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          * @param $id \type{\int} the page_id corresponding to the Title to create
 183          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 184          * @return \type{Title} the new object, or NULL on an error
 185          */
 186         public static function newFromID( $id, $flags = 0 ) {
 187                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 188                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 189                 if( $row !== false ) {
 190                         $title = Title::newFromRow( $row );
 191                 } else {
 192                         $title = NULL;
 193                 }
 194                 return $title;
 195         }
 196
 197         /**
 198          * Make an array of titles from an array of IDs
 199          * @param $ids \type{\arrayof{\int}} Array of IDs
 200          * @return \type{\arrayof{Title}} Array of Titles
 201          */
 202         public static function newFromIDs( $ids ) {
 203                 if ( !count( $ids ) ) {
 204                         return array();
 205                 }
 206                 $dbr = wfGetDB( DB_SLAVE );
 207                 $res = $dbr->select( 'page', array( 'page_namespace', 'page_title' ),
 208                         'page_id IN (' . $dbr->makeList( $ids ) . ')', __METHOD__ );
 209
 210                 $titles = array();
 211                 foreach( $res as $row ) {
 212                         $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
 213                 }
 214                 return $titles;
 215         }
 216
 217         /**
 218          * Make a Title object from a DB row
 219          * @param $row \type{Row} (needs at least page_title,page_namespace)
 220          * @return \type{Title} corresponding Title
 221          */
 222         public static function newFromRow( $row ) {
 223                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 224
 225                 $t->mArticleID = isset($row->page_id) ? intval($row->page_id) : -1;
 226                 $t->mLength = isset($row->page_len) ? intval($row->page_len) : -1;
 227                 $t->mRedirect = isset($row->page_is_redirect) ? (bool)$row->page_is_redirect : NULL;
 228                 $t->mLatestID = isset($row->page_latest) ? $row->page_latest : false;
 229
 230                 return $t;
 231         }
 232
 233         /**
 234          * Create a new Title from a namespace index and a DB key.
 235          * It's assumed that $ns and $title are *valid*, for instance when
 236          * they came directly from the database or a special page name.
 237          * For convenience, spaces are converted to underscores so that
 238          * eg user_text fields can be used directly.
 239          *
 240          * @param $ns \type{\int} the namespace of the article
 241          * @param $title \type{\string} the unprefixed database key form
 242          * @param $fragment \type{\string} The link fragment (after the "#")
 243          * @return \type{Title} the new object
 244          */
 245         public static function &makeTitle( $ns, $title, $fragment = '' ) {
 246                 $t = new Title();
 247                 $t->mInterwiki = '';
 248                 $t->mFragment = $fragment;
 249                 $t->mNamespace = $ns = intval( $ns );
 250                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 251                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 252                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 253                 $t->mTextform = str_replace( '_', ' ', $title );
 254                 return $t;
 255         }
 256
 257         /**
 258          * Create a new Title from a namespace index and a DB key.
 259          * The parameters will be checked for validity, which is a bit slower
 260          * than makeTitle() but safer for user-provided data.
 261          *
 262          * @param $ns \type{\int} the namespace of the article
 263          * @param $title \type{\string} the database key form
 264          * @param $fragment \type{\string} The link fragment (after the "#")
 265          * @return \type{Title} the new object, or NULL on an error
 266          */
 267         public static function makeTitleSafe( $ns, $title, $fragment = '' ) {
 268                 $t = new Title();
 269                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment );
 270                 if( $t->secureAndSplit() ) {
 271                         return $t;
 272                 } else {
 273                         return NULL;
 274                 }
 275         }
 276
 277         /**
 278          * Create a new Title for the Main Page
 279          * @return \type{Title} the new object
 280          */
 281         public static function newMainPage() {
 282                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 283                 // Don't give fatal errors if the message is broken
 284                 if ( !$title ) {
 285                         $title = Title::newFromText( 'Main Page' );
 286                 }
 287                 return $title;
 288         }
 289
 290         /**
 291          * Extract a redirect destination from a string and return the
 292          * Title, or null if the text doesn't contain a valid redirect
 293          * This will only return the very next target, useful for
 294          * the redirect table and other checks that don't need full recursion
 295          *
 296          * @param $text \type{\string} Text with possible redirect
 297          * @return \type{Title} The corresponding Title
 298          */
 299         public static function newFromRedirect( $text ) {
 300                 return self::newFromRedirectInternal( $text );
 301         }
 302
 303         /**
 304          * Extract a redirect destination from a string and return the
 305          * Title, or null if the text doesn't contain a valid redirect
 306          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 307          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 308          *
 309          * @param $text \type{\string} Text with possible redirect
 310          * @return \type{Title} The corresponding Title
 311          */
 312         public static function newFromRedirectRecurse( $text ) {
 313                 $titles = self::newFromRedirectArray( $text );
 314                 return $titles ? array_pop( $titles ) : null;
 315         }
 316
 317         /**
 318          * Extract a redirect destination from a string and return an
 319          * array of Titles, or null if the text doesn't contain a valid redirect
 320          * The last element in the array is the final destination after all redirects
 321          * have been resolved (up to $wgMaxRedirects times)
 322          *
 323          * @param $text \type{\string} Text with possible redirect
 324          * @return \type{\array} Array of Titles, with the destination last
 325          */
 326         public static function newFromRedirectArray( $text ) {
 327                 global $wgMaxRedirects;
 328                 // are redirects disabled?
 329                 if( $wgMaxRedirects < 1 )
 330                         return null;
 331                 $title = self::newFromRedirectInternal( $text );
 332                 if( is_null( $title ) )
 333                         return null;
 334                 // recursive check to follow double redirects
 335                 $recurse = $wgMaxRedirects;
 336                 $titles = array( $title );
 337                 while( --$recurse > 0 ) {
 338                         if( $title->isRedirect() ) {
 339                                 $article = new Article( $title, 0 );
 340                                 $newtitle = $article->getRedirectTarget();
 341                         } else {
 342                                 break;
 343                         }
 344                         // Redirects to some special pages are not permitted
 345                         if( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 346                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 347                                 $title = $newtitle;
 348                                 $titles[] = $newtitle;
 349                         } else {
 350                                 break;
 351                         }
 352                 }
 353                 return $titles;
 354         }
 355
 356         /**
 357          * Really extract the redirect destination
 358          * Do not call this function directly, use one of the newFromRedirect* functions above
 359          *
 360          * @param $text \type{\string} Text with possible redirect
 361          * @return \type{Title} The corresponding Title
 362          */
 363         protected static function newFromRedirectInternal( $text ) {
 364                 $redir = MagicWord::get( 'redirect' );
 365                 $text = trim($text);
 366                 if( $redir->matchStartAndRemove( $text ) ) {
 367                         // Extract the first link and see if it's usable
 368                         // Ensure that it really does come directly after #REDIRECT
 369                         // Some older redirects included a colon, so don't freak about that!
 370                         $m = array();
 371                         if( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 372                                 // Strip preceding colon used to "escape" categories, etc.
 373                                 // and URL-decode links
 374                                 if( strpos( $m[1], '%' ) !== false ) {
 375                                         // Match behavior of inline link parsing here;
 376                                         // don't interpret + as " " most of the time!
 377                                         // It might be safe to just use rawurldecode instead, though.
 378                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 379                                 }
 380                                 $title = Title::newFromText( $m[1] );
 381                                 // If the title is a redirect to bad special pages or is invalid, return null
 382                                 if( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 383                                         return null;
 384                                 }
 385                                 return $title;
 386                         }
 387                 }
 388                 return null;
 389         }
 390
 391 #----------------------------------------------------------------------------
 392 #       Static functions
 393 #----------------------------------------------------------------------------
 394
 395         /**
 396          * Get the prefixed DB key associated with an ID
 397          * @param $id \type{\int} the page_id of the article
 398          * @return \type{Title} an object representing the article, or NULL
 399          *      if no such article was found
 400          */
 401         public static function nameOf( $id ) {
 402                 $dbr = wfGetDB( DB_SLAVE );
 403
 404                 $s = $dbr->selectRow( 'page',
 405                         array( 'page_namespace','page_title' ),
 406                         array( 'page_id' => $id ),
 407                         __METHOD__ );
 408                 if ( $s === false ) { return NULL; }
 409
 410                 $n = self::makeName( $s->page_namespace, $s->page_title );
 411                 return $n;
 412         }
 413
 414         /**
 415          * Get a regex character class describing the legal characters in a link
 416          * @return \type{\string} the list of characters, not delimited
 417          */
 418         public static function legalChars() {
 419                 global $wgLegalTitleChars;
 420                 return $wgLegalTitleChars;
 421         }
 422
 423         /**
 424          * Get a string representation of a title suitable for
 425          * including in a search index
 426          *
 427          * @param $ns \type{\int} a namespace index
 428          * @param $title \type{\string} text-form main part
 429          * @return \type{\string} a stripped-down title string ready for the
 430          *      search index
 431          */
 432         public static function indexTitle( $ns, $title ) {
 433                 global $wgContLang;
 434
 435                 $lc = SearchEngine::legalSearchChars() . '&#;';
 436                 $t = $wgContLang->stripForSearch( $title );
 437                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 438                 $t = $wgContLang->lc( $t );
 439
 440                 # Handle 's, s'
 441                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 442                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 443
 444                 $t = preg_replace( "/\\s+/", ' ', $t );
 445
 446                 if ( $ns == NS_FILE ) {
 447                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 448                 }
 449                 return trim( $t );
 450         }
 451
 452         /*
 453          * Make a prefixed DB key from a DB key and a namespace index
 454          * @param $ns \type{\int} numerical representation of the namespace
 455          * @param $title \type{\string} the DB key form the title
 456          * @param $fragment \type{\string} The link fragment (after the "#")
 457          * @return \type{\string} the prefixed form of the title
 458          */
 459         public static function makeName( $ns, $title, $fragment = '' ) {
 460                 global $wgContLang;
 461
 462                 $namespace = $wgContLang->getNsText( $ns );
 463                 $name = $namespace == '' ? $title : "$namespace:$title";
 464                 if ( strval( $fragment ) != '' ) {
 465                         $name .= '#' . $fragment;
 466                 }
 467                 return $name;
 468         }
 469
 470         /**
 471          * Returns the URL associated with an interwiki prefix
 472          * @param $key \type{\string} the interwiki prefix (e.g. "MeatBall")
 473          * @return \type{\string} the associated URL, containing "$1",
 474          *      which should be replaced by an article title
 475          * @static (arguably)
 476          * @deprecated See Interwiki class
 477          */
 478         public function getInterwikiLink( $key )  {
 479                 return Interwiki::fetch( $key )->getURL( );
 480         }
 481
 482         /**
 483          * Determine whether the object refers to a page within
 484          * this project.
 485          *
 486          * @return \type{\bool} TRUE if this is an in-project interwiki link
 487          *      or a wikilink, FALSE otherwise
 488          */
 489         public function isLocal() {
 490                 if ( $this->mInterwiki != '' ) {
 491                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 492                 } else {
 493                         return true;
 494                 }
 495         }
 496
 497         /**
 498          * Determine whether the object refers to a page within
 499          * this project and is transcludable.
 500          *
 501          * @return \type{\bool} TRUE if this is transcludable
 502          */
 503         public function isTrans() {
 504                 if ($this->mInterwiki == '')
 505                         return false;
 506
 507                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 508         }
 509
 510         /**
 511          * Escape a text fragment, say from a link, for a URL
 512          */
 513         static function escapeFragmentForURL( $fragment ) {
 514                 global $wgEnforceHtmlIds;
 515                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 516                 # fragments appear not to work in IE (at least up to 7) or in at least
 517                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 518                 # to care if they aren't encoded.
 519                 return Sanitizer::escapeId( $fragment,
 520                         $wgEnforceHtmlIds ? 'noninitial' : 'xml' );
 521         }
 522
 523 #----------------------------------------------------------------------------
 524 #       Other stuff
 525 #----------------------------------------------------------------------------
 526
 527         /** Simple accessors */
 528         /**
 529          * Get the text form (spaces not underscores) of the main part
 530          * @return \type{\string} Main part of the title
 531          */
 532         public function getText() { return $this->mTextform; }
 533         /**
 534          * Get the URL-encoded form of the main part
 535          * @return \type{\string} Main part of the title, URL-encoded
 536          */
 537         public function getPartialURL() { return $this->mUrlform; }
 538         /**
 539          * Get the main part with underscores
 540          * @return \type{\string} Main part of the title, with underscores
 541          */
 542         public function getDBkey() { return $this->mDbkeyform; }
 543         /**
 544          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 545          * @return \type{\int} Namespace index
 546          */
 547         public function getNamespace() { return $this->mNamespace; }
 548         /**
 549          * Get the namespace text
 550          * @return \type{\string} Namespace text
 551          */
 552         public function getNsText() {
 553                 global $wgContLang, $wgCanonicalNamespaceNames;
 554
 555                 if ( '' != $this->mInterwiki ) {
 556                         // This probably shouldn't even happen. ohh man, oh yuck.
 557                         // But for interwiki transclusion it sometimes does.
 558                         // Shit. Shit shit shit.
 559                         //
 560                         // Use the canonical namespaces if possible to try to
 561                         // resolve a foreign namespace.
 562                         if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
 563                                 return $wgCanonicalNamespaceNames[$this->mNamespace];
 564                         }
 565                 }
 566                 return $wgContLang->getNsText( $this->mNamespace );
 567         }
 568         /**
 569          * Get the DB key with the initial letter case as specified by the user
 570          * @return \type{\string} DB key
 571          */
 572         function getUserCaseDBKey() {
 573                 return $this->mUserCaseDBKey;
 574         }
 575         /**
 576          * Get the namespace text of the subject (rather than talk) page
 577          * @return \type{\string} Namespace text
 578          */
 579         public function getSubjectNsText() {
 580                 global $wgContLang;
 581                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 582         }
 583         /**
 584          * Get the namespace text of the talk page
 585          * @return \type{\string} Namespace text
 586          */
 587         public function getTalkNsText() {
 588                 global $wgContLang;
 589                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 590         }
 591         /**
 592          * Could this title have a corresponding talk page?
 593          * @return \type{\bool} TRUE or FALSE
 594          */
 595         public function canTalk() {
 596                 return( MWNamespace::canTalk( $this->mNamespace ) );
 597         }
 598         /**
 599          * Get the interwiki prefix (or null string)
 600          * @return \type{\string} Interwiki prefix
 601          */
 602         public function getInterwiki() { return $this->mInterwiki; }
 603         /**
 604          * Get the Title fragment (i.e.\ the bit after the #) in text form
 605          * @return \type{\string} Title fragment
 606          */
 607         public function getFragment() { return $this->mFragment; }
 608         /**
 609          * Get the fragment in URL form, including the "#" character if there is one
 610          * @return \type{\string} Fragment in URL form
 611          */
 612         public function getFragmentForURL() {
 613                 if ( $this->mFragment == '' ) {
 614                         return '';
 615                 } else {
 616                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 617                 }
 618         }
 619         /**
 620          * Get the default namespace index, for when there is no namespace
 621          * @return \type{\int} Default namespace index
 622          */
 623         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 624
 625         /**
 626          * Get title for search index
 627          * @return \type{\string} a stripped-down title string ready for the
 628          *      search index
 629          */
 630         public function getIndexTitle() {
 631                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 632         }
 633
 634         /**
 635          * Get the prefixed database key form
 636          * @return \type{\string} the prefixed title, with underscores and
 637          *      any interwiki and namespace prefixes
 638          */
 639         public function getPrefixedDBkey() {
 640                 $s = $this->prefix( $this->mDbkeyform );
 641                 $s = str_replace( ' ', '_', $s );
 642                 return $s;
 643         }
 644
 645         /**
 646          * Get the prefixed title with spaces.
 647          * This is the form usually used for display
 648          * @return \type{\string} the prefixed title, with spaces
 649          */
 650         public function getPrefixedText() {
 651                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 652                         $s = $this->prefix( $this->mTextform );
 653                         $s = str_replace( '_', ' ', $s );
 654                         $this->mPrefixedText = $s;
 655                 }
 656                 return $this->mPrefixedText;
 657         }
 658
 659         /**
 660          * Get the prefixed title with spaces, plus any fragment
 661          * (part beginning with '#')
 662          * @return \type{\string} the prefixed title, with spaces and
 663          *      the fragment, including '#'
 664          */
 665         public function getFullText() {
 666                 $text = $this->getPrefixedText();
 667                 if( '' != $this->mFragment ) {
 668                         $text .= '#' . $this->mFragment;
 669                 }
 670                 return $text;
 671         }
 672
 673         /**
 674          * Get the base name, i.e. the leftmost parts before the /
 675          * @return \type{\string} Base name
 676          */
 677         public function getBaseText() {
 678                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 679                         return $this->getText();
 680                 }
 681
 682                 $parts = explode( '/', $this->getText() );
 683                 # Don't discard the real title if there's no subpage involved
 684                 if( count( $parts ) > 1 )
 685                         unset( $parts[ count( $parts ) - 1 ] );
 686                 return implode( '/', $parts );
 687         }
 688
 689         /**
 690          * Get the lowest-level subpage name, i.e. the rightmost part after /
 691          * @return \type{\string} Subpage name
 692          */
 693         public function getSubpageText() {
 694                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 695                         return( $this->mTextform );
 696                 }
 697                 $parts = explode( '/', $this->mTextform );
 698                 return( $parts[ count( $parts ) - 1 ] );
 699         }
 700
 701         /**
 702          * Get a URL-encoded form of the subpage text
 703          * @return \type{\string} URL-encoded subpage name
 704          */
 705         public function getSubpageUrlForm() {
 706                 $text = $this->getSubpageText();
 707                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 708                 return( $text );
 709         }
 710
 711         /**
 712          * Get a URL-encoded title (not an actual URL) including interwiki
 713          * @return \type{\string} the URL-encoded form
 714          */
 715         public function getPrefixedURL() {
 716                 $s = $this->prefix( $this->mDbkeyform );
 717                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 718                 return $s;
 719         }
 720
 721         /**
 722          * Get a real URL referring to this title, with interwiki link and
 723          * fragment
 724          *
 725          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 726          *   links. Can be specified as an associative array as well, e.g.,
 727          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 728          * @param $variant \type{\string} language variant of url (for sr, zh..)
 729          * @return \type{\string} the URL
 730          */
 731         public function getFullURL( $query = '', $variant = false ) {
 732                 global $wgContLang, $wgServer, $wgRequest;
 733
 734                 if( is_array( $query ) ) {
 735                         $query = wfArrayToCGI( $query );
 736                 }
 737
 738                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 739                 if ( !$interwiki ) {
 740                         $url = $this->getLocalUrl( $query, $variant );
 741
 742                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 743                         // Correct fix would be to move the prepending elsewhere.
 744                         if ($wgRequest->getVal('action') != 'render') {
 745                                 $url = $wgServer . $url;
 746                         }
 747                 } else {
 748                         $baseUrl = $interwiki->getURL( );
 749
 750                         $namespace = wfUrlencode( $this->getNsText() );
 751                         if ( '' != $namespace ) {
 752                                 # Can this actually happen? Interwikis shouldn't be parsed.
 753                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 754                                 $namespace .= ':';
 755                         }
 756                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 757                         $url = wfAppendQuery( $url, $query );
 758                 }
 759
 760                 # Finally, add the fragment.
 761                 $url .= $this->getFragmentForURL();
 762
 763                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 764                 return $url;
 765         }
 766
 767         /**
 768          * Get a URL with no fragment or server name.  If this page is generated
 769          * with action=render, $wgServer is prepended.
 770          * @param mixed $query an optional query string; if not specified,
 771          *       $wgArticlePath will be used.  Can be specified as an associative array
 772          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 773          *   URL-escaped).
 774          * @param $variant \type{\string} language variant of url (for sr, zh..)
 775          * @return \type{\string} the URL
 776          */
 777         public function getLocalURL( $query = '', $variant = false ) {
 778                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 779                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 780
 781                 if( is_array( $query ) ) {
 782                         $query = wfArrayToCGI( $query );
 783                 }
 784
 785                 // internal links should point to same variant as current page (only anonymous users)
 786                 if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
 787                         $pref = $wgContLang->getPreferredVariant(false);
 788                         if($pref != $wgContLang->getCode())
 789                                 $variant = $pref;
 790                 }
 791
 792                 if ( $this->isExternal() ) {
 793                         $url = $this->getFullURL();
 794                         if ( $query ) {
 795                                 // This is currently only used for edit section links in the
 796                                 // context of interwiki transclusion. In theory we should
 797                                 // append the query to the end of any existing query string,
 798                                 // but interwiki transclusion is already broken in that case.
 799                                 $url .= "?$query";
 800                         }
 801                 } else {
 802                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 803                         if ( $query == '' ) {
 804                                 if( $variant != false && $wgContLang->hasVariants() ) {
 805                                         if( $wgVariantArticlePath == false ) {
 806                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 807                                         } else {
 808                                                 $variantArticlePath = $wgVariantArticlePath;
 809                                         }
 810                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 811                                         $url = str_replace( '$1', $dbkey, $url  );
 812                                 } else {
 813                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 814                                 }
 815                         } else {
 816                                 global $wgActionPaths;
 817                                 $url = false;
 818                                 $matches = array();
 819                                 if( !empty( $wgActionPaths ) &&
 820                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 821                                 {
 822                                         $action = urldecode( $matches[2] );
 823                                         if( isset( $wgActionPaths[$action] ) ) {
 824                                                 $query = $matches[1];
 825                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 826                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 827                                                 if( $query != '' ) {
 828                                                         $url = wfAppendQuery( $url, $query );
 829                                                 }
 830                                         }
 831                                 }
 832                                 if ( $url === false ) {
 833                                         if ( $query == '-' ) {
 834                                                 $query = '';
 835                                         }
 836                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 837                                 }
 838                         }
 839
 840                         // FIXME: this causes breakage in various places when we
 841                         // actually expected a local URL and end up with dupe prefixes.
 842                         if ($wgRequest->getVal('action') == 'render') {
 843                                 $url = $wgServer . $url;
 844                         }
 845                 }
 846                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 847                 return $url;
 848         }
 849
 850         /**
 851          * Get a URL that's the simplest URL that will be valid to link, locally,
 852          * to the current Title.  It includes the fragment, but does not include
 853          * the server unless action=render is used (or the link is external).  If
 854          * there's a fragment but the prefixed text is empty, we just return a link
 855          * to the fragment.
 856          *
 857          * The result obviously should not be URL-escaped, but does need to be
 858          * HTML-escaped if it's being output in HTML.
 859          *
 860          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 861          *   query string.  Keys and values will be escaped.
 862          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 863          *   for external links.  Default is "false" (same variant as current page,
 864          *   for anonymous users).
 865          * @return \type{\string} the URL
 866          */
 867         public function getLinkUrl( $query = array(), $variant = false ) {
 868                 wfProfileIn( __METHOD__ );
 869                 if( !is_array( $query ) ) {
 870                         wfProfileOut( __METHOD__ );
 871                         throw new MWException( 'Title::getLinkUrl passed a non-array for '.
 872                         '$query' );
 873                 }
 874                 if( $this->isExternal() ) {
 875                         $ret = $this->getFullURL( $query );
 876                 } elseif( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 877                         $ret = $this->getFragmentForURL();
 878                 } else {
 879                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 880                 }
 881                 wfProfileOut( __METHOD__ );
 882                 return $ret;
 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          * Would anybody with sufficient privileges be able to move this page?
1468          * Some pages just aren't movable.
1469          *
1470          * @return \type{\bool} TRUE or FALSE
1471          */
1472         public function isMovable() {
1473                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1474         }
1475
1476         /**
1477          * Can $wgUser read this page?
1478          * @return \type{\bool} TRUE or FALSE
1479          * @todo fold these checks into userCan()
1480          */
1481         public function userCanRead() {
1482                 global $wgUser, $wgGroupPermissions;
1483
1484                 $result = null;
1485                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1486                 if ( $result !== null ) {
1487                         return $result;
1488                 }
1489
1490                 # Shortcut for public wikis, allows skipping quite a bit of code
1491                 if ( !empty( $wgGroupPermissions['*']['read'] ) )
1492                         return true;
1493
1494                 if( $wgUser->isAllowed( 'read' ) ) {
1495                         return true;
1496                 } else {
1497                         global $wgWhitelistRead;
1498
1499                         /**
1500                          * Always grant access to the login page.
1501                          * Even anons need to be able to log in.
1502                         */
1503                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1504                                 return true;
1505                         }
1506
1507                         /**
1508                          * Bail out if there isn't whitelist
1509                          */
1510                         if( !is_array($wgWhitelistRead) ) {
1511                                 return false;
1512                         }
1513
1514                         /**
1515                          * Check for explicit whitelisting
1516                          */
1517                         $name = $this->getPrefixedText();
1518                         $dbName = $this->getPrefixedDBKey();
1519                         // Check with and without underscores
1520                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1521                                 return true;
1522
1523                         /**
1524                          * Old settings might have the title prefixed with
1525                          * a colon for main-namespace pages
1526                          */
1527                         if( $this->getNamespace() == NS_MAIN ) {
1528                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1529                                         return true;
1530                         }
1531
1532                         /**
1533                          * If it's a special page, ditch the subpage bit
1534                          * and check again
1535                          */
1536                         if( $this->getNamespace() == NS_SPECIAL ) {
1537                                 $name = $this->getDBkey();
1538                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1539                                 if ( $name === false ) {
1540                                         # Invalid special page, but we show standard login required message
1541                                         return false;
1542                                 }
1543
1544                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1545                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1546                                         return true;
1547                         }
1548
1549                 }
1550                 return false;
1551         }
1552
1553         /**
1554          * Is this a talk page of some sort?
1555          * @return \type{\bool} TRUE or FALSE
1556          */
1557         public function isTalkPage() {
1558                 return MWNamespace::isTalk( $this->getNamespace() );
1559         }
1560
1561         /**
1562          * Is this a subpage?
1563          * @return \type{\bool} TRUE or FALSE
1564          */
1565         public function isSubpage() {
1566                 return MWNamespace::hasSubpages( $this->mNamespace )
1567                         ? strpos( $this->getText(), '/' ) !== false
1568                         : false;
1569         }
1570
1571         /**
1572          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1573          * @return \type{\bool} TRUE or FALSE
1574          */
1575         public function hasSubpages() {
1576                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1577                         # Duh
1578                         return false;
1579                 }
1580
1581                 # We dynamically add a member variable for the purpose of this method
1582                 # alone to cache the result.  There's no point in having it hanging
1583                 # around uninitialized in every Title object; therefore we only add it
1584                 # if needed and don't declare it statically.
1585                 if( isset( $this->mHasSubpages ) ) {
1586                         return $this->mHasSubpages;
1587                 }
1588
1589                 $subpages = $this->getSubpages( 1 );
1590                 if( $subpages instanceof TitleArray )
1591                         return $this->mHasSubpages = (bool)$subpages->count();
1592                 return $this->mHasSubpages = false;
1593         }
1594
1595         /**
1596          * Get all subpages of this page.
1597          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1598          * @return mixed TitleArray, or empty array if this page's namespace
1599          *  doesn't allow subpages
1600          */
1601         public function getSubpages( $limit = -1 ) {
1602                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1603                         return array();
1604
1605                 $dbr = wfGetDB( DB_SLAVE );
1606                 $conds['page_namespace'] = $this->getNamespace();
1607                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1608                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1609                 $options = array();
1610                 if( $limit > -1 )
1611                         $options['LIMIT'] = $limit;
1612                 return $this->mSubpages = TitleArray::newFromResult(
1613                         $dbr->select( 'page',
1614                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1615                                 $conds,
1616                                 __METHOD__,
1617                                 $options
1618                         )
1619                 );
1620         }
1621
1622         /**
1623          * Could this page contain custom CSS or JavaScript, based
1624          * on the title?
1625          *
1626          * @return \type{\bool} TRUE or FALSE
1627          */
1628         public function isCssOrJsPage() {
1629                 return $this->mNamespace == NS_MEDIAWIKI
1630                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1631         }
1632
1633         /**
1634          * Is this a .css or .js subpage of a user page?
1635          * @return \type{\bool} TRUE or FALSE
1636          */
1637         public function isCssJsSubpage() {
1638                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1639         }
1640         /**
1641          * Is this a *valid* .css or .js subpage of a user page?
1642          * Check that the corresponding skin exists
1643          * @return \type{\bool} TRUE or FALSE
1644          */
1645         public function isValidCssJsSubpage() {
1646                 if ( $this->isCssJsSubpage() ) {
1647                         $skinNames = Skin::getSkinNames();
1648                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1649                 } else {
1650                         return false;
1651                 }
1652         }
1653         /**
1654          * Trim down a .css or .js subpage title to get the corresponding skin name
1655          */
1656         public function getSkinFromCssJsSubpage() {
1657                 $subpage = explode( '/', $this->mTextform );
1658                 $subpage = $subpage[ count( $subpage ) - 1 ];
1659                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1660         }
1661         /**
1662          * Is this a .css subpage of a user page?
1663          * @return \type{\bool} TRUE or FALSE
1664          */
1665         public function isCssSubpage() {
1666                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1667         }
1668         /**
1669          * Is this a .js subpage of a user page?
1670          * @return \type{\bool} TRUE or FALSE
1671          */
1672         public function isJsSubpage() {
1673                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1674         }
1675         /**
1676          * Protect css/js subpages of user pages: can $wgUser edit
1677          * this page?
1678          *
1679          * @return \type{\bool} TRUE or FALSE
1680          * @todo XXX: this might be better using restrictions
1681          */
1682         public function userCanEditCssJsSubpage() {
1683                 global $wgUser;
1684                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1685         }
1686
1687         /**
1688          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1689          *
1690          * @return \type{\bool} If the page is subject to cascading restrictions.
1691          */
1692         public function isCascadeProtected() {
1693                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1694                 return ( $sources > 0 );
1695         }
1696
1697         /**
1698          * Cascading protection: Get the source of any cascading restrictions on this page.
1699          *
1700          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1701          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1702          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1703          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1704          */
1705         public function getCascadeProtectionSources( $get_pages = true ) {
1706                 global $wgRestrictionTypes;
1707
1708                 # Define our dimension of restrictions types
1709                 $pagerestrictions = array();
1710                 foreach( $wgRestrictionTypes as $action )
1711                         $pagerestrictions[$action] = array();
1712
1713                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1714                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1715                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1716                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1717                 }
1718
1719                 wfProfileIn( __METHOD__ );
1720
1721                 $dbr = wfGetDB( DB_SLAVE );
1722
1723                 if ( $this->getNamespace() == NS_FILE ) {
1724                         $tables = array ('imagelinks', 'page_restrictions');
1725                         $where_clauses = array(
1726                                 'il_to' => $this->getDBkey(),
1727                                 'il_from=pr_page',
1728                                 'pr_cascade' => 1 );
1729                 } else {
1730                         $tables = array ('templatelinks', 'page_restrictions');
1731                         $where_clauses = array(
1732                                 'tl_namespace' => $this->getNamespace(),
1733                                 'tl_title' => $this->getDBkey(),
1734                                 'tl_from=pr_page',
1735                                 'pr_cascade' => 1 );
1736                 }
1737
1738                 if ( $get_pages ) {
1739                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1740                         $where_clauses[] = 'page_id=pr_page';
1741                         $tables[] = 'page';
1742                 } else {
1743                         $cols = array( 'pr_expiry' );
1744                 }
1745
1746                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1747
1748                 $sources = $get_pages ? array() : false;
1749                 $now = wfTimestampNow();
1750                 $purgeExpired = false;
1751
1752                 foreach( $res as $row ) {
1753                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1754                         if( $expiry > $now ) {
1755                                 if ($get_pages) {
1756                                         $page_id = $row->pr_page;
1757                                         $page_ns = $row->page_namespace;
1758                                         $page_title = $row->page_title;
1759                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1760                                         # Add groups needed for each restriction type if its not already there
1761                                         # Make sure this restriction type still exists
1762                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1763                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1764                                         }
1765                                 } else {
1766                                         $sources = true;
1767                                 }
1768                         } else {
1769                                 // Trigger lazy purge of expired restrictions from the db
1770                                 $purgeExpired = true;
1771                         }
1772                 }
1773                 if( $purgeExpired ) {
1774                         Title::purgeExpiredRestrictions();
1775                 }
1776
1777                 wfProfileOut( __METHOD__ );
1778
1779                 if ( $get_pages ) {
1780                         $this->mCascadeSources = $sources;
1781                         $this->mCascadingRestrictions = $pagerestrictions;
1782                 } else {
1783                         $this->mHasCascadingRestrictions = $sources;
1784                 }
1785                 return array( $sources, $pagerestrictions );
1786         }
1787
1788         function areRestrictionsCascading() {
1789                 if (!$this->mRestrictionsLoaded) {
1790                         $this->loadRestrictions();
1791                 }
1792
1793                 return $this->mCascadeRestriction;
1794         }
1795
1796         /**
1797          * Loads a string into mRestrictions array
1798          * @param $res \type{Resource} restrictions as an SQL result.
1799          */
1800         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1801                 global $wgRestrictionTypes;
1802                 $dbr = wfGetDB( DB_SLAVE );
1803
1804                 foreach( $wgRestrictionTypes as $type ){
1805                         $this->mRestrictions[$type] = array();
1806                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1807                 }
1808
1809                 $this->mCascadeRestriction = false;
1810
1811                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1812
1813                 if ( $oldFashionedRestrictions === NULL ) {
1814                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1815                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1816                 }
1817
1818                 if ($oldFashionedRestrictions != '') {
1819
1820                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1821                                 $temp = explode( '=', trim( $restrict ) );
1822                                 if(count($temp) == 1) {
1823                                         // old old format should be treated as edit/move restriction
1824                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1825                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1826                                 } else {
1827                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1828                                 }
1829                         }
1830
1831                         $this->mOldRestrictions = true;
1832
1833                 }
1834
1835                 if( $dbr->numRows( $res ) ) {
1836                         # Current system - load second to make them override.
1837                         $now = wfTimestampNow();
1838                         $purgeExpired = false;
1839
1840                         foreach( $res as $row ) {
1841                                 # Cycle through all the restrictions.
1842
1843                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1844                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1845                                         continue;
1846
1847                                 // This code should be refactored, now that it's being used more generally,
1848                                 // But I don't really see any harm in leaving it in Block for now -werdna
1849                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1850
1851                                 // Only apply the restrictions if they haven't expired!
1852                                 if ( !$expiry || $expiry > $now ) {
1853                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1854                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1855
1856                                         $this->mCascadeRestriction |= $row->pr_cascade;
1857                                 } else {
1858                                         // Trigger a lazy purge of expired restrictions
1859                                         $purgeExpired = true;
1860                                 }
1861                         }
1862
1863                         if( $purgeExpired ) {
1864                                 Title::purgeExpiredRestrictions();
1865                         }
1866                 }
1867
1868                 $this->mRestrictionsLoaded = true;
1869         }
1870
1871         /**
1872          * Load restrictions from the page_restrictions table
1873          */
1874         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1875                 if( !$this->mRestrictionsLoaded ) {
1876                         if ($this->exists()) {
1877                                 $dbr = wfGetDB( DB_SLAVE );
1878
1879                                 $res = $dbr->select( 'page_restrictions', '*',
1880                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1881
1882                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1883                         } else {
1884                                 $title_protection = $this->getTitleProtection();
1885
1886                                 if (is_array($title_protection)) {
1887                                         extract($title_protection);
1888
1889                                         $now = wfTimestampNow();
1890                                         $expiry = Block::decodeExpiry($pt_expiry);
1891
1892                                         if (!$expiry || $expiry > $now) {
1893                                                 // Apply the restrictions
1894                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1895                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1896                                         } else { // Get rid of the old restrictions
1897                                                 Title::purgeExpiredRestrictions();
1898                                         }
1899                                 } else {
1900                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1901                                 }
1902                                 $this->mRestrictionsLoaded = true;
1903                         }
1904                 }
1905         }
1906
1907         /**
1908          * Purge expired restrictions from the page_restrictions table
1909          */
1910         static function purgeExpiredRestrictions() {
1911                 $dbw = wfGetDB( DB_MASTER );
1912                 $dbw->delete( 'page_restrictions',
1913                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1914                         __METHOD__ );
1915
1916                 $dbw->delete( 'protected_titles',
1917                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1918                         __METHOD__ );
1919         }
1920
1921         /**
1922          * Accessor/initialisation for mRestrictions
1923          *
1924          * @param $action \type{\string} action that permission needs to be checked for
1925          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1926          */
1927         public function getRestrictions( $action ) {
1928                 if( !$this->mRestrictionsLoaded ) {
1929                         $this->loadRestrictions();
1930                 }
1931                 return isset( $this->mRestrictions[$action] )
1932                                 ? $this->mRestrictions[$action]
1933                                 : array();
1934         }
1935
1936         /**
1937          * Get the expiry time for the restriction against a given action
1938          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1939          * or not protected at all, or false if the action is not recognised.
1940          */
1941         public function getRestrictionExpiry( $action ) {
1942                 if( !$this->mRestrictionsLoaded ) {
1943                         $this->loadRestrictions();
1944                 }
1945                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1946         }
1947
1948         /**
1949          * Is there a version of this page in the deletion archive?
1950          * @return \type{\int} the number of archived revisions
1951          */
1952         public function isDeleted() {
1953                 if( $this->getNamespace() < 0 ) {
1954                         $n = 0;
1955                 } else {
1956                         $dbr = wfGetDB( DB_SLAVE );
1957                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
1958                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1959                                 __METHOD__
1960                         );
1961                         if( $this->getNamespace() == NS_FILE ) {
1962                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1963                                         array( 'fa_name' => $this->getDBkey() ),
1964                                         __METHOD__
1965                                 );
1966                         }
1967                 }
1968                 return (int)$n;
1969         }
1970
1971         /**
1972          * Is there a version of this page in the deletion archive?
1973          * @return bool
1974          */
1975         public function isDeletedQuick() {
1976                 if( $this->getNamespace() < 0 ) {
1977                         return false;
1978                 }
1979                 $dbr = wfGetDB( DB_SLAVE );
1980                 $deleted = (bool)$dbr->selectField( 'archive', '1',
1981                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1982                         __METHOD__
1983                 );
1984                 if( !$deleted && $this->getNamespace() == NS_FILE ) {
1985                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
1986                                 array( 'fa_name' => $this->getDBkey() ),
1987                                 __METHOD__
1988                         );
1989                 }
1990                 return $deleted;
1991         }
1992
1993         /**
1994          * Get the article ID for this Title from the link cache,
1995          * adding it if necessary
1996          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
1997          *      for update
1998          * @return \type{\int} the ID
1999          */
2000         public function getArticleID( $flags = 0 ) {
2001                 if( $this->getNamespace() < 0 ) {
2002                         return $this->mArticleID = 0;
2003                 }
2004                 $linkCache = LinkCache::singleton();
2005                 if( $flags & GAID_FOR_UPDATE ) {
2006                         $oldUpdate = $linkCache->forUpdate( true );
2007                         $linkCache->clearLink( $this );
2008                         $this->mArticleID = $linkCache->addLinkObj( $this );
2009                         $linkCache->forUpdate( $oldUpdate );
2010                 } else {
2011                         if( -1 == $this->mArticleID ) {
2012                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2013                         }
2014                 }
2015                 return $this->mArticleID;
2016         }
2017
2018         /**
2019          * Is this an article that is a redirect page?
2020          * Uses link cache, adding it if necessary
2021          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2022          * @return \type{\bool}
2023          */
2024         public function isRedirect( $flags = 0 ) {
2025                 if( !is_null($this->mRedirect) )
2026                         return $this->mRedirect;
2027                 # Calling getArticleID() loads the field from cache as needed
2028                 if( !$this->getArticleID($flags) ) {
2029                         return $this->mRedirect = false;
2030                 }
2031                 $linkCache = LinkCache::singleton();
2032                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2033
2034                 return $this->mRedirect;
2035         }
2036
2037         /**
2038          * What is the length of this page?
2039          * Uses link cache, adding it if necessary
2040          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2041          * @return \type{\bool}
2042          */
2043         public function getLength( $flags = 0 ) {
2044                 if( $this->mLength != -1 )
2045                         return $this->mLength;
2046                 # Calling getArticleID() loads the field from cache as needed
2047                 if( !$this->getArticleID($flags) ) {
2048                         return $this->mLength = 0;
2049                 }
2050                 $linkCache = LinkCache::singleton();
2051                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2052
2053                 return $this->mLength;
2054         }
2055
2056         /**
2057          * What is the page_latest field for this page?
2058          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2059          * @return \type{\int}
2060          */
2061         public function getLatestRevID( $flags = 0 ) {
2062                 if( $this->mLatestID !== false )
2063                         return $this->mLatestID;
2064
2065                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2066                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2067                 return $this->mLatestID;
2068         }
2069
2070         /**
2071          * This clears some fields in this object, and clears any associated
2072          * keys in the "bad links" section of the link cache.
2073          *
2074          * - This is called from Article::insertNewArticle() to allow
2075          * loading of the new page_id. It's also called from
2076          * Article::doDeleteArticle()
2077          *
2078          * @param $newid \type{\int} the new Article ID
2079          */
2080         public function resetArticleID( $newid ) {
2081                 $linkCache = LinkCache::singleton();
2082                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2083
2084                 if ( $newid === false ) { $this->mArticleID = -1; }
2085                 else { $this->mArticleID = $newid; }
2086                 $this->mRestrictionsLoaded = false;
2087                 $this->mRestrictions = array();
2088         }
2089
2090         /**
2091          * Updates page_touched for this page; called from LinksUpdate.php
2092          * @return \type{\bool} true if the update succeded
2093          */
2094         public function invalidateCache() {
2095                 if( wfReadOnly() ) {
2096                         return;
2097                 }
2098                 $dbw = wfGetDB( DB_MASTER );
2099                 $success = $dbw->update( 'page',
2100                         array( 'page_touched' => $dbw->timestamp() ),
2101                         $this->pageCond(),
2102                         __METHOD__
2103                 );
2104                 HTMLFileCache::clearFileCache( $this );
2105                 return $success;
2106         }
2107
2108         /**
2109          * Prefix some arbitrary text with the namespace or interwiki prefix
2110          * of this object
2111          *
2112          * @param $name \type{\string} the text
2113          * @return \type{\string} the prefixed text
2114          * @private
2115          */
2116         /* private */ function prefix( $name ) {
2117                 $p = '';
2118                 if ( '' != $this->mInterwiki ) {
2119                         $p = $this->mInterwiki . ':';
2120                 }
2121                 if ( 0 != $this->mNamespace ) {
2122                         $p .= $this->getNsText() . ':';
2123                 }
2124                 return $p . $name;
2125         }
2126
2127         /**
2128          * Secure and split - main initialisation function for this object
2129          *
2130          * Assumes that mDbkeyform has been set, and is urldecoded
2131          * and uses underscores, but not otherwise munged.  This function
2132          * removes illegal characters, splits off the interwiki and
2133          * namespace prefixes, sets the other forms, and canonicalizes
2134          * everything.
2135          * @return \type{\bool} true on success
2136          */
2137         private function secureAndSplit() {
2138                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2139
2140                 # Initialisation
2141                 static $rxTc = false;
2142                 if( !$rxTc ) {
2143                         # Matching titles will be held as illegal.
2144                         $rxTc = '/' .
2145                                 # Any character not allowed is forbidden...
2146                                 '[^' . Title::legalChars() . ']' .
2147                                 # URL percent encoding sequences interfere with the ability
2148                                 # to round-trip titles -- you can't link to them consistently.
2149                                 '|%[0-9A-Fa-f]{2}' .
2150                                 # XML/HTML character references produce similar issues.
2151                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2152                                 '|&#[0-9]+;' .
2153                                 '|&#x[0-9A-Fa-f]+;' .
2154                                 '/S';
2155                 }
2156
2157                 $this->mInterwiki = $this->mFragment = '';
2158                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2159
2160                 $dbkey = $this->mDbkeyform;
2161
2162                 # Strip Unicode bidi override characters.
2163                 # Sometimes they slip into cut-n-pasted page titles, where the
2164                 # override chars get included in list displays.
2165                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2166
2167                 # Clean up whitespace
2168                 #
2169                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2170                 $dbkey = trim( $dbkey, '_' );
2171
2172                 if ( '' == $dbkey ) {
2173                         return false;
2174                 }
2175
2176                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2177                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2178                         return false;
2179                 }
2180
2181                 $this->mDbkeyform = $dbkey;
2182
2183                 # Initial colon indicates main namespace rather than specified default
2184                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2185                 if ( ':' == $dbkey{0} ) {
2186                         $this->mNamespace = NS_MAIN;
2187                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2188                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2189                 }
2190
2191                 # Namespace or interwiki prefix
2192                 $firstPass = true;
2193                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2194                 do {
2195                         $m = array();
2196                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2197                                 $p = $m[1];
2198                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2199                                         # Ordinary namespace
2200                                         $dbkey = $m[2];
2201                                         $this->mNamespace = $ns;
2202                                         # For Talk:X pages, check if X has a "namespace" prefix
2203                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2204                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2205                                                         return false; # Disallow Talk:File:x type titles...
2206                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2207                                                         return false; # Disallow Talk:Interwiki:x type titles...
2208                                         }
2209                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2210                                         if( !$firstPass ) {
2211                                                 # Can't make a local interwiki link to an interwiki link.
2212                                                 # That's just crazy!
2213                                                 return false;
2214                                         }
2215
2216                                         # Interwiki link
2217                                         $dbkey = $m[2];
2218                                         $this->mInterwiki = $wgContLang->lc( $p );
2219
2220                                         # Redundant interwiki prefix to the local wiki
2221                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2222                                                 if( $dbkey == '' ) {
2223                                                         # Can't have an empty self-link
2224                                                         return false;
2225                                                 }
2226                                                 $this->mInterwiki = '';
2227                                                 $firstPass = false;
2228                                                 # Do another namespace split...
2229                                                 continue;
2230                                         }
2231
2232                                         # If there's an initial colon after the interwiki, that also
2233                                         # resets the default namespace
2234                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2235                                                 $this->mNamespace = NS_MAIN;
2236                                                 $dbkey = substr( $dbkey, 1 );
2237                                         }
2238                                 }
2239                                 # If there's no recognized interwiki or namespace,
2240                                 # then let the colon expression be part of the title.
2241                         }
2242                         break;
2243                 } while( true );
2244
2245                 # We already know that some pages won't be in the database!
2246                 #
2247                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2248                         $this->mArticleID = 0;
2249                 }
2250                 $fragment = strstr( $dbkey, '#' );
2251                 if ( false !== $fragment ) {
2252                         $this->setFragment( $fragment );
2253                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2254                         # remove whitespace again: prevents "Foo_bar_#"
2255                         # becoming "Foo_bar_"
2256                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2257                 }
2258
2259                 # Reject illegal characters.
2260                 #
2261                 if( preg_match( $rxTc, $dbkey ) ) {
2262                         return false;
2263                 }
2264
2265                 /**
2266                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2267                  * reachable due to the way web browsers deal with 'relative' URLs.
2268                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2269                  */
2270                 if ( strpos( $dbkey, '.' ) !== false &&
2271                      ( $dbkey === '.' || $dbkey === '..' ||
2272                        strpos( $dbkey, './' ) === 0  ||
2273                        strpos( $dbkey, '../' ) === 0 ||
2274                        strpos( $dbkey, '/./' ) !== false ||
2275                        strpos( $dbkey, '/../' ) !== false  ||
2276                        substr( $dbkey, -2 ) == '/.' ||
2277                        substr( $dbkey, -3 ) == '/..' ) )
2278                 {
2279                         return false;
2280                 }
2281
2282                 /**
2283                  * Magic tilde sequences? Nu-uh!
2284                  */
2285                 if( strpos( $dbkey, '~~~' ) !== false ) {
2286                         return false;
2287                 }
2288
2289                 /**
2290                  * Limit the size of titles to 255 bytes.
2291                  * This is typically the size of the underlying database field.
2292                  * We make an exception for special pages, which don't need to be stored
2293                  * in the database, and may edge over 255 bytes due to subpage syntax
2294                  * for long titles, e.g. [[Special:Block/Long name]]
2295                  */
2296                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2297                   strlen( $dbkey ) > 512 )
2298                 {
2299                         return false;
2300                 }
2301
2302                 /**
2303                  * Normally, all wiki links are forced to have
2304                  * an initial capital letter so [[foo]] and [[Foo]]
2305                  * point to the same place.
2306                  *
2307                  * Don't force it for interwikis, since the other
2308                  * site might be case-sensitive.
2309                  */
2310                 $this->mUserCaseDBKey = $dbkey;
2311                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2312                         $dbkey = $wgContLang->ucfirst( $dbkey );
2313                 }
2314
2315                 /**
2316                  * Can't make a link to a namespace alone...
2317                  * "empty" local links can only be self-links
2318                  * with a fragment identifier.
2319                  */
2320                 if( $dbkey == '' &&
2321                         $this->mInterwiki == '' &&
2322                         $this->mNamespace != NS_MAIN ) {
2323                         return false;
2324                 }
2325                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2326                 // IP names are not allowed for accounts, and can only be referring to
2327                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2328                 // there are numerous ways to present the same IP. Having sp:contribs scan
2329                 // them all is silly and having some show the edits and others not is
2330                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2331                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2332                         IP::sanitizeIP( $dbkey ) : $dbkey;
2333                 // Any remaining initial :s are illegal.
2334                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2335                         return false;
2336                 }
2337
2338                 # Fill fields
2339                 $this->mDbkeyform = $dbkey;
2340                 $this->mUrlform = wfUrlencode( $dbkey );
2341
2342                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2343
2344                 return true;
2345         }
2346
2347         /**
2348          * Set the fragment for this title. Removes the first character from the
2349          * specified fragment before setting, so it assumes you're passing it with
2350          * an initial "#".
2351          *
2352          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2353          * Still in active use privately.
2354          *
2355          * @param $fragment \type{\string} text
2356          */
2357         public function setFragment( $fragment ) {
2358                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2359         }
2360
2361         /**
2362          * Get a Title object associated with the talk page of this article
2363          * @return \type{Title} the object for the talk page
2364          */
2365         public function getTalkPage() {
2366                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2367         }
2368
2369         /**
2370          * Get a title object associated with the subject page of this
2371          * talk page
2372          *
2373          * @return \type{Title} the object for the subject page
2374          */
2375         public function getSubjectPage() {
2376                 // Is this the same title?
2377                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2378                 if( $this->getNamespace() == $subjectNS ) {
2379                         return $this;
2380                 }
2381                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2382         }
2383
2384         /**
2385          * Get an array of Title objects linking to this Title
2386          * Also stores the IDs in the link cache.
2387          *
2388          * WARNING: do not use this function on arbitrary user-supplied titles!
2389          * On heavily-used templates it will max out the memory.
2390          *
2391          * @param array $options may be FOR UPDATE
2392          * @return \type{\arrayof{Title}} the Title objects linking here
2393          */
2394         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2395                 $linkCache = LinkCache::singleton();
2396
2397                 if ( count( $options ) > 0 ) {
2398                         $db = wfGetDB( DB_MASTER );
2399                 } else {
2400                         $db = wfGetDB( DB_SLAVE );
2401                 }
2402
2403                 $res = $db->select( array( 'page', $table ),
2404                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2405                         array(
2406                                 "{$prefix}_from=page_id",
2407                                 "{$prefix}_namespace" => $this->getNamespace(),
2408                                 "{$prefix}_title"     => $this->getDBkey() ),
2409                         __METHOD__,
2410                         $options );
2411
2412                 $retVal = array();
2413                 if ( $db->numRows( $res ) ) {
2414                         foreach( $res as $row ) {
2415                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2416                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2417                                         $retVal[] = $titleObj;
2418                                 }
2419                         }
2420                 }
2421                 $db->freeResult( $res );
2422                 return $retVal;
2423         }
2424
2425         /**
2426          * Get an array of Title objects using this Title as a template
2427          * Also stores the IDs in the link cache.
2428          *
2429          * WARNING: do not use this function on arbitrary user-supplied titles!
2430          * On heavily-used templates it will max out the memory.
2431          *
2432          * @param array $options may be FOR UPDATE
2433          * @return \type{\arrayof{Title}} the Title objects linking here
2434          */
2435         public function getTemplateLinksTo( $options = array() ) {
2436                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2437         }
2438
2439         /**
2440          * Get an array of Title objects referring to non-existent articles linked from this page
2441          *
2442          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2443          * @return \type{\arrayof{Title}} the Title objects
2444          */
2445         public function getBrokenLinksFrom() {
2446                 if ( $this->getArticleId() == 0 ) {
2447                         # All links from article ID 0 are false positives
2448                         return array();
2449                 }
2450
2451                 $dbr = wfGetDB( DB_SLAVE );
2452                 $res = $dbr->select(
2453                         array( 'page', 'pagelinks' ),
2454                         array( 'pl_namespace', 'pl_title' ),
2455                         array(
2456                                 'pl_from' => $this->getArticleId(),
2457                                 'page_namespace IS NULL'
2458                         ),
2459                         __METHOD__, array(),
2460                         array(
2461                                 'page' => array(
2462                                         'LEFT JOIN',
2463                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2464                                 )
2465                         )
2466                 );
2467
2468                 $retVal = array();
2469                 foreach( $res as $row ) {
2470                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2471                 }
2472                 return $retVal;
2473         }
2474
2475
2476         /**
2477          * Get a list of URLs to purge from the Squid cache when this
2478          * page changes
2479          *
2480          * @return \type{\arrayof{\string}} the URLs
2481          */
2482         public function getSquidURLs() {
2483                 global $wgContLang;
2484
2485                 $urls = array(
2486                         $this->getInternalURL(),
2487                         $this->getInternalURL( 'action=history' )
2488                 );
2489
2490                 // purge variant urls as well
2491                 if($wgContLang->hasVariants()){
2492                         $variants = $wgContLang->getVariants();
2493                         foreach($variants as $vCode){
2494                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2495                                 $urls[] = $this->getInternalURL('',$vCode);
2496                         }
2497                 }
2498
2499                 return $urls;
2500         }
2501
2502         /**
2503          * Purge all applicable Squid URLs
2504          */
2505         public function purgeSquid() {
2506                 global $wgUseSquid;
2507                 if ( $wgUseSquid ) {
2508                         $urls = $this->getSquidURLs();
2509                         $u = new SquidUpdate( $urls );
2510                         $u->doUpdate();
2511                 }
2512         }
2513
2514         /**
2515          * Move this page without authentication
2516          * @param &$nt \type{Title} the new page Title
2517          */
2518         public function moveNoAuth( &$nt ) {
2519                 return $this->moveTo( $nt, false );
2520         }
2521
2522         /**
2523          * Check whether a given move operation would be valid.
2524          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2525          * @param &$nt \type{Title} the new title
2526          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2527          *      should be checked
2528          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2529          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2530          */
2531         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2532                 global $wgUser;
2533
2534                 $errors = array();
2535                 if( !$nt ) {
2536                         // Normally we'd add this to $errors, but we'll get
2537                         // lots of syntax errors if $nt is not an object
2538                         return array(array('badtitletext'));
2539                 }
2540                 if( $this->equals( $nt ) ) {
2541                         $errors[] = array('selfmove');
2542                 }
2543                 if( !$this->isMovable() ) {
2544                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2545                 }
2546                 if ( $nt->getInterwiki() != '' ) {
2547                         $errors[] = array( 'immobile-target-namespace-iw' );
2548                 }
2549                 if ( !$nt->isMovable() ) {
2550                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2551                 }
2552
2553                 $oldid = $this->getArticleID();
2554                 $newid = $nt->getArticleID();
2555
2556                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2557                         $errors[] = array('articleexists');
2558                 }
2559                 if ( ( '' == $this->getDBkey() ) ||
2560                          ( !$oldid ) ||
2561                      ( '' == $nt->getDBkey() ) ) {
2562                         $errors[] = array('badarticleerror');
2563                 }
2564
2565                 // Image-specific checks
2566                 if( $this->getNamespace() == NS_FILE ) {
2567                         $file = wfLocalFile( $this );
2568                         if( $file->exists() ) {
2569                                 if( $nt->getNamespace() != NS_FILE ) {
2570                                         $errors[] = array('imagenocrossnamespace');
2571                                 }
2572                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2573                                         $errors[] = array('imageinvalidfilename');
2574                                 }
2575                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2576                                         $errors[] = array('imagetypemismatch');
2577                                 }
2578                         }
2579                 }
2580
2581                 if ( $auth ) {
2582                         $errors = wfMergeErrorArrays( $errors,
2583                                 $this->getUserPermissionsErrors('move', $wgUser),
2584                                 $this->getUserPermissionsErrors('edit', $wgUser),
2585                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2586                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2587                 }
2588
2589                 $match = EditPage::matchSummarySpamRegex( $reason );
2590                 if( $match !== false ) {
2591                         // This is kind of lame, won't display nice
2592                         $errors[] = array('spamprotectiontext');
2593                 }
2594
2595                 $err = null;
2596                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2597                         $errors[] = array('hookaborted', $err);
2598                 }
2599
2600                 # The move is allowed only if (1) the target doesn't exist, or
2601                 # (2) the target is a redirect to the source, and has no history
2602                 # (so we can undo bad moves right after they're done).
2603
2604                 if ( 0 != $newid ) { # Target exists; check for validity
2605                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2606                                 $errors[] = array('articleexists');
2607                         }
2608                 } else {
2609                         $tp = $nt->getTitleProtection();
2610                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2611                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2612                                 $errors[] = array('cantmove-titleprotected');
2613                         }
2614                 }
2615                 if(empty($errors))
2616                         return true;
2617                 return $errors;
2618         }
2619
2620         /**
2621          * Move a title to a new location
2622          * @param &$nt \type{Title} the new title
2623          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2624          *      should be checked
2625          * @param $reason \type{\string} The reason for the move
2626          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2627          *  Ignored if the user doesn't have the suppressredirect right.
2628          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2629          */
2630         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2631                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2632                 if( is_array( $err ) ) {
2633                         return $err;
2634                 }
2635
2636                 // If it is a file, more it first. It is done before all other moving stuff is done because it's hard to revert
2637                 $dbw = wfGetDB( DB_MASTER );
2638                 if( $this->getNamespace() == NS_FILE ) {
2639                         $file = wfLocalFile( $this );
2640                         if( $file->exists() ) {
2641                                 $status = $file->move( $nt );
2642                                 if( !$status->isOk() ) {
2643                                         return $status->getErrorsArray();
2644                                 }
2645                         }
2646                 }
2647
2648                 $pageid = $this->getArticleID();
2649                 $protected = $this->isProtected();
2650                 if( $nt->exists() ) {
2651                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2652                         $pageCountChange = ($createRedirect ? 0 : -1);
2653                 } else { # Target didn't exist, do normal move.
2654                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2655                         $pageCountChange = ($createRedirect ? 1 : 0);
2656                 }
2657
2658                 if( is_array( $err ) ) {
2659                         return $err;
2660                 }
2661                 $redirid = $this->getArticleID();
2662
2663                 // Category memberships include a sort key which may be customized.
2664                 // If it's left as the default (the page title), we need to update
2665                 // the sort key to match the new title.
2666                 //
2667                 // Be careful to avoid resetting cl_timestamp, which may disturb
2668                 // time-based lists on some sites.
2669                 //
2670                 // Warning -- if the sort key is *explicitly* set to the old title,
2671                 // we can't actually distinguish it from a default here, and it'll
2672                 // be set to the new title even though it really shouldn't.
2673                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2674                 $dbw->update( 'categorylinks',
2675                         array(
2676                                 'cl_sortkey' => $nt->getPrefixedText(),
2677                                 'cl_timestamp=cl_timestamp' ),
2678                         array(
2679                                 'cl_from' => $pageid,
2680                                 'cl_sortkey' => $this->getPrefixedText() ),
2681                         __METHOD__ );
2682
2683                 if( $protected ) {
2684                         # Protect the redirect title as the title used to be...
2685                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2686                                 array(
2687                                         'pr_page'    => $redirid,
2688                                         'pr_type'    => 'pr_type',
2689                                         'pr_level'   => 'pr_level',
2690                                         'pr_cascade' => 'pr_cascade',
2691                                         'pr_user'    => 'pr_user',
2692                                         'pr_expiry'  => 'pr_expiry'
2693                                 ),
2694                                 array( 'pr_page' => $pageid ),
2695                                 __METHOD__,
2696                                 array( 'IGNORE' )
2697                         );
2698                         # Update the protection log
2699                         $log = new LogPage( 'protect' );
2700                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2701                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2702                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2703                 }
2704
2705                 # Update watchlists
2706                 $oldnamespace = $this->getNamespace() & ~1;
2707                 $newnamespace = $nt->getNamespace() & ~1;
2708                 $oldtitle = $this->getDBkey();
2709                 $newtitle = $nt->getDBkey();
2710
2711                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2712                         WatchedItem::duplicateEntries( $this, $nt );
2713                 }
2714
2715                 # Update search engine
2716                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2717                 $u->doUpdate();
2718                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2719                 $u->doUpdate();
2720
2721                 # Update site_stats
2722                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2723                         # No longer a content page
2724                         # Not viewed, edited, removing
2725                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2726                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2727                         # Now a content page
2728                         # Not viewed, edited, adding
2729                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2730                 } elseif( $pageCountChange ) {
2731                         # Redirect added
2732                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2733                 } else {
2734                         # Nothing special
2735                         $u = false;
2736                 }
2737                 if( $u )
2738                         $u->doUpdate();
2739                 # Update message cache for interface messages
2740                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2741                         global $wgMessageCache;
2742
2743                         # @bug 17860: old article can be deleted, if this the case,
2744                         # delete it from message cache
2745                         if ( $this->getArticleID() === 0 ) {
2746                                 $wgMessageCache->replace( $this->getDBkey(), false );
2747                         } else {
2748                                 $oldarticle = new Article( $this );
2749                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2750                         }
2751
2752                         $newarticle = new Article( $nt );
2753                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2754                 }
2755
2756                 global $wgUser;
2757                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2758                 return true;
2759         }
2760
2761         /**
2762          * Move page to a title which is at present a redirect to the
2763          * source page
2764          *
2765          * @param &$nt \type{Title} the page to move to, which should currently
2766          *      be a redirect
2767          * @param $reason \type{\string} The reason for the move
2768          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2769          *  Ignored if the user doesn't have the suppressredirect right
2770          */
2771         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2772                 global $wgUseSquid, $wgUser;
2773                 $fname = 'Title::moveOverExistingRedirect';
2774                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2775
2776                 if ( $reason ) {
2777                         $comment .= ": $reason";
2778                 }
2779
2780                 $now = wfTimestampNow();
2781                 $newid = $nt->getArticleID();
2782                 $oldid = $this->getArticleID();
2783                 $latest = $this->getLatestRevID();
2784
2785                 $dbw = wfGetDB( DB_MASTER );
2786
2787                 # Delete the old redirect. We don't save it to history since
2788                 # by definition if we've got here it's rather uninteresting.
2789                 # We have to remove it so that the next step doesn't trigger
2790                 # a conflict on the unique namespace+title index...
2791                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2792                 if ( !$dbw->cascadingDeletes() ) {
2793                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2794                         global $wgUseTrackbacks;
2795                         if ($wgUseTrackbacks)
2796                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2797                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2798                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2799                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2800                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2801                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2802                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2803                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2804                 }
2805
2806                 # Save a null revision in the page's history notifying of the move
2807                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2808                 $nullRevId = $nullRevision->insertOn( $dbw );
2809
2810                 $article = new Article( $this );
2811                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2812
2813                 # Change the name of the target page:
2814                 $dbw->update( 'page',
2815                         /* SET */ array(
2816                                 'page_touched'   => $dbw->timestamp($now),
2817                                 'page_namespace' => $nt->getNamespace(),
2818                                 'page_title'     => $nt->getDBkey(),
2819                                 'page_latest'    => $nullRevId,
2820                         ),
2821                         /* WHERE */ array( 'page_id' => $oldid ),
2822                         $fname
2823                 );
2824                 $nt->resetArticleID( $oldid );
2825
2826                 # Recreate the redirect, this time in the other direction.
2827                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2828                         $mwRedir = MagicWord::get( 'redirect' );
2829                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2830                         $redirectArticle = new Article( $this );
2831                         $newid = $redirectArticle->insertOn( $dbw );
2832                         $redirectRevision = new Revision( array(
2833                                 'page'    => $newid,
2834                                 'comment' => $comment,
2835                                 'text'    => $redirectText ) );
2836                         $redirectRevision->insertOn( $dbw );
2837                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2838
2839                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2840
2841                         # Now, we record the link from the redirect to the new title.
2842                         # It should have no other outgoing links...
2843                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2844                         $dbw->insert( 'pagelinks',
2845                                 array(
2846                                         'pl_from'      => $newid,
2847                                         'pl_namespace' => $nt->getNamespace(),
2848                                         'pl_title'     => $nt->getDBkey() ),
2849                                 $fname );
2850                         $redirectSuppressed = false;
2851                 } else {
2852                         $this->resetArticleID( 0 );
2853                         $redirectSuppressed = true;
2854                 }
2855
2856                 # Log the move
2857                 $log = new LogPage( 'move' );
2858                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2859
2860                 # Purge squid
2861                 if ( $wgUseSquid ) {
2862                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2863                         $u = new SquidUpdate( $urls );
2864                         $u->doUpdate();
2865                 }
2866
2867         }
2868
2869         /**
2870          * Move page to non-existing title.
2871          * @param &$nt \type{Title} the new Title
2872          * @param $reason \type{\string} The reason for the move
2873          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2874          *  Ignored if the user doesn't have the suppressredirect right
2875          */
2876         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2877                 global $wgUseSquid, $wgUser;
2878                 $fname = 'MovePageForm::moveToNewTitle';
2879                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2880                 if ( $reason ) {
2881                         $comment .= wfMsgExt( 'colon-separator',
2882                                 array( 'escapenoentities', 'content' ) );
2883                         $comment .= $reason;
2884                 }
2885
2886                 $newid = $nt->getArticleID();
2887                 $oldid = $this->getArticleID();
2888                 $latest = $this->getLatestRevId();
2889
2890                 $dbw = wfGetDB( DB_MASTER );
2891                 $now = $dbw->timestamp();
2892
2893                 # Save a null revision in the page's history notifying of the move
2894                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2895                 $nullRevId = $nullRevision->insertOn( $dbw );
2896
2897                 $article = new Article( $this );
2898                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2899
2900                 # Rename page entry
2901                 $dbw->update( 'page',
2902                         /* SET */ array(
2903                                 'page_touched'   => $now,
2904                                 'page_namespace' => $nt->getNamespace(),
2905                                 'page_title'     => $nt->getDBkey(),
2906                                 'page_latest'    => $nullRevId,
2907                         ),
2908                         /* WHERE */ array( 'page_id' => $oldid ),
2909                         $fname
2910                 );
2911                 $nt->resetArticleID( $oldid );
2912
2913                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2914                         # Insert redirect
2915                         $mwRedir = MagicWord::get( 'redirect' );
2916                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2917                         $redirectArticle = new Article( $this );
2918                         $newid = $redirectArticle->insertOn( $dbw );
2919                         $redirectRevision = new Revision( array(
2920                                 'page'    => $newid,
2921                                 'comment' => $comment,
2922                                 'text'    => $redirectText ) );
2923                         $redirectRevision->insertOn( $dbw );
2924                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2925
2926                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2927
2928                         # Record the just-created redirect's linking to the page
2929                         $dbw->insert( 'pagelinks',
2930                                 array(
2931                                         'pl_from'      => $newid,
2932                                         'pl_namespace' => $nt->getNamespace(),
2933                                         'pl_title'     => $nt->getDBkey() ),
2934                                 $fname );
2935                         $redirectSuppressed = false;
2936                 } else {
2937                         $this->resetArticleID( 0 );
2938                         $redirectSuppressed = true;
2939                 }
2940
2941                 # Log the move
2942                 $log = new LogPage( 'move' );
2943                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2944
2945                 # Purge caches as per article creation
2946                 Article::onArticleCreate( $nt );
2947
2948                 # Purge old title from squid
2949                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2950                 $this->purgeSquid();
2951
2952         }
2953
2954         /**
2955          * Move this page's subpages to be subpages of $nt
2956          * @param $nt Title Move target
2957          * @param $auth bool Whether $wgUser's permissions should be checked
2958          * @param $reason string The reason for the move
2959          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2960          *  Ignored if the user doesn't have the 'suppressredirect' right
2961          * @return mixed array with old page titles as keys, and strings (new page titles) or
2962          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
2963          */
2964         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
2965                 global $wgMaximumMovedPages;
2966                 // Check permissions
2967                 if( !$this->userCan( 'move-subpages' ) )
2968                         return array( 'cant-move-subpages' );
2969                 // Do the source and target namespaces support subpages?
2970                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
2971                         return array( 'namespace-nosubpages',
2972                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
2973                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
2974                         return array( 'namespace-nosubpages',
2975                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
2976
2977                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
2978                 $retval = array();
2979                 $count = 0;
2980                 foreach( $subpages as $oldSubpage ) {
2981                         $count++;
2982                         if( $count > $wgMaximumMovedPages ) {
2983                                 $retval[$oldSubpage->getPrefixedTitle()] =
2984                                                 array( 'movepage-max-pages',
2985                                                         $wgMaximumMovedPages );
2986                                 break;
2987                         }
2988
2989                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
2990                                 // When moving a page to a subpage of itself,
2991                                 // don't move it twice
2992                                 continue;
2993                         $newPageName = preg_replace(
2994                                         '#^'.preg_quote( $this->getDBkey(), '#' ).'#',
2995                                         $nt->getDBkey(), $oldSubpage->getDBkey() );
2996                         if( $oldSubpage->isTalkPage() ) {
2997                                 $newNs = $nt->getTalkPage()->getNamespace();
2998                         } else {
2999                                 $newNs = $nt->getSubjectPage()->getNamespace();
3000                         }
3001                         # Bug 14385: we need makeTitleSafe because the new page names may
3002                         # be longer than 255 characters.
3003                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3004
3005                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3006                         if( $success === true ) {
3007                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3008                         } else {
3009                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3010                         }
3011                 }
3012                 return $retval;
3013         }
3014
3015         /**
3016          * Checks if this page is just a one-rev redirect.
3017          * Adds lock, so don't use just for light purposes.
3018          *
3019          * @return \type{\bool} TRUE or FALSE
3020          */
3021         public function isSingleRevRedirect() {
3022                 $dbw = wfGetDB( DB_MASTER );
3023                 # Is it a redirect?
3024                 $row = $dbw->selectRow( 'page',
3025                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3026                         $this->pageCond(),
3027                         __METHOD__,
3028                         array( 'FOR UPDATE' )
3029                 );
3030                 # Cache some fields we may want
3031                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3032                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3033                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3034                 if( !$this->mRedirect ) {
3035                         return false;
3036                 }
3037                 # Does the article have a history?
3038                 $row = $dbw->selectField( array( 'page', 'revision'),
3039                         'rev_id',
3040                         array( 'page_namespace' => $this->getNamespace(),
3041                                 'page_title' => $this->getDBkey(),
3042                                 'page_id=rev_page',
3043                                 'page_latest != rev_id'
3044                         ),
3045                         __METHOD__,
3046                         array( 'FOR UPDATE' )
3047                 );
3048                 # Return true if there was no history
3049                 return ($row === false);
3050         }
3051
3052         /**
3053          * Checks if $this can be moved to a given Title
3054          * - Selects for update, so don't call it unless you mean business
3055          *
3056          * @param &$nt \type{Title} the new title to check
3057          * @return \type{\bool} TRUE or FALSE
3058          */
3059         public function isValidMoveTarget( $nt ) {
3060                 $dbw = wfGetDB( DB_MASTER );
3061                 # Is it an existsing file?
3062                 if( $nt->getNamespace() == NS_FILE ) {
3063                         $file = wfLocalFile( $nt );
3064                         if( $file->exists() ) {
3065                                 wfDebug( __METHOD__ . ": file exists\n" );
3066                                 return false;
3067                         }
3068                 }
3069                 # Is it a redirect with no history?
3070                 if( !$nt->isSingleRevRedirect() ) {
3071                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3072                         return false;
3073                 }
3074                 # Get the article text
3075                 $rev = Revision::newFromTitle( $nt );
3076                 $text = $rev->getText();
3077                 # Does the redirect point to the source?
3078                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3079                 $m = array();
3080                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3081                         $redirTitle = Title::newFromText( $m[1] );
3082                         if( !is_object( $redirTitle ) ||
3083                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3084                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3085                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3086                                 return false;
3087                         }
3088                 } else {
3089                         # Fail safe
3090                         wfDebug( __METHOD__ . ": failsafe\n" );
3091                         return false;
3092                 }
3093                 return true;
3094         }
3095
3096         /**
3097          * Can this title be added to a user's watchlist?
3098          *
3099          * @return \type{\bool} TRUE or FALSE
3100          */
3101         public function isWatchable() {
3102                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3103         }
3104
3105         /**
3106          * Get categories to which this Title belongs and return an array of
3107          * categories' names.
3108          *
3109          * @return \type{\array} array an array of parents in the form:
3110          *      $parent => $currentarticle
3111          */
3112         public function getParentCategories() {
3113                 global $wgContLang;
3114
3115                 $titlekey = $this->getArticleId();
3116                 $dbr = wfGetDB( DB_SLAVE );
3117                 $categorylinks = $dbr->tableName( 'categorylinks' );
3118
3119                 # NEW SQL
3120                 $sql = "SELECT * FROM $categorylinks"
3121                      ." WHERE cl_from='$titlekey'"
3122                          ." AND cl_from <> '0'"
3123                          ." ORDER BY cl_sortkey";
3124
3125                 $res = $dbr->query( $sql );
3126
3127                 if( $dbr->numRows( $res ) > 0 ) {
3128                         foreach( $res as $row )
3129                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3130                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3131                         $dbr->freeResult( $res );
3132                 } else {
3133                         $data = array();
3134                 }
3135                 return $data;
3136         }
3137
3138         /**
3139          * Get a tree of parent categories
3140          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3141          * @return \type{\array} Tree of parent categories
3142          */
3143         public function getParentCategoryTree( $children = array() ) {
3144                 $stack = array();
3145                 $parents = $this->getParentCategories();
3146
3147                 if( $parents ) {
3148                         foreach( $parents as $parent => $current ) {
3149                                 if ( array_key_exists( $parent, $children ) ) {
3150                                         # Circular reference
3151                                         $stack[$parent] = array();
3152                                 } else {
3153                                         $nt = Title::newFromText($parent);
3154                                         if ( $nt ) {
3155                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3156                                         }
3157                                 }
3158                         }
3159                         return $stack;
3160                 } else {
3161                         return array();
3162                 }
3163         }
3164
3165
3166         /**
3167          * Get an associative array for selecting this title from
3168          * the "page" table
3169          *
3170          * @return \type{\array} Selection array
3171          */
3172         public function pageCond() {
3173                 if( $this->mArticleID > 0 ) {
3174                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3175                         return array( 'page_id' => $this->mArticleID );
3176                 } else {
3177                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3178                 }
3179         }
3180
3181         /**
3182          * Get the revision ID of the previous revision
3183          *
3184          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3185          * @param $flags \type{\int} GAID_FOR_UPDATE
3186          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3187          */
3188         public function getPreviousRevisionID( $revId, $flags=0 ) {
3189                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3190                 return $db->selectField( 'revision', 'rev_id',
3191                         array(
3192                                 'rev_page' => $this->getArticleId($flags),
3193                                 'rev_id < ' . intval( $revId )
3194                         ),
3195                         __METHOD__,
3196                         array( 'ORDER BY' => 'rev_id DESC' )
3197                 );
3198         }
3199
3200         /**
3201          * Get the revision ID of the next revision
3202          *
3203          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3204          * @param $flags \type{\int} GAID_FOR_UPDATE
3205          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3206          */
3207         public function getNextRevisionID( $revId, $flags=0 ) {
3208                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3209                 return $db->selectField( 'revision', 'rev_id',
3210                         array(
3211                                 'rev_page' => $this->getArticleId($flags),
3212                                 'rev_id > ' . intval( $revId )
3213                         ),
3214                         __METHOD__,
3215                         array( 'ORDER BY' => 'rev_id' )
3216                 );
3217         }
3218
3219         /**
3220          * Get the first revision of the page
3221          *
3222          * @param $flags \type{\int} GAID_FOR_UPDATE
3223          * @return Revision (or NULL if page doesn't exist)
3224          */
3225         public function getFirstRevision( $flags=0 ) {
3226                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3227                 $pageId = $this->getArticleId($flags);
3228                 if( !$pageId ) return NULL;
3229                 $row = $db->selectRow( 'revision', '*',
3230                         array( 'rev_page' => $pageId ),
3231                         __METHOD__,
3232                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3233                 );
3234                 if( !$row ) {
3235                         return NULL;
3236                 } else {
3237                         return new Revision( $row );
3238                 }
3239         }
3240
3241         /**
3242          * Check if this is a new page
3243          *
3244          * @return bool
3245          */
3246         public function isNewPage() {
3247                 $dbr = wfGetDB( DB_SLAVE );
3248                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3249         }
3250
3251         /**
3252          * Get the oldest revision timestamp of this page
3253          *
3254          * @return string, MW timestamp
3255          */
3256         public function getEarliestRevTime() {
3257                 $dbr = wfGetDB( DB_SLAVE );
3258                 if( $this->exists() ) {
3259                         $min = $dbr->selectField( 'revision',
3260                                 'MIN(rev_timestamp)',
3261                                 array( 'rev_page' => $this->getArticleId() ),
3262                                 __METHOD__ );
3263                         return wfTimestampOrNull( TS_MW, $min );
3264                 }
3265                 return null;
3266         }
3267
3268         /**
3269          * Get the number of revisions between the given revision IDs.
3270          * Used for diffs and other things that really need it.
3271          *
3272          * @param $old \type{\int} Revision ID.
3273          * @param $new \type{\int} Revision ID.
3274          * @return \type{\int} Number of revisions between these IDs.
3275          */
3276         public function countRevisionsBetween( $old, $new ) {
3277                 $dbr = wfGetDB( DB_SLAVE );
3278                 return $dbr->selectField( 'revision', 'count(*)',
3279                         'rev_page = ' . intval( $this->getArticleId() ) .
3280                         ' AND rev_id > ' . intval( $old ) .
3281                         ' AND rev_id < ' . intval( $new ),
3282                         __METHOD__
3283                 );
3284         }
3285
3286         /**
3287          * Compare with another title.
3288          *
3289          * @param \type{Title} $title
3290          * @return \type{\bool} TRUE or FALSE
3291          */
3292         public function equals( Title $title ) {
3293                 // Note: === is necessary for proper matching of number-like titles.
3294                 return $this->getInterwiki() === $title->getInterwiki()
3295                         && $this->getNamespace() == $title->getNamespace()
3296                         && $this->getDBkey() === $title->getDBkey();
3297         }
3298
3299         /**
3300          * Callback for usort() to do title sorts by (namespace, title)
3301          */
3302         public static function compare( $a, $b ) {
3303                 if( $a->getNamespace() == $b->getNamespace() ) {
3304                         return strcmp( $a->getText(), $b->getText() );
3305                 } else {
3306                         return $a->getNamespace() - $b->getNamespace();
3307                 }
3308         }
3309
3310         /**
3311          * Return a string representation of this title
3312          *
3313          * @return \type{\string} String representation of this title
3314          */
3315         public function __toString() {
3316                 return $this->getPrefixedText();
3317         }
3318
3319         /**
3320          * Check if page exists.  For historical reasons, this function simply
3321          * checks for the existence of the title in the page table, and will
3322          * thus return false for interwiki links, special pages and the like.
3323          * If you want to know if a title can be meaningfully viewed, you should
3324          * probably call the isKnown() method instead.
3325          *
3326          * @return \type{\bool} TRUE or FALSE
3327          */
3328         public function exists() {
3329                 return $this->getArticleId() != 0;
3330         }
3331
3332         /**
3333          * Should links to this title be shown as potentially viewable (i.e. as
3334          * "bluelinks"), even if there's no record by this title in the page
3335          * table?
3336          *
3337          * This function is semi-deprecated for public use, as well as somewhat
3338          * misleadingly named.  You probably just want to call isKnown(), which
3339          * calls this function internally.
3340          *
3341          * (ISSUE: Most of these checks are cheap, but the file existence check
3342          * can potentially be quite expensive.  Including it here fixes a lot of
3343          * existing code, but we might want to add an optional parameter to skip
3344          * it and any other expensive checks.)
3345          *
3346          * @return \type{\bool} TRUE or FALSE
3347          */
3348         public function isAlwaysKnown() {
3349                 if( $this->mInterwiki != '' ) {
3350                         return true;  // any interwiki link might be viewable, for all we know
3351                 }
3352                 switch( $this->mNamespace ) {
3353                 case NS_MEDIA:
3354                 case NS_FILE:
3355                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3356                 case NS_SPECIAL:
3357                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3358                 case NS_MAIN:
3359                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3360                 case NS_MEDIAWIKI:
3361                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3362                         // the full l10n of that language to be loaded. That takes much memory and
3363                         // isn't needed. So we strip the language part away.
3364                         // Also, extension messages which are not loaded, are shown as red, because
3365                         // we don't call MessageCache::loadAllMessages.
3366                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3367                         return wfMsgWeirdKey( $basename );  // known system message
3368                 default:
3369                         return false;
3370                 }
3371         }
3372
3373         /**
3374          * Does this title refer to a page that can (or might) be meaningfully
3375          * viewed?  In particular, this function may be used to determine if
3376          * links to the title should be rendered as "bluelinks" (as opposed to
3377          * "redlinks" to non-existent pages).
3378          *
3379          * @return \type{\bool} TRUE or FALSE
3380          */
3381         public function isKnown() {
3382                 return $this->exists() || $this->isAlwaysKnown();
3383         }
3384
3385         /**
3386         * Is this in a namespace that allows actual pages?
3387         *
3388         * @return \type{\bool} TRUE or FALSE
3389         */
3390         public function canExist() {
3391                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3392         }
3393
3394         /**
3395          * Update page_touched timestamps and send squid purge messages for
3396          * pages linking to this title. May be sent to the job queue depending
3397          * on the number of links. Typically called on create and delete.
3398          */
3399         public function touchLinks() {
3400                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3401                 $u->doUpdate();
3402
3403                 if ( $this->getNamespace() == NS_CATEGORY ) {
3404                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3405                         $u->doUpdate();
3406                 }
3407         }
3408
3409         /**
3410          * Get the last touched timestamp
3411          * @param Database $db, optional db
3412          * @return \type{\string} Last touched timestamp
3413          */
3414         public function getTouched( $db = NULL ) {
3415                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3416                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3417                 return $touched;
3418         }
3419
3420         /**
3421          * Get the timestamp when this page was updated since the user last saw it.
3422          * @param User $user
3423          * @return mixed string/NULL
3424          */
3425         public function getNotificationTimestamp( $user = NULL ) {
3426                 global $wgUser, $wgShowUpdatedMarker;
3427                 // Assume current user if none given
3428                 if( !$user ) $user = $wgUser;
3429                 // Check cache first
3430                 $uid = $user->getId();
3431                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3432                         return $this->mNotificationTimestamp[$uid];
3433                 }
3434                 if( !$uid || !$wgShowUpdatedMarker ) {
3435                         return $this->mNotificationTimestamp[$uid] = false;
3436                 }
3437                 // Don't cache too much!
3438                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3439                         $this->mNotificationTimestamp = array();
3440                 }
3441                 $dbr = wfGetDB( DB_SLAVE );
3442                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3443                         'wl_notificationtimestamp',
3444                         array( 'wl_namespace' => $this->getNamespace(),
3445                                 'wl_title' => $this->getDBkey(),
3446                                 'wl_user' => $user->getId()
3447                         ),
3448                         __METHOD__
3449                 );
3450                 return $this->mNotificationTimestamp[$uid];
3451         }
3452
3453         /**
3454          * Get the trackback URL for this page
3455          * @return \type{\string} Trackback URL
3456          */
3457         public function trackbackURL() {
3458                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3459
3460                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3461                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3462         }
3463
3464         /**
3465          * Get the trackback RDF for this page
3466          * @return \type{\string} Trackback RDF
3467          */
3468         public function trackbackRDF() {
3469                 $url = htmlspecialchars($this->getFullURL());
3470                 $title = htmlspecialchars($this->getText());
3471                 $tburl = $this->trackbackURL();
3472
3473                 // Autodiscovery RDF is placed in comments so HTML validator
3474                 // won't barf. This is a rather icky workaround, but seems
3475                 // frequently used by this kind of RDF thingy.
3476                 //
3477                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3478                 return "<!--
3479 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3480          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3481          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3482 <rdf:Description
3483    rdf:about=\"$url\"
3484    dc:identifier=\"$url\"
3485    dc:title=\"$title\"
3486    trackback:ping=\"$tburl\" />
3487 </rdf:RDF>
3488 -->";
3489         }
3490
3491         /**
3492          * Generate strings used for xml 'id' names in monobook tabs
3493          * @return \type{\string} XML 'id' name
3494          */
3495         public function getNamespaceKey() {
3496                 global $wgContLang;
3497                 switch ($this->getNamespace()) {
3498                         case NS_MAIN:
3499                         case NS_TALK:
3500                                 return 'nstab-main';
3501                         case NS_USER:
3502                         case NS_USER_TALK:
3503                                 return 'nstab-user';
3504                         case NS_MEDIA:
3505                                 return 'nstab-media';
3506                         case NS_SPECIAL:
3507                                 return 'nstab-special';
3508                         case NS_PROJECT:
3509                         case NS_PROJECT_TALK:
3510                                 return 'nstab-project';
3511                         case NS_FILE:
3512                         case NS_FILE_TALK:
3513                                 return 'nstab-image';
3514                         case NS_MEDIAWIKI:
3515                         case NS_MEDIAWIKI_TALK:
3516                                 return 'nstab-mediawiki';
3517                         case NS_TEMPLATE:
3518                         case NS_TEMPLATE_TALK:
3519                                 return 'nstab-template';
3520                         case NS_HELP:
3521                         case NS_HELP_TALK:
3522                                 return 'nstab-help';
3523                         case NS_CATEGORY:
3524                         case NS_CATEGORY_TALK:
3525                                 return 'nstab-category';
3526                         default:
3527                                 return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
3528                 }
3529         }
3530
3531         /**
3532          * Returns true if this title resolves to the named special page
3533          * @param $name \type{\string} The special page name
3534          */
3535         public function isSpecial( $name ) {
3536                 if ( $this->getNamespace() == NS_SPECIAL ) {
3537                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3538                         if ( $name == $thisName ) {
3539                                 return true;
3540                         }
3541                 }
3542                 return false;
3543         }
3544
3545         /**
3546          * If the Title refers to a special page alias which is not the local default,
3547          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3548          */
3549         public function fixSpecialName() {
3550                 if ( $this->getNamespace() == NS_SPECIAL ) {
3551                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3552                         if ( $canonicalName ) {
3553                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3554                                 if ( $localName != $this->mDbkeyform ) {
3555                                         return Title::makeTitle( NS_SPECIAL, $localName );
3556                                 }
3557                         }
3558                 }
3559                 return $this;
3560         }
3561
3562         /**
3563          * Is this Title in a namespace which contains content?
3564          * In other words, is this a content page, for the purposes of calculating
3565          * statistics, etc?
3566          *
3567          * @return \type{\bool} TRUE or FALSE
3568          */
3569         public function isContentPage() {
3570                 return MWNamespace::isContent( $this->getNamespace() );
3571         }
3572
3573         /**
3574          * Get all extant redirects to this Title
3575          *
3576          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3577          *            NULL to consider all namespaces
3578          * @return \type{\arrayof{Title}} Redirects to this title
3579          */
3580         public function getRedirectsHere( $ns = null ) {
3581                 $redirs = array();
3582
3583                 $dbr = wfGetDB( DB_SLAVE );
3584                 $where = array(
3585                         'rd_namespace' => $this->getNamespace(),
3586                         'rd_title' => $this->getDBkey(),
3587                         'rd_from = page_id'
3588                 );
3589                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3590
3591                 $res = $dbr->select(
3592                         array( 'redirect', 'page' ),
3593                         array( 'page_namespace', 'page_title' ),
3594                         $where,
3595                         __METHOD__
3596                 );
3597
3598
3599                 foreach( $res as $row ) {
3600                         $redirs[] = self::newFromRow( $row );
3601                 }
3602                 return $redirs;
3603         }
3604
3605         /**
3606          * Check if this Title is a valid redirect target
3607          *
3608          * @return \type{\bool} TRUE or FALSE
3609          */
3610         public function isValidRedirectTarget() {
3611                 global $wgInvalidRedirectTargets;
3612
3613                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3614                 if( $this->isSpecial( 'Userlogout' ) ) {
3615                         return false;
3616                 }
3617
3618                 foreach( $wgInvalidRedirectTargets as $target ) {
3619                         if( $this->isSpecial( $target ) ) {
3620                                 return false;
3621                         }
3622                 }
3623
3624                 return true;
3625         }
3626
3627         /**
3628          * Get a backlink cache object
3629          */
3630         function getBacklinkCache() {
3631                 if ( is_null( $this->mBacklinkCache ) ) {
3632                         $this->mBacklinkCache = new BacklinkCache( $this );
3633                 }
3634                 return $this->mBacklinkCache;
3635         }
3636 }