includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Represents a title within MediaWiki.
  25  * Optionally may contain an interwiki designation or namespace.
  26  * @note This class can fetch various kinds of data from the database;
  27  *       however, it does so inefficiently.
  28  *
  29  * @internal documentation reviewed 15 Mar 2010
  30  */
  31 class Title {
  32         /** @name Static cache variables */
  33         // @{
  34         static private $titleCache = array();
  35         // @}
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50
  51         /**
  52          * @name Private member variables
  53          * Please use the accessor functions instead.
  54          * @private
  55          */
  56         // @{
  57
  58         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  59         var $mUrlform = '';               // /< URL-encoded form of the main part
  60         var $mDbkeyform = '';             // /< Main part with underscores
  61         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  62         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  63         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  64         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  65         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  66         var $mLatestID = false;           // /< ID of most recent revision
  67         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  68         var $mOldRestrictions = false;
  69         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  70         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  71         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  72         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  73         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  74         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  75         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  76         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  77         # Don't change the following default, NS_MAIN is hardcoded in several
  78         # places.  See bug 696.
  79         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  80                                                                           # Zero except in {{transclusion}} tags
  81         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  82         var $mLength = -1;                // /< The page length, 0 for special pages
  83         var $mRedirect = null;            // /< Is the article at this title a redirect?
  84         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  85         var $mBacklinkCache = null;       // /< Cache of links to this title
  86         // @}
  87
  88
  89         /**
  90          * Constructor
  91          */
  92         /*protected*/ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255                 $t->loadFromRow( $row );
 256                 return $t;
 257         }
 258
 259         /**
 260          * Load Title object fields from a DB row.
 261          * If false is given, the title will be treated as non-existing.
 262          *
 263          * @param $row Object|false database row
 264          * @return void
 265          */
 266         public function loadFromRow( $row ) {
 267                 if ( $row ) { // page found
 268                         if ( isset( $row->page_id ) )
 269                                 $this->mArticleID = (int)$row->page_id;
 270                         if ( isset( $row->page_len ) )
 271                                 $this->mLength = (int)$row->page_len;
 272                         if ( isset( $row->page_is_redirect ) )
 273                                 $this->mRedirect = (bool)$row->page_is_redirect;
 274                         if ( isset( $row->page_latest ) )
 275                                 $this->mLatestID = (int)$row->page_latest;
 276                 } else { // page not found
 277                         $this->mArticleID = 0;
 278                         $this->mLength = 0;
 279                         $this->mRedirect = false;
 280                         $this->mLatestID = 0;
 281                 }
 282         }
 283
 284         /**
 285          * Create a new Title from a namespace index and a DB key.
 286          * It's assumed that $ns and $title are *valid*, for instance when
 287          * they came directly from the database or a special page name.
 288          * For convenience, spaces are converted to underscores so that
 289          * eg user_text fields can be used directly.
 290          *
 291          * @param $ns Int the namespace of the article
 292          * @param $title String the unprefixed database key form
 293          * @param $fragment String the link fragment (after the "#")
 294          * @param $interwiki String the interwiki prefix
 295          * @return Title the new object
 296          */
 297         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 298                 $t = new Title();
 299                 $t->mInterwiki = $interwiki;
 300                 $t->mFragment = $fragment;
 301                 $t->mNamespace = $ns = intval( $ns );
 302                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 303                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 304                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 305                 $t->mTextform = str_replace( '_', ' ', $title );
 306                 return $t;
 307         }
 308
 309         /**
 310          * Create a new Title from a namespace index and a DB key.
 311          * The parameters will be checked for validity, which is a bit slower
 312          * than makeTitle() but safer for user-provided data.
 313          *
 314          * @param $ns Int the namespace of the article
 315          * @param $title String database key form
 316          * @param $fragment String the link fragment (after the "#")
 317          * @param $interwiki String interwiki prefix
 318          * @return Title the new object, or NULL on an error
 319          */
 320         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 321                 $t = new Title();
 322                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 323                 if ( $t->secureAndSplit() ) {
 324                         return $t;
 325                 } else {
 326                         return null;
 327                 }
 328         }
 329
 330         /**
 331          * Create a new Title for the Main Page
 332          *
 333          * @return Title the new object
 334          */
 335         public static function newMainPage() {
 336                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 337                 // Don't give fatal errors if the message is broken
 338                 if ( !$title ) {
 339                         $title = Title::newFromText( 'Main Page' );
 340                 }
 341                 return $title;
 342         }
 343
 344         /**
 345          * Extract a redirect destination from a string and return the
 346          * Title, or null if the text doesn't contain a valid redirect
 347          * This will only return the very next target, useful for
 348          * the redirect table and other checks that don't need full recursion
 349          *
 350          * @param $text String: Text with possible redirect
 351          * @return Title: The corresponding Title
 352          */
 353         public static function newFromRedirect( $text ) {
 354                 return self::newFromRedirectInternal( $text );
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 361          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 362          *
 363          * @param $text String Text with possible redirect
 364          * @return Title
 365          */
 366         public static function newFromRedirectRecurse( $text ) {
 367                 $titles = self::newFromRedirectArray( $text );
 368                 return $titles ? array_pop( $titles ) : null;
 369         }
 370
 371         /**
 372          * Extract a redirect destination from a string and return an
 373          * array of Titles, or null if the text doesn't contain a valid redirect
 374          * The last element in the array is the final destination after all redirects
 375          * have been resolved (up to $wgMaxRedirects times)
 376          *
 377          * @param $text String Text with possible redirect
 378          * @return Array of Titles, with the destination last
 379          */
 380         public static function newFromRedirectArray( $text ) {
 381                 global $wgMaxRedirects;
 382                 $title = self::newFromRedirectInternal( $text );
 383                 if ( is_null( $title ) ) {
 384                         return null;
 385                 }
 386                 // recursive check to follow double redirects
 387                 $recurse = $wgMaxRedirects;
 388                 $titles = array( $title );
 389                 while ( --$recurse > 0 ) {
 390                         if ( $title->isRedirect() ) {
 391                                 $article = new Article( $title, 0 );
 392                                 $newtitle = $article->getRedirectTarget();
 393                         } else {
 394                                 break;
 395                         }
 396                         // Redirects to some special pages are not permitted
 397                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 398                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 399                                 $title = $newtitle;
 400                                 $titles[] = $newtitle;
 401                         } else {
 402                                 break;
 403                         }
 404                 }
 405                 return $titles;
 406         }
 407
 408         /**
 409          * Really extract the redirect destination
 410          * Do not call this function directly, use one of the newFromRedirect* functions above
 411          *
 412          * @param $text String Text with possible redirect
 413          * @return Title
 414          */
 415         protected static function newFromRedirectInternal( $text ) {
 416                 global $wgMaxRedirects;
 417                 if ( $wgMaxRedirects < 1 ) {
 418                         //redirects are disabled, so quit early
 419                         return null;
 420                 }
 421                 $redir = MagicWord::get( 'redirect' );
 422                 $text = trim( $text );
 423                 if ( $redir->matchStartAndRemove( $text ) ) {
 424                         // Extract the first link and see if it's usable
 425                         // Ensure that it really does come directly after #REDIRECT
 426                         // Some older redirects included a colon, so don't freak about that!
 427                         $m = array();
 428                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 429                                 // Strip preceding colon used to "escape" categories, etc.
 430                                 // and URL-decode links
 431                                 if ( strpos( $m[1], '%' ) !== false ) {
 432                                         // Match behavior of inline link parsing here;
 433                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 434                                 }
 435                                 $title = Title::newFromText( $m[1] );
 436                                 // If the title is a redirect to bad special pages or is invalid, return null
 437                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 438                                         return null;
 439                                 }
 440                                 return $title;
 441                         }
 442                 }
 443                 return null;
 444         }
 445
 446 # ----------------------------------------------------------------------------
 447 #       Static functions
 448 # ----------------------------------------------------------------------------
 449
 450         /**
 451          * Get the prefixed DB key associated with an ID
 452          *
 453          * @param $id Int the page_id of the article
 454          * @return Title an object representing the article, or NULL if no such article was found
 455          */
 456         public static function nameOf( $id ) {
 457                 $dbr = wfGetDB( DB_SLAVE );
 458
 459                 $s = $dbr->selectRow(
 460                         'page',
 461                         array( 'page_namespace', 'page_title' ),
 462                         array( 'page_id' => $id ),
 463                         __METHOD__
 464                 );
 465                 if ( $s === false ) {
 466                         return null;
 467                 }
 468
 469                 $n = self::makeName( $s->page_namespace, $s->page_title );
 470                 return $n;
 471         }
 472
 473         /**
 474          * Get a regex character class describing the legal characters in a link
 475          *
 476          * @return String the list of characters, not delimited
 477          */
 478         public static function legalChars() {
 479                 global $wgLegalTitleChars;
 480                 return $wgLegalTitleChars;
 481         }
 482
 483         /**
 484          * Get a string representation of a title suitable for
 485          * including in a search index
 486          *
 487          * @param $ns Int a namespace index
 488          * @param $title String text-form main part
 489          * @return String a stripped-down title string ready for the search index
 490          */
 491         public static function indexTitle( $ns, $title ) {
 492                 global $wgContLang;
 493
 494                 $lc = SearchEngine::legalSearchChars() . '&#;';
 495                 $t = $wgContLang->normalizeForSearch( $title );
 496                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 497                 $t = $wgContLang->lc( $t );
 498
 499                 # Handle 's, s'
 500                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 501                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 502
 503                 $t = preg_replace( "/\\s+/", ' ', $t );
 504
 505                 if ( $ns == NS_FILE ) {
 506                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 507                 }
 508                 return trim( $t );
 509         }
 510
 511         /**
 512          * Make a prefixed DB key from a DB key and a namespace index
 513          *
 514          * @param $ns Int numerical representation of the namespace
 515          * @param $title String the DB key form the title
 516          * @param $fragment String The link fragment (after the "#")
 517          * @param $interwiki String The interwiki prefix
 518          * @return String the prefixed form of the title
 519          */
 520         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 521                 global $wgContLang;
 522
 523                 $namespace = $wgContLang->getNsText( $ns );
 524                 $name = $namespace == '' ? $title : "$namespace:$title";
 525                 if ( strval( $interwiki ) != '' ) {
 526                         $name = "$interwiki:$name";
 527                 }
 528                 if ( strval( $fragment ) != '' ) {
 529                         $name .= '#' . $fragment;
 530                 }
 531                 return $name;
 532         }
 533
 534         /**
 535          * Determine whether the object refers to a page within
 536          * this project.
 537          *
 538          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 539          */
 540         public function isLocal() {
 541                 if ( $this->mInterwiki != '' ) {
 542                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 543                 } else {
 544                         return true;
 545                 }
 546         }
 547
 548         /**
 549          * Determine whether the object refers to a page within
 550          * this project and is transcludable.
 551          *
 552          * @return Bool TRUE if this is transcludable
 553          */
 554         public function isTrans() {
 555                 if ( $this->mInterwiki == '' ) {
 556                         return false;
 557                 }
 558
 559                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 560         }
 561
 562         /**
 563          * Returns the DB name of the distant wiki which owns the object.
 564          *
 565          * @return String the DB name
 566          */
 567         public function getTransWikiID() {
 568                 if ( $this->mInterwiki == '' ) {
 569                         return false;
 570                 }
 571
 572                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 573         }
 574
 575         /**
 576          * Escape a text fragment, say from a link, for a URL
 577          *
 578          * @param $fragment string containing a URL or link fragment (after the "#")
 579          * @return String: escaped string
 580          */
 581         static function escapeFragmentForURL( $fragment ) {
 582                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 583                 # fragments appear not to work in IE (at least up to 7) or in at least
 584                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 585                 # to care if they aren't encoded.
 586                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 587         }
 588
 589 # ----------------------------------------------------------------------------
 590 #       Other stuff
 591 # ----------------------------------------------------------------------------
 592
 593         /** Simple accessors */
 594         /**
 595          * Get the text form (spaces not underscores) of the main part
 596          *
 597          * @return String Main part of the title
 598          */
 599         public function getText() { return $this->mTextform; }
 600
 601         /**
 602          * Get the URL-encoded form of the main part
 603          *
 604          * @return String Main part of the title, URL-encoded
 605          */
 606         public function getPartialURL() { return $this->mUrlform; }
 607
 608         /**
 609          * Get the main part with underscores
 610          *
 611          * @return String: Main part of the title, with underscores
 612          */
 613         public function getDBkey() { return $this->mDbkeyform; }
 614
 615         /**
 616          * Get the namespace index, i.e. one of the NS_xxxx constants.
 617          *
 618          * @return Integer: Namespace index
 619          */
 620         public function getNamespace() { return $this->mNamespace; }
 621
 622         /**
 623          * Get the namespace text
 624          *
 625          * @return String: Namespace text
 626          */
 627         public function getNsText() {
 628                 global $wgContLang;
 629
 630                 if ( $this->mInterwiki != '' ) {
 631                         // This probably shouldn't even happen. ohh man, oh yuck.
 632                         // But for interwiki transclusion it sometimes does.
 633                         // Shit. Shit shit shit.
 634                         //
 635                         // Use the canonical namespaces if possible to try to
 636                         // resolve a foreign namespace.
 637                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 638                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 639                         }
 640                 }
 641
 642                 if ( $wgContLang->needsGenderDistinction() &&
 643                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 644                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 645                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 646                 }
 647
 648                 return $wgContLang->getNsText( $this->mNamespace );
 649         }
 650
 651         /**
 652          * Get the DB key with the initial letter case as specified by the user
 653          *
 654          * @return String DB key
 655          */
 656         function getUserCaseDBKey() {
 657                 return $this->mUserCaseDBKey;
 658         }
 659
 660         /**
 661          * Get the namespace text of the subject (rather than talk) page
 662          *
 663          * @return String Namespace text
 664          */
 665         public function getSubjectNsText() {
 666                 global $wgContLang;
 667                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 668         }
 669
 670         /**
 671          * Get the namespace text of the talk page
 672          *
 673          * @return String Namespace text
 674          */
 675         public function getTalkNsText() {
 676                 global $wgContLang;
 677                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 678         }
 679
 680         /**
 681          * Could this title have a corresponding talk page?
 682          *
 683          * @return Bool TRUE or FALSE
 684          */
 685         public function canTalk() {
 686                 return( MWNamespace::canTalk( $this->mNamespace ) );
 687         }
 688
 689         /**
 690          * Get the interwiki prefix (or null string)
 691          *
 692          * @return String Interwiki prefix
 693          */
 694         public function getInterwiki() { return $this->mInterwiki; }
 695
 696         /**
 697          * Get the Title fragment (i.e.\ the bit after the #) in text form
 698          *
 699          * @return String Title fragment
 700          */
 701         public function getFragment() { return $this->mFragment; }
 702
 703         /**
 704          * Get the fragment in URL form, including the "#" character if there is one
 705          * @return String Fragment in URL form
 706          */
 707         public function getFragmentForURL() {
 708                 if ( $this->mFragment == '' ) {
 709                         return '';
 710                 } else {
 711                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 712                 }
 713         }
 714
 715         /**
 716          * Get the default namespace index, for when there is no namespace
 717          *
 718          * @return Int Default namespace index
 719          */
 720         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 721
 722         /**
 723          * Get title for search index
 724          *
 725          * @return String a stripped-down title string ready for the
 726          *  search index
 727          */
 728         public function getIndexTitle() {
 729                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 730         }
 731
 732         /**
 733          * Get the prefixed database key form
 734          *
 735          * @return String the prefixed title, with underscores and
 736          *  any interwiki and namespace prefixes
 737          */
 738         public function getPrefixedDBkey() {
 739                 $s = $this->prefix( $this->mDbkeyform );
 740                 $s = str_replace( ' ', '_', $s );
 741                 return $s;
 742         }
 743
 744         /**
 745          * Get the prefixed title with spaces.
 746          * This is the form usually used for display
 747          *
 748          * @return String the prefixed title, with spaces
 749          */
 750         public function getPrefixedText() {
 751                 // @todo FIXME: Bad usage of empty() ?
 752                 if ( empty( $this->mPrefixedText ) ) {
 753                         $s = $this->prefix( $this->mTextform );
 754                         $s = str_replace( '_', ' ', $s );
 755                         $this->mPrefixedText = $s;
 756                 }
 757                 return $this->mPrefixedText;
 758         }
 759
 760         /**
 761          * Return the prefixed title with spaces _without_ the interwiki prefix
 762          *
 763          * @return \type{\string} the title, prefixed by the namespace but not by the interwiki prefix, with spaces
 764          */
 765         public function getSemiPrefixedText() {
 766                 if ( !isset( $this->mSemiPrefixedText ) ){
 767                         $s = ( $this->mNamespace === NS_MAIN ? '' : $this->getNsText() . ':' ) . $this->mTextform;
 768                         $s = str_replace( '_', ' ', $s );
 769                         $this->mSemiPrefixedText = $s;
 770                 }
 771                 return $this->mSemiPrefixedText;
 772         }
 773
 774         /**
 775          * Get the prefixed title with spaces, plus any fragment
 776          * (part beginning with '#')
 777          *
 778          * @return String the prefixed title, with spaces and the fragment, including '#'
 779          */
 780         public function getFullText() {
 781                 $text = $this->getPrefixedText();
 782                 if ( $this->mFragment != '' ) {
 783                         $text .= '#' . $this->mFragment;
 784                 }
 785                 return $text;
 786         }
 787
 788         /**
 789          * Get the base page name, i.e. the leftmost part before any slashes
 790          *
 791          * @return String Base name
 792          */
 793         public function getBaseText() {
 794                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 795                         return $this->getText();
 796                 }
 797
 798                 $parts = explode( '/', $this->getText() );
 799                 # Don't discard the real title if there's no subpage involved
 800                 if ( count( $parts ) > 1 ) {
 801                         unset( $parts[count( $parts ) - 1] );
 802                 }
 803                 return implode( '/', $parts );
 804         }
 805
 806         /**
 807          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
 808          *
 809          * @return String Subpage name
 810          */
 811         public function getSubpageText() {
 812                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 813                         return( $this->mTextform );
 814                 }
 815                 $parts = explode( '/', $this->mTextform );
 816                 return( $parts[count( $parts ) - 1] );
 817         }
 818
 819         /**
 820          * Get a URL-encoded form of the subpage text
 821          *
 822          * @return String URL-encoded subpage name
 823          */
 824         public function getSubpageUrlForm() {
 825                 $text = $this->getSubpageText();
 826                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 827                 return( $text );
 828         }
 829
 830         /**
 831          * Get a URL-encoded title (not an actual URL) including interwiki
 832          *
 833          * @return String the URL-encoded form
 834          */
 835         public function getPrefixedURL() {
 836                 $s = $this->prefix( $this->mDbkeyform );
 837                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 838                 return $s;
 839         }
 840
 841         /**
 842          * Get a real URL referring to this title, with interwiki link and
 843          * fragment
 844          *
 845          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 846          *   links. Can be specified as an associative array as well, e.g.,
 847          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 848          * @param $variant String language variant of url (for sr, zh..)
 849          * @return String the URL
 850          */
 851         public function getFullURL( $query = '', $variant = false ) {
 852                 # Hand off all the decisions on urls to getLocalURL
 853                 $url = $this->getLocalURL( $query, $variant );
 854
 855                 # Expand the url to make it a full url. Note that getLocalURL has the
 856                 # potential to output full urls for a variety of reasons, so we use
 857                 # wfExpandUrl instead of simply prepending $wgServer
 858                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
 859
 860                 # Finally, add the fragment.
 861                 $url .= $this->getFragmentForURL();
 862
 863                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 864                 return $url;
 865         }
 866
 867         /**
 868          * Get a URL with no fragment or server name.  If this page is generated
 869          * with action=render, $wgServer is prepended.
 870          *
 871          * @param $query Mixed: an optional query string; if not specified,
 872          *   $wgArticlePath will be used.  Can be specified as an associative array
 873          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 874          *   URL-escaped).
 875          * @param $variant String language variant of url (for sr, zh..)
 876          * @return String the URL
 877          */
 878         public function getLocalURL( $query = '', $variant = false ) {
 879                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 880                 global $wgVariantArticlePath, $wgContLang;
 881
 882                 if ( is_array( $query ) ) {
 883                         $query = wfArrayToCGI( $query );
 884                 }
 885
 886                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 887                 if ( $interwiki ) {
 888                         $namespace = $this->getNsText();
 889                         if ( $namespace != '' ) {
 890                                 # Can this actually happen? Interwikis shouldn't be parsed.
 891                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 892                                 $namespace .= ':';
 893                         }
 894                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
 895                         $url = wfAppendQuery( $url, $query );
 896                 } else {
 897                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 898                         if ( $query == '' ) {
 899                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 900                                         if ( !$wgVariantArticlePath ) {
 901                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 902                                         } else {
 903                                                 $variantArticlePath = $wgVariantArticlePath;
 904                                         }
 905                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 906                                         $url = str_replace( '$1', $dbkey, $url  );
 907                                 } else {
 908                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 909                                         wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
 910                                 }
 911                         } else {
 912                                 global $wgActionPaths;
 913                                 $url = false;
 914                                 $matches = array();
 915                                 if ( !empty( $wgActionPaths ) &&
 916                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 917                                 {
 918                                         $action = urldecode( $matches[2] );
 919                                         if ( isset( $wgActionPaths[$action] ) ) {
 920                                                 $query = $matches[1];
 921                                                 if ( isset( $matches[4] ) ) {
 922                                                         $query .= $matches[4];
 923                                                 }
 924                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 925                                                 if ( $query != '' ) {
 926                                                         $url = wfAppendQuery( $url, $query );
 927                                                 }
 928                                         }
 929                                 }
 930
 931                                 if ( $url === false ) {
 932                                         if ( $query == '-' ) {
 933                                                 $query = '';
 934                                         }
 935                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 936                                 }
 937                         }
 938
 939                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query, $variant ) );
 940
 941                         // @todo FIXME: This causes breakage in various places when we
 942                         // actually expected a local URL and end up with dupe prefixes.
 943                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 944                                 $url = $wgServer . $url;
 945                         }
 946                 }
 947                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query, $variant ) );
 948                 return $url;
 949         }
 950
 951         /**
 952          * Get a URL that's the simplest URL that will be valid to link, locally,
 953          * to the current Title.  It includes the fragment, but does not include
 954          * the server unless action=render is used (or the link is external).  If
 955          * there's a fragment but the prefixed text is empty, we just return a link
 956          * to the fragment.
 957          *
 958          * The result obviously should not be URL-escaped, but does need to be
 959          * HTML-escaped if it's being output in HTML.
 960          *
 961          * @param $query Array of Strings An associative array of key => value pairs for the
 962          *   query string.  Keys and values will be escaped.
 963          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 964          *   for external links.  Default is "false" (same variant as current page,
 965          *   for anonymous users).
 966          * @return String the URL
 967          */
 968         public function getLinkUrl( $query = array(), $variant = false ) {
 969                 wfProfileIn( __METHOD__ );
 970                 if ( $this->isExternal() ) {
 971                         $ret = $this->getFullURL( $query );
 972                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 973                         $ret = $this->getFragmentForURL();
 974                 } else {
 975                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 976                 }
 977                 wfProfileOut( __METHOD__ );
 978                 return $ret;
 979         }
 980
 981         /**
 982          * Get an HTML-escaped version of the URL form, suitable for
 983          * using in a link, without a server name or fragment
 984          *
 985          * @param $query String an optional query string
 986          * @return String the URL
 987          */
 988         public function escapeLocalURL( $query = '' ) {
 989                 return htmlspecialchars( $this->getLocalURL( $query ) );
 990         }
 991
 992         /**
 993          * Get an HTML-escaped version of the URL form, suitable for
 994          * using in a link, including the server name and fragment
 995          *
 996          * @param $query String an optional query string
 997          * @return String the URL
 998          */
 999         public function escapeFullURL( $query = '' ) {
1000                 return htmlspecialchars( $this->getFullURL( $query ) );
1001         }
1002
1003         /**
1004          * HTML-escaped version of getCanonicalURL()
1005          */
1006         public function escapeCanonicalURL( $query = '', $variant = false ) {
1007                 return htmlspecialchars( $this->getCanonicalURL( $query, $variant ) );
1008         }
1009
1010         /**
1011          * Get the URL form for an internal link.
1012          * - Used in various Squid-related code, in case we have a different
1013          * internal hostname for the server from the exposed one.
1014          *
1015          * This uses $wgInternalServer to qualify the path, or $wgServer
1016          * if $wgInternalServer is not set. If the server variable used is
1017          * protocol-relative, the URL will be expanded to http://
1018          *
1019          * @param $query String an optional query string
1020          * @param $variant String language variant of url (for sr, zh..)
1021          * @return String the URL
1022          */
1023         public function getInternalURL( $query = '', $variant = false ) {
1024                 if ( $this->isExternal( ) ) {
1025                         $server = '';
1026                 } else {
1027                         global $wgInternalServer, $wgServer;
1028                         $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1029                 }
1030                 $url = wfExpandUrl( $server . $this->getLocalURL( $query, $variant ), PROTO_HTTP );
1031                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1032                 return $url;
1033         }
1034
1035         /**
1036          * Get the URL for a canonical link, for use in things like IRC and
1037          * e-mail notifications. Uses $wgCanonicalServer and the
1038          * GetCanonicalURL hook.
1039          *
1040          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1041          *
1042          * @param $query string An optional query string
1043          * @param $variant string Language variant of URL (for sr, zh, ...)
1044          * @return string The URL
1045          */
1046         public function getCanonicalURL( $query = '', $variant = false ) {
1047                 global $wgCanonicalServer;
1048                 $url = $wgCanonicalServer . $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
1049                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1050                 return $url;
1051         }
1052
1053         /**
1054          * Get the edit URL for this Title
1055          *
1056          * @return String the URL, or a null string if this is an
1057          *  interwiki link
1058          */
1059         public function getEditURL() {
1060                 if ( $this->mInterwiki != '' ) {
1061                         return '';
1062                 }
1063                 $s = $this->getLocalURL( 'action=edit' );
1064
1065                 return $s;
1066         }
1067
1068         /**
1069          * Get the HTML-escaped displayable text form.
1070          * Used for the title field in <a> tags.
1071          *
1072          * @return String the text, including any prefixes
1073          */
1074         public function getEscapedText() {
1075                 return htmlspecialchars( $this->getPrefixedText() );
1076         }
1077
1078         /**
1079          * Is this Title interwiki?
1080          *
1081          * @return Bool
1082          */
1083         public function isExternal() {
1084                 return ( $this->mInterwiki != '' );
1085         }
1086
1087         /**
1088          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1089          *
1090          * @param $action String Action to check (default: edit)
1091          * @return Bool
1092          */
1093         public function isSemiProtected( $action = 'edit' ) {
1094                 if ( $this->exists() ) {
1095                         $restrictions = $this->getRestrictions( $action );
1096                         if ( count( $restrictions ) > 0 ) {
1097                                 foreach ( $restrictions as $restriction ) {
1098                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1099                                                 return false;
1100                                         }
1101                                 }
1102                         } else {
1103                                 # Not protected
1104                                 return false;
1105                         }
1106                         return true;
1107                 } else {
1108                         # If it doesn't exist, it can't be protected
1109                         return false;
1110                 }
1111         }
1112
1113         /**
1114          * Does the title correspond to a protected article?
1115          *
1116          * @param $action String the action the page is protected from,
1117          * by default checks all actions.
1118          * @return Bool
1119          */
1120         public function isProtected( $action = '' ) {
1121                 global $wgRestrictionLevels;
1122
1123                 $restrictionTypes = $this->getRestrictionTypes();
1124
1125                 # Special pages have inherent protection
1126                 if( $this->getNamespace() == NS_SPECIAL ) {
1127                         return true;
1128                 }
1129
1130                 # Check regular protection levels
1131                 foreach ( $restrictionTypes as $type ) {
1132                         if ( $action == $type || $action == '' ) {
1133                                 $r = $this->getRestrictions( $type );
1134                                 foreach ( $wgRestrictionLevels as $level ) {
1135                                         if ( in_array( $level, $r ) && $level != '' ) {
1136                                                 return true;
1137                                         }
1138                                 }
1139                         }
1140                 }
1141
1142                 return false;
1143         }
1144
1145         /**
1146          * Is this a conversion table for the LanguageConverter?
1147          *
1148          * @return Bool
1149          */
1150         public function isConversionTable() {
1151                 if(
1152                         $this->getNamespace() == NS_MEDIAWIKI &&
1153                         strpos( $this->getText(), 'Conversiontable' ) !== false
1154                 )
1155                 {
1156                         return true;
1157                 }
1158
1159                 return false;
1160         }
1161
1162         /**
1163          * Is $wgUser watching this page?
1164          *
1165          * @return Bool
1166          */
1167         public function userIsWatching() {
1168                 global $wgUser;
1169
1170                 if ( is_null( $this->mWatched ) ) {
1171                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1172                                 $this->mWatched = false;
1173                         } else {
1174                                 $this->mWatched = $wgUser->isWatched( $this );
1175                         }
1176                 }
1177                 return $this->mWatched;
1178         }
1179
1180         /**
1181          * Can $wgUser perform $action on this page?
1182          * This skips potentially expensive cascading permission checks
1183          * as well as avoids expensive error formatting
1184          *
1185          * Suitable for use for nonessential UI controls in common cases, but
1186          * _not_ for functional access control.
1187          *
1188          * May provide false positives, but should never provide a false negative.
1189          *
1190          * @param $action String action that permission needs to be checked for
1191          * @return Bool
1192          */
1193         public function quickUserCan( $action ) {
1194                 return $this->userCan( $action, false );
1195         }
1196
1197         /**
1198          * Determines if $user is unable to edit this page because it has been protected
1199          * by $wgNamespaceProtection.
1200          *
1201          * @param $user User object to check permissions
1202          * @return Bool
1203          */
1204         public function isNamespaceProtected( User $user ) {
1205                 global $wgNamespaceProtection;
1206
1207                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1208                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1209                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1210                                         return true;
1211                                 }
1212                         }
1213                 }
1214                 return false;
1215         }
1216
1217         /**
1218          * Can $wgUser perform $action on this page?
1219          *
1220          * @param $action String action that permission needs to be checked for
1221          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1222          * @return Bool
1223          */
1224         public function userCan( $action, $doExpensiveQueries = true ) {
1225                 global $wgUser;
1226                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1227         }
1228
1229         /**
1230          * Can $user perform $action on this page?
1231          *
1232          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1233          *
1234          * @param $action String action that permission needs to be checked for
1235          * @param $user User to check
1236          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1237          *   skipping checks for cascading protections and user blocks.
1238          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1239          * @return Array of arguments to wfMsg to explain permissions problems.
1240          */
1241         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1242                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1243
1244                 // Remove the errors being ignored.
1245                 foreach ( $errors as $index => $error ) {
1246                         $error_key = is_array( $error ) ? $error[0] : $error;
1247
1248                         if ( in_array( $error_key, $ignoreErrors ) ) {
1249                                 unset( $errors[$index] );
1250                         }
1251                 }
1252
1253                 return $errors;
1254         }
1255
1256         /**
1257          * Permissions checks that fail most often, and which are easiest to test.
1258          *
1259          * @param $action String the action to check
1260          * @param $user User user to check
1261          * @param $errors Array list of current errors
1262          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1263          * @param $short Boolean short circuit on first error
1264          *
1265          * @return Array list of errors
1266          */
1267         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1268                 $ns = $this->getNamespace();
1269
1270                 if ( $action == 'create' ) {
1271                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk', $ns ) ) ||
1272                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage', $ns ) ) ) {
1273                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1274                         }
1275                 } elseif ( $action == 'move' ) {
1276                         if ( !$user->isAllowed( 'move-rootuserpages', $ns )
1277                                         && $ns == NS_USER && !$this->isSubpage() ) {
1278                                 // Show user page-specific message only if the user can move other pages
1279                                 $errors[] = array( 'cant-move-user-page' );
1280                         }
1281
1282                         // Check if user is allowed to move files if it's a file
1283                         if ( $ns == NS_FILE && !$user->isAllowed( 'movefile', $ns ) ) {
1284                                 $errors[] = array( 'movenotallowedfile' );
1285                         }
1286
1287                         if ( !$user->isAllowed( 'move', $ns) ) {
1288                                 // User can't move anything
1289
1290                                 $userCanMove = in_array( 'move', User::getGroupPermissions(
1291                                         array( 'user' ), $ns ), true );
1292                                 $autoconfirmedCanMove = in_array( 'move', User::getGroupPermissions(
1293                                         array( 'autoconfirmed' ), $ns ), true );
1294
1295                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1296                                         // custom message if logged-in users without any special rights can move
1297                                         $errors[] = array( 'movenologintext' );
1298                                 } else {
1299                                         $errors[] = array( 'movenotallowed' );
1300                                 }
1301                         }
1302                 } elseif ( $action == 'move-target' ) {
1303                         if ( !$user->isAllowed( 'move', $ns ) ) {
1304                                 // User can't move anything
1305                                 $errors[] = array( 'movenotallowed' );
1306                         } elseif ( !$user->isAllowed( 'move-rootuserpages', $ns )
1307                                         && $ns == NS_USER && !$this->isSubpage() ) {
1308                                 // Show user page-specific message only if the user can move other pages
1309                                 $errors[] = array( 'cant-move-to-user-page' );
1310                         }
1311                 } elseif ( !$user->isAllowed( $action, $ns ) ) {
1312                         // We avoid expensive display logic for quickUserCan's and such
1313                         $groups = false;
1314                         if ( !$short ) {
1315                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1316                                         User::getGroupsWithPermission( $action, $ns ) );
1317                         }
1318
1319                         if ( $groups ) {
1320                                 global $wgLang;
1321                                 $return = array(
1322                                         'badaccess-groups',
1323                                         $wgLang->commaList( $groups ),
1324                                         count( $groups )
1325                                 );
1326                         } else {
1327                                 $return = array( 'badaccess-group0' );
1328                         }
1329                         $errors[] = $return;
1330                 }
1331
1332                 return $errors;
1333         }
1334
1335         /**
1336          * Add the resulting error code to the errors array
1337          *
1338          * @param $errors Array list of current errors
1339          * @param $result Mixed result of errors
1340          *
1341          * @return Array list of errors
1342          */
1343         private function resultToError( $errors, $result ) {
1344                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1345                         // A single array representing an error
1346                         $errors[] = $result;
1347                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1348                         // A nested array representing multiple errors
1349                         $errors = array_merge( $errors, $result );
1350                 } elseif ( $result !== '' && is_string( $result ) ) {
1351                         // A string representing a message-id
1352                         $errors[] = array( $result );
1353                 } elseif ( $result === false ) {
1354                         // a generic "We don't want them to do that"
1355                         $errors[] = array( 'badaccess-group0' );
1356                 }
1357                 return $errors;
1358         }
1359
1360         /**
1361          * Check various permission hooks
1362          *
1363          * @param $action String the action to check
1364          * @param $user User user to check
1365          * @param $errors Array list of current errors
1366          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1367          * @param $short Boolean short circuit on first error
1368          *
1369          * @return Array list of errors
1370          */
1371         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1372                 // Use getUserPermissionsErrors instead
1373                 $result = '';
1374                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1375                         return $result ? array() : array( array( 'badaccess-group0' ) );
1376                 }
1377                 // Check getUserPermissionsErrors hook
1378                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1379                         $errors = $this->resultToError( $errors, $result );
1380                 }
1381                 // Check getUserPermissionsErrorsExpensive hook
1382                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1383                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1384                         $errors = $this->resultToError( $errors, $result );
1385                 }
1386
1387                 return $errors;
1388         }
1389
1390         /**
1391          * Check permissions on special pages & namespaces
1392          *
1393          * @param $action String the action to check
1394          * @param $user User user to check
1395          * @param $errors Array list of current errors
1396          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1397          * @param $short Boolean short circuit on first error
1398          *
1399          * @return Array list of errors
1400          */
1401         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1402                 # Only 'createaccount' and 'execute' can be performed on
1403                 # special pages, which don't actually exist in the DB.
1404                 $specialOKActions = array( 'createaccount', 'execute' );
1405                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1406                         $errors[] = array( 'ns-specialprotected' );
1407                 }
1408
1409                 # Check $wgNamespaceProtection for restricted namespaces
1410                 if ( $this->isNamespaceProtected( $user ) ) {
1411                         $ns = $this->mNamespace == NS_MAIN ?
1412                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1413                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1414                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1415                 }
1416
1417                 return $errors;
1418         }
1419
1420         /**
1421          * Check CSS/JS sub-page permissions
1422          *
1423          * @param $action String the action to check
1424          * @param $user User user to check
1425          * @param $errors Array list of current errors
1426          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1427          * @param $short Boolean short circuit on first error
1428          *
1429          * @return Array list of errors
1430          */
1431         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1432                 # Protect css/js subpages of user pages
1433                 # XXX: this might be better using restrictions
1434                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1435                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1436                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1437                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1438                                 $errors[] = array( 'customcssprotected' );
1439                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1440                                 $errors[] = array( 'customjsprotected' );
1441                         }
1442                 }
1443
1444                 return $errors;
1445         }
1446
1447         /**
1448          * Check against page_restrictions table requirements on this
1449          * page. The user must possess all required rights for this
1450          * action.
1451          *
1452          * @param $action String the action to check
1453          * @param $user User user to check
1454          * @param $errors Array list of current errors
1455          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1456          * @param $short Boolean short circuit on first error
1457          *
1458          * @return Array list of errors
1459          */
1460         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1461                 foreach ( $this->getRestrictions( $action ) as $right ) {
1462                         // Backwards compatibility, rewrite sysop -> protect
1463                         if ( $right == 'sysop' ) {
1464                                 $right = 'protect';
1465                         }
1466                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1467                                 // Users with 'editprotected' permission can edit protected pages
1468                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected', $this->mNamespace ) ) {
1469                                         // Users with 'editprotected' permission cannot edit protected pages
1470                                         // with cascading option turned on.
1471                                         if ( $this->mCascadeRestriction ) {
1472                                                 $errors[] = array( 'protectedpagetext', $right );
1473                                         }
1474                                 } else {
1475                                         $errors[] = array( 'protectedpagetext', $right );
1476                                 }
1477                         }
1478                 }
1479
1480                 return $errors;
1481         }
1482
1483         /**
1484          * Check restrictions on cascading pages.
1485          *
1486          * @param $action String the action to check
1487          * @param $user User to check
1488          * @param $errors Array list of current errors
1489          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1490          * @param $short Boolean short circuit on first error
1491          *
1492          * @return Array list of errors
1493          */
1494         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1495                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1496                         # We /could/ use the protection level on the source page, but it's
1497                         # fairly ugly as we have to establish a precedence hierarchy for pages
1498                         # included by multiple cascade-protected pages. So just restrict
1499                         # it to people with 'protect' permission, as they could remove the
1500                         # protection anyway.
1501                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1502                         # Cascading protection depends on more than this page...
1503                         # Several cascading protected pages may include this page...
1504                         # Check each cascading level
1505                         # This is only for protection restrictions, not for all actions
1506                         if ( isset( $restrictions[$action] ) ) {
1507                                 foreach ( $restrictions[$action] as $right ) {
1508                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1509                                         if ( $right != '' && !$user->isAllowed( $right, $this->mNamespace ) ) {
1510                                                 $pages = '';
1511                                                 foreach ( $cascadingSources as $page )
1512                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1513                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1514                                         }
1515                                 }
1516                         }
1517                 }
1518
1519                 return $errors;
1520         }
1521
1522         /**
1523          * Check action permissions not already checked in checkQuickPermissions
1524          *
1525          * @param $action String the action to check
1526          * @param $user User to check
1527          * @param $errors Array list of current errors
1528          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1529          * @param $short Boolean short circuit on first error
1530          *
1531          * @return Array list of errors
1532          */
1533         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1534                 if ( $action == 'protect' ) {
1535                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1536                                 // If they can't edit, they shouldn't protect.
1537                                 $errors[] = array( 'protect-cantedit' );
1538                         }
1539                 } elseif ( $action == 'create' ) {
1540                         $title_protection = $this->getTitleProtection();
1541                         if( $title_protection ) {
1542                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1543                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1544                                 }
1545                                 if( $title_protection['pt_create_perm'] == '' ||
1546                                                 !$user->isAllowed( $title_protection['pt_create_perm'],
1547                                                 $this->mNamespace ) ) {
1548                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1549                                 }
1550                         }
1551                 } elseif ( $action == 'move' ) {
1552                         // Check for immobile pages
1553                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1554                                 // Specific message for this case
1555                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1556                         } elseif ( !$this->isMovable() ) {
1557                                 // Less specific message for rarer cases
1558                                 $errors[] = array( 'immobile-page' );
1559                         }
1560                 } elseif ( $action == 'move-target' ) {
1561                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1562                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1563                         } elseif ( !$this->isMovable() ) {
1564                                 $errors[] = array( 'immobile-target-page' );
1565                         }
1566                 }
1567                 return $errors;
1568         }
1569
1570         /**
1571          * Check that the user isn't blocked from editting.
1572          *
1573          * @param $action String the action to check
1574          * @param $user User to check
1575          * @param $errors Array list of current errors
1576          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1577          * @param $short Boolean short circuit on first error
1578          *
1579          * @return Array list of errors
1580          */
1581         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1582                 if( !$doExpensiveQueries ) {
1583                         return $errors;
1584                 }
1585
1586                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1587
1588                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1589                         $errors[] = array( 'confirmedittext' );
1590                 }
1591
1592                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1593                         // Edit blocks should not affect reading.
1594                         // Account creation blocks handled at userlogin.
1595                         // Unblocking handled in SpecialUnblock
1596                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1597                         // Don't block the user from editing their own talk page unless they've been
1598                         // explicitly blocked from that too.
1599                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1600                         $block = $user->mBlock;
1601
1602                         // This is from OutputPage::blockedPage
1603                         // Copied at r23888 by werdna
1604
1605                         $id = $user->blockedBy();
1606                         $reason = $user->blockedFor();
1607                         if ( $reason == '' ) {
1608                                 $reason = wfMsg( 'blockednoreason' );
1609                         }
1610                         $ip = $user->getRequest()->getIP();
1611
1612                         if ( is_numeric( $id ) ) {
1613                                 $name = User::whoIs( $id );
1614                         } else {
1615                                 $name = $id;
1616                         }
1617
1618                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1619                         $blockid = $block->getId();
1620                         $blockExpiry = $user->mBlock->mExpiry;
1621                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1622                         if ( $blockExpiry == 'infinity' ) {
1623                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1624                         } else {
1625                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1626                         }
1627
1628                         $intended = strval( $user->mBlock->getTarget() );
1629
1630                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1631                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1632                 }
1633
1634                 return $errors;
1635         }
1636
1637         /**
1638          * Can $user perform $action on this page? This is an internal function,
1639          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1640          * checks on wfReadOnly() and blocks)
1641          *
1642          * @param $action String action that permission needs to be checked for
1643          * @param $user User to check
1644          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1645          * @param $short Bool Set this to true to stop after the first permission error.
1646          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1647          */
1648         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1649                 wfProfileIn( __METHOD__ );
1650
1651                 $errors = array();
1652                 $checks = array(
1653                         'checkQuickPermissions',
1654                         'checkPermissionHooks',
1655                         'checkSpecialsAndNSPermissions',
1656                         'checkCSSandJSPermissions',
1657                         'checkPageRestrictions',
1658                         'checkCascadingSourcesRestrictions',
1659                         'checkActionPermissions',
1660                         'checkUserBlock'
1661                 );
1662
1663                 while( count( $checks ) > 0 &&
1664                            !( $short && count( $errors ) > 0 ) ) {
1665                         $method = array_shift( $checks );
1666                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1667                 }
1668
1669                 wfProfileOut( __METHOD__ );
1670                 return $errors;
1671         }
1672
1673         /**
1674          * Is this title subject to title protection?
1675          * Title protection is the one applied against creation of such title.
1676          *
1677          * @return Mixed An associative array representing any existent title
1678          *   protection, or false if there's none.
1679          */
1680         private function getTitleProtection() {
1681                 // Can't protect pages in special namespaces
1682                 if ( $this->getNamespace() < 0 ) {
1683                         return false;
1684                 }
1685
1686                 // Can't protect pages that exist.
1687                 if ( $this->exists() ) {
1688                         return false;
1689                 }
1690
1691                 if ( !isset( $this->mTitleProtection ) ) {
1692                         $dbr = wfGetDB( DB_SLAVE );
1693                         $res = $dbr->select( 'protected_titles', '*',
1694                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1695                                 __METHOD__ );
1696
1697                         // fetchRow returns false if there are no rows.
1698                         $this->mTitleProtection = $dbr->fetchRow( $res );
1699                 }
1700                 return $this->mTitleProtection;
1701         }
1702
1703         /**
1704          * Update the title protection status
1705          *
1706          * @param $create_perm String Permission required for creation
1707          * @param $reason String Reason for protection
1708          * @param $expiry String Expiry timestamp
1709          * @return boolean true
1710          */
1711         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1712                 global $wgUser, $wgContLang;
1713
1714                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1715                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1716                         // No change
1717                         return true;
1718                 }
1719
1720                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1721
1722                 $dbw = wfGetDB( DB_MASTER );
1723
1724                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1725
1726                 $expiry_description = '';
1727                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1728                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1729                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1730                 } else {
1731                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1732                 }
1733
1734                 # Update protection table
1735                 if ( $create_perm != '' ) {
1736                         $this->mTitleProtection = array(
1737                                         'pt_namespace' => $namespace,
1738                                         'pt_title' => $title,
1739                                         'pt_create_perm' => $create_perm,
1740                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1741                                         'pt_expiry' => $encodedExpiry,
1742                                         'pt_user' => $wgUser->getId(),
1743                                         'pt_reason' => $reason,
1744                                 );
1745                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1746                                 $this->mTitleProtection, __METHOD__     );
1747                 } else {
1748                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1749                                 'pt_title' => $title ), __METHOD__ );
1750                         $this->mTitleProtection = false;
1751                 }
1752
1753                 # Update the protection log
1754                 if ( $dbw->affectedRows() ) {
1755                         $log = new LogPage( 'protect' );
1756
1757                         if ( $create_perm ) {
1758                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1759                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1760                         } else {
1761                                 $log->addEntry( 'unprotect', $this, $reason );
1762                         }
1763                 }
1764
1765                 return true;
1766         }
1767
1768         /**
1769          * Remove any title protection due to page existing
1770          */
1771         public function deleteTitleProtection() {
1772                 $dbw = wfGetDB( DB_MASTER );
1773
1774                 $dbw->delete(
1775                         'protected_titles',
1776                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1777                         __METHOD__
1778                 );
1779                 $this->mTitleProtection = false;
1780         }
1781
1782         /**
1783          * Would anybody with sufficient privileges be able to move this page?
1784          * Some pages just aren't movable.
1785          *
1786          * @return Bool TRUE or FALSE
1787          */
1788         public function isMovable() {
1789                 $result = MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1790                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1791                 return $result;
1792         }
1793
1794         /**
1795          * Can $wgUser read this page?
1796          *
1797          * @return Bool
1798          * @todo fold these checks into userCan()
1799          */
1800         public function userCanRead() {
1801                 global $wgUser, $wgGroupPermissions;
1802
1803                 static $useShortcut = null;
1804
1805                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1806                 if ( is_null( $useShortcut ) ) {
1807                         global $wgRevokePermissions;
1808                         $useShortcut = true;
1809                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1810                                 # Not a public wiki, so no shortcut
1811                                 $useShortcut = false;
1812                         } elseif ( !empty( $wgRevokePermissions ) ) {
1813                                 /**
1814                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1815                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1816                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1817                                  * reading is allowed.
1818                                  */
1819                                 foreach ( $wgRevokePermissions as $perms ) {
1820                                         if ( !empty( $perms['read'] ) ) {
1821                                                 # We might be removing the read right from the user, so no shortcut
1822                                                 $useShortcut = false;
1823                                                 break;
1824                                         }
1825                                 }
1826                         }
1827                 }
1828
1829                 $result = null;
1830                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1831                 if ( $result !== null ) {
1832                         return $result;
1833                 }
1834
1835                 # Shortcut for public wikis, allows skipping quite a bit of code
1836                 if ( $useShortcut ) {
1837                         return true;
1838                 }
1839
1840                 if ( $wgUser->isAllowed( 'read' ) ) {
1841                         return true;
1842                 } else {
1843                         global $wgWhitelistRead;
1844
1845                         # Always grant access to the login page.
1846                         # Even anons need to be able to log in.
1847                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1848                                 return true;
1849                         }
1850
1851                         # Bail out if there isn't whitelist
1852                         if ( !is_array( $wgWhitelistRead ) ) {
1853                                 return false;
1854                         }
1855
1856                         # Check for explicit whitelisting
1857                         $name = $this->getPrefixedText();
1858                         $dbName = $this->getPrefixedDBKey();
1859                         // Check with and without underscores
1860                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1861                                 return true;
1862
1863                         # Old settings might have the title prefixed with
1864                         # a colon for main-namespace pages
1865                         if ( $this->getNamespace() == NS_MAIN ) {
1866                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1867                                         return true;
1868                                 }
1869                         }
1870
1871                         # If it's a special page, ditch the subpage bit and check again
1872                         if ( $this->getNamespace() == NS_SPECIAL ) {
1873                                 $name = $this->getDBkey();
1874                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1875                                 if ( $name === false ) {
1876                                         # Invalid special page, but we show standard login required message
1877                                         return false;
1878                                 }
1879
1880                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1881                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1882                                         return true;
1883                                 }
1884                         }
1885
1886                 }
1887                 return false;
1888         }
1889
1890         /**
1891          * Is this the mainpage?
1892          * @note Title::newFromText seams to be sufficiently optimized by the title
1893          * cache that we don't need to over-optimize by doing direct comparisons and
1894          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1895          * ends up reporting something differently than $title->isMainPage();
1896          *
1897          * @return Bool
1898          */
1899         public function isMainPage() {
1900                 return $this->equals( Title::newMainPage() );
1901         }
1902
1903         /**
1904          * Is this a talk page of some sort?
1905          *
1906          * @return Bool
1907          */
1908         public function isTalkPage() {
1909                 return MWNamespace::isTalk( $this->getNamespace() );
1910         }
1911
1912         /**
1913          * Is this a subpage?
1914          *
1915          * @return Bool
1916          */
1917         public function isSubpage() {
1918                 return MWNamespace::hasSubpages( $this->mNamespace )
1919                         ? strpos( $this->getText(), '/' ) !== false
1920                         : false;
1921         }
1922
1923         /**
1924          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1925          *
1926          * @return Bool
1927          */
1928         public function hasSubpages() {
1929                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1930                         # Duh
1931                         return false;
1932                 }
1933
1934                 # We dynamically add a member variable for the purpose of this method
1935                 # alone to cache the result.  There's no point in having it hanging
1936                 # around uninitialized in every Title object; therefore we only add it
1937                 # if needed and don't declare it statically.
1938                 if ( isset( $this->mHasSubpages ) ) {
1939                         return $this->mHasSubpages;
1940                 }
1941
1942                 $subpages = $this->getSubpages( 1 );
1943                 if ( $subpages instanceof TitleArray ) {
1944                         return $this->mHasSubpages = (bool)$subpages->count();
1945                 }
1946                 return $this->mHasSubpages = false;
1947         }
1948
1949         /**
1950          * Get all subpages of this page.
1951          *
1952          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1953          * @return mixed TitleArray, or empty array if this page's namespace
1954          *  doesn't allow subpages
1955          */
1956         public function getSubpages( $limit = -1 ) {
1957                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1958                         return array();
1959                 }
1960
1961                 $dbr = wfGetDB( DB_SLAVE );
1962                 $conds['page_namespace'] = $this->getNamespace();
1963                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1964                 $options = array();
1965                 if ( $limit > -1 ) {
1966                         $options['LIMIT'] = $limit;
1967                 }
1968                 return $this->mSubpages = TitleArray::newFromResult(
1969                         $dbr->select( 'page',
1970                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1971                                 $conds,
1972                                 __METHOD__,
1973                                 $options
1974                         )
1975                 );
1976         }
1977
1978         /**
1979          * Does that page contain wikitext, or it is JS, CSS or whatever?
1980          *
1981          * @return Bool
1982          */
1983         public function isWikitextPage() {
1984                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
1985                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
1986                 return $retval;
1987         }
1988
1989         /**
1990          * Could this page contain custom CSS or JavaScript, based
1991          * on the title?
1992          *
1993          * @return Bool
1994          */
1995         public function isCssOrJsPage() {
1996                 $retval = $this->mNamespace == NS_MEDIAWIKI
1997                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1998                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
1999                 return $retval;
2000         }
2001
2002         /**
2003          * Is this a .css or .js subpage of a user page?
2004          * @return Bool
2005          */
2006         public function isCssJsSubpage() {
2007                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
2008         }
2009
2010         /**
2011          * Is this a *valid* .css or .js subpage of a user page?
2012          *
2013          * @return Bool
2014          * @deprecated since 1.17
2015          */
2016         public function isValidCssJsSubpage() {
2017                 return $this->isCssJsSubpage();
2018         }
2019
2020         /**
2021          * Trim down a .css or .js subpage title to get the corresponding skin name
2022          *
2023          * @return string containing skin name from .css or .js subpage title
2024          */
2025         public function getSkinFromCssJsSubpage() {
2026                 $subpage = explode( '/', $this->mTextform );
2027                 $subpage = $subpage[ count( $subpage ) - 1 ];
2028                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
2029         }
2030
2031         /**
2032          * Is this a .css subpage of a user page?
2033          *
2034          * @return Bool
2035          */
2036         public function isCssSubpage() {
2037                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
2038         }
2039
2040         /**
2041          * Is this a .js subpage of a user page?
2042          *
2043          * @return Bool
2044          */
2045         public function isJsSubpage() {
2046                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2047         }
2048
2049         /**
2050          * Protect css subpages of user pages: can $wgUser edit
2051          * this page?
2052          *
2053          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2054          * @return Bool
2055          */
2056         public function userCanEditCssSubpage() {
2057                 global $wgUser;
2058                 wfDeprecated( __METHOD__ );
2059                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2060                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2061         }
2062
2063         /**
2064          * Protect js subpages of user pages: can $wgUser edit
2065          * this page?
2066          *
2067          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2068          * @return Bool
2069          */
2070         public function userCanEditJsSubpage() {
2071                 global $wgUser;
2072                 wfDeprecated( __METHOD__ );
2073                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2074                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2075         }
2076
2077         /**
2078          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2079          *
2080          * @return Bool If the page is subject to cascading restrictions.
2081          */
2082         public function isCascadeProtected() {
2083                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2084                 return ( $sources > 0 );
2085         }
2086
2087         /**
2088          * Cascading protection: Get the source of any cascading restrictions on this page.
2089          *
2090          * @param $getPages Bool Whether or not to retrieve the actual pages
2091          *        that the restrictions have come from.
2092          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2093          *     have come, false for none, or true if such restrictions exist, but $getPages
2094          *     was not set.  The restriction array is an array of each type, each of which
2095          *     contains a array of unique groups.
2096          */
2097         public function getCascadeProtectionSources( $getPages = true ) {
2098                 global $wgContLang;
2099                 $pagerestrictions = array();
2100
2101                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2102                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2103                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2104                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2105                 }
2106
2107                 wfProfileIn( __METHOD__ );
2108
2109                 $dbr = wfGetDB( DB_SLAVE );
2110
2111                 if ( $this->getNamespace() == NS_FILE ) {
2112                         $tables = array( 'imagelinks', 'page_restrictions' );
2113                         $where_clauses = array(
2114                                 'il_to' => $this->getDBkey(),
2115                                 'il_from=pr_page',
2116                                 'pr_cascade' => 1
2117                         );
2118                 } else {
2119                         $tables = array( 'templatelinks', 'page_restrictions' );
2120                         $where_clauses = array(
2121                                 'tl_namespace' => $this->getNamespace(),
2122                                 'tl_title' => $this->getDBkey(),
2123                                 'tl_from=pr_page',
2124                                 'pr_cascade' => 1
2125                         );
2126                 }
2127
2128                 if ( $getPages ) {
2129                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2130                                                    'pr_expiry', 'pr_type', 'pr_level' );
2131                         $where_clauses[] = 'page_id=pr_page';
2132                         $tables[] = 'page';
2133                 } else {
2134                         $cols = array( 'pr_expiry' );
2135                 }
2136
2137                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2138
2139                 $sources = $getPages ? array() : false;
2140                 $now = wfTimestampNow();
2141                 $purgeExpired = false;
2142
2143                 foreach ( $res as $row ) {
2144                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2145                         if ( $expiry > $now ) {
2146                                 if ( $getPages ) {
2147                                         $page_id = $row->pr_page;
2148                                         $page_ns = $row->page_namespace;
2149                                         $page_title = $row->page_title;
2150                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2151                                         # Add groups needed for each restriction type if its not already there
2152                                         # Make sure this restriction type still exists
2153
2154                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2155                                                 $pagerestrictions[$row->pr_type] = array();
2156                                         }
2157
2158                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2159                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2160                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2161                                         }
2162                                 } else {
2163                                         $sources = true;
2164                                 }
2165                         } else {
2166                                 // Trigger lazy purge of expired restrictions from the db
2167                                 $purgeExpired = true;
2168                         }
2169                 }
2170                 if ( $purgeExpired ) {
2171                         Title::purgeExpiredRestrictions();
2172                 }
2173
2174                 if ( $getPages ) {
2175                         $this->mCascadeSources = $sources;
2176                         $this->mCascadingRestrictions = $pagerestrictions;
2177                 } else {
2178                         $this->mHasCascadingRestrictions = $sources;
2179                 }
2180
2181                 wfProfileOut( __METHOD__ );
2182                 return array( $sources, $pagerestrictions );
2183         }
2184
2185         /**
2186          * Returns cascading restrictions for the current article
2187          *
2188          * @return Boolean
2189          */
2190         function areRestrictionsCascading() {
2191                 if ( !$this->mRestrictionsLoaded ) {
2192                         $this->loadRestrictions();
2193                 }
2194
2195                 return $this->mCascadeRestriction;
2196         }
2197
2198         /**
2199          * Loads a string into mRestrictions array
2200          *
2201          * @param $res Resource restrictions as an SQL result.
2202          * @param $oldFashionedRestrictions String comma-separated list of page
2203          *        restrictions from page table (pre 1.10)
2204          */
2205         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2206                 $rows = array();
2207
2208                 foreach ( $res as $row ) {
2209                         $rows[] = $row;
2210                 }
2211
2212                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2213         }
2214
2215         /**
2216          * Compiles list of active page restrictions from both page table (pre 1.10)
2217          * and page_restrictions table for this existing page.
2218          * Public for usage by LiquidThreads.
2219          *
2220          * @param $rows array of db result objects
2221          * @param $oldFashionedRestrictions string comma-separated list of page
2222          *        restrictions from page table (pre 1.10)
2223          */
2224         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2225                 global $wgContLang;
2226                 $dbr = wfGetDB( DB_SLAVE );
2227
2228                 $restrictionTypes = $this->getRestrictionTypes();
2229
2230                 foreach ( $restrictionTypes as $type ) {
2231                         $this->mRestrictions[$type] = array();
2232                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2233                 }
2234
2235                 $this->mCascadeRestriction = false;
2236
2237                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2238
2239                 if ( $oldFashionedRestrictions === null ) {
2240                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2241                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2242                 }
2243
2244                 if ( $oldFashionedRestrictions != '' ) {
2245
2246                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2247                                 $temp = explode( '=', trim( $restrict ) );
2248                                 if ( count( $temp ) == 1 ) {
2249                                         // old old format should be treated as edit/move restriction
2250                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2251                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2252                                 } else {
2253                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2254                                 }
2255                         }
2256
2257                         $this->mOldRestrictions = true;
2258
2259                 }
2260
2261                 if ( count( $rows ) ) {
2262                         # Current system - load second to make them override.
2263                         $now = wfTimestampNow();
2264                         $purgeExpired = false;
2265
2266                         # Cycle through all the restrictions.
2267                         foreach ( $rows as $row ) {
2268
2269                                 // Don't take care of restrictions types that aren't allowed
2270                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2271                                         continue;
2272
2273                                 // This code should be refactored, now that it's being used more generally,
2274                                 // But I don't really see any harm in leaving it in Block for now -werdna
2275                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2276
2277                                 // Only apply the restrictions if they haven't expired!
2278                                 if ( !$expiry || $expiry > $now ) {
2279                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2280                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2281
2282                                         $this->mCascadeRestriction |= $row->pr_cascade;
2283                                 } else {
2284                                         // Trigger a lazy purge of expired restrictions
2285                                         $purgeExpired = true;
2286                                 }
2287                         }
2288
2289                         if ( $purgeExpired ) {
2290                                 Title::purgeExpiredRestrictions();
2291                         }
2292                 }
2293
2294                 $this->mRestrictionsLoaded = true;
2295         }
2296
2297         /**
2298          * Load restrictions from the page_restrictions table
2299          *
2300          * @param $oldFashionedRestrictions String comma-separated list of page
2301          *        restrictions from page table (pre 1.10)
2302          */
2303         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2304                 global $wgContLang;
2305                 if ( !$this->mRestrictionsLoaded ) {
2306                         if ( $this->exists() ) {
2307                                 $dbr = wfGetDB( DB_SLAVE );
2308
2309                                 $res = $dbr->select(
2310                                         'page_restrictions',
2311                                         '*',
2312                                         array( 'pr_page' => $this->getArticleId() ),
2313                                         __METHOD__
2314                                 );
2315
2316                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2317                         } else {
2318                                 $title_protection = $this->getTitleProtection();
2319
2320                                 if ( $title_protection ) {
2321                                         $now = wfTimestampNow();
2322                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2323
2324                                         if ( !$expiry || $expiry > $now ) {
2325                                                 // Apply the restrictions
2326                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2327                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2328                                         } else { // Get rid of the old restrictions
2329                                                 Title::purgeExpiredRestrictions();
2330                                                 $this->mTitleProtection = false;
2331                                         }
2332                                 } else {
2333                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2334                                 }
2335                                 $this->mRestrictionsLoaded = true;
2336                         }
2337                 }
2338         }
2339
2340         /**
2341          * Purge expired restrictions from the page_restrictions table
2342          */
2343         static function purgeExpiredRestrictions() {
2344                 $dbw = wfGetDB( DB_MASTER );
2345                 $dbw->delete(
2346                         'page_restrictions',
2347                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2348                         __METHOD__
2349                 );
2350
2351                 $dbw->delete(
2352                         'protected_titles',
2353                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2354                         __METHOD__
2355                 );
2356         }
2357
2358         /**
2359          * Accessor/initialisation for mRestrictions
2360          *
2361          * @param $action String action that permission needs to be checked for
2362          * @return Array of Strings the array of groups allowed to edit this article
2363          */
2364         public function getRestrictions( $action ) {
2365                 if ( !$this->mRestrictionsLoaded ) {
2366                         $this->loadRestrictions();
2367                 }
2368                 return isset( $this->mRestrictions[$action] )
2369                                 ? $this->mRestrictions[$action]
2370                                 : array();
2371         }
2372
2373         /**
2374          * Get the expiry time for the restriction against a given action
2375          *
2376          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2377          *      or not protected at all, or false if the action is not recognised.
2378          */
2379         public function getRestrictionExpiry( $action ) {
2380                 if ( !$this->mRestrictionsLoaded ) {
2381                         $this->loadRestrictions();
2382                 }
2383                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2384         }
2385
2386         /**
2387          * Is there a version of this page in the deletion archive?
2388          *
2389          * @param $includeSuppressed Boolean Include suppressed revisions?
2390          * @return Int the number of archived revisions
2391          */
2392         public function isDeleted( $includeSuppressed = false ) {
2393                 if ( $this->getNamespace() < 0 ) {
2394                         $n = 0;
2395                 } else {
2396                         $dbr = wfGetDB( DB_SLAVE );
2397                         $conditions = array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() );
2398
2399                         if( !$includeSuppressed ) {
2400                                 $suppressedTextBits = Revision::DELETED_TEXT | Revision::DELETED_RESTRICTED;
2401                                 $conditions[] = $dbr->bitAnd('ar_deleted', $suppressedTextBits ) .
2402                                 ' != ' . $suppressedTextBits;
2403                         }
2404
2405                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2406                                 $conditions,
2407                                 __METHOD__
2408                         );
2409                         if ( $this->getNamespace() == NS_FILE ) {
2410                                 $fconditions = array( 'fa_name' => $this->getDBkey() );
2411                                 if( !$includeSuppressed ) {
2412                                         $suppressedTextBits = File::DELETED_FILE | File::DELETED_RESTRICTED;
2413                                         $fconditions[] = $dbr->bitAnd('fa_deleted', $suppressedTextBits ) .
2414                                         ' != ' . $suppressedTextBits;
2415                                 }
2416
2417                                 $n += $dbr->selectField( 'filearchive',
2418                                         'COUNT(*)',
2419                                         $fconditions,
2420                                         __METHOD__
2421                                 );
2422                         }
2423                 }
2424                 return (int)$n;
2425         }
2426
2427         /**
2428          * Is there a version of this page in the deletion archive?
2429          *
2430          * @return Boolean
2431          */
2432         public function isDeletedQuick() {
2433                 if ( $this->getNamespace() < 0 ) {
2434                         return false;
2435                 }
2436                 $dbr = wfGetDB( DB_SLAVE );
2437                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2438                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2439                         __METHOD__
2440                 );
2441                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2442                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2443                                 array( 'fa_name' => $this->getDBkey() ),
2444                                 __METHOD__
2445                         );
2446                 }
2447                 return $deleted;
2448         }
2449
2450         /**
2451          * Get the article ID for this Title from the link cache,
2452          * adding it if necessary
2453          *
2454          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2455          *  for update
2456          * @return Int the ID
2457          */
2458         public function getArticleID( $flags = 0 ) {
2459                 if ( $this->getNamespace() < 0 ) {
2460                         return $this->mArticleID = 0;
2461                 }
2462                 $linkCache = LinkCache::singleton();
2463                 if ( $flags & self::GAID_FOR_UPDATE ) {
2464                         $oldUpdate = $linkCache->forUpdate( true );
2465                         $linkCache->clearLink( $this );
2466                         $this->mArticleID = $linkCache->addLinkObj( $this );
2467                         $linkCache->forUpdate( $oldUpdate );
2468                 } else {
2469                         if ( -1 == $this->mArticleID ) {
2470                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2471                         }
2472                 }
2473                 return $this->mArticleID;
2474         }
2475
2476         /**
2477          * Is this an article that is a redirect page?
2478          * Uses link cache, adding it if necessary
2479          *
2480          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2481          * @return Bool
2482          */
2483         public function isRedirect( $flags = 0 ) {
2484                 if ( !is_null( $this->mRedirect ) ) {
2485                         return $this->mRedirect;
2486                 }
2487                 # Calling getArticleID() loads the field from cache as needed
2488                 if ( !$this->getArticleID( $flags ) ) {
2489                         return $this->mRedirect = false;
2490                 }
2491                 $linkCache = LinkCache::singleton();
2492                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2493
2494                 return $this->mRedirect;
2495         }
2496
2497         /**
2498          * What is the length of this page?
2499          * Uses link cache, adding it if necessary
2500          *
2501          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2502          * @return Int
2503          */
2504         public function getLength( $flags = 0 ) {
2505                 if ( $this->mLength != -1 ) {
2506                         return $this->mLength;
2507                 }
2508                 # Calling getArticleID() loads the field from cache as needed
2509                 if ( !$this->getArticleID( $flags ) ) {
2510                         return $this->mLength = 0;
2511                 }
2512                 $linkCache = LinkCache::singleton();
2513                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2514
2515                 return $this->mLength;
2516         }
2517
2518         /**
2519          * What is the page_latest field for this page?
2520          *
2521          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2522          * @return Int or 0 if the page doesn't exist
2523          */
2524         public function getLatestRevID( $flags = 0 ) {
2525                 if ( $this->mLatestID !== false ) {
2526                         return intval( $this->mLatestID );
2527                 }
2528                 # Calling getArticleID() loads the field from cache as needed
2529                 if ( !$this->getArticleID( $flags ) ) {
2530                         return $this->mLatestID = 0;
2531                 }
2532                 $linkCache = LinkCache::singleton();
2533                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2534
2535                 return $this->mLatestID;
2536         }
2537
2538         /**
2539          * This clears some fields in this object, and clears any associated
2540          * keys in the "bad links" section of the link cache.
2541          *
2542          * - This is called from Article::doEdit() and Article::insertOn() to allow
2543          * loading of the new page_id. It's also called from
2544          * Article::doDeleteArticle()
2545          *
2546          * @param $newid Int the new Article ID
2547          */
2548         public function resetArticleID( $newid ) {
2549                 $linkCache = LinkCache::singleton();
2550                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2551
2552                 if ( $newid === false ) {
2553                         $this->mArticleID = -1;
2554                 } else {
2555                         $this->mArticleID = intval( $newid );
2556                 }
2557                 $this->mRestrictionsLoaded = false;
2558                 $this->mRestrictions = array();
2559                 $this->mRedirect = null;
2560                 $this->mLength = -1;
2561                 $this->mLatestID = false;
2562         }
2563
2564         /**
2565          * Updates page_touched for this page; called from LinksUpdate.php
2566          *
2567          * @return Bool true if the update succeded
2568          */
2569         public function invalidateCache() {
2570                 if ( wfReadOnly() ) {
2571                         return;
2572                 }
2573                 $dbw = wfGetDB( DB_MASTER );
2574                 $success = $dbw->update(
2575                         'page',
2576                         array( 'page_touched' => $dbw->timestamp() ),
2577                         $this->pageCond(),
2578                         __METHOD__
2579                 );
2580                 HTMLFileCache::clearFileCache( $this );
2581                 return $success;
2582         }
2583
2584         /**
2585          * Prefix some arbitrary text with the namespace or interwiki prefix
2586          * of this object
2587          *
2588          * @param $name String the text
2589          * @return String the prefixed text
2590          * @private
2591          */
2592         private function prefix( $name ) {
2593                 $p = '';
2594                 if ( $this->mInterwiki != '' ) {
2595                         $p = $this->mInterwiki . ':';
2596                 }
2597
2598                 if ( 0 != $this->mNamespace ) {
2599                         $p .= $this->getNsText() . ':';
2600                 }
2601                 return $p . $name;
2602         }
2603
2604         /**
2605          * Returns a simple regex that will match on characters and sequences invalid in titles.
2606          * Note that this doesn't pick up many things that could be wrong with titles, but that
2607          * replacing this regex with something valid will make many titles valid.
2608          *
2609          * @return String regex string
2610          */
2611         static function getTitleInvalidRegex() {
2612                 static $rxTc = false;
2613                 if ( !$rxTc ) {
2614                         # Matching titles will be held as illegal.
2615                         $rxTc = '/' .
2616                                 # Any character not allowed is forbidden...
2617                                 '[^' . Title::legalChars() . ']' .
2618                                 # URL percent encoding sequences interfere with the ability
2619                                 # to round-trip titles -- you can't link to them consistently.
2620                                 '|%[0-9A-Fa-f]{2}' .
2621                                 # XML/HTML character references produce similar issues.
2622                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2623                                 '|&#[0-9]+;' .
2624                                 '|&#x[0-9A-Fa-f]+;' .
2625                                 '/S';
2626                 }
2627
2628                 return $rxTc;
2629         }
2630
2631         /**
2632          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2633          *
2634          * @param $text String containing title to capitalize
2635          * @param $ns int namespace index, defaults to NS_MAIN
2636          * @return String containing capitalized title
2637          */
2638         public static function capitalize( $text, $ns = NS_MAIN ) {
2639                 global $wgContLang;
2640
2641                 if ( MWNamespace::isCapitalized( $ns ) ) {
2642                         return $wgContLang->ucfirst( $text );
2643                 } else {
2644                         return $text;
2645                 }
2646         }
2647
2648         /**
2649          * Secure and split - main initialisation function for this object
2650          *
2651          * Assumes that mDbkeyform has been set, and is urldecoded
2652          * and uses underscores, but not otherwise munged.  This function
2653          * removes illegal characters, splits off the interwiki and
2654          * namespace prefixes, sets the other forms, and canonicalizes
2655          * everything.
2656          *
2657          * @return Bool true on success
2658          */
2659         private function secureAndSplit() {
2660                 global $wgContLang, $wgLocalInterwiki;
2661
2662                 # Initialisation
2663                 $this->mInterwiki = $this->mFragment = '';
2664                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2665
2666                 $dbkey = $this->mDbkeyform;
2667
2668                 # Strip Unicode bidi override characters.
2669                 # Sometimes they slip into cut-n-pasted page titles, where the
2670                 # override chars get included in list displays.
2671                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2672
2673                 # Clean up whitespace
2674                 # Note: use of the /u option on preg_replace here will cause
2675                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2676                 # conveniently disabling them.
2677                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2678                 $dbkey = trim( $dbkey, '_' );
2679
2680                 if ( $dbkey == '' ) {
2681                         return false;
2682                 }
2683
2684                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2685                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2686                         return false;
2687                 }
2688
2689                 $this->mDbkeyform = $dbkey;
2690
2691                 # Initial colon indicates main namespace rather than specified default
2692                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2693                 if ( ':' == $dbkey[0] ) {
2694                         $this->mNamespace = NS_MAIN;
2695                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2696                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2697                 }
2698
2699                 # Namespace or interwiki prefix
2700                 $firstPass = true;
2701                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2702                 do {
2703                         $m = array();
2704                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2705                                 $p = $m[1];
2706                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2707                                         # Ordinary namespace
2708                                         $dbkey = $m[2];
2709                                         $this->mNamespace = $ns;
2710                                         # For Talk:X pages, check if X has a "namespace" prefix
2711                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2712                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2713                                                         # Disallow Talk:File:x type titles...
2714                                                         return false;
2715                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2716                                                         # Disallow Talk:Interwiki:x type titles...
2717                                                         return false;
2718                                                 }
2719                                         }
2720                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2721                                         if ( !$firstPass ) {
2722                                                 # Can't make a local interwiki link to an interwiki link.
2723                                                 # That's just crazy!
2724                                                 return false;
2725                                         }
2726
2727                                         # Interwiki link
2728                                         $dbkey = $m[2];
2729                                         $this->mInterwiki = $wgContLang->lc( $p );
2730
2731                                         # Redundant interwiki prefix to the local wiki
2732                                         if ( $wgLocalInterwiki !== false
2733                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2734                                         {
2735                                                 if ( $dbkey == '' ) {
2736                                                         # Can't have an empty self-link
2737                                                         return false;
2738                                                 }
2739                                                 $this->mInterwiki = '';
2740                                                 $firstPass = false;
2741                                                 # Do another namespace split...
2742                                                 continue;
2743                                         }
2744
2745                                         # If there's an initial colon after the interwiki, that also
2746                                         # resets the default namespace
2747                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2748                                                 $this->mNamespace = NS_MAIN;
2749                                                 $dbkey = substr( $dbkey, 1 );
2750                                         }
2751                                 }
2752                                 # If there's no recognized interwiki or namespace,
2753                                 # then let the colon expression be part of the title.
2754                         }
2755                         break;
2756                 } while ( true );
2757
2758                 # We already know that some pages won't be in the database!
2759                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2760                         $this->mArticleID = 0;
2761                 }
2762                 $fragment = strstr( $dbkey, '#' );
2763                 if ( false !== $fragment ) {
2764                         $this->setFragment( $fragment );
2765                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2766                         # remove whitespace again: prevents "Foo_bar_#"
2767                         # becoming "Foo_bar_"
2768                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2769                 }
2770
2771                 # Reject illegal characters.
2772                 $rxTc = self::getTitleInvalidRegex();
2773                 if ( preg_match( $rxTc, $dbkey ) ) {
2774                         return false;
2775                 }
2776
2777                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2778                 # reachable due to the way web browsers deal with 'relative' URLs.
2779                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2780                 if ( strpos( $dbkey, '.' ) !== false &&
2781                          ( $dbkey === '.' || $dbkey === '..' ||
2782                            strpos( $dbkey, './' ) === 0  ||
2783                            strpos( $dbkey, '../' ) === 0 ||
2784                            strpos( $dbkey, '/./' ) !== false ||
2785                            strpos( $dbkey, '/../' ) !== false  ||
2786                            substr( $dbkey, -2 ) == '/.' ||
2787                            substr( $dbkey, -3 ) == '/..' ) )
2788                 {
2789                         return false;
2790                 }
2791
2792                 # Magic tilde sequences? Nu-uh!
2793                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2794                         return false;
2795                 }
2796
2797                 # Limit the size of titles to 255 bytes. This is typically the size of the
2798                 # underlying database field. We make an exception for special pages, which
2799                 # don't need to be stored in the database, and may edge over 255 bytes due
2800                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2801                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2802                   strlen( $dbkey ) > 512 )
2803                 {
2804                         return false;
2805                 }
2806
2807                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2808                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2809                 # other site might be case-sensitive.
2810                 $this->mUserCaseDBKey = $dbkey;
2811                 if ( $this->mInterwiki == '' ) {
2812                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2813                 }
2814
2815                 # Can't make a link to a namespace alone... "empty" local links can only be
2816                 # self-links with a fragment identifier.
2817                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2818                         return false;
2819                 }
2820
2821                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2822                 // IP names are not allowed for accounts, and can only be referring to
2823                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2824                 // there are numerous ways to present the same IP. Having sp:contribs scan
2825                 // them all is silly and having some show the edits and others not is
2826                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2827                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2828                         ? IP::sanitizeIP( $dbkey )
2829                         : $dbkey;
2830
2831                 // Any remaining initial :s are illegal.
2832                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2833                         return false;
2834                 }
2835
2836                 # Fill fields
2837                 $this->mDbkeyform = $dbkey;
2838                 $this->mUrlform = wfUrlencode( $dbkey );
2839
2840                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2841
2842                 return true;
2843         }
2844
2845         /**
2846          * Set the fragment for this title. Removes the first character from the
2847          * specified fragment before setting, so it assumes you're passing it with
2848          * an initial "#".
2849          *
2850          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2851          * Still in active use privately.
2852          *
2853          * @param $fragment String text
2854          */
2855         public function setFragment( $fragment ) {
2856                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2857         }
2858
2859         public function setInterwiki( $interwiki ) {
2860                 $this->mInterwiki = $interwiki;
2861         }
2862
2863         /**
2864          * Get a Title object associated with the talk page of this article
2865          *
2866          * @return Title the object for the talk page
2867          */
2868         public function getTalkPage() {
2869                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2870         }
2871
2872         /**
2873          * Get a title object associated with the subject page of this
2874          * talk page
2875          *
2876          * @return Title the object for the subject page
2877          */
2878         public function getSubjectPage() {
2879                 // Is this the same title?
2880                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2881                 if ( $this->getNamespace() == $subjectNS ) {
2882                         return $this;
2883                 }
2884                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2885         }
2886
2887         /**
2888          * Get an array of Title objects linking to this Title
2889          * Also stores the IDs in the link cache.
2890          *
2891          * WARNING: do not use this function on arbitrary user-supplied titles!
2892          * On heavily-used templates it will max out the memory.
2893          *
2894          * @param $options Array: may be FOR UPDATE
2895          * @param $table String: table name
2896          * @param $prefix String: fields prefix
2897          * @return Array of Title objects linking here
2898          */
2899         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2900                 $linkCache = LinkCache::singleton();
2901
2902                 if ( count( $options ) > 0 ) {
2903                         $db = wfGetDB( DB_MASTER );
2904                 } else {
2905                         $db = wfGetDB( DB_SLAVE );
2906                 }
2907
2908                 $res = $db->select(
2909                         array( 'page', $table ),
2910                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2911                         array(
2912                                 "{$prefix}_from=page_id",
2913                                 "{$prefix}_namespace" => $this->getNamespace(),
2914                                 "{$prefix}_title"     => $this->getDBkey() ),
2915                         __METHOD__,
2916                         $options
2917                 );
2918
2919                 $retVal = array();
2920                 if ( $db->numRows( $res ) ) {
2921                         foreach ( $res as $row ) {
2922                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2923                                 if ( $titleObj ) {
2924                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2925                                         $retVal[] = $titleObj;
2926                                 }
2927                         }
2928                 }
2929                 return $retVal;
2930         }
2931
2932         /**
2933          * Get an array of Title objects using this Title as a template
2934          * Also stores the IDs in the link cache.
2935          *
2936          * WARNING: do not use this function on arbitrary user-supplied titles!
2937          * On heavily-used templates it will max out the memory.
2938          *
2939          * @param $options Array: may be FOR UPDATE
2940          * @return Array of Title the Title objects linking here
2941          */
2942         public function getTemplateLinksTo( $options = array() ) {
2943                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2944         }
2945
2946         /**
2947          * Get an array of Title objects referring to non-existent articles linked from this page
2948          *
2949          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2950          * @return Array of Title the Title objects
2951          */
2952         public function getBrokenLinksFrom() {
2953                 if ( $this->getArticleId() == 0 ) {
2954                         # All links from article ID 0 are false positives
2955                         return array();
2956                 }
2957
2958                 $dbr = wfGetDB( DB_SLAVE );
2959                 $res = $dbr->select(
2960                         array( 'page', 'pagelinks' ),
2961                         array( 'pl_namespace', 'pl_title' ),
2962                         array(
2963                                 'pl_from' => $this->getArticleId(),
2964                                 'page_namespace IS NULL'
2965                         ),
2966                         __METHOD__, array(),
2967                         array(
2968                                 'page' => array(
2969                                         'LEFT JOIN',
2970                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2971                                 )
2972                         )
2973                 );
2974
2975                 $retVal = array();
2976                 foreach ( $res as $row ) {
2977                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2978                 }
2979                 return $retVal;
2980         }
2981
2982
2983         /**
2984          * Get a list of URLs to purge from the Squid cache when this
2985          * page changes
2986          *
2987          * @return Array of String the URLs
2988          */
2989         public function getSquidURLs() {
2990                 global $wgContLang;
2991
2992                 $urls = array(
2993                         $this->getInternalURL(),
2994                         $this->getInternalURL( 'action=history' )
2995                 );
2996
2997                 // purge variant urls as well
2998                 if ( $wgContLang->hasVariants() ) {
2999                         $variants = $wgContLang->getVariants();
3000                         foreach ( $variants as $vCode ) {
3001                                 $urls[] = $this->getInternalURL( '', $vCode );
3002                         }
3003                 }
3004
3005                 return $urls;
3006         }
3007
3008         /**
3009          * Purge all applicable Squid URLs
3010          */
3011         public function purgeSquid() {
3012                 global $wgUseSquid;
3013                 if ( $wgUseSquid ) {
3014                         $urls = $this->getSquidURLs();
3015                         $u = new SquidUpdate( $urls );
3016                         $u->doUpdate();
3017                 }
3018         }
3019
3020         /**
3021          * Move this page without authentication
3022          *
3023          * @param $nt Title the new page Title
3024          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3025          */
3026         public function moveNoAuth( &$nt ) {
3027                 return $this->moveTo( $nt, false );
3028         }
3029
3030         /**
3031          * Check whether a given move operation would be valid.
3032          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3033          *
3034          * @param $nt Title the new title
3035          * @param $auth Bool indicates whether $wgUser's permissions
3036          *  should be checked
3037          * @param $reason String is the log summary of the move, used for spam checking
3038          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3039          */
3040         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3041                 global $wgUser;
3042
3043                 $errors = array();
3044                 if ( !$nt ) {
3045                         // Normally we'd add this to $errors, but we'll get
3046                         // lots of syntax errors if $nt is not an object
3047                         return array( array( 'badtitletext' ) );
3048                 }
3049                 if ( $this->equals( $nt ) ) {
3050                         $errors[] = array( 'selfmove' );
3051                 }
3052                 if ( !$this->isMovable() ) {
3053                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3054                 }
3055                 if ( $nt->getInterwiki() != '' ) {
3056                         $errors[] = array( 'immobile-target-namespace-iw' );
3057                 }
3058                 if ( !$nt->isMovable() ) {
3059                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3060                 }
3061
3062                 $oldid = $this->getArticleID();
3063                 $newid = $nt->getArticleID();
3064
3065                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3066                         $errors[] = array( 'articleexists' );
3067                 }
3068                 if ( ( $this->getDBkey() == '' ) ||
3069                          ( !$oldid ) ||
3070                          ( $nt->getDBkey() == '' ) ) {
3071                         $errors[] = array( 'badarticleerror' );
3072                 }
3073
3074                 // Image-specific checks
3075                 if ( $this->getNamespace() == NS_FILE ) {
3076                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3077                 }
3078
3079                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3080                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3081                 }
3082
3083                 if ( $auth ) {
3084                         $errors = wfMergeErrorArrays( $errors,
3085                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3086                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3087                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3088                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3089                 }
3090
3091                 $match = EditPage::matchSummarySpamRegex( $reason );
3092                 if ( $match !== false ) {
3093                         // This is kind of lame, won't display nice
3094                         $errors[] = array( 'spamprotectiontext' );
3095                 }
3096
3097                 $err = null;
3098                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3099                         $errors[] = array( 'hookaborted', $err );
3100                 }
3101
3102                 # The move is allowed only if (1) the target doesn't exist, or
3103                 # (2) the target is a redirect to the source, and has no history
3104                 # (so we can undo bad moves right after they're done).
3105
3106                 if ( 0 != $newid ) { # Target exists; check for validity
3107                         if ( !$this->isValidMoveTarget( $nt ) ) {
3108                                 $errors[] = array( 'articleexists' );
3109                         }
3110                 } else {
3111                         $tp = $nt->getTitleProtection();
3112                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3113                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3114                                 $errors[] = array( 'cantmove-titleprotected' );
3115                         }
3116                 }
3117                 if ( empty( $errors ) ) {
3118                         return true;
3119                 }
3120                 return $errors;
3121         }
3122
3123         /**
3124          * Check if the requested move target is a valid file move target
3125          * @param Title $nt Target title
3126          * @return array List of errors
3127          */
3128         protected function validateFileMoveOperation( $nt ) {
3129                 global $wgUser;
3130
3131                 $errors = array();
3132
3133                 if ( $nt->getNamespace() != NS_FILE ) {
3134                         $errors[] = array( 'imagenocrossnamespace' );
3135                 }
3136
3137                 $file = wfLocalFile( $this );
3138                 if ( $file->exists() ) {
3139                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3140                                 $errors[] = array( 'imageinvalidfilename' );
3141                         }
3142                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3143                                 $errors[] = array( 'imagetypemismatch' );
3144                         }
3145                 }
3146
3147                 $destFile = wfLocalFile( $nt );
3148                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3149                         $errors[] = array( 'file-exists-sharedrepo' );
3150                 }
3151
3152                 return $errors;
3153         }
3154
3155         /**
3156          * Move a title to a new location
3157          *
3158          * @param $nt Title the new title
3159          * @param $auth Bool indicates whether $wgUser's permissions
3160          *  should be checked
3161          * @param $reason String the reason for the move
3162          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3163          *  Ignored if the user doesn't have the suppressredirect right.
3164          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3165          */
3166         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3167                 global $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3168
3169                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3170                 if ( is_array( $err ) ) {
3171                         return $err;
3172                 }
3173
3174                 // If it is a file, move it first. It is done before all other moving stuff is
3175                 // done because it's hard to revert
3176                 $dbw = wfGetDB( DB_MASTER );
3177                 if ( $this->getNamespace() == NS_FILE ) {
3178                         $file = wfLocalFile( $this );
3179                         if ( $file->exists() ) {
3180                                 $status = $file->move( $nt );
3181                                 if ( !$status->isOk() ) {
3182                                         return $status->getErrorsArray();
3183                                 }
3184                         }
3185                 }
3186
3187                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3188                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3189                 $protected = $this->isProtected();
3190                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3191
3192                 // Do the actual move
3193                 $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3194                 if ( is_array( $err ) ) {
3195                         # @todo FIXME: What about the File we have already moved?
3196                         $dbw->rollback();
3197                         return $err;
3198                 }
3199
3200                 $redirid = $this->getArticleID();
3201
3202                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3203                 // cl_timestamp, which may disturb time-based lists on some sites.
3204                 $prefixes = $dbw->select(
3205                         'categorylinks',
3206                         array( 'cl_sortkey_prefix', 'cl_to' ),
3207                         array( 'cl_from' => $pageid ),
3208                         __METHOD__
3209                 );
3210                 foreach ( $prefixes as $prefixRow ) {
3211                         $prefix = $prefixRow->cl_sortkey_prefix;
3212                         $catTo = $prefixRow->cl_to;
3213                         $dbw->update( 'categorylinks',
3214                                 array(
3215                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3216                                                 $nt->getCategorySortkey( $prefix ) ),
3217                                         'cl_timestamp=cl_timestamp' ),
3218                                 array(
3219                                         'cl_from' => $pageid,
3220                                         'cl_to' => $catTo ),
3221                                 __METHOD__
3222                         );
3223                 }
3224
3225                 if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3226                         $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3227                         $dbw2->update( 'globaltemplatelinks',
3228                                                 array(  'gtl_from_namespace' => $nt->getNamespace(),
3229                                                                 'gtl_from_title' => $nt->getText() ),
3230                                                 array ( 'gtl_from_page' => $pageid ),
3231                                                 __METHOD__ );
3232                 }
3233
3234                 if ( $protected ) {
3235                         # Protect the redirect title as the title used to be...
3236                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3237                                 array(
3238                                         'pr_page'    => $redirid,
3239                                         'pr_type'    => 'pr_type',
3240                                         'pr_level'   => 'pr_level',
3241                                         'pr_cascade' => 'pr_cascade',
3242                                         'pr_user'    => 'pr_user',
3243                                         'pr_expiry'  => 'pr_expiry'
3244                                 ),
3245                                 array( 'pr_page' => $pageid ),
3246                                 __METHOD__,
3247                                 array( 'IGNORE' )
3248                         );
3249                         # Update the protection log
3250                         $log = new LogPage( 'protect' );
3251                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3252                         if ( $reason ) {
3253                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3254                         }
3255                         // @todo FIXME: $params?
3256                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3257                 }
3258
3259                 # Update watchlists
3260                 $oldnamespace = $this->getNamespace() & ~1;
3261                 $newnamespace = $nt->getNamespace() & ~1;
3262                 $oldtitle = $this->getDBkey();
3263                 $newtitle = $nt->getDBkey();
3264
3265                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3266                         WatchedItem::duplicateEntries( $this, $nt );
3267                 }
3268
3269                 # Update search engine
3270                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3271                 $u->doUpdate();
3272                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3273                 $u->doUpdate();
3274
3275                 $dbw->commit();
3276
3277                 # Update site_stats
3278                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3279                         # No longer a content page
3280                         # Not viewed, edited, removing
3281                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3282                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3283                         # Now a content page
3284                         # Not viewed, edited, adding
3285                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3286                 } elseif ( $pageCountChange ) {
3287                         # Redirect added
3288                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3289                 } else {
3290                         # Nothing special
3291                         $u = false;
3292                 }
3293                 if ( $u ) {
3294                         $u->doUpdate();
3295                 }
3296
3297                 # Update message cache for interface messages
3298                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3299                         # @bug 17860: old article can be deleted, if this the case,
3300                         # delete it from message cache
3301                         if ( $this->getArticleID() === 0 ) {
3302                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3303                         } else {
3304                                 $oldarticle = new Article( $this );
3305                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3306                         }
3307                 }
3308                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3309                         $newarticle = new Article( $nt );
3310                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3311                 }
3312
3313                 global $wgUser;
3314                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3315                 return true;
3316         }
3317
3318         /**
3319          * Move page to a title which is either a redirect to the
3320          * source page or nonexistent
3321          *
3322          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3323          * @param $reason String The reason for the move
3324          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3325          *   if the user doesn't have the suppressredirect right
3326          */
3327         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3328                 global $wgUser, $wgContLang, $wgEnableInterwikiTemplatesTracking, $wgGlobalDatabase;
3329
3330                 $moveOverRedirect = $nt->exists();
3331
3332                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3333                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3334
3335                 if ( $reason ) {
3336                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3337                 }
3338                 # Truncate for whole multibyte characters.
3339                 $comment = $wgContLang->truncate( $comment, 255 );
3340
3341                 $oldid = $this->getArticleID();
3342                 $latest = $this->getLatestRevID();
3343
3344                 $dbw = wfGetDB( DB_MASTER );
3345
3346                 if ( $moveOverRedirect ) {
3347                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3348
3349                         $newid = $nt->getArticleID();
3350                         $newns = $nt->getNamespace();
3351                         $newdbk = $nt->getDBkey();
3352
3353                         # Delete the old redirect. We don't save it to history since
3354                         # by definition if we've got here it's rather uninteresting.
3355                         # We have to remove it so that the next step doesn't trigger
3356                         # a conflict on the unique namespace+title index...
3357                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3358                         if ( !$dbw->cascadingDeletes() ) {
3359                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3360                                 global $wgUseTrackbacks;
3361                                 if ( $wgUseTrackbacks ) {
3362                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3363                                 }
3364                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3365                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3366                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3367                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3368                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3369                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3370                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3371                                 $dbw->delete( 'page_props', array( 'pp_page' => $newid ), __METHOD__ );
3372                         }
3373                         // If the target page was recently created, it may have an entry in recentchanges still
3374                         $dbw->delete( 'recentchanges',
3375                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3376                                 __METHOD__
3377                         );
3378
3379                          if ( $wgEnableInterwikiTemplatesTracking && $wgGlobalDatabase ) {
3380                                 $dbw2 = wfGetDB( DB_MASTER, array(), $wgGlobalDatabase );
3381                                 $dbw2->delete( 'globaltemplatelinks',
3382                                                         array(  'gtl_from_wiki' => wfGetID(),
3383                                                                         'gtl_from_page' => $newid ),
3384                                                         __METHOD__ );
3385                 }
3386                 }
3387
3388                 # Save a null revision in the page's history notifying of the move
3389                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3390                 if ( !is_object( $nullRevision ) ) {
3391                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3392                 }
3393                 $nullRevId = $nullRevision->insertOn( $dbw );
3394
3395                 $now = wfTimestampNow();
3396                 # Change the name of the target page:
3397                 $dbw->update( 'page',
3398                         /* SET */ array(
3399                                 'page_touched'   => $dbw->timestamp( $now ),
3400                                 'page_namespace' => $nt->getNamespace(),
3401                                 'page_title'     => $nt->getDBkey(),
3402                                 'page_latest'    => $nullRevId,
3403                         ),
3404                         /* WHERE */ array( 'page_id' => $oldid ),
3405                         __METHOD__
3406                 );
3407                 $nt->resetArticleID( $oldid );
3408
3409                 $article = new Article( $nt );
3410                 wfRunHooks( 'NewRevisionFromEditComplete',
3411                         array( $article, $nullRevision, $latest, $wgUser ) );
3412                 $article->setCachedLastEditTime( $now );
3413
3414                 # Recreate the redirect, this time in the other direction.
3415                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3416                         $mwRedir = MagicWord::get( 'redirect' );
3417                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3418                         $redirectArticle = new Article( $this );
3419                         $newid = $redirectArticle->insertOn( $dbw );
3420                         if ( $newid ) { // sanity
3421                                 $redirectRevision = new Revision( array(
3422                                         'page'    => $newid,
3423                                         'comment' => $comment,
3424                                         'text'    => $redirectText ) );
3425                                 $redirectRevision->insertOn( $dbw );
3426                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3427
3428                                 wfRunHooks( 'NewRevisionFromEditComplete',
3429                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3430
3431                                 # Now, we record the link from the redirect to the new title.
3432                                 # It should have no other outgoing links...
3433                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3434                                 $dbw->insert( 'pagelinks',
3435                                         array(
3436                                                 'pl_from'      => $newid,
3437                                                 'pl_namespace' => $nt->getNamespace(),
3438                                                 'pl_title'     => $nt->getDBkey() ),
3439                                         __METHOD__ );
3440                         }
3441                         $redirectSuppressed = false;
3442                 } else {
3443                         $this->resetArticleID( 0 );
3444                         $redirectSuppressed = true;
3445                 }
3446
3447                 # Log the move
3448                 $log = new LogPage( 'move' );
3449                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3450                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3451
3452                 # Purge caches for old and new titles
3453                 if ( $moveOverRedirect ) {
3454                         # A simple purge is enough when moving over a redirect
3455                         $nt->purgeSquid();
3456                 } else {
3457                         # Purge caches as per article creation, including any pages that link to this title
3458                         Article::onArticleCreate( $nt );
3459                 }
3460                 $this->purgeSquid();
3461         }
3462
3463         /**
3464          * Move this page's subpages to be subpages of $nt
3465          *
3466          * @param $nt Title Move target
3467          * @param $auth bool Whether $wgUser's permissions should be checked
3468          * @param $reason string The reason for the move
3469          * @param $createRedirect bool Whether to create redirects from the old subpages to
3470          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3471          * @return mixed array with old page titles as keys, and strings (new page titles) or
3472          *     arrays (errors) as values, or an error array with numeric indices if no pages
3473          *     were moved
3474          */
3475         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3476                 global $wgMaximumMovedPages;
3477                 // Check permissions
3478                 if ( !$this->userCan( 'move-subpages' ) ) {
3479                         return array( 'cant-move-subpages' );
3480                 }
3481                 // Do the source and target namespaces support subpages?
3482                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3483                         return array( 'namespace-nosubpages',
3484                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3485                 }
3486                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3487                         return array( 'namespace-nosubpages',
3488                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3489                 }
3490
3491                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3492                 $retval = array();
3493                 $count = 0;
3494                 foreach ( $subpages as $oldSubpage ) {
3495                         $count++;
3496                         if ( $count > $wgMaximumMovedPages ) {
3497                                 $retval[$oldSubpage->getPrefixedTitle()] =
3498                                                 array( 'movepage-max-pages',
3499                                                         $wgMaximumMovedPages );
3500                                 break;
3501                         }
3502
3503                         // We don't know whether this function was called before
3504                         // or after moving the root page, so check both
3505                         // $this and $nt
3506                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3507                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3508                         {
3509                                 // When moving a page to a subpage of itself,
3510                                 // don't move it twice
3511                                 continue;
3512                         }
3513                         $newPageName = preg_replace(
3514                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3515                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3516                                         $oldSubpage->getDBkey() );
3517                         if ( $oldSubpage->isTalkPage() ) {
3518                                 $newNs = $nt->getTalkPage()->getNamespace();
3519                         } else {
3520                                 $newNs = $nt->getSubjectPage()->getNamespace();
3521                         }
3522                         # Bug 14385: we need makeTitleSafe because the new page names may
3523                         # be longer than 255 characters.
3524                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3525
3526                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3527                         if ( $success === true ) {
3528                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3529                         } else {
3530                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3531                         }
3532                 }
3533                 return $retval;
3534         }
3535
3536         /**
3537          * Checks if this page is just a one-rev redirect.
3538          * Adds lock, so don't use just for light purposes.
3539          *
3540          * @return Bool
3541          */
3542         public function isSingleRevRedirect() {
3543                 $dbw = wfGetDB( DB_MASTER );
3544                 # Is it a redirect?
3545                 $row = $dbw->selectRow( 'page',
3546                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3547                         $this->pageCond(),
3548                         __METHOD__,
3549                         array( 'FOR UPDATE' )
3550                 );
3551                 # Cache some fields we may want
3552                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3553                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3554                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3555                 if ( !$this->mRedirect ) {
3556                         return false;
3557                 }
3558                 # Does the article have a history?
3559                 $row = $dbw->selectField( array( 'page', 'revision' ),
3560                         'rev_id',
3561                         array( 'page_namespace' => $this->getNamespace(),
3562                                 'page_title' => $this->getDBkey(),
3563                                 'page_id=rev_page',
3564                                 'page_latest != rev_id'
3565                         ),
3566                         __METHOD__,
3567                         array( 'FOR UPDATE' )
3568                 );
3569                 # Return true if there was no history
3570                 return ( $row === false );
3571         }
3572
3573         /**
3574          * Checks if $this can be moved to a given Title
3575          * - Selects for update, so don't call it unless you mean business
3576          *
3577          * @param $nt Title the new title to check
3578          * @return Bool
3579          */
3580         public function isValidMoveTarget( $nt ) {
3581                 # Is it an existing file?
3582                 if ( $nt->getNamespace() == NS_FILE ) {
3583                         $file = wfLocalFile( $nt );
3584                         if ( $file->exists() ) {
3585                                 wfDebug( __METHOD__ . ": file exists\n" );
3586                                 return false;
3587                         }
3588                 }
3589                 # Is it a redirect with no history?
3590                 if ( !$nt->isSingleRevRedirect() ) {
3591                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3592                         return false;
3593                 }
3594                 # Get the article text
3595                 $rev = Revision::newFromTitle( $nt );
3596                 $text = $rev->getText();
3597                 # Does the redirect point to the source?
3598                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3599                 $m = array();
3600                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3601                         $redirTitle = Title::newFromText( $m[1] );
3602                         if ( !is_object( $redirTitle ) ||
3603                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3604                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3605                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3606                                 return false;
3607                         }
3608                 } else {
3609                         # Fail safe
3610                         wfDebug( __METHOD__ . ": failsafe\n" );
3611                         return false;
3612                 }
3613                 return true;
3614         }
3615
3616         /**
3617          * Can this title be added to a user's watchlist?
3618          *
3619          * @return Bool TRUE or FALSE
3620          */
3621         public function isWatchable() {
3622                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3623         }
3624
3625         /**
3626          * Get categories to which this Title belongs and return an array of
3627          * categories' names.
3628          *
3629          * @return Array of parents in the form:
3630          *        $parent => $currentarticle
3631          */
3632         public function getParentCategories() {
3633                 global $wgContLang;
3634
3635                 $data = array();
3636
3637                 $titleKey = $this->getArticleId();
3638
3639                 if ( $titleKey === 0 ) {
3640                         return $data;
3641                 }
3642
3643                 $dbr = wfGetDB( DB_SLAVE );
3644
3645                 $res = $dbr->select( 'categorylinks', '*',
3646                         array(
3647                                 'cl_from' => $titleKey,
3648                         ),
3649                         __METHOD__,
3650                         array()
3651                 );
3652
3653                 if ( $dbr->numRows( $res ) > 0 ) {
3654                         foreach ( $res as $row ) {
3655                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3656                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3657                         }
3658                 }
3659                 return $data;
3660         }
3661
3662         /**
3663          * Get a tree of parent categories
3664          *
3665          * @param $children Array with the children in the keys, to check for circular refs
3666          * @return Array Tree of parent categories
3667          */
3668         public function getParentCategoryTree( $children = array() ) {
3669                 $stack = array();
3670                 $parents = $this->getParentCategories();
3671
3672                 if ( $parents ) {
3673                         foreach ( $parents as $parent => $current ) {
3674                                 if ( array_key_exists( $parent, $children ) ) {
3675                                         # Circular reference
3676                                         $stack[$parent] = array();
3677                                 } else {
3678                                         $nt = Title::newFromText( $parent );
3679                                         if ( $nt ) {
3680                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3681                                         }
3682                                 }
3683                         }
3684                 }
3685
3686                 return $stack;
3687         }
3688
3689         /**
3690          * Get an associative array for selecting this title from
3691          * the "page" table
3692          *
3693          * @return Array suitable for the $where parameter of DB::select()
3694          */
3695         public function pageCond() {
3696                 if ( $this->mArticleID > 0 ) {
3697                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3698                         return array( 'page_id' => $this->mArticleID );
3699                 } else {
3700                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3701                 }
3702         }
3703
3704         /**
3705          * Get the revision ID of the previous revision
3706          *
3707          * @param $revId Int Revision ID. Get the revision that was before this one.
3708          * @param $flags Int Title::GAID_FOR_UPDATE
3709          * @return Int|Bool Old revision ID, or FALSE if none exists
3710          */
3711         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3712                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3713                 return $db->selectField( 'revision', 'rev_id',
3714                         array(
3715                                 'rev_page' => $this->getArticleId( $flags ),
3716                                 'rev_id < ' . intval( $revId )
3717                         ),
3718                         __METHOD__,
3719                         array( 'ORDER BY' => 'rev_id DESC' )
3720                 );
3721         }
3722
3723         /**
3724          * Get the revision ID of the next revision
3725          *
3726          * @param $revId Int Revision ID. Get the revision that was after this one.
3727          * @param $flags Int Title::GAID_FOR_UPDATE
3728          * @return Int|Bool Next revision ID, or FALSE if none exists
3729          */
3730         public function getNextRevisionID( $revId, $flags = 0 ) {
3731                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3732                 return $db->selectField( 'revision', 'rev_id',
3733                         array(
3734                                 'rev_page' => $this->getArticleId( $flags ),
3735                                 'rev_id > ' . intval( $revId )
3736                         ),
3737                         __METHOD__,
3738                         array( 'ORDER BY' => 'rev_id' )
3739                 );
3740         }
3741
3742         /**
3743          * Get the first revision of the page
3744          *
3745          * @param $flags Int Title::GAID_FOR_UPDATE
3746          * @return Revision|Null if page doesn't exist
3747          */
3748         public function getFirstRevision( $flags = 0 ) {
3749                 $pageId = $this->getArticleId( $flags );
3750                 if ( $pageId ) {
3751                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3752                         $row = $db->selectRow( 'revision', '*',
3753                                 array( 'rev_page' => $pageId ),
3754                                 __METHOD__,
3755                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3756                         );
3757                         if ( $row ) {
3758                                 return new Revision( $row );
3759                         }
3760                 }
3761                 return null;
3762         }
3763
3764         /**
3765          * Get the oldest revision timestamp of this page
3766          *
3767          * @param $flags Int Title::GAID_FOR_UPDATE
3768          * @return String: MW timestamp
3769          */
3770         public function getEarliestRevTime( $flags = 0 ) {
3771                 $rev = $this->getFirstRevision( $flags );
3772                 return $rev ? $rev->getTimestamp() : null;
3773         }
3774
3775         /**
3776          * Check if this is a new page
3777          *
3778          * @return bool
3779          */
3780         public function isNewPage() {
3781                 $dbr = wfGetDB( DB_SLAVE );
3782                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3783         }
3784
3785         /**
3786          * Get the number of revisions between the given revision.
3787          * Used for diffs and other things that really need it.
3788          *
3789          * @param $old int|Revision Old revision or rev ID (first before range)
3790          * @param $new int|Revision New revision or rev ID (first after range)
3791          * @return Int Number of revisions between these revisions.
3792          */
3793         public function countRevisionsBetween( $old, $new ) {
3794                 if ( !( $old instanceof Revision ) ) {
3795                         $old = Revision::newFromTitle( $this, (int)$old );
3796                 }
3797                 if ( !( $new instanceof Revision ) ) {
3798                         $new = Revision::newFromTitle( $this, (int)$new );
3799                 }
3800                 if ( !$old || !$new ) {
3801                         return 0; // nothing to compare
3802                 }
3803                 $dbr = wfGetDB( DB_SLAVE );
3804                 return (int)$dbr->selectField( 'revision', 'count(*)',
3805                         array(
3806                                 'rev_page' => $this->getArticleId(),
3807                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3808                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3809                         ),
3810                         __METHOD__
3811                 );
3812         }
3813
3814         /**
3815          * Get the number of authors between the given revision IDs.
3816          * Used for diffs and other things that really need it.
3817          *
3818          * @param $old int|Revision Old revision or rev ID (first before range)
3819          * @param $new int|Revision New revision or rev ID (first after range)
3820          * @param $limit Int Maximum number of authors
3821          * @return Int Number of revision authors between these revisions.
3822          */
3823         public function countAuthorsBetween( $old, $new, $limit ) {
3824                 if ( !( $old instanceof Revision ) ) {
3825                         $old = Revision::newFromTitle( $this, (int)$old );
3826                 }
3827                 if ( !( $new instanceof Revision ) ) {
3828                         $new = Revision::newFromTitle( $this, (int)$new );
3829                 }
3830                 if ( !$old || !$new ) {
3831                         return 0; // nothing to compare
3832                 }
3833                 $dbr = wfGetDB( DB_SLAVE );
3834                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3835                         array(
3836                                 'rev_page' => $this->getArticleID(),
3837                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3838                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3839                         ), __METHOD__,
3840                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3841                 );
3842                 return (int)$dbr->numRows( $res );
3843         }
3844
3845         /**
3846          * Compare with another title.
3847          *
3848          * @param $title Title
3849          * @return Bool
3850          */
3851         public function equals( Title $title ) {
3852                 // Note: === is necessary for proper matching of number-like titles.
3853                 return $this->getInterwiki() === $title->getInterwiki()
3854                         && $this->getNamespace() == $title->getNamespace()
3855                         && $this->getDBkey() === $title->getDBkey();
3856         }
3857
3858         /**
3859          * Callback for usort() to do title sorts by (namespace, title)
3860          *
3861          * @param $a Title
3862          * @param $b Title
3863          *
3864          * @return Integer: result of string comparison, or namespace comparison
3865          */
3866         public static function compare( $a, $b ) {
3867                 if ( $a->getNamespace() == $b->getNamespace() ) {
3868                         return strcmp( $a->getText(), $b->getText() );
3869                 } else {
3870                         return $a->getNamespace() - $b->getNamespace();
3871                 }
3872         }
3873
3874         /**
3875          * Return a string representation of this title
3876          *
3877          * @return String representation of this title
3878          */
3879         public function __toString() {
3880                 return $this->getPrefixedText();
3881         }
3882
3883         /**
3884          * Check if page exists.  For historical reasons, this function simply
3885          * checks for the existence of the title in the page table, and will
3886          * thus return false for interwiki links, special pages and the like.
3887          * If you want to know if a title can be meaningfully viewed, you should
3888          * probably call the isKnown() method instead.
3889          *
3890          * @return Bool
3891          */
3892         public function exists() {
3893                 return $this->getArticleId() != 0;
3894         }
3895
3896         /**
3897          * Should links to this title be shown as potentially viewable (i.e. as
3898          * "bluelinks"), even if there's no record by this title in the page
3899          * table?
3900          *
3901          * This function is semi-deprecated for public use, as well as somewhat
3902          * misleadingly named.  You probably just want to call isKnown(), which
3903          * calls this function internally.
3904          *
3905          * (ISSUE: Most of these checks are cheap, but the file existence check
3906          * can potentially be quite expensive.  Including it here fixes a lot of
3907          * existing code, but we might want to add an optional parameter to skip
3908          * it and any other expensive checks.)
3909          *
3910          * @return Bool
3911          */
3912         public function isAlwaysKnown() {
3913                 if ( $this->mInterwiki != '' ) {
3914                         return true;  // any interwiki link might be viewable, for all we know
3915                 }
3916                 switch( $this->mNamespace ) {
3917                         case NS_MEDIA:
3918                         case NS_FILE:
3919                                 // file exists, possibly in a foreign repo
3920                                 return (bool)wfFindFile( $this );
3921                         case NS_SPECIAL:
3922                                 // valid special page
3923                                 return SpecialPageFactory::exists( $this->getDBkey() );
3924                         case NS_MAIN:
3925                                 // selflink, possibly with fragment
3926                                 return $this->mDbkeyform == '';
3927                         case NS_MEDIAWIKI:
3928                                 // known system message
3929                                 return $this->getDefaultMessageText() !== false;
3930                         default:
3931                                 return false;
3932                 }
3933         }
3934
3935         /**
3936          * Does this title refer to a page that can (or might) be meaningfully
3937          * viewed?  In particular, this function may be used to determine if
3938          * links to the title should be rendered as "bluelinks" (as opposed to
3939          * "redlinks" to non-existent pages).
3940          *
3941          * @return Bool
3942          */
3943         public function isKnown() {
3944                 return $this->isAlwaysKnown() || $this->exists();
3945         }
3946
3947         /**
3948          * Does this page have source text?
3949          *
3950          * @return Boolean
3951          */
3952         public function hasSourceText() {
3953                 if ( $this->exists() ) {
3954                         return true;
3955                 }
3956
3957                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3958                         // If the page doesn't exist but is a known system message, default
3959                         // message content will be displayed, same for language subpages
3960                         return $this->getDefaultMessageText() !== false;
3961                 }
3962
3963                 return false;
3964         }
3965
3966         /**
3967          * Get the default message text or false if the message doesn't exist
3968          *
3969          * @return String or false
3970          */
3971         public function getDefaultMessageText() {
3972                 global $wgContLang;
3973
3974                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3975                         return false;
3976                 }
3977
3978                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3979                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3980
3981                 if ( $message->exists() ) {
3982                         return $message->plain();
3983                 } else {
3984                         return false;
3985                 }
3986         }
3987
3988         /**
3989          * Is this in a namespace that allows actual pages?
3990          *
3991          * @return Bool
3992          * @internal note -- uses hardcoded namespace index instead of constants
3993          */
3994         public function canExist() {
3995                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3996         }
3997
3998         /**
3999          * Update page_touched timestamps and send squid purge messages for
4000          * pages linking to this title. May be sent to the job queue depending
4001          * on the number of links. Typically called on create and delete.
4002          */
4003         public function touchLinks() {
4004                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4005                 $u->doUpdate();
4006
4007                 if ( $this->getNamespace() == NS_CATEGORY ) {
4008                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4009                         $u->doUpdate();
4010                 }
4011         }
4012
4013         /**
4014          * Get the last touched timestamp
4015          *
4016          * @param $db DatabaseBase: optional db
4017          * @return String last-touched timestamp
4018          */
4019         public function getTouched( $db = null ) {
4020                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4021                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4022                 return $touched;
4023         }
4024
4025         /**
4026          * Get the timestamp when this page was updated since the user last saw it.
4027          *
4028          * @param $user User
4029          * @return String|Null
4030          */
4031         public function getNotificationTimestamp( $user = null ) {
4032                 global $wgUser, $wgShowUpdatedMarker;
4033                 // Assume current user if none given
4034                 if ( !$user ) {
4035                         $user = $wgUser;
4036                 }
4037                 // Check cache first
4038                 $uid = $user->getId();
4039                 // avoid isset here, as it'll return false for null entries
4040                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4041                         return $this->mNotificationTimestamp[$uid];
4042                 }
4043                 if ( !$uid || !$wgShowUpdatedMarker ) {
4044                         return $this->mNotificationTimestamp[$uid] = false;
4045                 }
4046                 // Don't cache too much!
4047                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4048                         $this->mNotificationTimestamp = array();
4049                 }
4050                 $dbr = wfGetDB( DB_SLAVE );
4051                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4052                         'wl_notificationtimestamp',
4053                         array( 'wl_namespace' => $this->getNamespace(),
4054                                 'wl_title' => $this->getDBkey(),
4055                                 'wl_user' => $user->getId()
4056                         ),
4057                         __METHOD__
4058                 );
4059                 return $this->mNotificationTimestamp[$uid];
4060         }
4061
4062         /**
4063          * Get the trackback URL for this page
4064          *
4065          * @return String Trackback URL
4066          */
4067         public function trackbackURL() {
4068                 global $wgScriptPath, $wgServer, $wgScriptExtension;
4069
4070                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
4071                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
4072         }
4073
4074         /**
4075          * Get the trackback RDF for this page
4076          *
4077          * @return String Trackback RDF
4078          */
4079         public function trackbackRDF() {
4080                 $url = htmlspecialchars( $this->getFullURL() );
4081                 $title = htmlspecialchars( $this->getText() );
4082                 $tburl = $this->trackbackURL();
4083
4084                 // Autodiscovery RDF is placed in comments so HTML validator
4085                 // won't barf. This is a rather icky workaround, but seems
4086                 // frequently used by this kind of RDF thingy.
4087                 //
4088                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
4089                 return "<!--
4090 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4091                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4092                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4093 <rdf:Description
4094    rdf:about=\"$url\"
4095    dc:identifier=\"$url\"
4096    dc:title=\"$title\"
4097    trackback:ping=\"$tburl\" />
4098 </rdf:RDF>
4099 -->";
4100         }
4101
4102         /**
4103          * Generate strings used for xml 'id' names in monobook tabs
4104          *
4105          * @param $prepend string defaults to 'nstab-'
4106          * @return String XML 'id' name
4107          */
4108         public function getNamespaceKey( $prepend = 'nstab-' ) {
4109                 global $wgContLang;
4110                 // Gets the subject namespace if this title
4111                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4112                 // Checks if cononical namespace name exists for namespace
4113                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4114                         // Uses canonical namespace name
4115                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4116                 } else {
4117                         // Uses text of namespace
4118                         $namespaceKey = $this->getSubjectNsText();
4119                 }
4120                 // Makes namespace key lowercase
4121                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4122                 // Uses main
4123                 if ( $namespaceKey == '' ) {
4124                         $namespaceKey = 'main';
4125                 }
4126                 // Changes file to image for backwards compatibility
4127                 if ( $namespaceKey == 'file' ) {
4128                         $namespaceKey = 'image';
4129                 }
4130                 return $prepend . $namespaceKey;
4131         }
4132
4133         /**
4134          * Returns true if this is a special page.
4135          *
4136          * @return boolean
4137          */
4138         public function isSpecialPage() {
4139                 return $this->getNamespace() == NS_SPECIAL;
4140         }
4141
4142         /**
4143          * Returns true if this title resolves to the named special page
4144          *
4145          * @param $name String The special page name
4146          * @return boolean
4147          */
4148         public function isSpecial( $name ) {
4149                 if ( $this->getNamespace() == NS_SPECIAL ) {
4150                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4151                         if ( $name == $thisName ) {
4152                                 return true;
4153                         }
4154                 }
4155                 return false;
4156         }
4157
4158         /**
4159          * If the Title refers to a special page alias which is not the local default, resolve
4160          * the alias, and localise the name as necessary.  Otherwise, return $this
4161          *
4162          * @return Title
4163          */
4164         public function fixSpecialName() {
4165                 if ( $this->getNamespace() == NS_SPECIAL ) {
4166                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4167                         if ( $canonicalName ) {
4168                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4169                                 if ( $localName != $this->mDbkeyform ) {
4170                                         return Title::makeTitle( NS_SPECIAL, $localName );
4171                                 }
4172                         }
4173                 }
4174                 return $this;
4175         }
4176
4177         /**
4178          * Is this Title in a namespace which contains content?
4179          * In other words, is this a content page, for the purposes of calculating
4180          * statistics, etc?
4181          *
4182          * @return Boolean
4183          */
4184         public function isContentPage() {
4185                 return MWNamespace::isContent( $this->getNamespace() );
4186         }
4187
4188         /**
4189          * Get all extant redirects to this Title
4190          *
4191          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4192          * @return Array of Title redirects to this title
4193          */
4194         public function getRedirectsHere( $ns = null ) {
4195                 $redirs = array();
4196
4197                 $dbr = wfGetDB( DB_SLAVE );
4198                 $where = array(
4199                         'rd_namespace' => $this->getNamespace(),
4200                         'rd_title' => $this->getDBkey(),
4201                         'rd_from = page_id'
4202                 );
4203                 if ( !is_null( $ns ) ) {
4204                         $where['page_namespace'] = $ns;
4205                 }
4206
4207                 $res = $dbr->select(
4208                         array( 'redirect', 'page' ),
4209                         array( 'page_namespace', 'page_title' ),
4210                         $where,
4211                         __METHOD__
4212                 );
4213
4214                 foreach ( $res as $row ) {
4215                         $redirs[] = self::newFromRow( $row );
4216                 }
4217                 return $redirs;
4218         }
4219
4220         /**
4221          * Check if this Title is a valid redirect target
4222          *
4223          * @return Bool
4224          */
4225         public function isValidRedirectTarget() {
4226                 global $wgInvalidRedirectTargets;
4227
4228                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4229                 if ( $this->isSpecial( 'Userlogout' ) ) {
4230                         return false;
4231                 }
4232
4233                 foreach ( $wgInvalidRedirectTargets as $target ) {
4234                         if ( $this->isSpecial( $target ) ) {
4235                                 return false;
4236                         }
4237                 }
4238
4239                 return true;
4240         }
4241
4242         /**
4243          * Get a backlink cache object
4244          *
4245          * @return object BacklinkCache
4246          */
4247         function getBacklinkCache() {
4248                 if ( is_null( $this->mBacklinkCache ) ) {
4249                         $this->mBacklinkCache = new BacklinkCache( $this );
4250                 }
4251                 return $this->mBacklinkCache;
4252         }
4253
4254         /**
4255          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4256          *
4257          * @return Boolean
4258          */
4259         public function canUseNoindex() {
4260                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4261
4262                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4263                         ? $wgContentNamespaces
4264                         : $wgExemptFromUserRobotsControl;
4265
4266                 return !in_array( $this->mNamespace, $bannedNamespaces );
4267
4268         }
4269
4270         /**
4271          * Returns restriction types for the current Title
4272          *
4273          * @return array applicable restriction types
4274          */
4275         public function getRestrictionTypes() {
4276                 if ( $this->getNamespace() == NS_SPECIAL ) {
4277                         return array();
4278                 }
4279
4280                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4281
4282                 if ( $this->getNamespace() != NS_FILE ) {
4283                         # Remove the upload restriction for non-file titles
4284                         $types = array_diff( $types, array( 'upload' ) );
4285                 }
4286
4287                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4288
4289                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4290                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4291
4292                 return $types;
4293         }
4294         /**
4295          * Get a filtered list of all restriction types supported by this wiki.
4296          * @param bool $exists True to get all restriction types that apply to
4297          * titles that do exist, False for all restriction types that apply to
4298          * titles that do not exist
4299          * @return array
4300          */
4301         public static function getFilteredRestrictionTypes( $exists = true ) {
4302                 global $wgRestrictionTypes;
4303                 $types = $wgRestrictionTypes;
4304                 if ( $exists ) {
4305                         # Remove the create restriction for existing titles
4306                         $types = array_diff( $types, array( 'create' ) );
4307                 } else {
4308                         # Only the create and upload restrictions apply to non-existing titles
4309                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4310                 }
4311                 return $types;
4312         }
4313
4314         /**
4315          * Returns the raw sort key to be used for categories, with the specified
4316          * prefix.  This will be fed to Collation::getSortKey() to get a
4317          * binary sortkey that can be used for actual sorting.
4318          *
4319          * @param $prefix string The prefix to be used, specified using
4320          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4321          *   prefix.
4322          * @return string
4323          */
4324         public function getCategorySortkey( $prefix = '' ) {
4325                 $unprefixed = $this->getText();
4326
4327                 // Anything that uses this hook should only depend
4328                 // on the Title object passed in, and should probably
4329                 // tell the users to run updateCollations.php --force
4330                 // in order to re-sort existing category relations.
4331                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4332                 if ( $prefix !== '' ) {
4333                         # Separate with a line feed, so the unprefixed part is only used as
4334                         # a tiebreaker when two pages have the exact same prefix.
4335                         # In UCA, tab is the only character that can sort above LF
4336                         # so we strip both of them from the original prefix.
4337                         $prefix = strtr( $prefix, "\n\t", '  ' );
4338                         return "$prefix\n$unprefixed";
4339                 }
4340                 return $unprefixed;
4341         }
4342
4343         /**
4344          * Get the language in which the content of this page is written.
4345          * Defaults to $wgContLang, but in certain cases it can be e.g.
4346          * $wgLang (such as special pages, which are in the user language).
4347          *
4348          * @since 1.18
4349          * @return object Language
4350          */
4351         public function getPageLanguage() {
4352                 global $wgLang;
4353                 if ( $this->getNamespace() == NS_SPECIAL ) {
4354                         // special pages are in the user language
4355                         return $wgLang;
4356                 } elseif ( $this->isRedirect() ) {
4357                         // the arrow on a redirect page is aligned according to the user language
4358                         return $wgLang;
4359                 } elseif ( $this->isCssOrJsPage() ) {
4360                         // css/js should always be LTR and is, in fact, English
4361                         return wfGetLangObj( 'en' );
4362                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4363                         // Parse mediawiki messages with correct target language
4364                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4365                         return wfGetLangObj( $lang );
4366                 }
4367                 global $wgContLang;
4368                 // If nothing special, it should be in the wiki content language
4369                 $pageLang = $wgContLang;
4370                 // Hook at the end because we don't want to override the above stuff
4371                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4372                 return wfGetLangObj( $pageLang );
4373         }
4374 }