includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 if ( !class_exists( 'UtfNormal' ) ) {
   8         require_once( dirname(__FILE__) . '/normal/UtfNormal.php' );
   9 }
  10
  11 define ( 'GAID_FOR_UPDATE', 1 );
  12
  13
  14 /**
  15  * Constants for pr_cascade bitfield
  16  */
  17 define( 'CASCADE', 1 );
  18
  19 /**
  20  * Represents a title within MediaWiki.
  21  * Optionally may contain an interwiki designation or namespace.
  22  * @note This class can fetch various kinds of data from the database;
  23  *       however, it does so inefficiently.
  24  */
  25 class Title {
  26         /** @name Static cache variables */
  27         //@{
  28         static private $titleCache=array();
  29         static private $interwikiCache=array();
  30         //@}
  31
  32         /**
  33          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  34          * commonly used titles. On a batch operation this can become a memory leak
  35          * if not bounded. After hitting this many titles reset the cache.
  36          */
  37         const CACHE_MAX = 1000;
  38
  39
  40         /**
  41          * @name Private member variables
  42          * Please use the accessor functions instead.
  43          * @private
  44          */
  45         //@{
  46
  47         var $mTextform = '';              ///< Text form (spaces not underscores) of the main part
  48         var $mUrlform = '';               ///< URL-encoded form of the main part
  49         var $mDbkeyform = '';             ///< Main part with underscores
  50         var $mUserCaseDBKey;              ///< DB key with the initial letter in the case specified by the user
  51         var $mNamespace = NS_MAIN;        ///< Namespace index, i.e. one of the NS_xxxx constants
  52         var $mInterwiki = '';             ///< Interwiki prefix (or null string)
  53         var $mFragment;                   ///< Title fragment (i.e. the bit after the #)
  54         var $mArticleID = -1;             ///< Article ID, fetched from the link cache on demand
  55         var $mLatestID = false;           ///< ID of most recent revision
  56         var $mRestrictions = array();     ///< Array of groups allowed to edit this article
  57         var $mOldRestrictions = false;
  58         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  59         var $mRestrictionsExpiry = array();       ///< When do the restrictions on this page expire?
  60         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  61         var $mCascadeSources;  ///< Where are the cascading restrictions coming from on this page?
  62         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  63         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  64         # Don't change the following default, NS_MAIN is hardcoded in several
  65         # places.  See bug 696.
  66         var $mDefaultNamespace = NS_MAIN; ///< Namespace index when there is no namespace
  67                                           # Zero except in {{transclusion}} tags
  68         var $mWatched = null;             ///< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  69         var $mLength = -1;                ///< The page length, 0 for special pages
  70         var $mRedirect = null;            ///< Is the article at this title a redirect?
  71         var $mNotificationTimestamp = array(); ///< Associative array of user ID -> timestamp/false
  72         var $mBacklinkCache = null; ///< Cache of links to this title
  73         //@}
  74
  75
  76         /**
  77          * Constructor
  78          * @private
  79          */
  80         /* private */ function __construct() {}
  81
  82         /**
  83          * Create a new Title from a prefixed DB key
  84          * @param $key \type{\string} The database key, which has underscores
  85          *      instead of spaces, possibly including namespace and
  86          *      interwiki prefixes
  87          * @return \type{Title} the new object, or NULL on an error
  88          */
  89         public static function newFromDBkey( $key ) {
  90                 $t = new Title();
  91                 $t->mDbkeyform = $key;
  92                 if( $t->secureAndSplit() )
  93                         return $t;
  94                 else
  95                         return NULL;
  96         }
  97
  98         /**
  99          * Create a new Title from text, such as what one would find in a link. De-
 100          * codes any HTML entities in the text.
 101          *
 102          * @param $text             string  The link text; spaces, prefixes, and an
 103          *   initial ':' indicating the main namespace are accepted.
 104          * @param $defaultNamespace int     The namespace to use if none is speci-
 105          *   fied by a prefix.  If you want to force a specific namespace even if
 106          *   $text might begin with a namespace prefix, use makeTitle() or
 107          *   makeTitleSafe().
 108          * @return Title  The new object, or null on an error.
 109          */
 110         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 111                 if( is_object( $text ) ) {
 112                         throw new MWException( 'Title::newFromText given an object' );
 113                 }
 114
 115                 /**
 116                  * Wiki pages often contain multiple links to the same page.
 117                  * Title normalization and parsing can become expensive on
 118                  * pages with many links, so we can save a little time by
 119                  * caching them.
 120                  *
 121                  * In theory these are value objects and won't get changed...
 122                  */
 123                 if( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 124                         return Title::$titleCache[$text];
 125                 }
 126
 127                 /**
 128                  * Convert things like &eacute; &#257; or &#x3017; into real text...
 129                  */
 130                 $filteredText = Sanitizer::decodeCharReferences( $text );
 131
 132                 $t = new Title();
 133                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 134                 $t->mDefaultNamespace = $defaultNamespace;
 135
 136                 static $cachedcount = 0 ;
 137                 if( $t->secureAndSplit() ) {
 138                         if( $defaultNamespace == NS_MAIN ) {
 139                                 if( $cachedcount >= self::CACHE_MAX ) {
 140                                         # Avoid memory leaks on mass operations...
 141                                         Title::$titleCache = array();
 142                                         $cachedcount=0;
 143                                 }
 144                                 $cachedcount++;
 145                                 Title::$titleCache[$text] =& $t;
 146                         }
 147                         return $t;
 148                 } else {
 149                         $ret = NULL;
 150                         return $ret;
 151                 }
 152         }
 153
 154         /**
 155          * Create a new Title from URL-encoded text. Ensures that
 156          * the given title's length does not exceed the maximum.
 157          * @param $url \type{\string} the title, as might be taken from a URL
 158          * @return \type{Title} the new object, or NULL on an error
 159          */
 160         public static function newFromURL( $url ) {
 161                 global $wgLegalTitleChars;
 162                 $t = new Title();
 163
 164                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 165                 # but some URLs used it as a space replacement and they still come
 166                 # from some external search tools.
 167                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 168                         $url = str_replace( '+', ' ', $url );
 169                 }
 170
 171                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 172                 if( $t->secureAndSplit() ) {
 173                         return $t;
 174                 } else {
 175                         return NULL;
 176                 }
 177         }
 178
 179         /**
 180          * Create a new Title from an article ID
 181          *
 182          * @todo This is inefficiently implemented, the page row is requested
 183          *       but not used for anything else
 184          *
 185          * @param $id \type{\int} the page_id corresponding to the Title to create
 186          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 187          * @return \type{Title} the new object, or NULL on an error
 188          */
 189         public static function newFromID( $id, $flags = 0 ) {
 190                 $fname = 'Title::newFromID';
 191                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 192                 $row = $db->selectRow( 'page', array( 'page_namespace', 'page_title' ),
 193                         array( 'page_id' => $id ), $fname );
 194                 if ( $row !== false ) {
 195                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 196                 } else {
 197                         $title = NULL;
 198                 }
 199                 return $title;
 200         }
 201
 202         /**
 203          * Make an array of titles from an array of IDs
 204          * @param $ids \type{\arrayof{\int}} Array of IDs
 205          * @return \type{\arrayof{Title}} Array of Titles
 206          */
 207         public static function newFromIDs( $ids ) {
 208                 if ( !count( $ids ) ) {
 209                         return array();
 210                 }
 211                 $dbr = wfGetDB( DB_SLAVE );
 212                 $res = $dbr->select( 'page', array( 'page_namespace', 'page_title' ),
 213                         'page_id IN (' . $dbr->makeList( $ids ) . ')', __METHOD__ );
 214
 215                 $titles = array();
 216                 foreach( $res as $row ) {
 217                         $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
 218                 }
 219                 return $titles;
 220         }
 221
 222         /**
 223          * Make a Title object from a DB row
 224          * @param $row \type{Row} (needs at least page_title,page_namespace)
 225          * @return \type{Title} corresponding Title
 226          */
 227         public static function newFromRow( $row ) {
 228                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 229
 230                 $t->mArticleID = isset($row->page_id) ? intval($row->page_id) : -1;
 231                 $t->mLength = isset($row->page_len) ? intval($row->page_len) : -1;
 232                 $t->mRedirect = isset($row->page_is_redirect) ? (bool)$row->page_is_redirect : NULL;
 233                 $t->mLatestID = isset($row->page_latest) ? $row->page_latest : false;
 234
 235                 return $t;
 236         }
 237
 238         /**
 239          * Create a new Title from a namespace index and a DB key.
 240          * It's assumed that $ns and $title are *valid*, for instance when
 241          * they came directly from the database or a special page name.
 242          * For convenience, spaces are converted to underscores so that
 243          * eg user_text fields can be used directly.
 244          *
 245          * @param $ns \type{\int} the namespace of the article
 246          * @param $title \type{\string} the unprefixed database key form
 247          * @param $fragment \type{\string} The link fragment (after the "#")
 248          * @return \type{Title} the new object
 249          */
 250         public static function &makeTitle( $ns, $title, $fragment = '' ) {
 251                 $t = new Title();
 252                 $t->mInterwiki = '';
 253                 $t->mFragment = $fragment;
 254                 $t->mNamespace = $ns = intval( $ns );
 255                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 256                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 257                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 258                 $t->mTextform = str_replace( '_', ' ', $title );
 259                 return $t;
 260         }
 261
 262         /**
 263          * Create a new Title from a namespace index and a DB key.
 264          * The parameters will be checked for validity, which is a bit slower
 265          * than makeTitle() but safer for user-provided data.
 266          *
 267          * @param $ns \type{\int} the namespace of the article
 268          * @param $title \type{\string} the database key form
 269          * @param $fragment \type{\string} The link fragment (after the "#")
 270          * @return \type{Title} the new object, or NULL on an error
 271          */
 272         public static function makeTitleSafe( $ns, $title, $fragment = '' ) {
 273                 $t = new Title();
 274                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment );
 275                 if( $t->secureAndSplit() ) {
 276                         return $t;
 277                 } else {
 278                         return NULL;
 279                 }
 280         }
 281
 282         /**
 283          * Create a new Title for the Main Page
 284          * @return \type{Title} the new object
 285          */
 286         public static function newMainPage() {
 287                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 288                 // Don't give fatal errors if the message is broken
 289                 if ( !$title ) {
 290                         $title = Title::newFromText( 'Main Page' );
 291                 }
 292                 return $title;
 293         }
 294
 295         /**
 296          * Extract a redirect destination from a string and return the
 297          * Title, or null if the text doesn't contain a valid redirect
 298          * This will only return the very next target, useful for
 299          * the redirect table and other checks that don't need full recursion
 300          *
 301          * @param $text \type{\string} Text with possible redirect
 302          * @return \type{Title} The corresponding Title
 303          */
 304         public static function newFromRedirect( $text ) {
 305                 return self::newFromRedirectInternal( $text );
 306         }
 307
 308         /**
 309          * Extract a redirect destination from a string and return the
 310          * Title, or null if the text doesn't contain a valid redirect
 311          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 312          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 313          *
 314          * @param $text \type{\string} Text with possible redirect
 315          * @return \type{Title} The corresponding Title
 316          */
 317         public static function newFromRedirectRecurse( $text ) {
 318                 $titles = self::newFromRedirectArray( $text );
 319                 return $titles ? array_pop( $titles ) : null;
 320         }
 321
 322         /**
 323          * Extract a redirect destination from a string and return an
 324          * array of Titles, or null if the text doesn't contain a valid redirect
 325          * The last element in the array is the final destination after all redirects
 326          * have been resolved (up to $wgMaxRedirects times)
 327          *
 328          * @param $text \type{\string} Text with possible redirect
 329          * @return \type{\array} Array of Titles, with the destination last
 330          */
 331         public static function newFromRedirectArray( $text ) {
 332                 global $wgMaxRedirects;
 333                 // are redirects disabled?
 334                 if( $wgMaxRedirects < 1 )
 335                         return null;
 336                 $title = self::newFromRedirectInternal( $text );
 337                 if( is_null( $title ) )
 338                         return null;
 339                 // recursive check to follow double redirects
 340                 $recurse = $wgMaxRedirects;
 341                 $titles = array( $title );
 342                 while( --$recurse >= 0 ) {
 343                         if( $title->isRedirect() ) {
 344                                 $article = new Article( $title, 0 );
 345                                 $newtitle = $article->getRedirectTarget();
 346                         } else {
 347                                 break;
 348                         }
 349                         // Redirects to some special pages are not permitted
 350                         if( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 351                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 352                                 $title = $newtitle;
 353                                 $titles[] = $newtitle;
 354                         } else {
 355                                 break;
 356                         }
 357                 }
 358                 return $titles;
 359         }
 360
 361         /**
 362          * Really extract the redirect destination
 363          * Do not call this function directly, use one of the newFromRedirect* functions above
 364          *
 365          * @param $text \type{\string} Text with possible redirect
 366          * @return \type{Title} The corresponding Title
 367          */
 368         protected static function newFromRedirectInternal( $text ) {
 369                 $redir = MagicWord::get( 'redirect' );
 370                 $text = trim($text);
 371                 if( $redir->matchStartAndRemove( $text ) ) {
 372                         // Extract the first link and see if it's usable
 373                         // Ensure that it really does come directly after #REDIRECT
 374                         // Some older redirects included a colon, so don't freak about that!
 375                         $m = array();
 376                         if( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 377                                 // Strip preceding colon used to "escape" categories, etc.
 378                                 // and URL-decode links
 379                                 if( strpos( $m[1], '%' ) !== false ) {
 380                                         // Match behavior of inline link parsing here;
 381                                         // don't interpret + as " " most of the time!
 382                                         // It might be safe to just use rawurldecode instead, though.
 383                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 384                                 }
 385                                 $title = Title::newFromText( $m[1] );
 386                                 // If the title is a redirect to bad special pages or is invalid, return null
 387                                 if( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 388                                         return null;
 389                                 }
 390                                 return $title;
 391                         }
 392                 }
 393                 return null;
 394         }
 395
 396 #----------------------------------------------------------------------------
 397 #       Static functions
 398 #----------------------------------------------------------------------------
 399
 400         /**
 401          * Get the prefixed DB key associated with an ID
 402          * @param $id \type{\int} the page_id of the article
 403          * @return \type{Title} an object representing the article, or NULL
 404          *      if no such article was found
 405          */
 406         public static function nameOf( $id ) {
 407                 $dbr = wfGetDB( DB_SLAVE );
 408
 409                 $s = $dbr->selectRow( 'page',
 410                         array( 'page_namespace','page_title' ),
 411                         array( 'page_id' => $id ),
 412                         __METHOD__ );
 413                 if ( $s === false ) { return NULL; }
 414
 415                 $n = self::makeName( $s->page_namespace, $s->page_title );
 416                 return $n;
 417         }
 418
 419         /**
 420          * Get a regex character class describing the legal characters in a link
 421          * @return \type{\string} the list of characters, not delimited
 422          */
 423         public static function legalChars() {
 424                 global $wgLegalTitleChars;
 425                 return $wgLegalTitleChars;
 426         }
 427
 428         /**
 429          * Get a string representation of a title suitable for
 430          * including in a search index
 431          *
 432          * @param $ns \type{\int} a namespace index
 433          * @param $title \type{\string} text-form main part
 434          * @return \type{\string} a stripped-down title string ready for the
 435          *      search index
 436          */
 437         public static function indexTitle( $ns, $title ) {
 438                 global $wgContLang;
 439
 440                 $lc = SearchEngine::legalSearchChars() . '&#;';
 441                 $t = $wgContLang->stripForSearch( $title );
 442                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 443                 $t = $wgContLang->lc( $t );
 444
 445                 # Handle 's, s'
 446                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 447                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 448
 449                 $t = preg_replace( "/\\s+/", ' ', $t );
 450
 451                 if ( $ns == NS_FILE ) {
 452                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 453                 }
 454                 return trim( $t );
 455         }
 456
 457         /*
 458          * Make a prefixed DB key from a DB key and a namespace index
 459          * @param $ns \type{\int} numerical representation of the namespace
 460          * @param $title \type{\string} the DB key form the title
 461          * @param $fragment \type{\string} The link fragment (after the "#")
 462          * @return \type{\string} the prefixed form of the title
 463          */
 464         public static function makeName( $ns, $title, $fragment = '' ) {
 465                 global $wgContLang;
 466
 467                 $namespace = $wgContLang->getNsText( $ns );
 468                 $name = $namespace == '' ? $title : "$namespace:$title";
 469                 if ( strval( $fragment ) != '' ) {
 470                         $name .= '#' . $fragment;
 471                 }
 472                 return $name;
 473         }
 474
 475         /**
 476          * Returns the URL associated with an interwiki prefix
 477          * @param $key \type{\string} the interwiki prefix (e.g. "MeatBall")
 478          * @return \type{\string} the associated URL, containing "$1",
 479          *      which should be replaced by an article title
 480          * @static (arguably)
 481          * @deprecated See Interwiki class
 482          */
 483         public function getInterwikiLink( $key )  {
 484                 return Interwiki::fetch( $key )->getURL( );
 485         }
 486
 487         /**
 488          * Determine whether the object refers to a page within
 489          * this project.
 490          *
 491          * @return \type{\bool} TRUE if this is an in-project interwiki link
 492          *      or a wikilink, FALSE otherwise
 493          */
 494         public function isLocal() {
 495                 if ( $this->mInterwiki != '' ) {
 496                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 497                 } else {
 498                         return true;
 499                 }
 500         }
 501
 502         /**
 503          * Determine whether the object refers to a page within
 504          * this project and is transcludable.
 505          *
 506          * @return \type{\bool} TRUE if this is transcludable
 507          */
 508         public function isTrans() {
 509                 if ($this->mInterwiki == '')
 510                         return false;
 511
 512                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 513         }
 514
 515         /**
 516          * Escape a text fragment, say from a link, for a URL
 517          */
 518         static function escapeFragmentForURL( $fragment ) {
 519                 global $wgEnforceHtmlIds;
 520                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 521                 # fragments appear not to work in IE (at least up to 7) or in at least
 522                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 523                 # to care if they aren't encoded.
 524                 return Sanitizer::escapeId( $fragment,
 525                         $wgEnforceHtmlIds ? 'noninitial' : 'xml' );
 526         }
 527
 528 #----------------------------------------------------------------------------
 529 #       Other stuff
 530 #----------------------------------------------------------------------------
 531
 532         /** Simple accessors */
 533         /**
 534          * Get the text form (spaces not underscores) of the main part
 535          * @return \type{\string} Main part of the title
 536          */
 537         public function getText() { return $this->mTextform; }
 538         /**
 539          * Get the URL-encoded form of the main part
 540          * @return \type{\string} Main part of the title, URL-encoded
 541          */
 542         public function getPartialURL() { return $this->mUrlform; }
 543         /**
 544          * Get the main part with underscores
 545          * @return \type{\string} Main part of the title, with underscores
 546          */
 547         public function getDBkey() { return $this->mDbkeyform; }
 548         /**
 549          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 550          * @return \type{\int} Namespace index
 551          */
 552         public function getNamespace() { return $this->mNamespace; }
 553         /**
 554          * Get the namespace text
 555          * @return \type{\string} Namespace text
 556          */
 557         public function getNsText() {
 558                 global $wgContLang, $wgCanonicalNamespaceNames;
 559
 560                 if ( '' != $this->mInterwiki ) {
 561                         // This probably shouldn't even happen. ohh man, oh yuck.
 562                         // But for interwiki transclusion it sometimes does.
 563                         // Shit. Shit shit shit.
 564                         //
 565                         // Use the canonical namespaces if possible to try to
 566                         // resolve a foreign namespace.
 567                         if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
 568                                 return $wgCanonicalNamespaceNames[$this->mNamespace];
 569                         }
 570                 }
 571                 return $wgContLang->getNsText( $this->mNamespace );
 572         }
 573         /**
 574          * Get the DB key with the initial letter case as specified by the user
 575          * @return \type{\string} DB key
 576          */
 577         function getUserCaseDBKey() {
 578                 return $this->mUserCaseDBKey;
 579         }
 580         /**
 581          * Get the namespace text of the subject (rather than talk) page
 582          * @return \type{\string} Namespace text
 583          */
 584         public function getSubjectNsText() {
 585                 global $wgContLang;
 586                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 587         }
 588         /**
 589          * Get the namespace text of the talk page
 590          * @return \type{\string} Namespace text
 591          */
 592         public function getTalkNsText() {
 593                 global $wgContLang;
 594                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 595         }
 596         /**
 597          * Could this title have a corresponding talk page?
 598          * @return \type{\bool} TRUE or FALSE
 599          */
 600         public function canTalk() {
 601                 return( MWNamespace::canTalk( $this->mNamespace ) );
 602         }
 603         /**
 604          * Get the interwiki prefix (or null string)
 605          * @return \type{\string} Interwiki prefix
 606          */
 607         public function getInterwiki() { return $this->mInterwiki; }
 608         /**
 609          * Get the Title fragment (i.e.\ the bit after the #) in text form
 610          * @return \type{\string} Title fragment
 611          */
 612         public function getFragment() { return $this->mFragment; }
 613         /**
 614          * Get the fragment in URL form, including the "#" character if there is one
 615          * @return \type{\string} Fragment in URL form
 616          */
 617         public function getFragmentForURL() {
 618                 if ( $this->mFragment == '' ) {
 619                         return '';
 620                 } else {
 621                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 622                 }
 623         }
 624         /**
 625          * Get the default namespace index, for when there is no namespace
 626          * @return \type{\int} Default namespace index
 627          */
 628         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 629
 630         /**
 631          * Get title for search index
 632          * @return \type{\string} a stripped-down title string ready for the
 633          *      search index
 634          */
 635         public function getIndexTitle() {
 636                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 637         }
 638
 639         /**
 640          * Get the prefixed database key form
 641          * @return \type{\string} the prefixed title, with underscores and
 642          *      any interwiki and namespace prefixes
 643          */
 644         public function getPrefixedDBkey() {
 645                 $s = $this->prefix( $this->mDbkeyform );
 646                 $s = str_replace( ' ', '_', $s );
 647                 return $s;
 648         }
 649
 650         /**
 651          * Get the prefixed title with spaces.
 652          * This is the form usually used for display
 653          * @return \type{\string} the prefixed title, with spaces
 654          */
 655         public function getPrefixedText() {
 656                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 657                         $s = $this->prefix( $this->mTextform );
 658                         $s = str_replace( '_', ' ', $s );
 659                         $this->mPrefixedText = $s;
 660                 }
 661                 return $this->mPrefixedText;
 662         }
 663
 664         /**
 665          * Get the prefixed title with spaces, plus any fragment
 666          * (part beginning with '#')
 667          * @return \type{\string} the prefixed title, with spaces and
 668          *      the fragment, including '#'
 669          */
 670         public function getFullText() {
 671                 $text = $this->getPrefixedText();
 672                 if( '' != $this->mFragment ) {
 673                         $text .= '#' . $this->mFragment;
 674                 }
 675                 return $text;
 676         }
 677
 678         /**
 679          * Get the base name, i.e. the leftmost parts before the /
 680          * @return \type{\string} Base name
 681          */
 682         public function getBaseText() {
 683                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 684                         return $this->getText();
 685                 }
 686
 687                 $parts = explode( '/', $this->getText() );
 688                 # Don't discard the real title if there's no subpage involved
 689                 if( count( $parts ) > 1 )
 690                         unset( $parts[ count( $parts ) - 1 ] );
 691                 return implode( '/', $parts );
 692         }
 693
 694         /**
 695          * Get the lowest-level subpage name, i.e. the rightmost part after /
 696          * @return \type{\string} Subpage name
 697          */
 698         public function getSubpageText() {
 699                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 700                         return( $this->mTextform );
 701                 }
 702                 $parts = explode( '/', $this->mTextform );
 703                 return( $parts[ count( $parts ) - 1 ] );
 704         }
 705
 706         /**
 707          * Get a URL-encoded form of the subpage text
 708          * @return \type{\string} URL-encoded subpage name
 709          */
 710         public function getSubpageUrlForm() {
 711                 $text = $this->getSubpageText();
 712                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 713                 return( $text );
 714         }
 715
 716         /**
 717          * Get a URL-encoded title (not an actual URL) including interwiki
 718          * @return \type{\string} the URL-encoded form
 719          */
 720         public function getPrefixedURL() {
 721                 $s = $this->prefix( $this->mDbkeyform );
 722                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 723                 return $s;
 724         }
 725
 726         /**
 727          * Get a real URL referring to this title, with interwiki link and
 728          * fragment
 729          *
 730          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 731          *   links. Can be specified as an associative array as well, e.g.,
 732          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 733          * @param $variant \type{\string} language variant of url (for sr, zh..)
 734          * @return \type{\string} the URL
 735          */
 736         public function getFullURL( $query = '', $variant = false ) {
 737                 global $wgContLang, $wgServer, $wgRequest;
 738
 739                 if( is_array( $query ) ) {
 740                         $query = wfArrayToCGI( $query );
 741                 }
 742
 743                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 744                 if ( !$interwiki ) {
 745                         $url = $this->getLocalUrl( $query, $variant );
 746
 747                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 748                         // Correct fix would be to move the prepending elsewhere.
 749                         if ($wgRequest->getVal('action') != 'render') {
 750                                 $url = $wgServer . $url;
 751                         }
 752                 } else {
 753                         $baseUrl = $interwiki->getURL( );
 754
 755                         $namespace = wfUrlencode( $this->getNsText() );
 756                         if ( '' != $namespace ) {
 757                                 # Can this actually happen? Interwikis shouldn't be parsed.
 758                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 759                                 $namespace .= ':';
 760                         }
 761                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 762                         $url = wfAppendQuery( $url, $query );
 763                 }
 764
 765                 # Finally, add the fragment.
 766                 $url .= $this->getFragmentForURL();
 767
 768                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 769                 return $url;
 770         }
 771
 772         /**
 773          * Get a URL with no fragment or server name.  If this page is generated
 774          * with action=render, $wgServer is prepended.
 775          * @param mixed $query an optional query string; if not specified,
 776          *       $wgArticlePath will be used.  Can be specified as an associative array
 777          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 778          *   URL-escaped).
 779          * @param $variant \type{\string} language variant of url (for sr, zh..)
 780          * @return \type{\string} the URL
 781          */
 782         public function getLocalURL( $query = '', $variant = false ) {
 783                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 784                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 785
 786                 if( is_array( $query ) ) {
 787                         $query = wfArrayToCGI( $query );
 788                 }
 789
 790                 // internal links should point to same variant as current page (only anonymous users)
 791                 if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
 792                         $pref = $wgContLang->getPreferredVariant(false);
 793                         if($pref != $wgContLang->getCode())
 794                                 $variant = $pref;
 795                 }
 796
 797                 if ( $this->isExternal() ) {
 798                         $url = $this->getFullURL();
 799                         if ( $query ) {
 800                                 // This is currently only used for edit section links in the
 801                                 // context of interwiki transclusion. In theory we should
 802                                 // append the query to the end of any existing query string,
 803                                 // but interwiki transclusion is already broken in that case.
 804                                 $url .= "?$query";
 805                         }
 806                 } else {
 807                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 808                         if ( $query == '' ) {
 809                                 if( $variant != false && $wgContLang->hasVariants() ) {
 810                                         if( $wgVariantArticlePath == false ) {
 811                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 812                                         } else {
 813                                                 $variantArticlePath = $wgVariantArticlePath;
 814                                         }
 815                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 816                                         $url = str_replace( '$1', $dbkey, $url  );
 817                                 } else {
 818                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 819                                 }
 820                         } else {
 821                                 global $wgActionPaths;
 822                                 $url = false;
 823                                 $matches = array();
 824                                 if( !empty( $wgActionPaths ) &&
 825                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 826                                 {
 827                                         $action = urldecode( $matches[2] );
 828                                         if( isset( $wgActionPaths[$action] ) ) {
 829                                                 $query = $matches[1];
 830                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 831                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 832                                                 if( $query != '' ) {
 833                                                         $url = wfAppendQuery( $url, $query );
 834                                                 }
 835                                         }
 836                                 }
 837                                 if ( $url === false ) {
 838                                         if ( $query == '-' ) {
 839                                                 $query = '';
 840                                         }
 841                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 842                                 }
 843                         }
 844
 845                         // FIXME: this causes breakage in various places when we
 846                         // actually expected a local URL and end up with dupe prefixes.
 847                         if ($wgRequest->getVal('action') == 'render') {
 848                                 $url = $wgServer . $url;
 849                         }
 850                 }
 851                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 852                 return $url;
 853         }
 854
 855         /**
 856          * Get a URL that's the simplest URL that will be valid to link, locally,
 857          * to the current Title.  It includes the fragment, but does not include
 858          * the server unless action=render is used (or the link is external).  If
 859          * there's a fragment but the prefixed text is empty, we just return a link
 860          * to the fragment.
 861          *
 862          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 863          *   query string.  Keys and values will be escaped.
 864          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 865          *   for external links.  Default is "false" (same variant as current page,
 866          *   for anonymous users).
 867          * @return \type{\string} the URL
 868          */
 869         public function getLinkUrl( $query = array(), $variant = false ) {
 870                 if( !is_array( $query ) ) {
 871                         throw new MWException( 'Title::getLinkUrl passed a non-array for '.
 872                         '$query' );
 873                 }
 874                 if( $this->isExternal() ) {
 875                         return $this->getFullURL( $query );
 876                 } elseif( $this->getPrefixedText() === ''
 877                 and $this->getFragment() !== '' ) {
 878                         return $this->getFragmentForURL();
 879                 } else {
 880                         return $this->getLocalURL( $query, $variant )
 881                                 . $this->getFragmentForURL();
 882                 }
 883         }
 884
 885         /**
 886          * Get an HTML-escaped version of the URL form, suitable for
 887          * using in a link, without a server name or fragment
 888          * @param $query \type{\string} an optional query string
 889          * @return \type{\string} the URL
 890          */
 891         public function escapeLocalURL( $query = '' ) {
 892                 return htmlspecialchars( $this->getLocalURL( $query ) );
 893         }
 894
 895         /**
 896          * Get an HTML-escaped version of the URL form, suitable for
 897          * using in a link, including the server name and fragment
 898          *
 899          * @param $query \type{\string} an optional query string
 900          * @return \type{\string} the URL
 901          */
 902         public function escapeFullURL( $query = '' ) {
 903                 return htmlspecialchars( $this->getFullURL( $query ) );
 904         }
 905
 906         /**
 907          * Get the URL form for an internal link.
 908          * - Used in various Squid-related code, in case we have a different
 909          * internal hostname for the server from the exposed one.
 910          *
 911          * @param $query \type{\string} an optional query string
 912          * @param $variant \type{\string} language variant of url (for sr, zh..)
 913          * @return \type{\string} the URL
 914          */
 915         public function getInternalURL( $query = '', $variant = false ) {
 916                 global $wgInternalServer;
 917                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 918                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 919                 return $url;
 920         }
 921
 922         /**
 923          * Get the edit URL for this Title
 924          * @return \type{\string} the URL, or a null string if this is an
 925          *      interwiki link
 926          */
 927         public function getEditURL() {
 928                 if ( '' != $this->mInterwiki ) { return ''; }
 929                 $s = $this->getLocalURL( 'action=edit' );
 930
 931                 return $s;
 932         }
 933
 934         /**
 935          * Get the HTML-escaped displayable text form.
 936          * Used for the title field in <a> tags.
 937          * @return \type{\string} the text, including any prefixes
 938          */
 939         public function getEscapedText() {
 940                 return htmlspecialchars( $this->getPrefixedText() );
 941         }
 942
 943         /**
 944          * Is this Title interwiki?
 945          * @return \type{\bool}
 946          */
 947         public function isExternal() { return ( '' != $this->mInterwiki ); }
 948
 949         /**
 950          * Is this page "semi-protected" - the *only* protection is autoconfirm?
 951          *
 952          * @param @action \type{\string} Action to check (default: edit)
 953          * @return \type{\bool}
 954          */
 955         public function isSemiProtected( $action = 'edit' ) {
 956                 if( $this->exists() ) {
 957                         $restrictions = $this->getRestrictions( $action );
 958                         if( count( $restrictions ) > 0 ) {
 959                                 foreach( $restrictions as $restriction ) {
 960                                         if( strtolower( $restriction ) != 'autoconfirmed' )
 961                                                 return false;
 962                                 }
 963                         } else {
 964                                 # Not protected
 965                                 return false;
 966                         }
 967                         return true;
 968                 } else {
 969                         # If it doesn't exist, it can't be protected
 970                         return false;
 971                 }
 972         }
 973
 974         /**
 975          * Does the title correspond to a protected article?
 976          * @param $what \type{\string} the action the page is protected from,
 977          * by default checks move and edit
 978          * @return \type{\bool}
 979          */
 980         public function isProtected( $action = '' ) {
 981                 global $wgRestrictionLevels, $wgRestrictionTypes;
 982
 983                 # Special pages have inherent protection
 984                 if( $this->getNamespace() == NS_SPECIAL )
 985                         return true;
 986
 987                 # Check regular protection levels
 988                 foreach( $wgRestrictionTypes as $type ){
 989                         if( $action == $type || $action == '' ) {
 990                                 $r = $this->getRestrictions( $type );
 991                                 foreach( $wgRestrictionLevels as $level ) {
 992                                         if( in_array( $level, $r ) && $level != '' ) {
 993                                                 return true;
 994                                         }
 995                                 }
 996                         }
 997                 }
 998
 999                 return false;
1000         }
1001
1002         /**
1003          * Is $wgUser watching this page?
1004          * @return \type{\bool}
1005          */
1006         public function userIsWatching() {
1007                 global $wgUser;
1008
1009                 if ( is_null( $this->mWatched ) ) {
1010                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
1011                                 $this->mWatched = false;
1012                         } else {
1013                                 $this->mWatched = $wgUser->isWatched( $this );
1014                         }
1015                 }
1016                 return $this->mWatched;
1017         }
1018
1019         /**
1020          * Can $wgUser perform $action on this page?
1021          * This skips potentially expensive cascading permission checks.
1022          *
1023          * Suitable for use for nonessential UI controls in common cases, but
1024          * _not_ for functional access control.
1025          *
1026          * May provide false positives, but should never provide a false negative.
1027          *
1028          * @param $action \type{\string} action that permission needs to be checked for
1029          * @return \type{\bool}
1030          */
1031         public function quickUserCan( $action ) {
1032                 return $this->userCan( $action, false );
1033         }
1034
1035         /**
1036          * Determines if $wgUser is unable to edit this page because it has been protected
1037          * by $wgNamespaceProtection.
1038          *
1039          * @return \type{\bool}
1040          */
1041         public function isNamespaceProtected() {
1042                 global $wgNamespaceProtection, $wgUser;
1043                 if( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1044                         foreach( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1045                                 if( $right != '' && !$wgUser->isAllowed( $right ) )
1046                                         return true;
1047                         }
1048                 }
1049                 return false;
1050         }
1051
1052         /**
1053          * Can $wgUser perform $action on this page?
1054          * @param $action \type{\string} action that permission needs to be checked for
1055          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1056          * @return \type{\bool}
1057          */
1058         public function userCan( $action, $doExpensiveQueries = true ) {
1059                 global $wgUser;
1060                 return ($this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array());
1061         }
1062
1063         /**
1064          * Can $user perform $action on this page?
1065          *
1066          * FIXME: This *does not* check throttles (User::pingLimiter()).
1067          *
1068          * @param $action \type{\string}action that permission needs to be checked for
1069          * @param $user \type{User} user to check
1070          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1071          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1072          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1073          */
1074         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1075                 if( !StubObject::isRealObject( $user ) ) {
1076                         //Since StubObject is always used on globals, we can unstub $wgUser here and set $user = $wgUser
1077                         global $wgUser;
1078                         $wgUser->_unstub( '', 5 );
1079                         $user = $wgUser;
1080                 }
1081                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1082
1083                 global $wgContLang;
1084                 global $wgLang;
1085                 global $wgEmailConfirmToEdit;
1086
1087                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1088                         $errors[] = array( 'confirmedittext' );
1089                 }
1090
1091                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1092                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1093                         $block = $user->mBlock;
1094
1095                         // This is from OutputPage::blockedPage
1096                         // Copied at r23888 by werdna
1097
1098                         $id = $user->blockedBy();
1099                         $reason = $user->blockedFor();
1100                         if( $reason == '' ) {
1101                                 $reason = wfMsg( 'blockednoreason' );
1102                         }
1103                         $ip = wfGetIP();
1104
1105                         if ( is_numeric( $id ) ) {
1106                                 $name = User::whoIs( $id );
1107                         } else {
1108                                 $name = $id;
1109                         }
1110
1111                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1112                         $blockid = $block->mId;
1113                         $blockExpiry = $user->mBlock->mExpiry;
1114                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1115
1116                         if ( $blockExpiry == 'infinity' ) {
1117                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1118                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1119
1120                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1121                                         if ( strpos( $option, ':' ) == false )
1122                                                 continue;
1123
1124                                         list ($show, $value) = explode( ":", $option );
1125
1126                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1127                                                 $blockExpiry = $show;
1128                                                 break;
1129                                         }
1130                                 }
1131                         } else {
1132                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1133                         }
1134
1135                         $intended = $user->mBlock->mAddress;
1136
1137                         $errors[] = array( ($block->mAuto ? 'autoblockedtext' : 'blockedtext'), $link, $reason, $ip, $name,
1138                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1139                 }
1140
1141                 // Remove the errors being ignored.
1142
1143                 foreach( $errors as $index => $error ) {
1144                         $error_key = is_array($error) ? $error[0] : $error;
1145
1146                         if (in_array( $error_key, $ignoreErrors )) {
1147                                 unset($errors[$index]);
1148                         }
1149                 }
1150
1151                 return $errors;
1152         }
1153
1154         /**
1155          * Can $user perform $action on this page? This is an internal function,
1156          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1157          * checks on wfReadOnly() and blocks)
1158          *
1159          * @param $action \type{\string} action that permission needs to be checked for
1160          * @param $user \type{User} user to check
1161          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1162          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1163          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1164          */
1165         private function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries=true, $short=false ) {
1166                 wfProfileIn( __METHOD__ );
1167
1168                 $errors = array();
1169
1170                 // First stop is permissions checks, which fail most often, and which are easiest to test.
1171                 if ( $action == 'move' ) {
1172                         if( !$user->isAllowed( 'move-rootuserpages' )
1173                                         && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1174                         {
1175                                 // Show user page-specific message only if the user can move other pages
1176                                 $errors[] = array( 'cant-move-user-page' );
1177                         }
1178
1179                         // Check if user is allowed to move files if it's a file
1180                         if( $this->getNamespace() == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1181                                 $errors[] = array( 'movenotallowedfile' );
1182                         }
1183
1184                         if( !$user->isAllowed( 'move' ) ) {
1185                                 // User can't move anything
1186                                 $errors[] = $user->isAnon() ? array ( 'movenologintext' ) : array ('movenotallowed');
1187                         }
1188                 } elseif ( $action == 'create' ) {
1189                         if( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1190                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) )
1191                         {
1192                                 $errors[] = $user->isAnon() ? array ('nocreatetext') : array ('nocreate-loggedin');
1193                         }
1194                 } elseif( $action == 'move-target' ) {
1195                         if( !$user->isAllowed( 'move' ) ) {
1196                                 // User can't move anything
1197                                 $errors[] = $user->isAnon() ? array ( 'movenologintext' ) : array ('movenotallowed');
1198                         } elseif( !$user->isAllowed( 'move-rootuserpages' )
1199                                 && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1200                         {
1201                                 // Show user page-specific message only if the user can move other pages
1202                                 $errors[] = array( 'cant-move-to-user-page' );
1203                         }
1204                 } elseif( !$user->isAllowed( $action ) ) {
1205                         $return = null;
1206                         $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1207                                 User::getGroupsWithPermission( $action ) );
1208                         if( $groups ) {
1209                                 $return = array( 'badaccess-groups',
1210                                         array( implode( ', ', $groups ), count( $groups ) ) );
1211                         } else {
1212                                 $return = array( "badaccess-group0" );
1213                         }
1214                         $errors[] = $return;
1215                 }
1216
1217                 # Short-circuit point
1218                 if( $short && count($errors) > 0 ) {
1219                         wfProfileOut( __METHOD__ );
1220                         return $errors;
1221                 }
1222
1223                 // Use getUserPermissionsErrors instead
1224                 if( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1225                         wfProfileOut( __METHOD__ );
1226                         return $result ? array() : array( array( 'badaccess-group0' ) );
1227                 }
1228                 // Check getUserPermissionsErrors hook
1229                 if( !wfRunHooks( 'getUserPermissionsErrors', array(&$this,&$user,$action,&$result) ) ) {
1230                         if( is_array($result) && count($result) && !is_array($result[0]) )
1231                                 $errors[] = $result; # A single array representing an error
1232                         else if( is_array($result) && is_array($result[0]) )
1233                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1234                         else if( $result !== '' && is_string($result) )
1235                                 $errors[] = array($result); # A string representing a message-id
1236                         else if( $result === false )
1237                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1238                 }
1239                 # Short-circuit point
1240                 if( $short && count($errors) > 0 ) {
1241                         wfProfileOut( __METHOD__ );
1242                         return $errors;
1243                 }
1244                 // Check getUserPermissionsErrorsExpensive hook
1245                 if( $doExpensiveQueries && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array(&$this,&$user,$action,&$result) ) ) {
1246                         if( is_array($result) && count($result) && !is_array($result[0]) )
1247                                 $errors[] = $result; # A single array representing an error
1248                         else if( is_array($result) && is_array($result[0]) )
1249                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1250                         else if( $result !== '' && is_string($result) )
1251                                 $errors[] = array($result); # A string representing a message-id
1252                         else if( $result === false )
1253                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1254                 }
1255                 # Short-circuit point
1256                 if( $short && count($errors) > 0 ) {
1257                         wfProfileOut( __METHOD__ );
1258                         return $errors;
1259                 }
1260
1261                 # Only 'createaccount' and 'execute' can be performed on
1262                 # special pages, which don't actually exist in the DB.
1263                 $specialOKActions = array( 'createaccount', 'execute' );
1264                 if( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions) ) {
1265                         $errors[] = array('ns-specialprotected');
1266                 }
1267
1268                 # Check $wgNamespaceProtection for restricted namespaces
1269                 if( $this->isNamespaceProtected() ) {
1270                         $ns = $this->getNamespace() == NS_MAIN ?
1271                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1272                         $errors[] = NS_MEDIAWIKI == $this->mNamespace ?
1273                                 array('protectedinterface') : array( 'namespaceprotected',  $ns );
1274                 }
1275
1276                 # Protect css/js subpages of user pages
1277                 # XXX: this might be better using restrictions
1278                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
1279                 if( $this->isCssJsSubpage() && !$user->isAllowed('editusercssjs')
1280                         && !preg_match('/^'.preg_quote($user->getName(), '/').'\//', $this->mTextform) )
1281                 {
1282                         $errors[] = array('customcssjsprotected');
1283                 }
1284
1285                 # Check against page_restrictions table requirements on this
1286                 # page. The user must possess all required rights for this action.
1287                 foreach( $this->getRestrictions($action) as $right ) {
1288                         // Backwards compatibility, rewrite sysop -> protect
1289                         if( $right == 'sysop' ) {
1290                                 $right = 'protect';
1291                         }
1292                         if( '' != $right && !$user->isAllowed( $right ) ) {
1293                                 // Users with 'editprotected' permission can edit protected pages
1294                                 if( $action=='edit' && $user->isAllowed( 'editprotected' ) ) {
1295                                         // Users with 'editprotected' permission cannot edit protected pages
1296                                         // with cascading option turned on.
1297                                         if( $this->mCascadeRestriction ) {
1298                                                 $errors[] = array( 'protectedpagetext', $right );
1299                                         }
1300                                 } else {
1301                                         $errors[] = array( 'protectedpagetext', $right );
1302                                 }
1303                         }
1304                 }
1305                 # Short-circuit point
1306                 if( $short && count($errors) > 0 ) {
1307                         wfProfileOut( __METHOD__ );
1308                         return $errors;
1309                 }
1310
1311                 if( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1312                         # We /could/ use the protection level on the source page, but it's fairly ugly
1313                         #  as we have to establish a precedence hierarchy for pages included by multiple
1314                         #  cascade-protected pages. So just restrict it to people with 'protect' permission,
1315                         #  as they could remove the protection anyway.
1316                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1317                         # Cascading protection depends on more than this page...
1318                         # Several cascading protected pages may include this page...
1319                         # Check each cascading level
1320                         # This is only for protection restrictions, not for all actions
1321                         if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
1322                                 foreach( $restrictions[$action] as $right ) {
1323                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1324                                         if( '' != $right && !$user->isAllowed( $right ) ) {
1325                                                 $pages = '';
1326                                                 foreach( $cascadingSources as $page )
1327                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1328                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1329                                         }
1330                                 }
1331                         }
1332                 }
1333                 # Short-circuit point
1334                 if( $short && count($errors) > 0 ) {
1335                         wfProfileOut( __METHOD__ );
1336                         return $errors;
1337                 }
1338
1339                 if( $action == 'protect' ) {
1340                         if( $this->getUserPermissionsErrors('edit', $user) != array() ) {
1341                                 $errors[] = array( 'protect-cantedit' ); // If they can't edit, they shouldn't protect.
1342                         }
1343                 }
1344
1345                 if( $action == 'create' ) {
1346                         $title_protection = $this->getTitleProtection();
1347                         if( is_array($title_protection) ) {
1348                                 extract($title_protection); // is this extract() really needed?
1349
1350                                 if( $pt_create_perm == 'sysop' ) {
1351                                         $pt_create_perm = 'protect'; // B/C
1352                                 }
1353                                 if( $pt_create_perm == '' || !$user->isAllowed($pt_create_perm) ) {
1354                                         $errors[] = array( 'titleprotected', User::whoIs($pt_user), $pt_reason );
1355                                 }
1356                         }
1357                 } elseif( $action == 'move' ) {
1358                         // Check for immobile pages
1359                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1360                                 // Specific message for this case
1361                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1362                         } elseif( !$this->isMovable() ) {
1363                                 // Less specific message for rarer cases
1364                                 $errors[] = array( 'immobile-page' );
1365                         }
1366                 } elseif( $action == 'move-target' ) {
1367                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1368                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1369                         } elseif( !$this->isMovable() ) {
1370                                 $errors[] = array( 'immobile-target-page' );
1371                         }
1372                 }
1373
1374                 wfProfileOut( __METHOD__ );
1375                 return $errors;
1376         }
1377
1378         /**
1379          * Is this title subject to title protection?
1380          * @return \type{\mixed} An associative array representing any existent title
1381          *   protection, or false if there's none.
1382          */
1383         private function getTitleProtection() {
1384                 // Can't protect pages in special namespaces
1385                 if ( $this->getNamespace() < 0 ) {
1386                         return false;
1387                 }
1388
1389                 $dbr = wfGetDB( DB_SLAVE );
1390                 $res = $dbr->select( 'protected_titles', '*',
1391                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1392                         __METHOD__ );
1393
1394                 if ($row = $dbr->fetchRow( $res )) {
1395                         return $row;
1396                 } else {
1397                         return false;
1398                 }
1399         }
1400
1401         /**
1402          * Update the title protection status
1403          * @param $create_perm \type{\string} Permission required for creation
1404          * @param $reason \type{\string} Reason for protection
1405          * @param $expiry \type{\string} Expiry timestamp
1406          */
1407         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1408                 global $wgUser,$wgContLang;
1409
1410                 if ($create_perm == implode(',',$this->getRestrictions('create'))
1411                         && $expiry == $this->mRestrictionsExpiry['create']) {
1412                         // No change
1413                         return true;
1414                 }
1415
1416                 list ($namespace, $title) = array( $this->getNamespace(), $this->getDBkey() );
1417
1418                 $dbw = wfGetDB( DB_MASTER );
1419
1420                 $encodedExpiry = Block::encodeExpiry($expiry, $dbw );
1421
1422                 $expiry_description = '';
1423                 if ( $encodedExpiry != 'infinity' ) {
1424                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ) , $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ).')';
1425                 }
1426                 else {
1427                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ).')';
1428                 }
1429
1430                 # Update protection table
1431                 if ($create_perm != '' ) {
1432                         $dbw->replace( 'protected_titles', array(array('pt_namespace', 'pt_title')),
1433                                 array( 'pt_namespace' => $namespace, 'pt_title' => $title
1434                                         , 'pt_create_perm' => $create_perm
1435                                         , 'pt_timestamp' => Block::encodeExpiry(wfTimestampNow(), $dbw)
1436                                         , 'pt_expiry' => $encodedExpiry
1437                                         , 'pt_user' => $wgUser->getId(), 'pt_reason' => $reason ), __METHOD__  );
1438                 } else {
1439                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1440                                 'pt_title' => $title ), __METHOD__ );
1441                 }
1442                 # Update the protection log
1443                 $log = new LogPage( 'protect' );
1444
1445                 if( $create_perm ) {
1446                         $params = array("[create=$create_perm] $expiry_description",'');
1447                         $log->addEntry( $this->mRestrictions['create'] ? 'modify' : 'protect', $this, trim( $reason ), $params );
1448                 } else {
1449                         $log->addEntry( 'unprotect', $this, $reason );
1450                 }
1451
1452                 return true;
1453         }
1454
1455         /**
1456          * Remove any title protection due to page existing
1457          */
1458         public function deleteTitleProtection() {
1459                 $dbw = wfGetDB( DB_MASTER );
1460
1461                 $dbw->delete( 'protected_titles',
1462                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1463                         __METHOD__ );
1464         }
1465
1466         /**
1467          * Can $wgUser edit this page?
1468          * @return \type{\bool} TRUE or FALSE
1469          * @deprecated use userCan('edit')
1470          */
1471         public function userCanEdit( $doExpensiveQueries = true ) {
1472                 return $this->userCan( 'edit', $doExpensiveQueries );
1473         }
1474
1475         /**
1476          * Can $wgUser create this page?
1477          * @return \type{\bool} TRUE or FALSE
1478          * @deprecated use userCan('create')
1479          */
1480         public function userCanCreate( $doExpensiveQueries = true ) {
1481                 return $this->userCan( 'create', $doExpensiveQueries );
1482         }
1483
1484         /**
1485          * Can $wgUser move this page?
1486          * @return \type{\bool} TRUE or FALSE
1487          * @deprecated use userCan('move')
1488          */
1489         public function userCanMove( $doExpensiveQueries = true ) {
1490                 return $this->userCan( 'move', $doExpensiveQueries );
1491         }
1492
1493         /**
1494          * Would anybody with sufficient privileges be able to move this page?
1495          * Some pages just aren't movable.
1496          *
1497          * @return \type{\bool} TRUE or FALSE
1498          */
1499         public function isMovable() {
1500                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1501         }
1502
1503         /**
1504          * Can $wgUser read this page?
1505          * @return \type{\bool} TRUE or FALSE
1506          * @todo fold these checks into userCan()
1507          */
1508         public function userCanRead() {
1509                 global $wgUser, $wgGroupPermissions;
1510
1511                 $result = null;
1512                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1513                 if ( $result !== null ) {
1514                         return $result;
1515                 }
1516
1517                 # Shortcut for public wikis, allows skipping quite a bit of code
1518                 if ( !empty( $wgGroupPermissions['*']['read'] ) )
1519                         return true;
1520
1521                 if( $wgUser->isAllowed( 'read' ) ) {
1522                         return true;
1523                 } else {
1524                         global $wgWhitelistRead;
1525
1526                         /**
1527                          * Always grant access to the login page.
1528                          * Even anons need to be able to log in.
1529                         */
1530                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1531                                 return true;
1532                         }
1533
1534                         /**
1535                          * Bail out if there isn't whitelist
1536                          */
1537                         if( !is_array($wgWhitelistRead) ) {
1538                                 return false;
1539                         }
1540
1541                         /**
1542                          * Check for explicit whitelisting
1543                          */
1544                         $name = $this->getPrefixedText();
1545                         $dbName = $this->getPrefixedDBKey();
1546                         // Check with and without underscores
1547                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1548                                 return true;
1549
1550                         /**
1551                          * Old settings might have the title prefixed with
1552                          * a colon for main-namespace pages
1553                          */
1554                         if( $this->getNamespace() == NS_MAIN ) {
1555                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1556                                         return true;
1557                         }
1558
1559                         /**
1560                          * If it's a special page, ditch the subpage bit
1561                          * and check again
1562                          */
1563                         if( $this->getNamespace() == NS_SPECIAL ) {
1564                                 $name = $this->getDBkey();
1565                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1566                                 if ( $name === false ) {
1567                                         # Invalid special page, but we show standard login required message
1568                                         return false;
1569                                 }
1570
1571                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1572                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1573                                         return true;
1574                         }
1575
1576                 }
1577                 return false;
1578         }
1579
1580         /**
1581          * Is this a talk page of some sort?
1582          * @return \type{\bool} TRUE or FALSE
1583          */
1584         public function isTalkPage() {
1585                 return MWNamespace::isTalk( $this->getNamespace() );
1586         }
1587
1588         /**
1589          * Is this a subpage?
1590          * @return \type{\bool} TRUE or FALSE
1591          */
1592         public function isSubpage() {
1593                 return MWNamespace::hasSubpages( $this->mNamespace )
1594                         ? strpos( $this->getText(), '/' ) !== false
1595                         : false;
1596         }
1597
1598         /**
1599          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1600          * @return \type{\bool} TRUE or FALSE
1601          */
1602         public function hasSubpages() {
1603                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1604                         # Duh
1605                         return false;
1606                 }
1607
1608                 # We dynamically add a member variable for the purpose of this method
1609                 # alone to cache the result.  There's no point in having it hanging
1610                 # around uninitialized in every Title object; therefore we only add it
1611                 # if needed and don't declare it statically.
1612                 if( isset( $this->mHasSubpages ) ) {
1613                         return $this->mHasSubpages;
1614                 }
1615
1616                 $db = wfGetDB( DB_SLAVE );
1617                 $subpages = $this->getSubpages( 1 );
1618                 if( $subpages instanceof TitleArray )
1619                         return $this->mHasSubpages = (bool)$subpages->count();
1620                 return $this->mHasSubpages = false;
1621         }
1622
1623         /**
1624          * Get all subpages of this page.
1625          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1626          * @return mixed TitleArray, or empty array if this page's namespace
1627          *  doesn't allow subpages
1628          */
1629         public function getSubpages($limit = -1) {
1630                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1631                         return array();
1632
1633                 $dbr = wfGetDB( DB_SLAVE );
1634                 $conds['page_namespace'] = $this->getNamespace();
1635                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1636                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1637                 $options = array();
1638                 if( $limit > -1 )
1639                         $options['LIMIT'] = $limit;
1640                 return $this->mSubpages = TitleArray::newFromResult(
1641                         $dbr->select( 'page',
1642                                 array( 'page_id', 'page_namespace', 'page_title' ),
1643                                 $conds,
1644                                 __METHOD__,
1645                                 $options
1646                         )
1647                 );
1648         }
1649
1650         /**
1651          * Could this page contain custom CSS or JavaScript, based
1652          * on the title?
1653          *
1654          * @return \type{\bool} TRUE or FALSE
1655          */
1656         public function isCssOrJsPage() {
1657                 return $this->mNamespace == NS_MEDIAWIKI
1658                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1659         }
1660
1661         /**
1662          * Is this a .css or .js subpage of a user page?
1663          * @return \type{\bool} TRUE or FALSE
1664          */
1665         public function isCssJsSubpage() {
1666                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1667         }
1668         /**
1669          * Is this a *valid* .css or .js subpage of a user page?
1670          * Check that the corresponding skin exists
1671          * @return \type{\bool} TRUE or FALSE
1672          */
1673         public function isValidCssJsSubpage() {
1674                 if ( $this->isCssJsSubpage() ) {
1675                         $skinNames = Skin::getSkinNames();
1676                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1677                 } else {
1678                         return false;
1679                 }
1680         }
1681         /**
1682          * Trim down a .css or .js subpage title to get the corresponding skin name
1683          */
1684         public function getSkinFromCssJsSubpage() {
1685                 $subpage = explode( '/', $this->mTextform );
1686                 $subpage = $subpage[ count( $subpage ) - 1 ];
1687                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1688         }
1689         /**
1690          * Is this a .css subpage of a user page?
1691          * @return \type{\bool} TRUE or FALSE
1692          */
1693         public function isCssSubpage() {
1694                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1695         }
1696         /**
1697          * Is this a .js subpage of a user page?
1698          * @return \type{\bool} TRUE or FALSE
1699          */
1700         public function isJsSubpage() {
1701                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1702         }
1703         /**
1704          * Protect css/js subpages of user pages: can $wgUser edit
1705          * this page?
1706          *
1707          * @return \type{\bool} TRUE or FALSE
1708          * @todo XXX: this might be better using restrictions
1709          */
1710         public function userCanEditCssJsSubpage() {
1711                 global $wgUser;
1712                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1713         }
1714
1715         /**
1716          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1717          *
1718          * @return \type{\bool} If the page is subject to cascading restrictions.
1719          */
1720         public function isCascadeProtected() {
1721                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1722                 return ( $sources > 0 );
1723         }
1724
1725         /**
1726          * Cascading protection: Get the source of any cascading restrictions on this page.
1727          *
1728          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1729          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1730          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1731          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1732          */
1733         public function getCascadeProtectionSources( $get_pages = true ) {
1734                 global $wgRestrictionTypes;
1735
1736                 # Define our dimension of restrictions types
1737                 $pagerestrictions = array();
1738                 foreach( $wgRestrictionTypes as $action )
1739                         $pagerestrictions[$action] = array();
1740
1741                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1742                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1743                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1744                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1745                 }
1746
1747                 wfProfileIn( __METHOD__ );
1748
1749                 $dbr = wfGetDB( DB_SLAVE );
1750
1751                 if ( $this->getNamespace() == NS_FILE ) {
1752                         $tables = array ('imagelinks', 'page_restrictions');
1753                         $where_clauses = array(
1754                                 'il_to' => $this->getDBkey(),
1755                                 'il_from=pr_page',
1756                                 'pr_cascade' => 1 );
1757                 } else {
1758                         $tables = array ('templatelinks', 'page_restrictions');
1759                         $where_clauses = array(
1760                                 'tl_namespace' => $this->getNamespace(),
1761                                 'tl_title' => $this->getDBkey(),
1762                                 'tl_from=pr_page',
1763                                 'pr_cascade' => 1 );
1764                 }
1765
1766                 if ( $get_pages ) {
1767                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1768                         $where_clauses[] = 'page_id=pr_page';
1769                         $tables[] = 'page';
1770                 } else {
1771                         $cols = array( 'pr_expiry' );
1772                 }
1773
1774                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1775
1776                 $sources = $get_pages ? array() : false;
1777                 $now = wfTimestampNow();
1778                 $purgeExpired = false;
1779
1780                 foreach( $res as $row ) {
1781                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1782                         if( $expiry > $now ) {
1783                                 if ($get_pages) {
1784                                         $page_id = $row->pr_page;
1785                                         $page_ns = $row->page_namespace;
1786                                         $page_title = $row->page_title;
1787                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1788                                         # Add groups needed for each restriction type if its not already there
1789                                         # Make sure this restriction type still exists
1790                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1791                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1792                                         }
1793                                 } else {
1794                                         $sources = true;
1795                                 }
1796                         } else {
1797                                 // Trigger lazy purge of expired restrictions from the db
1798                                 $purgeExpired = true;
1799                         }
1800                 }
1801                 if( $purgeExpired ) {
1802                         Title::purgeExpiredRestrictions();
1803                 }
1804
1805                 wfProfileOut( __METHOD__ );
1806
1807                 if ( $get_pages ) {
1808                         $this->mCascadeSources = $sources;
1809                         $this->mCascadingRestrictions = $pagerestrictions;
1810                 } else {
1811                         $this->mHasCascadingRestrictions = $sources;
1812                 }
1813                 return array( $sources, $pagerestrictions );
1814         }
1815
1816         function areRestrictionsCascading() {
1817                 if (!$this->mRestrictionsLoaded) {
1818                         $this->loadRestrictions();
1819                 }
1820
1821                 return $this->mCascadeRestriction;
1822         }
1823
1824         /**
1825          * Loads a string into mRestrictions array
1826          * @param $res \type{Resource} restrictions as an SQL result.
1827          */
1828         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1829                 global $wgRestrictionTypes;
1830                 $dbr = wfGetDB( DB_SLAVE );
1831
1832                 foreach( $wgRestrictionTypes as $type ){
1833                         $this->mRestrictions[$type] = array();
1834                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1835                 }
1836
1837                 $this->mCascadeRestriction = false;
1838
1839                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1840
1841                 if ( $oldFashionedRestrictions === NULL ) {
1842                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1843                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1844                 }
1845
1846                 if ($oldFashionedRestrictions != '') {
1847
1848                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1849                                 $temp = explode( '=', trim( $restrict ) );
1850                                 if(count($temp) == 1) {
1851                                         // old old format should be treated as edit/move restriction
1852                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1853                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1854                                 } else {
1855                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1856                                 }
1857                         }
1858
1859                         $this->mOldRestrictions = true;
1860
1861                 }
1862
1863                 if( $dbr->numRows( $res ) ) {
1864                         # Current system - load second to make them override.
1865                         $now = wfTimestampNow();
1866                         $purgeExpired = false;
1867
1868                         foreach( $res as $row ) {
1869                                 # Cycle through all the restrictions.
1870
1871                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1872                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1873                                         continue;
1874
1875                                 // This code should be refactored, now that it's being used more generally,
1876                                 // But I don't really see any harm in leaving it in Block for now -werdna
1877                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1878
1879                                 // Only apply the restrictions if they haven't expired!
1880                                 if ( !$expiry || $expiry > $now ) {
1881                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1882                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1883
1884                                         $this->mCascadeRestriction |= $row->pr_cascade;
1885                                 } else {
1886                                         // Trigger a lazy purge of expired restrictions
1887                                         $purgeExpired = true;
1888                                 }
1889                         }
1890
1891                         if( $purgeExpired ) {
1892                                 Title::purgeExpiredRestrictions();
1893                         }
1894                 }
1895
1896                 $this->mRestrictionsLoaded = true;
1897         }
1898
1899         /**
1900          * Load restrictions from the page_restrictions table
1901          */
1902         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1903                 if( !$this->mRestrictionsLoaded ) {
1904                         if ($this->exists()) {
1905                                 $dbr = wfGetDB( DB_SLAVE );
1906
1907                                 $res = $dbr->select( 'page_restrictions', '*',
1908                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1909
1910                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1911                         } else {
1912                                 $title_protection = $this->getTitleProtection();
1913
1914                                 if (is_array($title_protection)) {
1915                                         extract($title_protection);
1916
1917                                         $now = wfTimestampNow();
1918                                         $expiry = Block::decodeExpiry($pt_expiry);
1919
1920                                         if (!$expiry || $expiry > $now) {
1921                                                 // Apply the restrictions
1922                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1923                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1924                                         } else { // Get rid of the old restrictions
1925                                                 Title::purgeExpiredRestrictions();
1926                                         }
1927                                 } else {
1928                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1929                                 }
1930                                 $this->mRestrictionsLoaded = true;
1931                         }
1932                 }
1933         }
1934
1935         /**
1936          * Purge expired restrictions from the page_restrictions table
1937          */
1938         static function purgeExpiredRestrictions() {
1939                 $dbw = wfGetDB( DB_MASTER );
1940                 $dbw->delete( 'page_restrictions',
1941                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1942                         __METHOD__ );
1943
1944                 $dbw->delete( 'protected_titles',
1945                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1946                         __METHOD__ );
1947         }
1948
1949         /**
1950          * Accessor/initialisation for mRestrictions
1951          *
1952          * @param $action \type{\string} action that permission needs to be checked for
1953          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1954          */
1955         public function getRestrictions( $action ) {
1956                 if( !$this->mRestrictionsLoaded ) {
1957                         $this->loadRestrictions();
1958                 }
1959                 return isset( $this->mRestrictions[$action] )
1960                                 ? $this->mRestrictions[$action]
1961                                 : array();
1962         }
1963
1964         /**
1965          * Get the expiry time for the restriction against a given action
1966          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1967          * or not protected at all, or false if the action is not recognised.
1968          */
1969         public function getRestrictionExpiry( $action ) {
1970                 if( !$this->mRestrictionsLoaded ) {
1971                         $this->loadRestrictions();
1972                 }
1973                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1974         }
1975
1976         /**
1977          * Is there a version of this page in the deletion archive?
1978          * @return \type{\int} the number of archived revisions
1979          */
1980         public function isDeleted() {
1981                 $fname = 'Title::isDeleted';
1982                 if ( $this->getNamespace() < 0 ) {
1983                         $n = 0;
1984                 } else {
1985                         $dbr = wfGetDB( DB_SLAVE );
1986                         $n = $dbr->selectField( 'archive', 'COUNT(*)', array( 'ar_namespace' => $this->getNamespace(),
1987                                 'ar_title' => $this->getDBkey() ), $fname );
1988                         if( $this->getNamespace() == NS_FILE ) {
1989                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1990                                         array( 'fa_name' => $this->getDBkey() ), $fname );
1991                         }
1992                 }
1993                 return (int)$n;
1994         }
1995
1996         /**
1997          * Get the article ID for this Title from the link cache,
1998          * adding it if necessary
1999          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2000          *      for update
2001          * @return \type{\int} the ID
2002          */
2003         public function getArticleID( $flags = 0 ) {
2004                 if( $this->getNamespace() < 0 ) {
2005                         return $this->mArticleID = 0;
2006                 }
2007                 $linkCache = LinkCache::singleton();
2008                 if( $flags & GAID_FOR_UPDATE ) {
2009                         $oldUpdate = $linkCache->forUpdate( true );
2010                         $linkCache->clearLink( $this );
2011                         $this->mArticleID = $linkCache->addLinkObj( $this );
2012                         $linkCache->forUpdate( $oldUpdate );
2013                 } else {
2014                         if( -1 == $this->mArticleID ) {
2015                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2016                         }
2017                 }
2018                 return $this->mArticleID;
2019         }
2020
2021         /**
2022          * Is this an article that is a redirect page?
2023          * Uses link cache, adding it if necessary
2024          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2025          * @return \type{\bool}
2026          */
2027         public function isRedirect( $flags = 0 ) {
2028                 if( !is_null($this->mRedirect) )
2029                         return $this->mRedirect;
2030                 # Calling getArticleID() loads the field from cache as needed
2031                 if( !$this->getArticleID($flags) ) {
2032                         return $this->mRedirect = false;
2033                 }
2034                 $linkCache = LinkCache::singleton();
2035                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2036
2037                 return $this->mRedirect;
2038         }
2039
2040         /**
2041          * What is the length of this page?
2042          * Uses link cache, adding it if necessary
2043          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2044          * @return \type{\bool}
2045          */
2046         public function getLength( $flags = 0 ) {
2047                 if( $this->mLength != -1 )
2048                         return $this->mLength;
2049                 # Calling getArticleID() loads the field from cache as needed
2050                 if( !$this->getArticleID($flags) ) {
2051                         return $this->mLength = 0;
2052                 }
2053                 $linkCache = LinkCache::singleton();
2054                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2055
2056                 return $this->mLength;
2057         }
2058
2059         /**
2060          * What is the page_latest field for this page?
2061          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2062          * @return \type{\int}
2063          */
2064         public function getLatestRevID( $flags = 0 ) {
2065                 if( $this->mLatestID !== false )
2066                         return $this->mLatestID;
2067
2068                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2069                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2070                 return $this->mLatestID;
2071         }
2072
2073         /**
2074          * This clears some fields in this object, and clears any associated
2075          * keys in the "bad links" section of the link cache.
2076          *
2077          * - This is called from Article::insertNewArticle() to allow
2078          * loading of the new page_id. It's also called from
2079          * Article::doDeleteArticle()
2080          *
2081          * @param $newid \type{\int} the new Article ID
2082          */
2083         public function resetArticleID( $newid ) {
2084                 $linkCache = LinkCache::singleton();
2085                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2086
2087                 if ( 0 == $newid ) { $this->mArticleID = -1; }
2088                 else { $this->mArticleID = $newid; }
2089                 $this->mRestrictionsLoaded = false;
2090                 $this->mRestrictions = array();
2091         }
2092
2093         /**
2094          * Updates page_touched for this page; called from LinksUpdate.php
2095          * @return \type{\bool} true if the update succeded
2096          */
2097         public function invalidateCache() {
2098                 if( wfReadOnly() ) {
2099                         return;
2100                 }
2101                 $dbw = wfGetDB( DB_MASTER );
2102                 $success = $dbw->update( 'page',
2103                         array( 'page_touched' => $dbw->timestamp() ),
2104                         $this->pageCond(),
2105                         __METHOD__
2106                 );
2107                 HTMLFileCache::clearFileCache( $this );
2108                 return $success;
2109         }
2110
2111         /**
2112          * Prefix some arbitrary text with the namespace or interwiki prefix
2113          * of this object
2114          *
2115          * @param $name \type{\string} the text
2116          * @return \type{\string} the prefixed text
2117          * @private
2118          */
2119         /* private */ function prefix( $name ) {
2120                 $p = '';
2121                 if ( '' != $this->mInterwiki ) {
2122                         $p = $this->mInterwiki . ':';
2123                 }
2124                 if ( 0 != $this->mNamespace ) {
2125                         $p .= $this->getNsText() . ':';
2126                 }
2127                 return $p . $name;
2128         }
2129
2130         /**
2131          * Secure and split - main initialisation function for this object
2132          *
2133          * Assumes that mDbkeyform has been set, and is urldecoded
2134          * and uses underscores, but not otherwise munged.  This function
2135          * removes illegal characters, splits off the interwiki and
2136          * namespace prefixes, sets the other forms, and canonicalizes
2137          * everything.
2138          * @return \type{\bool} true on success
2139          */
2140         private function secureAndSplit() {
2141                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2142
2143                 # Initialisation
2144                 static $rxTc = false;
2145                 if( !$rxTc ) {
2146                         # Matching titles will be held as illegal.
2147                         $rxTc = '/' .
2148                                 # Any character not allowed is forbidden...
2149                                 '[^' . Title::legalChars() . ']' .
2150                                 # URL percent encoding sequences interfere with the ability
2151                                 # to round-trip titles -- you can't link to them consistently.
2152                                 '|%[0-9A-Fa-f]{2}' .
2153                                 # XML/HTML character references produce similar issues.
2154                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2155                                 '|&#[0-9]+;' .
2156                                 '|&#x[0-9A-Fa-f]+;' .
2157                                 '/S';
2158                 }
2159
2160                 $this->mInterwiki = $this->mFragment = '';
2161                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2162
2163                 $dbkey = $this->mDbkeyform;
2164
2165                 # Strip Unicode bidi override characters.
2166                 # Sometimes they slip into cut-n-pasted page titles, where the
2167                 # override chars get included in list displays.
2168                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2169
2170                 # Clean up whitespace
2171                 #
2172                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2173                 $dbkey = trim( $dbkey, '_' );
2174
2175                 if ( '' == $dbkey ) {
2176                         return false;
2177                 }
2178
2179                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2180                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2181                         return false;
2182                 }
2183
2184                 $this->mDbkeyform = $dbkey;
2185
2186                 # Initial colon indicates main namespace rather than specified default
2187                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2188                 if ( ':' == $dbkey{0} ) {
2189                         $this->mNamespace = NS_MAIN;
2190                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2191                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2192                 }
2193
2194                 # Namespace or interwiki prefix
2195                 $firstPass = true;
2196                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2197                 do {
2198                         $m = array();
2199                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2200                                 $p = $m[1];
2201                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2202                                         # Ordinary namespace
2203                                         $dbkey = $m[2];
2204                                         $this->mNamespace = $ns;
2205                                         # For Talk:X pages, check if X has a "namespace" prefix
2206                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2207                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2208                                                         return false; # Disallow Talk:File:x type titles...
2209                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2210                                                         return false; # Disallow Talk:Interwiki:x type titles...
2211                                         }
2212                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2213                                         if( !$firstPass ) {
2214                                                 # Can't make a local interwiki link to an interwiki link.
2215                                                 # That's just crazy!
2216                                                 return false;
2217                                         }
2218
2219                                         # Interwiki link
2220                                         $dbkey = $m[2];
2221                                         $this->mInterwiki = $wgContLang->lc( $p );
2222
2223                                         # Redundant interwiki prefix to the local wiki
2224                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2225                                                 if( $dbkey == '' ) {
2226                                                         # Can't have an empty self-link
2227                                                         return false;
2228                                                 }
2229                                                 $this->mInterwiki = '';
2230                                                 $firstPass = false;
2231                                                 # Do another namespace split...
2232                                                 continue;
2233                                         }
2234
2235                                         # If there's an initial colon after the interwiki, that also
2236                                         # resets the default namespace
2237                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2238                                                 $this->mNamespace = NS_MAIN;
2239                                                 $dbkey = substr( $dbkey, 1 );
2240                                         }
2241                                 }
2242                                 # If there's no recognized interwiki or namespace,
2243                                 # then let the colon expression be part of the title.
2244                         }
2245                         break;
2246                 } while( true );
2247
2248                 # We already know that some pages won't be in the database!
2249                 #
2250                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2251                         $this->mArticleID = 0;
2252                 }
2253                 $fragment = strstr( $dbkey, '#' );
2254                 if ( false !== $fragment ) {
2255                         $this->setFragment( $fragment );
2256                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2257                         # remove whitespace again: prevents "Foo_bar_#"
2258                         # becoming "Foo_bar_"
2259                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2260                 }
2261
2262                 # Reject illegal characters.
2263                 #
2264                 if( preg_match( $rxTc, $dbkey ) ) {
2265                         return false;
2266                 }
2267
2268                 /**
2269                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2270                  * reachable due to the way web browsers deal with 'relative' URLs.
2271                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2272                  */
2273                 if ( strpos( $dbkey, '.' ) !== false &&
2274                      ( $dbkey === '.' || $dbkey === '..' ||
2275                        strpos( $dbkey, './' ) === 0  ||
2276                        strpos( $dbkey, '../' ) === 0 ||
2277                        strpos( $dbkey, '/./' ) !== false ||
2278                        strpos( $dbkey, '/../' ) !== false  ||
2279                        substr( $dbkey, -2 ) == '/.' ||
2280                        substr( $dbkey, -3 ) == '/..' ) )
2281                 {
2282                         return false;
2283                 }
2284
2285                 /**
2286                  * Magic tilde sequences? Nu-uh!
2287                  */
2288                 if( strpos( $dbkey, '~~~' ) !== false ) {
2289                         return false;
2290                 }
2291
2292                 /**
2293                  * Limit the size of titles to 255 bytes.
2294                  * This is typically the size of the underlying database field.
2295                  * We make an exception for special pages, which don't need to be stored
2296                  * in the database, and may edge over 255 bytes due to subpage syntax
2297                  * for long titles, e.g. [[Special:Block/Long name]]
2298                  */
2299                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2300                   strlen( $dbkey ) > 512 )
2301                 {
2302                         return false;
2303                 }
2304
2305                 /**
2306                  * Normally, all wiki links are forced to have
2307                  * an initial capital letter so [[foo]] and [[Foo]]
2308                  * point to the same place.
2309                  *
2310                  * Don't force it for interwikis, since the other
2311                  * site might be case-sensitive.
2312                  */
2313                 $this->mUserCaseDBKey = $dbkey;
2314                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2315                         $dbkey = $wgContLang->ucfirst( $dbkey );
2316                 }
2317
2318                 /**
2319                  * Can't make a link to a namespace alone...
2320                  * "empty" local links can only be self-links
2321                  * with a fragment identifier.
2322                  */
2323                 if( $dbkey == '' &&
2324                         $this->mInterwiki == '' &&
2325                         $this->mNamespace != NS_MAIN ) {
2326                         return false;
2327                 }
2328                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2329                 // IP names are not allowed for accounts, and can only be referring to
2330                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2331                 // there are numerous ways to present the same IP. Having sp:contribs scan
2332                 // them all is silly and having some show the edits and others not is
2333                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2334                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2335                         IP::sanitizeIP( $dbkey ) : $dbkey;
2336                 // Any remaining initial :s are illegal.
2337                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2338                         return false;
2339                 }
2340
2341                 # Fill fields
2342                 $this->mDbkeyform = $dbkey;
2343                 $this->mUrlform = wfUrlencode( $dbkey );
2344
2345                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2346
2347                 return true;
2348         }
2349
2350         /**
2351          * Set the fragment for this title. Removes the first character from the
2352          * specified fragment before setting, so it assumes you're passing it with
2353          * an initial "#".
2354          *
2355          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2356          * Still in active use privately.
2357          *
2358          * @param $fragment \type{\string} text
2359          */
2360         public function setFragment( $fragment ) {
2361                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2362         }
2363
2364         /**
2365          * Get a Title object associated with the talk page of this article
2366          * @return \type{Title} the object for the talk page
2367          */
2368         public function getTalkPage() {
2369                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2370         }
2371
2372         /**
2373          * Get a title object associated with the subject page of this
2374          * talk page
2375          *
2376          * @return \type{Title} the object for the subject page
2377          */
2378         public function getSubjectPage() {
2379                 // Is this the same title?
2380                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2381                 if( $this->getNamespace() == $subjectNS ) {
2382                         return $this;
2383                 }
2384                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2385         }
2386
2387         /**
2388          * Get an array of Title objects linking to this Title
2389          * Also stores the IDs in the link cache.
2390          *
2391          * WARNING: do not use this function on arbitrary user-supplied titles!
2392          * On heavily-used templates it will max out the memory.
2393          *
2394          * @param array $options may be FOR UPDATE
2395          * @return \type{\arrayof{Title}} the Title objects linking here
2396          */
2397         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2398                 $linkCache = LinkCache::singleton();
2399
2400                 if ( count( $options ) > 0 ) {
2401                         $db = wfGetDB( DB_MASTER );
2402                 } else {
2403                         $db = wfGetDB( DB_SLAVE );
2404                 }
2405
2406                 $res = $db->select( array( 'page', $table ),
2407                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2408                         array(
2409                                 "{$prefix}_from=page_id",
2410                                 "{$prefix}_namespace" => $this->getNamespace(),
2411                                 "{$prefix}_title"     => $this->getDBkey() ),
2412                         __METHOD__,
2413                         $options );
2414
2415                 $retVal = array();
2416                 if ( $db->numRows( $res ) ) {
2417                         foreach( $res as $row ) {
2418                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2419                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2420                                         $retVal[] = $titleObj;
2421                                 }
2422                         }
2423                 }
2424                 $db->freeResult( $res );
2425                 return $retVal;
2426         }
2427
2428         /**
2429          * Get an array of Title objects using this Title as a template
2430          * Also stores the IDs in the link cache.
2431          *
2432          * WARNING: do not use this function on arbitrary user-supplied titles!
2433          * On heavily-used templates it will max out the memory.
2434          *
2435          * @param array $options may be FOR UPDATE
2436          * @return \type{\arrayof{Title}} the Title objects linking here
2437          */
2438         public function getTemplateLinksTo( $options = array() ) {
2439                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2440         }
2441
2442         /**
2443          * Get an array of Title objects referring to non-existent articles linked from this page
2444          *
2445          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2446          * @param array $options may be FOR UPDATE
2447          * @return \type{\arrayof{Title}} the Title objects
2448          */
2449         public function getBrokenLinksFrom( $options = array() ) {
2450                 if ( $this->getArticleId() == 0 ) {
2451                         # All links from article ID 0 are false positives
2452                         return array();
2453                 }
2454
2455                 if ( count( $options ) > 0 ) {
2456                         $db = wfGetDB( DB_MASTER );
2457                 } else {
2458                         $db = wfGetDB( DB_SLAVE );
2459                 }
2460
2461                 $res = $db->safeQuery(
2462                           "SELECT pl_namespace, pl_title
2463                              FROM !
2464                         LEFT JOIN !
2465                                ON pl_namespace=page_namespace
2466                               AND pl_title=page_title
2467                             WHERE pl_from=?
2468                               AND page_namespace IS NULL
2469                                   !",
2470                         $db->tableName( 'pagelinks' ),
2471                         $db->tableName( 'page' ),
2472                         $this->getArticleId(),
2473                         $options );
2474
2475                 $retVal = array();
2476                 if ( $db->numRows( $res ) ) {
2477                         foreach( $res as $row ) {
2478                                 $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2479                         }
2480                 }
2481                 $db->freeResult( $res );
2482                 return $retVal;
2483         }
2484
2485
2486         /**
2487          * Get a list of URLs to purge from the Squid cache when this
2488          * page changes
2489          *
2490          * @return \type{\arrayof{\string}} the URLs
2491          */
2492         public function getSquidURLs() {
2493                 global $wgContLang;
2494
2495                 $urls = array(
2496                         $this->getInternalURL(),
2497                         $this->getInternalURL( 'action=history' )
2498                 );
2499
2500                 // purge variant urls as well
2501                 if($wgContLang->hasVariants()){
2502                         $variants = $wgContLang->getVariants();
2503                         foreach($variants as $vCode){
2504                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2505                                 $urls[] = $this->getInternalURL('',$vCode);
2506                         }
2507                 }
2508
2509                 return $urls;
2510         }
2511
2512         /**
2513          * Purge all applicable Squid URLs
2514          */
2515         public function purgeSquid() {
2516                 global $wgUseSquid;
2517                 if ( $wgUseSquid ) {
2518                         $urls = $this->getSquidURLs();
2519                         $u = new SquidUpdate( $urls );
2520                         $u->doUpdate();
2521                 }
2522         }
2523
2524         /**
2525          * Move this page without authentication
2526          * @param &$nt \type{Title} the new page Title
2527          */
2528         public function moveNoAuth( &$nt ) {
2529                 return $this->moveTo( $nt, false );
2530         }
2531
2532         /**
2533          * Check whether a given move operation would be valid.
2534          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2535          * @param &$nt \type{Title} the new title
2536          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2537          *      should be checked
2538          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2539          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2540          */
2541         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2542                 global $wgUser;
2543
2544                 $errors = array();
2545                 if( !$nt ) {
2546                         // Normally we'd add this to $errors, but we'll get
2547                         // lots of syntax errors if $nt is not an object
2548                         return array(array('badtitletext'));
2549                 }
2550                 if( $this->equals( $nt ) ) {
2551                         $errors[] = array('selfmove');
2552                 }
2553                 if( !$this->isMovable() ) {
2554                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2555                 }
2556                 if ( $nt->getInterwiki() != '' ) {
2557                         $errors[] = array( 'immobile-target-namespace-iw' );
2558                 }
2559                 if ( !$nt->isMovable() ) {
2560                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2561                 }
2562
2563                 $oldid = $this->getArticleID();
2564                 $newid = $nt->getArticleID();
2565
2566                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2567                         $errors[] = array('articleexists');
2568                 }
2569                 if ( ( '' == $this->getDBkey() ) ||
2570                          ( !$oldid ) ||
2571                      ( '' == $nt->getDBkey() ) ) {
2572                         $errors[] = array('badarticleerror');
2573                 }
2574
2575                 // Image-specific checks
2576                 if( $this->getNamespace() == NS_FILE ) {
2577                         $file = wfLocalFile( $this );
2578                         if( $file->exists() ) {
2579                                 if( $nt->getNamespace() != NS_FILE ) {
2580                                         $errors[] = array('imagenocrossnamespace');
2581                                 }
2582                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2583                                         $errors[] = array('imageinvalidfilename');
2584                                 }
2585                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBKey() ) ) {
2586                                         $errors[] = array('imagetypemismatch');
2587                                 }
2588                         }
2589                 }
2590
2591                 if ( $auth ) {
2592                         $errors = wfMergeErrorArrays( $errors,
2593                                 $this->getUserPermissionsErrors('move', $wgUser),
2594                                 $this->getUserPermissionsErrors('edit', $wgUser),
2595                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2596                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2597                 }
2598
2599                 $match = EditPage::matchSpamRegex( $reason );
2600                 if( $match !== false ) {
2601                         // This is kind of lame, won't display nice
2602                         $errors[] = array('spamprotectiontext');
2603                 }
2604
2605                 $err = null;
2606                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2607                         $errors[] = array('hookaborted', $err);
2608                 }
2609
2610                 # The move is allowed only if (1) the target doesn't exist, or
2611                 # (2) the target is a redirect to the source, and has no history
2612                 # (so we can undo bad moves right after they're done).
2613
2614                 if ( 0 != $newid ) { # Target exists; check for validity
2615                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2616                                 $errors[] = array('articleexists');
2617                         }
2618                 } else {
2619                         $tp = $nt->getTitleProtection();
2620                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2621                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2622                                 $errors[] = array('cantmove-titleprotected');
2623                         }
2624                 }
2625                 if(empty($errors))
2626                         return true;
2627                 return $errors;
2628         }
2629
2630         /**
2631          * Move a title to a new location
2632          * @param &$nt \type{Title} the new title
2633          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2634          *      should be checked
2635          * @param $reason \type{\string} The reason for the move
2636          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2637          *  Ignored if the user doesn't have the suppressredirect right.
2638          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2639          */
2640         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2641                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2642                 if( is_array( $err ) ) {
2643                         return $err;
2644                 }
2645
2646                 $pageid = $this->getArticleID();
2647                 $protected = $this->isProtected();
2648                 if( $nt->exists() ) {
2649                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2650                         $pageCountChange = ($createRedirect ? 0 : -1);
2651                 } else { # Target didn't exist, do normal move.
2652                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2653                         $pageCountChange = ($createRedirect ? 1 : 0);
2654                 }
2655
2656                 if( is_array( $err ) ) {
2657                         return $err;
2658                 }
2659                 $redirid = $this->getArticleID();
2660
2661                 // Category memberships include a sort key which may be customized.
2662                 // If it's left as the default (the page title), we need to update
2663                 // the sort key to match the new title.
2664                 //
2665                 // Be careful to avoid resetting cl_timestamp, which may disturb
2666                 // time-based lists on some sites.
2667                 //
2668                 // Warning -- if the sort key is *explicitly* set to the old title,
2669                 // we can't actually distinguish it from a default here, and it'll
2670                 // be set to the new title even though it really shouldn't.
2671                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2672                 $dbw = wfGetDB( DB_MASTER );
2673                 $dbw->update( 'categorylinks',
2674                         array(
2675                                 'cl_sortkey' => $nt->getPrefixedText(),
2676                                 'cl_timestamp=cl_timestamp' ),
2677                         array(
2678                                 'cl_from' => $pageid,
2679                                 'cl_sortkey' => $this->getPrefixedText() ),
2680                         __METHOD__ );
2681
2682                 if( $protected ) {
2683                         # Protect the redirect title as the title used to be...
2684                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2685                                 array(
2686                                         'pr_page'    => $redirid,
2687                                         'pr_type'    => 'pr_type',
2688                                         'pr_level'   => 'pr_level',
2689                                         'pr_cascade' => 'pr_cascade',
2690                                         'pr_user'    => 'pr_user',
2691                                         'pr_expiry'  => 'pr_expiry'
2692                                 ),
2693                                 array( 'pr_page' => $pageid ),
2694                                 __METHOD__,
2695                                 array( 'IGNORE' )
2696                         );
2697                         # Update the protection log
2698                         $log = new LogPage( 'protect' );
2699                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2700                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2701                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2702                 }
2703
2704                 # Update watchlists
2705                 $oldnamespace = $this->getNamespace() & ~1;
2706                 $newnamespace = $nt->getNamespace() & ~1;
2707                 $oldtitle = $this->getDBkey();
2708                 $newtitle = $nt->getDBkey();
2709
2710                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2711                         WatchedItem::duplicateEntries( $this, $nt );
2712                 }
2713
2714                 # Update search engine
2715                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2716                 $u->doUpdate();
2717                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2718                 $u->doUpdate();
2719
2720                 # Update site_stats
2721                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2722                         # No longer a content page
2723                         # Not viewed, edited, removing
2724                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2725                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2726                         # Now a content page
2727                         # Not viewed, edited, adding
2728                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2729                 } elseif( $pageCountChange ) {
2730                         # Redirect added
2731                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2732                 } else {
2733                         # Nothing special
2734                         $u = false;
2735                 }
2736                 if( $u )
2737                         $u->doUpdate();
2738                 # Update message cache for interface messages
2739                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2740                         global $wgMessageCache;
2741                         $oldarticle = new Article( $this );
2742                         $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2743                         $newarticle = new Article( $nt );
2744                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2745                 }
2746
2747                 global $wgUser;
2748                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2749                 return true;
2750         }
2751
2752         /**
2753          * Move page to a title which is at present a redirect to the
2754          * source page
2755          *
2756          * @param &$nt \type{Title} the page to move to, which should currently
2757          *      be a redirect
2758          * @param $reason \type{\string} The reason for the move
2759          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2760          *  Ignored if the user doesn't have the suppressredirect right
2761          */
2762         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2763                 global $wgUseSquid, $wgUser;
2764                 $fname = 'Title::moveOverExistingRedirect';
2765                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2766
2767                 if ( $reason ) {
2768                         $comment .= ": $reason";
2769                 }
2770
2771                 $now = wfTimestampNow();
2772                 $newid = $nt->getArticleID();
2773                 $oldid = $this->getArticleID();
2774                 $latest = $this->getLatestRevID();
2775
2776                 $dbw = wfGetDB( DB_MASTER );
2777
2778                 # Delete the old redirect. We don't save it to history since
2779                 # by definition if we've got here it's rather uninteresting.
2780                 # We have to remove it so that the next step doesn't trigger
2781                 # a conflict on the unique namespace+title index...
2782                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2783                 if ( !$dbw->cascadingDeletes() ) {
2784                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2785                         global $wgUseTrackbacks;
2786                         if ($wgUseTrackbacks)
2787                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2788                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2789                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2790                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2791                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2792                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2793                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2794                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2795                 }
2796
2797                 # Save a null revision in the page's history notifying of the move
2798                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2799                 $nullRevId = $nullRevision->insertOn( $dbw );
2800
2801                 $article = new Article( $this );
2802                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2803
2804                 # Change the name of the target page:
2805                 $dbw->update( 'page',
2806                         /* SET */ array(
2807                                 'page_touched'   => $dbw->timestamp($now),
2808                                 'page_namespace' => $nt->getNamespace(),
2809                                 'page_title'     => $nt->getDBkey(),
2810                                 'page_latest'    => $nullRevId,
2811                         ),
2812                         /* WHERE */ array( 'page_id' => $oldid ),
2813                         $fname
2814                 );
2815                 $nt->resetArticleID( $oldid );
2816
2817                 # Recreate the redirect, this time in the other direction.
2818                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2819                         $mwRedir = MagicWord::get( 'redirect' );
2820                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2821                         $redirectArticle = new Article( $this );
2822                         $newid = $redirectArticle->insertOn( $dbw );
2823                         $redirectRevision = new Revision( array(
2824                                 'page'    => $newid,
2825                                 'comment' => $comment,
2826                                 'text'    => $redirectText ) );
2827                         $redirectRevision->insertOn( $dbw );
2828                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2829
2830                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2831
2832                         # Now, we record the link from the redirect to the new title.
2833                         # It should have no other outgoing links...
2834                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2835                         $dbw->insert( 'pagelinks',
2836                                 array(
2837                                         'pl_from'      => $newid,
2838                                         'pl_namespace' => $nt->getNamespace(),
2839                                         'pl_title'     => $nt->getDBkey() ),
2840                                 $fname );
2841                         $redirectSuppressed = false;
2842                 } else {
2843                         $this->resetArticleID( 0 );
2844                         $redirectSuppressed = true;
2845                 }
2846
2847                 # Move an image if this is a file
2848                 if( $this->getNamespace() == NS_FILE ) {
2849                         $file = wfLocalFile( $this );
2850                         if( $file->exists() ) {
2851                                 $status = $file->move( $nt );
2852                                 if( !$status->isOk() ) {
2853                                         $dbw->rollback();
2854                                         return $status->getErrorsArray();
2855                                 }
2856                         }
2857                 }
2858
2859                 # Log the move
2860                 $log = new LogPage( 'move' );
2861                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2862
2863                 # Purge squid
2864                 if ( $wgUseSquid ) {
2865                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2866                         $u = new SquidUpdate( $urls );
2867                         $u->doUpdate();
2868                 }
2869
2870         }
2871
2872         /**
2873          * Move page to non-existing title.
2874          * @param &$nt \type{Title} the new Title
2875          * @param $reason \type{\string} The reason for the move
2876          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2877          *  Ignored if the user doesn't have the suppressredirect right
2878          */
2879         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2880                 global $wgUseSquid, $wgUser;
2881                 $fname = 'MovePageForm::moveToNewTitle';
2882                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2883                 if ( $reason ) {
2884                         $comment .= wfMsgExt( 'colon-separator',
2885                                 array( 'escapenoentities', 'content' ) );
2886                         $comment .= $reason;
2887                 }
2888
2889                 $newid = $nt->getArticleID();
2890                 $oldid = $this->getArticleID();
2891                 $latest = $this->getLatestRevId();
2892
2893                 $dbw = wfGetDB( DB_MASTER );
2894                 $now = $dbw->timestamp();
2895
2896                 # Save a null revision in the page's history notifying of the move
2897                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2898                 $nullRevId = $nullRevision->insertOn( $dbw );
2899
2900                 $article = new Article( $this );
2901                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2902
2903                 # Rename page entry
2904                 $dbw->update( 'page',
2905                         /* SET */ array(
2906                                 'page_touched'   => $now,
2907                                 'page_namespace' => $nt->getNamespace(),
2908                                 'page_title'     => $nt->getDBkey(),
2909                                 'page_latest'    => $nullRevId,
2910                         ),
2911                         /* WHERE */ array( 'page_id' => $oldid ),
2912                         $fname
2913                 );
2914                 $nt->resetArticleID( $oldid );
2915
2916                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2917                         # Insert redirect
2918                         $mwRedir = MagicWord::get( 'redirect' );
2919                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2920                         $redirectArticle = new Article( $this );
2921                         $newid = $redirectArticle->insertOn( $dbw );
2922                         $redirectRevision = new Revision( array(
2923                                 'page'    => $newid,
2924                                 'comment' => $comment,
2925                                 'text'    => $redirectText ) );
2926                         $redirectRevision->insertOn( $dbw );
2927                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2928
2929                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2930
2931                         # Record the just-created redirect's linking to the page
2932                         $dbw->insert( 'pagelinks',
2933                                 array(
2934                                         'pl_from'      => $newid,
2935                                         'pl_namespace' => $nt->getNamespace(),
2936                                         'pl_title'     => $nt->getDBkey() ),
2937                                 $fname );
2938                         $redirectSuppressed = false;
2939                 } else {
2940                         $this->resetArticleID( 0 );
2941                         $redirectSuppressed = true;
2942                 }
2943
2944                 # Move an image if this is a file
2945                 if( $this->getNamespace() == NS_FILE ) {
2946                         $file = wfLocalFile( $this );
2947                         if( $file->exists() ) {
2948                                 $status = $file->move( $nt );
2949                                 if( !$status->isOk() ) {
2950                                         $dbw->rollback();
2951                                         return $status->getErrorsArray();
2952                                 }
2953                         }
2954                 }
2955
2956                 # Log the move
2957                 $log = new LogPage( 'move' );
2958                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2959
2960                 # Purge caches as per article creation
2961                 Article::onArticleCreate( $nt );
2962
2963                 # Purge old title from squid
2964                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2965                 $this->purgeSquid();
2966
2967         }
2968
2969         /**
2970          * Move this page's subpages to be subpages of $nt
2971          * @param $nt Title Move target
2972          * @param $auth bool Whether $wgUser's permissions should be checked
2973          * @param $reason string The reason for the move
2974          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2975          *  Ignored if the user doesn't have the 'suppressredirect' right
2976          * @return mixed array with old page titles as keys, and strings (new page titles) or
2977          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
2978          */
2979         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
2980                 global $wgUser, $wgMaximumMovedPages;
2981                 // Check permissions
2982                 if( !$this->userCan( 'move-subpages' ) )
2983                         return array( 'cant-move-subpages' );
2984                 // Do the source and target namespaces support subpages?
2985                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
2986                         return array( 'namespace-nosubpages',
2987                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
2988                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
2989                         return array( 'namespace-nosubpages',
2990                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
2991
2992                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
2993                 $retval = array();
2994                 $count = 0;
2995                 foreach( $subpages as $oldSubpage ) {
2996                         $count++;
2997                         if( $count > $wgMaximumMovedPages ) {
2998                                 $retval[$oldSubpage->getPrefixedTitle()] =
2999                                                 array( 'movepage-max-pages',
3000                                                         $wgMaximumMovedPages );
3001                                 break;
3002                         }
3003
3004                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
3005                                 // When moving a page to a subpage of itself,
3006                                 // don't move it twice
3007                                 continue;
3008                         $newPageName = preg_replace(
3009                                         '#^'.preg_quote( $this->getDBKey(), '#' ).'#',
3010                                         $nt->getDBKey(), $oldSubpage->getDBKey() );
3011                         if( $oldSubpage->isTalkPage() ) {
3012                                 $newNs = $nt->getTalkPage()->getNamespace();
3013                         } else {
3014                                 $newNs = $nt->getSubjectPage()->getNamespace();
3015                         }
3016                         # Bug 14385: we need makeTitleSafe because the new page names may
3017                         # be longer than 255 characters.
3018                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3019
3020                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3021                         if( $success === true ) {
3022                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3023                         } else {
3024                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3025                         }
3026                 }
3027                 return $retval;
3028         }
3029
3030         /**
3031          * Checks if this page is just a one-rev redirect.
3032          * Adds lock, so don't use just for light purposes.
3033          *
3034          * @return \type{\bool} TRUE or FALSE
3035          */
3036         public function isSingleRevRedirect() {
3037                 $dbw = wfGetDB( DB_MASTER );
3038                 # Is it a redirect?
3039                 $row = $dbw->selectRow( 'page',
3040                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3041                         $this->pageCond(),
3042                         __METHOD__,
3043                         array( 'FOR UPDATE' )
3044                 );
3045                 # Cache some fields we may want
3046                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3047                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3048                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3049                 if( !$this->mRedirect ) {
3050                         return false;
3051                 }
3052                 # Does the article have a history?
3053                 $row = $dbw->selectField( array( 'page', 'revision'),
3054                         'rev_id',
3055                         array( 'page_namespace' => $this->getNamespace(),
3056                                 'page_title' => $this->getDBkey(),
3057                                 'page_id=rev_page',
3058                                 'page_latest != rev_id'
3059                         ),
3060                         __METHOD__,
3061                         array( 'FOR UPDATE' )
3062                 );
3063                 # Return true if there was no history
3064                 return ($row === false);
3065         }
3066
3067         /**
3068          * Checks if $this can be moved to a given Title
3069          * - Selects for update, so don't call it unless you mean business
3070          *
3071          * @param &$nt \type{Title} the new title to check
3072          * @return \type{\bool} TRUE or FALSE
3073          */
3074         public function isValidMoveTarget( $nt ) {
3075                 $dbw = wfGetDB( DB_MASTER );
3076                 # Is it an existsing file?
3077                 if( $nt->getNamespace() == NS_FILE ) {
3078                         $file = wfLocalFile( $nt );
3079                         if( $file->exists() ) {
3080                                 wfDebug( __METHOD__ . ": file exists\n" );
3081                                 return false;
3082                         }
3083                 }
3084                 # Is it a redirect with no history?
3085                 if( !$nt->isSingleRevRedirect() ) {
3086                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3087                         return false;
3088                 }
3089                 # Get the article text
3090                 $rev = Revision::newFromTitle( $nt );
3091                 $text = $rev->getText();
3092                 # Does the redirect point to the source?
3093                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3094                 $m = array();
3095                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3096                         $redirTitle = Title::newFromText( $m[1] );
3097                         if( !is_object( $redirTitle ) ||
3098                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3099                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3100                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3101                                 return false;
3102                         }
3103                 } else {
3104                         # Fail safe
3105                         wfDebug( __METHOD__ . ": failsafe\n" );
3106                         return false;
3107                 }
3108                 return true;
3109         }
3110
3111         /**
3112          * Can this title be added to a user's watchlist?
3113          *
3114          * @return \type{\bool} TRUE or FALSE
3115          */
3116         public function isWatchable() {
3117                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3118         }
3119
3120         /**
3121          * Get categories to which this Title belongs and return an array of
3122          * categories' names.
3123          *
3124          * @return \type{\array} array an array of parents in the form:
3125          *      $parent => $currentarticle
3126          */
3127         public function getParentCategories() {
3128                 global $wgContLang;
3129
3130                 $titlekey = $this->getArticleId();
3131                 $dbr = wfGetDB( DB_SLAVE );
3132                 $categorylinks = $dbr->tableName( 'categorylinks' );
3133
3134                 # NEW SQL
3135                 $sql = "SELECT * FROM $categorylinks"
3136                      ." WHERE cl_from='$titlekey'"
3137                          ." AND cl_from <> '0'"
3138                          ." ORDER BY cl_sortkey";
3139
3140                 $res = $dbr->query( $sql );
3141
3142                 if( $dbr->numRows( $res ) > 0 ) {
3143                         foreach( $res as $row )
3144                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3145                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3146                         $dbr->freeResult( $res );
3147                 } else {
3148                         $data = array();
3149                 }
3150                 return $data;
3151         }
3152
3153         /**
3154          * Get a tree of parent categories
3155          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3156          * @return \type{\array} Tree of parent categories
3157          */
3158         public function getParentCategoryTree( $children = array() ) {
3159                 $stack = array();
3160                 $parents = $this->getParentCategories();
3161
3162                 if( $parents ) {
3163                         foreach( $parents as $parent => $current ) {
3164                                 if ( array_key_exists( $parent, $children ) ) {
3165                                         # Circular reference
3166                                         $stack[$parent] = array();
3167                                 } else {
3168                                         $nt = Title::newFromText($parent);
3169                                         if ( $nt ) {
3170                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3171                                         }
3172                                 }
3173                         }
3174                         return $stack;
3175                 } else {
3176                         return array();
3177                 }
3178         }
3179
3180
3181         /**
3182          * Get an associative array for selecting this title from
3183          * the "page" table
3184          *
3185          * @return \type{\array} Selection array
3186          */
3187         public function pageCond() {
3188                 if( $this->mArticleID > 0 ) {
3189                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3190                         return array( 'page_id' => $this->mArticleID );
3191                 } else {
3192                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3193                 }
3194         }
3195
3196         /**
3197          * Get the revision ID of the previous revision
3198          *
3199          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3200          * @param $flags \type{\int} GAID_FOR_UPDATE
3201          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3202          */
3203         public function getPreviousRevisionID( $revId, $flags=0 ) {
3204                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3205                 return $db->selectField( 'revision', 'rev_id',
3206                         array(
3207                                 'rev_page' => $this->getArticleId($flags),
3208                                 'rev_id < ' . intval( $revId )
3209                         ),
3210                         __METHOD__,
3211                         array( 'ORDER BY' => 'rev_id DESC' )
3212                 );
3213         }
3214
3215         /**
3216          * Get the revision ID of the next revision
3217          *
3218          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3219          * @param $flags \type{\int} GAID_FOR_UPDATE
3220          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3221          */
3222         public function getNextRevisionID( $revId, $flags=0 ) {
3223                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3224                 return $db->selectField( 'revision', 'rev_id',
3225                         array(
3226                                 'rev_page' => $this->getArticleId($flags),
3227                                 'rev_id > ' . intval( $revId )
3228                         ),
3229                         __METHOD__,
3230                         array( 'ORDER BY' => 'rev_id' )
3231                 );
3232         }
3233
3234         /**
3235          * Get the first revision of the page
3236          *
3237          * @param $flags \type{\int} GAID_FOR_UPDATE
3238          * @return Revision (or NULL if page doesn't exist)
3239          */
3240         public function getFirstRevision( $flags=0 ) {
3241                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3242                 $pageId = $this->getArticleId($flags);
3243                 if( !$pageId ) return NULL;
3244                 $row = $db->selectRow( 'revision', '*',
3245                         array( 'rev_page' => $pageId ),
3246                         __METHOD__,
3247                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3248                 );
3249                 if( !$row ) {
3250                         return NULL;
3251                 } else {
3252                         return new Revision( $row );
3253                 }
3254         }
3255
3256         /**
3257          * Check if this is a new page
3258          *
3259          * @return bool
3260          */
3261         public function isNewPage() {
3262                 $dbr = wfGetDB( DB_SLAVE );
3263                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3264         }
3265
3266         /**
3267          * Get the oldest revision timestamp of this page
3268          *
3269          * @return string, MW timestamp
3270          */
3271         public function getEarliestRevTime() {
3272                 $dbr = wfGetDB( DB_SLAVE );
3273                 if( $this->exists() ) {
3274                         $min = $dbr->selectField( 'revision',
3275                                 'MIN(rev_timestamp)',
3276                                 array( 'rev_page' => $this->getArticleId() ),
3277                                 __METHOD__ );
3278                         return wfTimestampOrNull( TS_MW, $min );
3279                 }
3280                 return null;
3281         }
3282
3283         /**
3284          * Get the number of revisions between the given revision IDs.
3285          * Used for diffs and other things that really need it.
3286          *
3287          * @param $old \type{\int} Revision ID.
3288          * @param $new \type{\int} Revision ID.
3289          * @return \type{\int} Number of revisions between these IDs.
3290          */
3291         public function countRevisionsBetween( $old, $new ) {
3292                 $dbr = wfGetDB( DB_SLAVE );
3293                 return $dbr->selectField( 'revision', 'count(*)',
3294                         'rev_page = ' . intval( $this->getArticleId() ) .
3295                         ' AND rev_id > ' . intval( $old ) .
3296                         ' AND rev_id < ' . intval( $new ),
3297                         __METHOD__,
3298                         array( 'USE INDEX' => 'PRIMARY' ) );
3299         }
3300
3301         /**
3302          * Compare with another title.
3303          *
3304          * @param \type{Title} $title
3305          * @return \type{\bool} TRUE or FALSE
3306          */
3307         public function equals( Title $title ) {
3308                 // Note: === is necessary for proper matching of number-like titles.
3309                 return $this->getInterwiki() === $title->getInterwiki()
3310                         && $this->getNamespace() == $title->getNamespace()
3311                         && $this->getDBkey() === $title->getDBkey();
3312         }
3313
3314         /**
3315          * Callback for usort() to do title sorts by (namespace, title)
3316          */
3317         static function compare( $a, $b ) {
3318                 if( $a->getNamespace() == $b->getNamespace() ) {
3319                         return strcmp( $a->getText(), $b->getText() );
3320                 } else {
3321                         return $a->getNamespace() - $b->getNamespace();
3322                 }
3323         }
3324
3325         /**
3326          * Return a string representation of this title
3327          *
3328          * @return \type{\string} String representation of this title
3329          */
3330         public function __toString() {
3331                 return $this->getPrefixedText();
3332         }
3333
3334         /**
3335          * Check if page exists.  For historical reasons, this function simply
3336          * checks for the existence of the title in the page table, and will
3337          * thus return false for interwiki links, special pages and the like.
3338          * If you want to know if a title can be meaningfully viewed, you should
3339          * probably call the isKnown() method instead.
3340          *
3341          * @return \type{\bool} TRUE or FALSE
3342          */
3343         public function exists() {
3344                 return $this->getArticleId() != 0;
3345         }
3346
3347         /**
3348          * Should links to this title be shown as potentially viewable (i.e. as
3349          * "bluelinks"), even if there's no record by this title in the page
3350          * table?
3351          *
3352          * This function is semi-deprecated for public use, as well as somewhat
3353          * misleadingly named.  You probably just want to call isKnown(), which
3354          * calls this function internally.
3355          *
3356          * (ISSUE: Most of these checks are cheap, but the file existence check
3357          * can potentially be quite expensive.  Including it here fixes a lot of
3358          * existing code, but we might want to add an optional parameter to skip
3359          * it and any other expensive checks.)
3360          *
3361          * @return \type{\bool} TRUE or FALSE
3362          */
3363         public function isAlwaysKnown() {
3364                 if( $this->mInterwiki != '' ) {
3365                         return true;  // any interwiki link might be viewable, for all we know
3366                 }
3367                 switch( $this->mNamespace ) {
3368                 case NS_MEDIA:
3369                 case NS_FILE:
3370                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3371                 case NS_SPECIAL:
3372                         return SpecialPage::exists( $this->getDBKey() );  // valid special page
3373                 case NS_MAIN:
3374                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3375                 case NS_MEDIAWIKI:
3376                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3377                         // the full l10n of that language to be loaded. That takes much memory and
3378                         // isn't needed. So we strip the language part away.
3379                         // Also, extension messages which are not loaded, are shown as red, because
3380                         // we don't call MessageCache::loadAllMessages.
3381                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3382                         return wfMsgWeirdKey( $basename );  // known system message
3383                 default:
3384                         return false;
3385                 }
3386         }
3387
3388         /**
3389          * Does this title refer to a page that can (or might) be meaningfully
3390          * viewed?  In particular, this function may be used to determine if
3391          * links to the title should be rendered as "bluelinks" (as opposed to
3392          * "redlinks" to non-existent pages).
3393          *
3394          * @return \type{\bool} TRUE or FALSE
3395          */
3396         public function isKnown() {
3397                 return $this->exists() || $this->isAlwaysKnown();
3398         }
3399
3400         /**
3401         * Is this in a namespace that allows actual pages?
3402         *
3403         * @return \type{\bool} TRUE or FALSE
3404         */
3405         public function canExist() {
3406                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3407         }
3408
3409         /**
3410          * Update page_touched timestamps and send squid purge messages for
3411          * pages linking to this title. May be sent to the job queue depending
3412          * on the number of links. Typically called on create and delete.
3413          */
3414         public function touchLinks() {
3415                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3416                 $u->doUpdate();
3417
3418                 if ( $this->getNamespace() == NS_CATEGORY ) {
3419                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3420                         $u->doUpdate();
3421                 }
3422         }
3423
3424         /**
3425          * Get the last touched timestamp
3426          * @param Database $db, optional db
3427          * @return \type{\string} Last touched timestamp
3428          */
3429         public function getTouched( $db = NULL ) {
3430                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3431                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3432                 return $touched;
3433         }
3434
3435         /**
3436          * Get the timestamp when this page was updated since the user last saw it.
3437          * @param User $user
3438          * @return mixed string/NULL
3439          */
3440         public function getNotificationTimestamp( $user = NULL ) {
3441                 global $wgUser, $wgShowUpdatedMarker;
3442                 // Assume current user if none given
3443                 if( !$user ) $user = $wgUser;
3444                 // Check cache first
3445                 $uid = $user->getId();
3446                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3447                         return $this->mNotificationTimestamp[$uid];
3448                 }
3449                 if( !$uid || !$wgShowUpdatedMarker ) {
3450                         return $this->mNotificationTimestamp[$uid] = false;
3451                 }
3452                 // Don't cache too much!
3453                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3454                         $this->mNotificationTimestamp = array();
3455                 }
3456                 $dbr = wfGetDB( DB_SLAVE );
3457                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3458                         'wl_notificationtimestamp',
3459                         array( 'wl_namespace' => $this->getNamespace(),
3460                                 'wl_title' => $this->getDBkey(),
3461                                 'wl_user' => $user->getId()
3462                         ),
3463                         __METHOD__
3464                 );
3465                 return $this->mNotificationTimestamp[$uid];
3466         }
3467
3468         /**
3469          * Get the trackback URL for this page
3470          * @return \type{\string} Trackback URL
3471          */
3472         public function trackbackURL() {
3473                 global $wgScriptPath, $wgServer;
3474
3475                 return "$wgServer$wgScriptPath/trackback.php?article="
3476                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3477         }
3478
3479         /**
3480          * Get the trackback RDF for this page
3481          * @return \type{\string} Trackback RDF
3482          */
3483         public function trackbackRDF() {
3484                 $url = htmlspecialchars($this->getFullURL());
3485                 $title = htmlspecialchars($this->getText());
3486                 $tburl = $this->trackbackURL();
3487
3488                 // Autodiscovery RDF is placed in comments so HTML validator
3489                 // won't barf. This is a rather icky workaround, but seems
3490                 // frequently used by this kind of RDF thingy.
3491                 //
3492                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3493                 return "<!--
3494 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3495          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3496          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3497 <rdf:Description
3498    rdf:about=\"$url\"
3499    dc:identifier=\"$url\"
3500    dc:title=\"$title\"
3501    trackback:ping=\"$tburl\" />
3502 </rdf:RDF>
3503 -->";
3504         }
3505
3506         /**
3507          * Generate strings used for xml 'id' names in monobook tabs
3508          * @return \type{\string} XML 'id' name
3509          */
3510         public function getNamespaceKey() {
3511                 global $wgContLang;
3512                 switch ($this->getNamespace()) {
3513                         case NS_MAIN:
3514                         case NS_TALK:
3515                                 return 'nstab-main';
3516                         case NS_USER:
3517                         case NS_USER_TALK:
3518                                 return 'nstab-user';
3519                         case NS_MEDIA:
3520                                 return 'nstab-media';
3521                         case NS_SPECIAL:
3522                                 return 'nstab-special';
3523                         case NS_PROJECT:
3524                         case NS_PROJECT_TALK:
3525                                 return 'nstab-project';
3526                         case NS_FILE:
3527                         case NS_FILE_TALK:
3528                                 return 'nstab-image';
3529                         case NS_MEDIAWIKI:
3530                         case NS_MEDIAWIKI_TALK:
3531                                 return 'nstab-mediawiki';
3532                         case NS_TEMPLATE:
3533                         case NS_TEMPLATE_TALK:
3534                                 return 'nstab-template';
3535                         case NS_HELP:
3536                         case NS_HELP_TALK:
3537                                 return 'nstab-help';
3538                         case NS_CATEGORY:
3539                         case NS_CATEGORY_TALK:
3540                                 return 'nstab-category';
3541                         default:
3542                                 return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
3543                 }
3544         }
3545
3546         /**
3547          * Returns true if this title resolves to the named special page
3548          * @param $name \type{\string} The special page name
3549          */
3550         public function isSpecial( $name ) {
3551                 if ( $this->getNamespace() == NS_SPECIAL ) {
3552                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3553                         if ( $name == $thisName ) {
3554                                 return true;
3555                         }
3556                 }
3557                 return false;
3558         }
3559
3560         /**
3561          * If the Title refers to a special page alias which is not the local default,
3562          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3563          */
3564         public function fixSpecialName() {
3565                 if ( $this->getNamespace() == NS_SPECIAL ) {
3566                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3567                         if ( $canonicalName ) {
3568                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3569                                 if ( $localName != $this->mDbkeyform ) {
3570                                         return Title::makeTitle( NS_SPECIAL, $localName );
3571                                 }
3572                         }
3573                 }
3574                 return $this;
3575         }
3576
3577         /**
3578          * Is this Title in a namespace which contains content?
3579          * In other words, is this a content page, for the purposes of calculating
3580          * statistics, etc?
3581          *
3582          * @return \type{\bool} TRUE or FALSE
3583          */
3584         public function isContentPage() {
3585                 return MWNamespace::isContent( $this->getNamespace() );
3586         }
3587
3588         /**
3589          * Get all extant redirects to this Title
3590          *
3591          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3592          *            NULL to consider all namespaces
3593          * @return \type{\arrayof{Title}} Redirects to this title
3594          */
3595         public function getRedirectsHere( $ns = null ) {
3596                 $redirs = array();
3597
3598                 $dbr = wfGetDB( DB_SLAVE );
3599                 $where = array(
3600                         'rd_namespace' => $this->getNamespace(),
3601                         'rd_title' => $this->getDBkey(),
3602                         'rd_from = page_id'
3603                 );
3604                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3605
3606                 $res = $dbr->select(
3607                         array( 'redirect', 'page' ),
3608                         array( 'page_namespace', 'page_title' ),
3609                         $where,
3610                         __METHOD__
3611                 );
3612
3613
3614                 foreach( $res as $row ) {
3615                         $redirs[] = self::newFromRow( $row );
3616                 }
3617                 return $redirs;
3618         }
3619
3620         /**
3621          * Check if this Title is a valid redirect target
3622          *
3623          * @return \type{\bool} TRUE or FALSE
3624          */
3625         public function isValidRedirectTarget() {
3626                 global $wgInvalidRedirectTargets;
3627
3628                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3629                 if( $this->isSpecial( 'Userlogout' ) ) {
3630                         return false;
3631                 }
3632
3633                 foreach( $wgInvalidRedirectTargets as $target ) {
3634                         if( $this->isSpecial( $target ) ) {
3635                                 return false;
3636                         }
3637                 }
3638
3639                 return true;
3640         }
3641
3642         /**
3643          * Get a backlink cache object
3644          */
3645         function getBacklinkCache() {
3646                 if ( is_null( $this->mBacklinkCache ) ) {
3647                         $this->mBacklinkCache = new BacklinkCache( $this );
3648                 }
3649                 return $this->mBacklinkCache;
3650         }
3651 }