4229         /**
4230          * Compare with another title.
4231          *
4232          * @param $title Title
4233          * @return Bool
4234          */
4235         public function equals( Title $title ) {
4236                 // Note: === is necessary for proper matching of number-like titles.
4237                 return $this->getInterwiki() === $title->getInterwiki()
4238                         && $this->getNamespace() == $title->getNamespace()
4239                         && $this->getDBkey() === $title->getDBkey();
4240         }
4241
4242         /**
4243          * Check if this title is a subpage of another title
4244          *
4245          * @param $title Title
4246          * @return Bool
4247          */
4248         public function isSubpageOf( Title $title ) {
4249                 return $this->getInterwiki() === $title->getInterwiki()
4250                         && $this->getNamespace() == $title->getNamespace()
4251                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4252         }
4253
4254         /**
4255          * Check if page exists.  For historical reasons, this function simply
4256          * checks for the existence of the title in the page table, and will
4257          * thus return false for interwiki links, special pages and the like.
4258          * If you want to know if a title can be meaningfully viewed, you should
4259          * probably call the isKnown() method instead.
4260          *
4261          * @return Bool
4262          */
4263         public function exists() {
4264                 return $this->getArticleID() != 0;
4265         }
4266
4267         /**
4268          * Should links to this title be shown as potentially viewable (i.e. as
4269          * "bluelinks"), even if there's no record by this title in the page
4270          * table?
4271          *
4272          * This function is semi-deprecated for public use, as well as somewhat
4273          * misleadingly named.  You probably just want to call isKnown(), which
4274          * calls this function internally.
4275          *
4276          * (ISSUE: Most of these checks are cheap, but the file existence check
4277          * can potentially be quite expensive.  Including it here fixes a lot of
4278          * existing code, but we might want to add an optional parameter to skip
4279          * it and any other expensive checks.)
4280          *
4281          * @return Bool
4282          */
4283         public function isAlwaysKnown() {
4284                 $isKnown = null;
4285
4286                 /**
4287                  * Allows overriding default behaviour for determining if a page exists.
4288                  * If $isKnown is kept as null, regular checks happen. If it's
4289                  * a boolean, this value is returned by the isKnown method.
4290                  *
4291                  * @since 1.20
4292                  *
4293                  * @param Title $title
4294                  * @param boolean|null $isKnown
4295                  */
4296                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4297
4298                 if ( !is_null( $isKnown ) ) {
4299                         return $isKnown;
4300                 }
4301
4302                 if ( $this->mInterwiki != '' ) {
4303                         return true;  // any interwiki link might be viewable, for all we know
4304                 }
4305
4306                 switch( $this->mNamespace ) {
4307                         case NS_MEDIA:
4308                         case NS_FILE:
4309                                 // file exists, possibly in a foreign repo
4310                                 return (bool)wfFindFile( $this );
4311                         case NS_SPECIAL:
4312                                 // valid special page
4313                                 return SpecialPageFactory::exists( $this->getDBkey() );
4314                         case NS_MAIN:
4315                                 // selflink, possibly with fragment
4316                                 return $this->mDbkeyform == '';
4317                         case NS_MEDIAWIKI:
4318                                 // known system message
4319                                 return $this->hasSourceText() !== false;
4320                         default:
4321                                 return false;
4322                 }
4323         }
4324
4325         /**
4326          * Does this title refer to a page that can (or might) be meaningfully
4327          * viewed?  In particular, this function may be used to determine if
4328          * links to the title should be rendered as "bluelinks" (as opposed to
4329          * "redlinks" to non-existent pages).
4330          * Adding something else to this function will cause inconsistency
4331          * since LinkHolderArray calls isAlwaysKnown() and does its own
4332          * page existence check.
4333          *
4334          * @return Bool
4335          */
4336         public function isKnown() {
4337                 return $this->isAlwaysKnown() || $this->exists();
4338         }
4339
4340         /**
4341          * Does this page have source text?
4342          *
4343          * @return Boolean
4344          */
4345         public function hasSourceText() {
4346                 if ( $this->exists() ) {
4347                         return true;
4348                 }
4349
4350                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4351                         // If the page doesn't exist but is a known system message, default
4352                         // message content will be displayed, same for language subpages-
4353                         // Use always content language to avoid loading hundreds of languages
4354                         // to get the link color.
4355                         global $wgContLang;
4356                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4357                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4358                         return $message->exists();
4359                 }
4360
4361                 return false;
4362         }
4363
4364         /**
4365          * Get the default message text or false if the message doesn't exist
4366          *
4367          * @return String or false
4368          */
4369         public function getDefaultMessageText() {
4370                 global $wgContLang;
4371
4372                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4373                         return false;
4374                 }
4375
4376                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4377                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4378
4379                 if ( $message->exists() ) {
4380                         return $message->plain();
4381                 } else {
4382                         return false;
4383                 }
4384         }
4385
4386         /**
4387          * Updates page_touched for this page; called from LinksUpdate.php
4388          *
4389          * @return Bool true if the update succeded
4390          */
4391         public function invalidateCache() {
4392                 if ( wfReadOnly() ) {
4393                         return false;
4394                 }
4395                 $dbw = wfGetDB( DB_MASTER );
4396                 $success = $dbw->update(
4397                         'page',
4398                         array( 'page_touched' => $dbw->timestamp() ),
4399                         $this->pageCond(),
4400                         __METHOD__
4401                 );
4402                 HTMLFileCache::clearFileCache( $this );
4403                 return $success;
4404         }
4405
4406         /**
4407          * Update page_touched timestamps and send squid purge messages for
4408          * pages linking to this title. May be sent to the job queue depending
4409          * on the number of links. Typically called on create and delete.
4410          */
4411         public function touchLinks() {
4412                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4413                 $u->doUpdate();
4414
4415                 if ( $this->getNamespace() == NS_CATEGORY ) {
4416                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4417                         $u->doUpdate();
4418                 }
4419         }
4420
4421         /**
4422          * Get the last touched timestamp
4423          *
4424          * @param $db DatabaseBase: optional db
4425          * @return String last-touched timestamp
4426          */
4427         public function getTouched( $db = null ) {
4428                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4429                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4430                 return $touched;
4431         }
4432
4433         /**
4434          * Get the timestamp when this page was updated since the user last saw it.
4435          *
4436          * @param $user User
4437          * @return String|Null
4438          */
4439         public function getNotificationTimestamp( $user = null ) {
4440                 global $wgUser, $wgShowUpdatedMarker;
4441                 // Assume current user if none given
4442                 if ( !$user ) {
4443                         $user = $wgUser;
4444                 }
4445                 // Check cache first
4446                 $uid = $user->getId();
4447                 // avoid isset here, as it'll return false for null entries
4448                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4449                         return $this->mNotificationTimestamp[$uid];
4450                 }
4451                 if ( !$uid || !$wgShowUpdatedMarker ) {
4452                         return $this->mNotificationTimestamp[$uid] = false;
4453                 }
4454                 // Don't cache too much!
4455                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4456                         $this->mNotificationTimestamp = array();
4457                 }
4458                 $dbr = wfGetDB( DB_SLAVE );
4459                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4460                         'wl_notificationtimestamp',
4461                         array(
4462                                 'wl_user' => $user->getId(),
4463                                 'wl_namespace' => $this->getNamespace(),
4464                                 'wl_title' => $this->getDBkey(),
4465                         ),
4466                         __METHOD__
4467                 );
4468                 return $this->mNotificationTimestamp[$uid];
4469         }
4470
4471         /**
4472          * Generate strings used for xml 'id' names in monobook tabs
4473          *
4474          * @param $prepend string defaults to 'nstab-'
4475          * @return String XML 'id' name
4476          */
4477         public function getNamespaceKey( $prepend = 'nstab-' ) {
4478                 global $wgContLang;
4479                 // Gets the subject namespace if this title
4480                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4481                 // Checks if cononical namespace name exists for namespace
4482                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4483                         // Uses canonical namespace name
4484                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4485                 } else {
4486                         // Uses text of namespace
4487                         $namespaceKey = $this->getSubjectNsText();
4488                 }
4489                 // Makes namespace key lowercase
4490                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4491                 // Uses main
4492                 if ( $namespaceKey == '' ) {
4493                         $namespaceKey = 'main';
4494                 }
4495                 // Changes file to image for backwards compatibility
4496                 if ( $namespaceKey == 'file' ) {
4497                         $namespaceKey = 'image';
4498                 }
4499                 return $prepend . $namespaceKey;
4500         }
4501
4502         /**
4503          * Get all extant redirects to this Title
4504          *
4505          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4506          * @return Array of Title redirects to this title
4507          */
4508         public function getRedirectsHere( $ns = null ) {
4509                 $redirs = array();
4510
4511                 $dbr = wfGetDB( DB_SLAVE );
4512                 $where = array(
4513                         'rd_namespace' => $this->getNamespace(),
4514                         'rd_title' => $this->getDBkey(),
4515                         'rd_from = page_id'
4516                 );
4517                 if ( $this->isExternal() ) {
4518                         $where['rd_interwiki'] = $this->getInterwiki();
4519                 } else {
4520                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4521                 }
4522                 if ( !is_null( $ns ) ) {
4523                         $where['page_namespace'] = $ns;
4524                 }
4525
4526                 $res = $dbr->select(
4527                         array( 'redirect', 'page' ),
4528                         array( 'page_namespace', 'page_title' ),
4529                         $where,
4530                         __METHOD__
4531                 );
4532
4533                 foreach ( $res as $row ) {
4534                         $redirs[] = self::newFromRow( $row );
4535                 }
4536                 return $redirs;
4537         }
4538
4539         /**
4540          * Check if this Title is a valid redirect target
4541          *
4542          * @return Bool
4543          */
4544         public function isValidRedirectTarget() {
4545                 global $wgInvalidRedirectTargets;
4546
4547                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4548                 if ( $this->isSpecial( 'Userlogout' ) ) {
4549                         return false;
4550                 }
4551
4552                 foreach ( $wgInvalidRedirectTargets as $target ) {
4553                         if ( $this->isSpecial( $target ) ) {
4554                                 return false;
4555                         }
4556                 }
4557
4558                 return true;
4559         }
4560
4561         /**
4562          * Get a backlink cache object
4563          *
4564          * @return BacklinkCache
4565          */
4566         public function getBacklinkCache() {
4567                 return BacklinkCache::get( $this );
4568         }
4569
4570         /**
4571          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4572          *
4573          * @return Boolean
4574          */
4575         public function canUseNoindex() {
4576                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4577
4578                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4579                         ? $wgContentNamespaces
4580                         : $wgExemptFromUserRobotsControl;
4581
4582                 return !in_array( $this->mNamespace, $bannedNamespaces );
4583
4584         }
4585
4586         /**
4587          * Returns the raw sort key to be used for categories, with the specified
4588          * prefix.  This will be fed to Collation::getSortKey() to get a
4589          * binary sortkey that can be used for actual sorting.
4590          *
4591          * @param $prefix string The prefix to be used, specified using
4592          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4593          *   prefix.
4594          * @return string
4595          */
4596         public function getCategorySortkey( $prefix = '' ) {
4597                 $unprefixed = $this->getText();
4598
4599                 // Anything that uses this hook should only depend
4600                 // on the Title object passed in, and should probably
4601                 // tell the users to run updateCollations.php --force
4602                 // in order to re-sort existing category relations.
4603                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4604                 if ( $prefix !== '' ) {
4605                         # Separate with a line feed, so the unprefixed part is only used as
4606                         # a tiebreaker when two pages have the exact same prefix.
4607                         # In UCA, tab is the only character that can sort above LF
4608                         # so we strip both of them from the original prefix.
4609                         $prefix = strtr( $prefix, "\n\t", '  ' );
4610                         return "$prefix\n$unprefixed";
4611                 }
4612                 return $unprefixed;
4613         }
4614
4615         /**
4616          * Get the language in which the content of this page is written in
4617          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4618          * e.g. $wgLang (such as special pages, which are in the user language).
4619          *
4620          * @since 1.18
4621          * @return Language
4622          */
4623         public function getPageLanguage() {
4624                 global $wgLang;
4625                 if ( $this->isSpecialPage() ) {
4626                         // special pages are in the user language
4627                         return $wgLang;
4628                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4629                         // css/js should always be LTR and is, in fact, English
4630                         return wfGetLangObj( 'en' );
4631                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4632                         // Parse mediawiki messages with correct target language
4633                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4634                         return wfGetLangObj( $lang );
4635                 }
4636                 global $wgContLang;
4637                 // If nothing special, it should be in the wiki content language
4638                 $pageLang = $wgContLang;
4639                 // Hook at the end because we don't want to override the above stuff
4640                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4641                 return wfGetLangObj( $pageLang );
4642         }
4643
4644         /**
4645          * Get the language in which the content of this page is written when
4646          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4647          * e.g. $wgLang (such as special pages, which are in the user language).
4648          *
4649          * @since 1.20
4650          * @return Language
4651          */
4652         public function getPageViewLanguage() {
4653                 $pageLang = $this->getPageLanguage();
4654                 // If this is nothing special (so the content is converted when viewed)
4655                 if ( !$this->isSpecialPage()
4656                         && !$this->isCssOrJsPage() && !$this->isCssJsSubpage()
4657                         && $this->getNamespace() !== NS_MEDIAWIKI
4658                 ) {
4659                         // If the user chooses a variant, the content is actually
4660                         // in a language whose code is the variant code.
4661                         $variant = $pageLang->getPreferredVariant();
4662                         if ( $pageLang->getCode() !== $variant ) {
4663                                 $pageLang = Language::factory( $variant );
4664                         }
4665                 }
4666                 return $pageLang;
4667         }
4668 }