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          * Determine whether the object refers to a page within
 472          * this project.
 473          *
 474          * @return \type{\bool} TRUE if this is an in-project interwiki link
 475          *      or a wikilink, FALSE otherwise
 476          */
 477         public function isLocal() {
 478                 if ( $this->mInterwiki != '' ) {
 479                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 480                 } else {
 481                         return true;
 482                 }
 483         }
 484
 485         /**
 486          * Determine whether the object refers to a page within
 487          * this project and is transcludable.
 488          *
 489          * @return \type{\bool} TRUE if this is transcludable
 490          */
 491         public function isTrans() {
 492                 if ($this->mInterwiki == '')
 493                         return false;
 494
 495                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 496         }
 497
 498         /**
 499          * Escape a text fragment, say from a link, for a URL
 500          */
 501         static function escapeFragmentForURL( $fragment ) {
 502                 global $wgEnforceHtmlIds;
 503                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 504                 # fragments appear not to work in IE (at least up to 7) or in at least
 505                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 506                 # to care if they aren't encoded.
 507                 return Sanitizer::escapeId( $fragment,
 508                         $wgEnforceHtmlIds ? 'noninitial' : 'xml' );
 509         }
 510
 511 #----------------------------------------------------------------------------
 512 #       Other stuff
 513 #----------------------------------------------------------------------------
 514
 515         /** Simple accessors */
 516         /**
 517          * Get the text form (spaces not underscores) of the main part
 518          * @return \type{\string} Main part of the title
 519          */
 520         public function getText() { return $this->mTextform; }
 521         /**
 522          * Get the URL-encoded form of the main part
 523          * @return \type{\string} Main part of the title, URL-encoded
 524          */
 525         public function getPartialURL() { return $this->mUrlform; }
 526         /**
 527          * Get the main part with underscores
 528          * @return \type{\string} Main part of the title, with underscores
 529          */
 530         public function getDBkey() { return $this->mDbkeyform; }
 531         /**
 532          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 533          * @return \type{\int} Namespace index
 534          */
 535         public function getNamespace() { return $this->mNamespace; }
 536         /**
 537          * Get the namespace text
 538          * @return \type{\string} Namespace text
 539          */
 540         public function getNsText() {
 541                 global $wgContLang, $wgCanonicalNamespaceNames;
 542
 543                 if ( '' != $this->mInterwiki ) {
 544                         // This probably shouldn't even happen. ohh man, oh yuck.
 545                         // But for interwiki transclusion it sometimes does.
 546                         // Shit. Shit shit shit.
 547                         //
 548                         // Use the canonical namespaces if possible to try to
 549                         // resolve a foreign namespace.
 550                         if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
 551                                 return $wgCanonicalNamespaceNames[$this->mNamespace];
 552                         }
 553                 }
 554                 return $wgContLang->getNsText( $this->mNamespace );
 555         }
 556         /**
 557          * Get the DB key with the initial letter case as specified by the user
 558          * @return \type{\string} DB key
 559          */
 560         function getUserCaseDBKey() {
 561                 return $this->mUserCaseDBKey;
 562         }
 563         /**
 564          * Get the namespace text of the subject (rather than talk) page
 565          * @return \type{\string} Namespace text
 566          */
 567         public function getSubjectNsText() {
 568                 global $wgContLang;
 569                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 570         }
 571         /**
 572          * Get the namespace text of the talk page
 573          * @return \type{\string} Namespace text
 574          */
 575         public function getTalkNsText() {
 576                 global $wgContLang;
 577                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 578         }
 579         /**
 580          * Could this title have a corresponding talk page?
 581          * @return \type{\bool} TRUE or FALSE
 582          */
 583         public function canTalk() {
 584                 return( MWNamespace::canTalk( $this->mNamespace ) );
 585         }
 586         /**
 587          * Get the interwiki prefix (or null string)
 588          * @return \type{\string} Interwiki prefix
 589          */
 590         public function getInterwiki() { return $this->mInterwiki; }
 591         /**
 592          * Get the Title fragment (i.e.\ the bit after the #) in text form
 593          * @return \type{\string} Title fragment
 594          */
 595         public function getFragment() { return $this->mFragment; }
 596         /**
 597          * Get the fragment in URL form, including the "#" character if there is one
 598          * @return \type{\string} Fragment in URL form
 599          */
 600         public function getFragmentForURL() {
 601                 if ( $this->mFragment == '' ) {
 602                         return '';
 603                 } else {
 604                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 605                 }
 606         }
 607         /**
 608          * Get the default namespace index, for when there is no namespace
 609          * @return \type{\int} Default namespace index
 610          */
 611         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 612
 613         /**
 614          * Get title for search index
 615          * @return \type{\string} a stripped-down title string ready for the
 616          *      search index
 617          */
 618         public function getIndexTitle() {
 619                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 620         }
 621
 622         /**
 623          * Get the prefixed database key form
 624          * @return \type{\string} the prefixed title, with underscores and
 625          *      any interwiki and namespace prefixes
 626          */
 627         public function getPrefixedDBkey() {
 628                 $s = $this->prefix( $this->mDbkeyform );
 629                 $s = str_replace( ' ', '_', $s );
 630                 return $s;
 631         }
 632
 633         /**
 634          * Get the prefixed title with spaces.
 635          * This is the form usually used for display
 636          * @return \type{\string} the prefixed title, with spaces
 637          */
 638         public function getPrefixedText() {
 639                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 640                         $s = $this->prefix( $this->mTextform );
 641                         $s = str_replace( '_', ' ', $s );
 642                         $this->mPrefixedText = $s;
 643                 }
 644                 return $this->mPrefixedText;
 645         }
 646
 647         /**
 648          * Get the prefixed title with spaces, plus any fragment
 649          * (part beginning with '#')
 650          * @return \type{\string} the prefixed title, with spaces and
 651          *      the fragment, including '#'
 652          */
 653         public function getFullText() {
 654                 $text = $this->getPrefixedText();
 655                 if( '' != $this->mFragment ) {
 656                         $text .= '#' . $this->mFragment;
 657                 }
 658                 return $text;
 659         }
 660
 661         /**
 662          * Get the base name, i.e. the leftmost parts before the /
 663          * @return \type{\string} Base name
 664          */
 665         public function getBaseText() {
 666                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 667                         return $this->getText();
 668                 }
 669
 670                 $parts = explode( '/', $this->getText() );
 671                 # Don't discard the real title if there's no subpage involved
 672                 if( count( $parts ) > 1 )
 673                         unset( $parts[ count( $parts ) - 1 ] );
 674                 return implode( '/', $parts );
 675         }
 676
 677         /**
 678          * Get the lowest-level subpage name, i.e. the rightmost part after /
 679          * @return \type{\string} Subpage name
 680          */
 681         public function getSubpageText() {
 682                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 683                         return( $this->mTextform );
 684                 }
 685                 $parts = explode( '/', $this->mTextform );
 686                 return( $parts[ count( $parts ) - 1 ] );
 687         }
 688
 689         /**
 690          * Get a URL-encoded form of the subpage text
 691          * @return \type{\string} URL-encoded subpage name
 692          */
 693         public function getSubpageUrlForm() {
 694                 $text = $this->getSubpageText();
 695                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 696                 return( $text );
 697         }
 698
 699         /**
 700          * Get a URL-encoded title (not an actual URL) including interwiki
 701          * @return \type{\string} the URL-encoded form
 702          */
 703         public function getPrefixedURL() {
 704                 $s = $this->prefix( $this->mDbkeyform );
 705                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 706                 return $s;
 707         }
 708
 709         /**
 710          * Get a real URL referring to this title, with interwiki link and
 711          * fragment
 712          *
 713          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 714          *   links. Can be specified as an associative array as well, e.g.,
 715          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 716          * @param $variant \type{\string} language variant of url (for sr, zh..)
 717          * @return \type{\string} the URL
 718          */
 719         public function getFullURL( $query = '', $variant = false ) {
 720                 global $wgContLang, $wgServer, $wgRequest;
 721
 722                 if( is_array( $query ) ) {
 723                         $query = wfArrayToCGI( $query );
 724                 }
 725
 726                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 727                 if ( !$interwiki ) {
 728                         $url = $this->getLocalUrl( $query, $variant );
 729
 730                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 731                         // Correct fix would be to move the prepending elsewhere.
 732                         if ($wgRequest->getVal('action') != 'render') {
 733                                 $url = $wgServer . $url;
 734                         }
 735                 } else {
 736                         $baseUrl = $interwiki->getURL( );
 737
 738                         $namespace = wfUrlencode( $this->getNsText() );
 739                         if ( '' != $namespace ) {
 740                                 # Can this actually happen? Interwikis shouldn't be parsed.
 741                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 742                                 $namespace .= ':';
 743                         }
 744                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 745                         $url = wfAppendQuery( $url, $query );
 746                 }
 747
 748                 # Finally, add the fragment.
 749                 $url .= $this->getFragmentForURL();
 750
 751                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 752                 return $url;
 753         }
 754
 755         /**
 756          * Get a URL with no fragment or server name.  If this page is generated
 757          * with action=render, $wgServer is prepended.
 758          * @param mixed $query an optional query string; if not specified,
 759          *       $wgArticlePath will be used.  Can be specified as an associative array
 760          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 761          *   URL-escaped).
 762          * @param $variant \type{\string} language variant of url (for sr, zh..)
 763          * @return \type{\string} the URL
 764          */
 765         public function getLocalURL( $query = '', $variant = false ) {
 766                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 767                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 768
 769                 if( is_array( $query ) ) {
 770                         $query = wfArrayToCGI( $query );
 771                 }
 772
 773                 // internal links should point to same variant as current page (only anonymous users)
 774                 if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
 775                         $pref = $wgContLang->getPreferredVariant(false);
 776                         if($pref != $wgContLang->getCode())
 777                                 $variant = $pref;
 778                 }
 779
 780                 if ( $this->isExternal() ) {
 781                         $url = $this->getFullURL();
 782                         if ( $query ) {
 783                                 // This is currently only used for edit section links in the
 784                                 // context of interwiki transclusion. In theory we should
 785                                 // append the query to the end of any existing query string,
 786                                 // but interwiki transclusion is already broken in that case.
 787                                 $url .= "?$query";
 788                         }
 789                 } else {
 790                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 791                         if ( $query == '' ) {
 792                                 if( $variant != false && $wgContLang->hasVariants() ) {
 793                                         if( $wgVariantArticlePath == false ) {
 794                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 795                                         } else {
 796                                                 $variantArticlePath = $wgVariantArticlePath;
 797                                         }
 798                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 799                                         $url = str_replace( '$1', $dbkey, $url  );
 800                                 } else {
 801                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 802                                 }
 803                         } else {
 804                                 global $wgActionPaths;
 805                                 $url = false;
 806                                 $matches = array();
 807                                 if( !empty( $wgActionPaths ) &&
 808                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 809                                 {
 810                                         $action = urldecode( $matches[2] );
 811                                         if( isset( $wgActionPaths[$action] ) ) {
 812                                                 $query = $matches[1];
 813                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 814                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 815                                                 if( $query != '' ) {
 816                                                         $url = wfAppendQuery( $url, $query );
 817                                                 }
 818                                         }
 819                                 }
 820                                 if ( $url === false ) {
 821                                         if ( $query == '-' ) {
 822                                                 $query = '';
 823                                         }
 824                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 825                                 }
 826                         }
 827
 828                         // FIXME: this causes breakage in various places when we
 829                         // actually expected a local URL and end up with dupe prefixes.
 830                         if ($wgRequest->getVal('action') == 'render') {
 831                                 $url = $wgServer . $url;
 832                         }
 833                 }
 834                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 835                 return $url;
 836         }
 837
 838         /**
 839          * Get a URL that's the simplest URL that will be valid to link, locally,
 840          * to the current Title.  It includes the fragment, but does not include
 841          * the server unless action=render is used (or the link is external).  If
 842          * there's a fragment but the prefixed text is empty, we just return a link
 843          * to the fragment.
 844          *
 845          * The result obviously should not be URL-escaped, but does need to be
 846          * HTML-escaped if it's being output in HTML.
 847          *
 848          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 849          *   query string.  Keys and values will be escaped.
 850          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 851          *   for external links.  Default is "false" (same variant as current page,
 852          *   for anonymous users).
 853          * @return \type{\string} the URL
 854          */
 855         public function getLinkUrl( $query = array(), $variant = false ) {
 856                 wfProfileIn( __METHOD__ );
 857                 if( !is_array( $query ) ) {
 858                         wfProfileOut( __METHOD__ );
 859                         throw new MWException( 'Title::getLinkUrl passed a non-array for '.
 860                         '$query' );
 861                 }
 862                 if( $this->isExternal() ) {
 863                         $ret = $this->getFullURL( $query );
 864                 } elseif( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 865                         $ret = $this->getFragmentForURL();
 866                 } else {
 867                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 868                 }
 869                 wfProfileOut( __METHOD__ );
 870                 return $ret;
 871         }
 872
 873         /**
 874          * Get an HTML-escaped version of the URL form, suitable for
 875          * using in a link, without a server name or fragment
 876          * @param $query \type{\string} an optional query string
 877          * @return \type{\string} the URL
 878          */
 879         public function escapeLocalURL( $query = '' ) {
 880                 return htmlspecialchars( $this->getLocalURL( $query ) );
 881         }
 882
 883         /**
 884          * Get an HTML-escaped version of the URL form, suitable for
 885          * using in a link, including the server name and fragment
 886          *
 887          * @param $query \type{\string} an optional query string
 888          * @return \type{\string} the URL
 889          */
 890         public function escapeFullURL( $query = '' ) {
 891                 return htmlspecialchars( $this->getFullURL( $query ) );
 892         }
 893
 894         /**
 895          * Get the URL form for an internal link.
 896          * - Used in various Squid-related code, in case we have a different
 897          * internal hostname for the server from the exposed one.
 898          *
 899          * @param $query \type{\string} an optional query string
 900          * @param $variant \type{\string} language variant of url (for sr, zh..)
 901          * @return \type{\string} the URL
 902          */
 903         public function getInternalURL( $query = '', $variant = false ) {
 904                 global $wgInternalServer;
 905                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 906                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 907                 return $url;
 908         }
 909
 910         /**
 911          * Get the edit URL for this Title
 912          * @return \type{\string} the URL, or a null string if this is an
 913          *      interwiki link
 914          */
 915         public function getEditURL() {
 916                 if ( '' != $this->mInterwiki ) { return ''; }
 917                 $s = $this->getLocalURL( 'action=edit' );
 918
 919                 return $s;
 920         }
 921
 922         /**
 923          * Get the HTML-escaped displayable text form.
 924          * Used for the title field in <a> tags.
 925          * @return \type{\string} the text, including any prefixes
 926          */
 927         public function getEscapedText() {
 928                 return htmlspecialchars( $this->getPrefixedText() );
 929         }
 930
 931         /**
 932          * Is this Title interwiki?
 933          * @return \type{\bool}
 934          */
 935         public function isExternal() { return ( '' != $this->mInterwiki ); }
 936
 937         /**
 938          * Is this page "semi-protected" - the *only* protection is autoconfirm?
 939          *
 940          * @param @action \type{\string} Action to check (default: edit)
 941          * @return \type{\bool}
 942          */
 943         public function isSemiProtected( $action = 'edit' ) {
 944                 if( $this->exists() ) {
 945                         $restrictions = $this->getRestrictions( $action );
 946                         if( count( $restrictions ) > 0 ) {
 947                                 foreach( $restrictions as $restriction ) {
 948                                         if( strtolower( $restriction ) != 'autoconfirmed' )
 949                                                 return false;
 950                                 }
 951                         } else {
 952                                 # Not protected
 953                                 return false;
 954                         }
 955                         return true;
 956                 } else {
 957                         # If it doesn't exist, it can't be protected
 958                         return false;
 959                 }
 960         }
 961
 962         /**
 963          * Does the title correspond to a protected article?
 964          * @param $what \type{\string} the action the page is protected from,
 965          * by default checks move and edit
 966          * @return \type{\bool}
 967          */
 968         public function isProtected( $action = '' ) {
 969                 global $wgRestrictionLevels, $wgRestrictionTypes;
 970
 971                 # Special pages have inherent protection
 972                 if( $this->getNamespace() == NS_SPECIAL )
 973                         return true;
 974
 975                 # Check regular protection levels
 976                 foreach( $wgRestrictionTypes as $type ){
 977                         if( $action == $type || $action == '' ) {
 978                                 $r = $this->getRestrictions( $type );
 979                                 foreach( $wgRestrictionLevels as $level ) {
 980                                         if( in_array( $level, $r ) && $level != '' ) {
 981                                                 return true;
 982                                         }
 983                                 }
 984                         }
 985                 }
 986
 987                 return false;
 988         }
 989
 990         /**
 991          * Is $wgUser watching this page?
 992          * @return \type{\bool}
 993          */
 994         public function userIsWatching() {
 995                 global $wgUser;
 996
 997                 if ( is_null( $this->mWatched ) ) {
 998                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
 999                                 $this->mWatched = false;
1000                         } else {
1001                                 $this->mWatched = $wgUser->isWatched( $this );
1002                         }
1003                 }
1004                 return $this->mWatched;
1005         }
1006
1007         /**
1008          * Can $wgUser perform $action on this page?
1009          * This skips potentially expensive cascading permission checks.
1010          *
1011          * Suitable for use for nonessential UI controls in common cases, but
1012          * _not_ for functional access control.
1013          *
1014          * May provide false positives, but should never provide a false negative.
1015          *
1016          * @param $action \type{\string} action that permission needs to be checked for
1017          * @return \type{\bool}
1018          */
1019         public function quickUserCan( $action ) {
1020                 return $this->userCan( $action, false );
1021         }
1022
1023         /**
1024          * Determines if $wgUser is unable to edit this page because it has been protected
1025          * by $wgNamespaceProtection.
1026          *
1027          * @return \type{\bool}
1028          */
1029         public function isNamespaceProtected() {
1030                 global $wgNamespaceProtection, $wgUser;
1031                 if( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1032                         foreach( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1033                                 if( $right != '' && !$wgUser->isAllowed( $right ) )
1034                                         return true;
1035                         }
1036                 }
1037                 return false;
1038         }
1039
1040         /**
1041          * Can $wgUser perform $action on this page?
1042          * @param $action \type{\string} action that permission needs to be checked for
1043          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1044          * @return \type{\bool}
1045          */
1046         public function userCan( $action, $doExpensiveQueries = true ) {
1047                 global $wgUser;
1048                 return ($this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array());
1049         }
1050
1051         /**
1052          * Can $user perform $action on this page?
1053          *
1054          * FIXME: This *does not* check throttles (User::pingLimiter()).
1055          *
1056          * @param $action \type{\string}action that permission needs to be checked for
1057          * @param $user \type{User} user to check
1058          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1059          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1060          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1061          */
1062         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1063                 if( !StubObject::isRealObject( $user ) ) {
1064                         //Since StubObject is always used on globals, we can unstub $wgUser here and set $user = $wgUser
1065                         global $wgUser;
1066                         $wgUser->_unstub( '', 5 );
1067                         $user = $wgUser;
1068                 }
1069                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1070
1071                 global $wgContLang;
1072                 global $wgLang;
1073                 global $wgEmailConfirmToEdit;
1074
1075                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1076                         $errors[] = array( 'confirmedittext' );
1077                 }
1078
1079                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1080                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1081                         $block = $user->mBlock;
1082
1083                         // This is from OutputPage::blockedPage
1084                         // Copied at r23888 by werdna
1085
1086                         $id = $user->blockedBy();
1087                         $reason = $user->blockedFor();
1088                         if( $reason == '' ) {
1089                                 $reason = wfMsg( 'blockednoreason' );
1090                         }
1091                         $ip = wfGetIP();
1092
1093                         if ( is_numeric( $id ) ) {
1094                                 $name = User::whoIs( $id );
1095                         } else {
1096                                 $name = $id;
1097                         }
1098
1099                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1100                         $blockid = $block->mId;
1101                         $blockExpiry = $user->mBlock->mExpiry;
1102                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1103
1104                         if ( $blockExpiry == 'infinity' ) {
1105                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1106                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1107
1108                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1109                                         if ( strpos( $option, ':' ) == false )
1110                                                 continue;
1111
1112                                         list ($show, $value) = explode( ":", $option );
1113
1114                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1115                                                 $blockExpiry = $show;
1116                                                 break;
1117                                         }
1118                                 }
1119                         } else {
1120                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1121                         }
1122
1123                         $intended = $user->mBlock->mAddress;
1124
1125                         $errors[] = array( ($block->mAuto ? 'autoblockedtext' : 'blockedtext'), $link, $reason, $ip, $name,
1126                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1127                 }
1128
1129                 // Remove the errors being ignored.
1130
1131                 foreach( $errors as $index => $error ) {
1132                         $error_key = is_array($error) ? $error[0] : $error;
1133
1134                         if (in_array( $error_key, $ignoreErrors )) {
1135                                 unset($errors[$index]);
1136                         }
1137                 }
1138
1139                 return $errors;
1140         }
1141
1142         /**
1143          * Can $user perform $action on this page? This is an internal function,
1144          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1145          * checks on wfReadOnly() and blocks)
1146          *
1147          * @param $action \type{\string} action that permission needs to be checked for
1148          * @param $user \type{User} user to check
1149          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1150          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1151          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1152          */
1153         private function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries=true, $short=false ) {
1154                 wfProfileIn( __METHOD__ );
1155
1156                 $errors = array();
1157
1158                 // First stop is permissions checks, which fail most often, and which are easiest to test.
1159                 if ( $action == 'move' ) {
1160                         if( !$user->isAllowed( 'move-rootuserpages' )
1161                                         && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1162                         {
1163                                 // Show user page-specific message only if the user can move other pages
1164                                 $errors[] = array( 'cant-move-user-page' );
1165                         }
1166
1167                         // Check if user is allowed to move files if it's a file
1168                         if( $this->getNamespace() == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1169                                 $errors[] = array( 'movenotallowedfile' );
1170                         }
1171
1172                         if( !$user->isAllowed( 'move' ) ) {
1173                                 // User can't move anything
1174                                 global $wgGroupPermissions;
1175                                 if( $user->isAnon() && ( $wgGroupPermissions['user']['move']
1176                                 || $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1177                                         // custom message if logged-in users without any special rights can move
1178                                         $errors[] = array ( 'movenologintext' );
1179                                 } else {
1180                                         $errors[] = array ('movenotallowed');
1181                                 }
1182                         }
1183                 } elseif ( $action == 'create' ) {
1184                         if( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1185                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) )
1186                         {
1187                                 $errors[] = $user->isAnon() ? array ('nocreatetext') : array ('nocreate-loggedin');
1188                         }
1189                 } elseif( $action == 'move-target' ) {
1190                         if( !$user->isAllowed( 'move' ) ) {
1191                                 // User can't move anything
1192                                 $errors[] = array ('movenotallowed');
1193                         } elseif( !$user->isAllowed( 'move-rootuserpages' )
1194                                 && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1195                         {
1196                                 // Show user page-specific message only if the user can move other pages
1197                                 $errors[] = array( 'cant-move-to-user-page' );
1198                         }
1199                 } elseif( !$user->isAllowed( $action ) ) {
1200                         $return = null;
1201                         $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1202                                 User::getGroupsWithPermission( $action ) );
1203                         if( $groups ) {
1204                                 $return = array( 'badaccess-groups',
1205                                         array( implode( ', ', $groups ), count( $groups ) ) );
1206                         } else {
1207                                 $return = array( "badaccess-group0" );
1208                         }
1209                         $errors[] = $return;
1210                 }
1211
1212                 # Short-circuit point
1213                 if( $short && count($errors) > 0 ) {
1214                         wfProfileOut( __METHOD__ );
1215                         return $errors;
1216                 }
1217
1218                 // Use getUserPermissionsErrors instead
1219                 if( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1220                         wfProfileOut( __METHOD__ );
1221                         return $result ? array() : array( array( 'badaccess-group0' ) );
1222                 }
1223                 // Check getUserPermissionsErrors hook
1224                 if( !wfRunHooks( 'getUserPermissionsErrors', array(&$this,&$user,$action,&$result) ) ) {
1225                         if( is_array($result) && count($result) && !is_array($result[0]) )
1226                                 $errors[] = $result; # A single array representing an error
1227                         else if( is_array($result) && is_array($result[0]) )
1228                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1229                         else if( $result !== '' && is_string($result) )
1230                                 $errors[] = array($result); # A string representing a message-id
1231                         else if( $result === false )
1232                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1233                 }
1234                 # Short-circuit point
1235                 if( $short && count($errors) > 0 ) {
1236                         wfProfileOut( __METHOD__ );
1237                         return $errors;
1238                 }
1239                 // Check getUserPermissionsErrorsExpensive hook
1240                 if( $doExpensiveQueries && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array(&$this,&$user,$action,&$result) ) ) {
1241                         if( is_array($result) && count($result) && !is_array($result[0]) )
1242                                 $errors[] = $result; # A single array representing an error
1243                         else if( is_array($result) && is_array($result[0]) )
1244                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1245                         else if( $result !== '' && is_string($result) )
1246                                 $errors[] = array($result); # A string representing a message-id
1247                         else if( $result === false )
1248                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1249                 }
1250                 # Short-circuit point
1251                 if( $short && count($errors) > 0 ) {
1252                         wfProfileOut( __METHOD__ );
1253                         return $errors;
1254                 }
1255
1256                 # Only 'createaccount' and 'execute' can be performed on
1257                 # special pages, which don't actually exist in the DB.
1258                 $specialOKActions = array( 'createaccount', 'execute' );
1259                 if( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions) ) {
1260                         $errors[] = array('ns-specialprotected');
1261                 }
1262
1263                 # Check $wgNamespaceProtection for restricted namespaces
1264                 if( $this->isNamespaceProtected() ) {
1265                         $ns = $this->getNamespace() == NS_MAIN ?
1266                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1267                         $errors[] = NS_MEDIAWIKI == $this->mNamespace ?
1268                                 array('protectedinterface') : array( 'namespaceprotected',  $ns );
1269                 }
1270
1271                 # Protect css/js subpages of user pages
1272                 # XXX: this might be better using restrictions
1273                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
1274                 if( $this->isCssJsSubpage() && !$user->isAllowed('editusercssjs')
1275                         && !preg_match('/^'.preg_quote($user->getName(), '/').'\//', $this->mTextform) )
1276                 {
1277                         $errors[] = array('customcssjsprotected');
1278                 }
1279
1280                 # Check against page_restrictions table requirements on this
1281                 # page. The user must possess all required rights for this action.
1282                 foreach( $this->getRestrictions($action) as $right ) {
1283                         // Backwards compatibility, rewrite sysop -> protect
1284                         if( $right == 'sysop' ) {
1285                                 $right = 'protect';
1286                         }
1287                         if( '' != $right && !$user->isAllowed( $right ) ) {
1288                                 // Users with 'editprotected' permission can edit protected pages
1289                                 if( $action=='edit' && $user->isAllowed( 'editprotected' ) ) {
1290                                         // Users with 'editprotected' permission cannot edit protected pages
1291                                         // with cascading option turned on.
1292                                         if( $this->mCascadeRestriction ) {
1293                                                 $errors[] = array( 'protectedpagetext', $right );
1294                                         }
1295                                 } else {
1296                                         $errors[] = array( 'protectedpagetext', $right );
1297                                 }
1298                         }
1299                 }
1300                 # Short-circuit point
1301                 if( $short && count($errors) > 0 ) {
1302                         wfProfileOut( __METHOD__ );
1303                         return $errors;
1304                 }
1305
1306                 if( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1307                         # We /could/ use the protection level on the source page, but it's fairly ugly
1308                         #  as we have to establish a precedence hierarchy for pages included by multiple
1309                         #  cascade-protected pages. So just restrict it to people with 'protect' permission,
1310                         #  as they could remove the protection anyway.
1311                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1312                         # Cascading protection depends on more than this page...
1313                         # Several cascading protected pages may include this page...
1314                         # Check each cascading level
1315                         # This is only for protection restrictions, not for all actions
1316                         if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
1317                                 foreach( $restrictions[$action] as $right ) {
1318                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1319                                         if( '' != $right && !$user->isAllowed( $right ) ) {
1320                                                 $pages = '';
1321                                                 foreach( $cascadingSources as $page )
1322                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1323                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1324                                         }
1325                                 }
1326                         }
1327                 }
1328                 # Short-circuit point
1329                 if( $short && count($errors) > 0 ) {
1330                         wfProfileOut( __METHOD__ );
1331                         return $errors;
1332                 }
1333
1334                 if( $action == 'protect' ) {
1335                         if( $this->getUserPermissionsErrors('edit', $user) != array() ) {
1336                                 $errors[] = array( 'protect-cantedit' ); // If they can't edit, they shouldn't protect.
1337                         }
1338                 }
1339
1340                 if( $action == 'create' ) {
1341                         $title_protection = $this->getTitleProtection();
1342                         if( is_array($title_protection) ) {
1343                                 extract($title_protection); // is this extract() really needed?
1344
1345                                 if( $pt_create_perm == 'sysop' ) {
1346                                         $pt_create_perm = 'protect'; // B/C
1347                                 }
1348                                 if( $pt_create_perm == '' || !$user->isAllowed($pt_create_perm) ) {
1349                                         $errors[] = array( 'titleprotected', User::whoIs($pt_user), $pt_reason );
1350                                 }
1351                         }
1352                 } elseif( $action == 'move' ) {
1353                         // Check for immobile pages
1354                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1355                                 // Specific message for this case
1356                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1357                         } elseif( !$this->isMovable() ) {
1358                                 // Less specific message for rarer cases
1359                                 $errors[] = array( 'immobile-page' );
1360                         }
1361                 } elseif( $action == 'move-target' ) {
1362                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1363                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1364                         } elseif( !$this->isMovable() ) {
1365                                 $errors[] = array( 'immobile-target-page' );
1366                         }
1367                 }
1368
1369                 wfProfileOut( __METHOD__ );
1370                 return $errors;
1371         }
1372
1373         /**
1374          * Is this title subject to title protection?
1375          * @return \type{\mixed} An associative array representing any existent title
1376          *   protection, or false if there's none.
1377          */
1378         private function getTitleProtection() {
1379                 // Can't protect pages in special namespaces
1380                 if ( $this->getNamespace() < 0 ) {
1381                         return false;
1382                 }
1383
1384                 $dbr = wfGetDB( DB_SLAVE );
1385                 $res = $dbr->select( 'protected_titles', '*',
1386                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1387                         __METHOD__ );
1388
1389                 if ($row = $dbr->fetchRow( $res )) {
1390                         return $row;
1391                 } else {
1392                         return false;
1393                 }
1394         }
1395
1396         /**
1397          * Update the title protection status
1398          * @param $create_perm \type{\string} Permission required for creation
1399          * @param $reason \type{\string} Reason for protection
1400          * @param $expiry \type{\string} Expiry timestamp
1401          */
1402         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1403                 global $wgUser,$wgContLang;
1404
1405                 if ($create_perm == implode(',',$this->getRestrictions('create'))
1406                         && $expiry == $this->mRestrictionsExpiry['create']) {
1407                         // No change
1408                         return true;
1409                 }
1410
1411                 list ($namespace, $title) = array( $this->getNamespace(), $this->getDBkey() );
1412
1413                 $dbw = wfGetDB( DB_MASTER );
1414
1415                 $encodedExpiry = Block::encodeExpiry($expiry, $dbw );
1416
1417                 $expiry_description = '';
1418                 if ( $encodedExpiry != 'infinity' ) {
1419                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ) , $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ).')';
1420                 }
1421                 else {
1422                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ).')';
1423                 }
1424
1425                 # Update protection table
1426                 if ($create_perm != '' ) {
1427                         $dbw->replace( 'protected_titles', array(array('pt_namespace', 'pt_title')),
1428                                 array( 'pt_namespace' => $namespace, 'pt_title' => $title
1429                                         , 'pt_create_perm' => $create_perm
1430                                         , 'pt_timestamp' => Block::encodeExpiry(wfTimestampNow(), $dbw)
1431                                         , 'pt_expiry' => $encodedExpiry
1432                                         , 'pt_user' => $wgUser->getId(), 'pt_reason' => $reason ), __METHOD__  );
1433                 } else {
1434                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1435                                 'pt_title' => $title ), __METHOD__ );
1436                 }
1437                 # Update the protection log
1438                 $log = new LogPage( 'protect' );
1439
1440                 if( $create_perm ) {
1441                         $params = array("[create=$create_perm] $expiry_description",'');
1442                         $log->addEntry( $this->mRestrictions['create'] ? 'modify' : 'protect', $this, trim( $reason ), $params );
1443                 } else {
1444                         $log->addEntry( 'unprotect', $this, $reason );
1445                 }
1446
1447                 return true;
1448         }
1449
1450         /**
1451          * Remove any title protection due to page existing
1452          */
1453         public function deleteTitleProtection() {
1454                 $dbw = wfGetDB( DB_MASTER );
1455
1456                 $dbw->delete( 'protected_titles',
1457                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1458                         __METHOD__ );
1459         }
1460
1461         /**
1462          * Would anybody with sufficient privileges be able to move this page?
1463          * Some pages just aren't movable.
1464          *
1465          * @return \type{\bool} TRUE or FALSE
1466          */
1467         public function isMovable() {
1468                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1469         }
1470
1471         /**
1472          * Can $wgUser read this page?
1473          * @return \type{\bool} TRUE or FALSE
1474          * @todo fold these checks into userCan()
1475          */
1476         public function userCanRead() {
1477                 global $wgUser, $wgGroupPermissions;
1478
1479                 $result = null;
1480                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1481                 if ( $result !== null ) {
1482                         return $result;
1483                 }
1484
1485                 # Shortcut for public wikis, allows skipping quite a bit of code
1486                 if ( !empty( $wgGroupPermissions['*']['read'] ) )
1487                         return true;
1488
1489                 if( $wgUser->isAllowed( 'read' ) ) {
1490                         return true;
1491                 } else {
1492                         global $wgWhitelistRead;
1493
1494                         /**
1495                          * Always grant access to the login page.
1496                          * Even anons need to be able to log in.
1497                         */
1498                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1499                                 return true;
1500                         }
1501
1502                         /**
1503                          * Bail out if there isn't whitelist
1504                          */
1505                         if( !is_array($wgWhitelistRead) ) {
1506                                 return false;
1507                         }
1508
1509                         /**
1510                          * Check for explicit whitelisting
1511                          */
1512                         $name = $this->getPrefixedText();
1513                         $dbName = $this->getPrefixedDBKey();
1514                         // Check with and without underscores
1515                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1516                                 return true;
1517
1518                         /**
1519                          * Old settings might have the title prefixed with
1520                          * a colon for main-namespace pages
1521                          */
1522                         if( $this->getNamespace() == NS_MAIN ) {
1523                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1524                                         return true;
1525                         }
1526
1527                         /**
1528                          * If it's a special page, ditch the subpage bit
1529                          * and check again
1530                          */
1531                         if( $this->getNamespace() == NS_SPECIAL ) {
1532                                 $name = $this->getDBkey();
1533                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1534                                 if ( $name === false ) {
1535                                         # Invalid special page, but we show standard login required message
1536                                         return false;
1537                                 }
1538
1539                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1540                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1541                                         return true;
1542                         }
1543
1544                 }
1545                 return false;
1546         }
1547
1548         /**
1549          * Is this a talk page of some sort?
1550          * @return \type{\bool} TRUE or FALSE
1551          */
1552         public function isTalkPage() {
1553                 return MWNamespace::isTalk( $this->getNamespace() );
1554         }
1555
1556         /**
1557          * Is this a subpage?
1558          * @return \type{\bool} TRUE or FALSE
1559          */
1560         public function isSubpage() {
1561                 return MWNamespace::hasSubpages( $this->mNamespace )
1562                         ? strpos( $this->getText(), '/' ) !== false
1563                         : false;
1564         }
1565
1566         /**
1567          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1568          * @return \type{\bool} TRUE or FALSE
1569          */
1570         public function hasSubpages() {
1571                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1572                         # Duh
1573                         return false;
1574                 }
1575
1576                 # We dynamically add a member variable for the purpose of this method
1577                 # alone to cache the result.  There's no point in having it hanging
1578                 # around uninitialized in every Title object; therefore we only add it
1579                 # if needed and don't declare it statically.
1580                 if( isset( $this->mHasSubpages ) ) {
1581                         return $this->mHasSubpages;
1582                 }
1583
1584                 $subpages = $this->getSubpages( 1 );
1585                 if( $subpages instanceof TitleArray )
1586                         return $this->mHasSubpages = (bool)$subpages->count();
1587                 return $this->mHasSubpages = false;
1588         }
1589
1590         /**
1591          * Get all subpages of this page.
1592          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1593          * @return mixed TitleArray, or empty array if this page's namespace
1594          *  doesn't allow subpages
1595          */
1596         public function getSubpages( $limit = -1 ) {
1597                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1598                         return array();
1599
1600                 $dbr = wfGetDB( DB_SLAVE );
1601                 $conds['page_namespace'] = $this->getNamespace();
1602                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1603                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1604                 $options = array();
1605                 if( $limit > -1 )
1606                         $options['LIMIT'] = $limit;
1607                 return $this->mSubpages = TitleArray::newFromResult(
1608                         $dbr->select( 'page',
1609                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1610                                 $conds,
1611                                 __METHOD__,
1612                                 $options
1613                         )
1614                 );
1615         }
1616
1617         /**
1618          * Could this page contain custom CSS or JavaScript, based
1619          * on the title?
1620          *
1621          * @return \type{\bool} TRUE or FALSE
1622          */
1623         public function isCssOrJsPage() {
1624                 return $this->mNamespace == NS_MEDIAWIKI
1625                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1626         }
1627
1628         /**
1629          * Is this a .css or .js subpage of a user page?
1630          * @return \type{\bool} TRUE or FALSE
1631          */
1632         public function isCssJsSubpage() {
1633                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1634         }
1635         /**
1636          * Is this a *valid* .css or .js subpage of a user page?
1637          * Check that the corresponding skin exists
1638          * @return \type{\bool} TRUE or FALSE
1639          */
1640         public function isValidCssJsSubpage() {
1641                 if ( $this->isCssJsSubpage() ) {
1642                         $skinNames = Skin::getSkinNames();
1643                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1644                 } else {
1645                         return false;
1646                 }
1647         }
1648         /**
1649          * Trim down a .css or .js subpage title to get the corresponding skin name
1650          */
1651         public function getSkinFromCssJsSubpage() {
1652                 $subpage = explode( '/', $this->mTextform );
1653                 $subpage = $subpage[ count( $subpage ) - 1 ];
1654                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1655         }
1656         /**
1657          * Is this a .css subpage of a user page?
1658          * @return \type{\bool} TRUE or FALSE
1659          */
1660         public function isCssSubpage() {
1661                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1662         }
1663         /**
1664          * Is this a .js subpage of a user page?
1665          * @return \type{\bool} TRUE or FALSE
1666          */
1667         public function isJsSubpage() {
1668                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1669         }
1670         /**
1671          * Protect css/js subpages of user pages: can $wgUser edit
1672          * this page?
1673          *
1674          * @return \type{\bool} TRUE or FALSE
1675          * @todo XXX: this might be better using restrictions
1676          */
1677         public function userCanEditCssJsSubpage() {
1678                 global $wgUser;
1679                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1680         }
1681
1682         /**
1683          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1684          *
1685          * @return \type{\bool} If the page is subject to cascading restrictions.
1686          */
1687         public function isCascadeProtected() {
1688                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1689                 return ( $sources > 0 );
1690         }
1691
1692         /**
1693          * Cascading protection: Get the source of any cascading restrictions on this page.
1694          *
1695          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1696          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1697          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1698          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1699          */
1700         public function getCascadeProtectionSources( $get_pages = true ) {
1701                 global $wgRestrictionTypes;
1702
1703                 # Define our dimension of restrictions types
1704                 $pagerestrictions = array();
1705                 foreach( $wgRestrictionTypes as $action )
1706                         $pagerestrictions[$action] = array();
1707
1708                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1709                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1710                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1711                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1712                 }
1713
1714                 wfProfileIn( __METHOD__ );
1715
1716                 $dbr = wfGetDB( DB_SLAVE );
1717
1718                 if ( $this->getNamespace() == NS_FILE ) {
1719                         $tables = array ('imagelinks', 'page_restrictions');
1720                         $where_clauses = array(
1721                                 'il_to' => $this->getDBkey(),
1722                                 'il_from=pr_page',
1723                                 'pr_cascade' => 1 );
1724                 } else {
1725                         $tables = array ('templatelinks', 'page_restrictions');
1726                         $where_clauses = array(
1727                                 'tl_namespace' => $this->getNamespace(),
1728                                 'tl_title' => $this->getDBkey(),
1729                                 'tl_from=pr_page',
1730                                 'pr_cascade' => 1 );
1731                 }
1732
1733                 if ( $get_pages ) {
1734                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1735                         $where_clauses[] = 'page_id=pr_page';
1736                         $tables[] = 'page';
1737                 } else {
1738                         $cols = array( 'pr_expiry' );
1739                 }
1740
1741                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1742
1743                 $sources = $get_pages ? array() : false;
1744                 $now = wfTimestampNow();
1745                 $purgeExpired = false;
1746
1747                 foreach( $res as $row ) {
1748                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1749                         if( $expiry > $now ) {
1750                                 if ($get_pages) {
1751                                         $page_id = $row->pr_page;
1752                                         $page_ns = $row->page_namespace;
1753                                         $page_title = $row->page_title;
1754                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1755                                         # Add groups needed for each restriction type if its not already there
1756                                         # Make sure this restriction type still exists
1757                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1758                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1759                                         }
1760                                 } else {
1761                                         $sources = true;
1762                                 }
1763                         } else {
1764                                 // Trigger lazy purge of expired restrictions from the db
1765                                 $purgeExpired = true;
1766                         }
1767                 }
1768                 if( $purgeExpired ) {
1769                         Title::purgeExpiredRestrictions();
1770                 }
1771
1772                 wfProfileOut( __METHOD__ );
1773
1774                 if ( $get_pages ) {
1775                         $this->mCascadeSources = $sources;
1776                         $this->mCascadingRestrictions = $pagerestrictions;
1777                 } else {
1778                         $this->mHasCascadingRestrictions = $sources;
1779                 }
1780                 return array( $sources, $pagerestrictions );
1781         }
1782
1783         function areRestrictionsCascading() {
1784                 if (!$this->mRestrictionsLoaded) {
1785                         $this->loadRestrictions();
1786                 }
1787
1788                 return $this->mCascadeRestriction;
1789         }
1790
1791         /**
1792          * Loads a string into mRestrictions array
1793          * @param $res \type{Resource} restrictions as an SQL result.
1794          */
1795         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1796                 global $wgRestrictionTypes;
1797                 $dbr = wfGetDB( DB_SLAVE );
1798
1799                 foreach( $wgRestrictionTypes as $type ){
1800                         $this->mRestrictions[$type] = array();
1801                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1802                 }
1803
1804                 $this->mCascadeRestriction = false;
1805
1806                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1807
1808                 if ( $oldFashionedRestrictions === NULL ) {
1809                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1810                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1811                 }
1812
1813                 if ($oldFashionedRestrictions != '') {
1814
1815                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1816                                 $temp = explode( '=', trim( $restrict ) );
1817                                 if(count($temp) == 1) {
1818                                         // old old format should be treated as edit/move restriction
1819                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1820                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1821                                 } else {
1822                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1823                                 }
1824                         }
1825
1826                         $this->mOldRestrictions = true;
1827
1828                 }
1829
1830                 if( $dbr->numRows( $res ) ) {
1831                         # Current system - load second to make them override.
1832                         $now = wfTimestampNow();
1833                         $purgeExpired = false;
1834
1835                         foreach( $res as $row ) {
1836                                 # Cycle through all the restrictions.
1837
1838                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1839                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1840                                         continue;
1841
1842                                 // This code should be refactored, now that it's being used more generally,
1843                                 // But I don't really see any harm in leaving it in Block for now -werdna
1844                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1845
1846                                 // Only apply the restrictions if they haven't expired!
1847                                 if ( !$expiry || $expiry > $now ) {
1848                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1849                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1850
1851                                         $this->mCascadeRestriction |= $row->pr_cascade;
1852                                 } else {
1853                                         // Trigger a lazy purge of expired restrictions
1854                                         $purgeExpired = true;
1855                                 }
1856                         }
1857
1858                         if( $purgeExpired ) {
1859                                 Title::purgeExpiredRestrictions();
1860                         }
1861                 }
1862
1863                 $this->mRestrictionsLoaded = true;
1864         }
1865
1866         /**
1867          * Load restrictions from the page_restrictions table
1868          */
1869         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1870                 if( !$this->mRestrictionsLoaded ) {
1871                         if ($this->exists()) {
1872                                 $dbr = wfGetDB( DB_SLAVE );
1873
1874                                 $res = $dbr->select( 'page_restrictions', '*',
1875                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1876
1877                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1878                         } else {
1879                                 $title_protection = $this->getTitleProtection();
1880
1881                                 if (is_array($title_protection)) {
1882                                         extract($title_protection);
1883
1884                                         $now = wfTimestampNow();
1885                                         $expiry = Block::decodeExpiry($pt_expiry);
1886
1887                                         if (!$expiry || $expiry > $now) {
1888                                                 // Apply the restrictions
1889                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1890                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1891                                         } else { // Get rid of the old restrictions
1892                                                 Title::purgeExpiredRestrictions();
1893                                         }
1894                                 } else {
1895                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1896                                 }
1897                                 $this->mRestrictionsLoaded = true;
1898                         }
1899                 }
1900         }
1901
1902         /**
1903          * Purge expired restrictions from the page_restrictions table
1904          */
1905         static function purgeExpiredRestrictions() {
1906                 $dbw = wfGetDB( DB_MASTER );
1907                 $dbw->delete( 'page_restrictions',
1908                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1909                         __METHOD__ );
1910
1911                 $dbw->delete( 'protected_titles',
1912                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1913                         __METHOD__ );
1914         }
1915
1916         /**
1917          * Accessor/initialisation for mRestrictions
1918          *
1919          * @param $action \type{\string} action that permission needs to be checked for
1920          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1921          */
1922         public function getRestrictions( $action ) {
1923                 if( !$this->mRestrictionsLoaded ) {
1924                         $this->loadRestrictions();
1925                 }
1926                 return isset( $this->mRestrictions[$action] )
1927                                 ? $this->mRestrictions[$action]
1928                                 : array();
1929         }
1930
1931         /**
1932          * Get the expiry time for the restriction against a given action
1933          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1934          * or not protected at all, or false if the action is not recognised.
1935          */
1936         public function getRestrictionExpiry( $action ) {
1937                 if( !$this->mRestrictionsLoaded ) {
1938                         $this->loadRestrictions();
1939                 }
1940                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1941         }
1942
1943         /**
1944          * Is there a version of this page in the deletion archive?
1945          * @return \type{\int} the number of archived revisions
1946          */
1947         public function isDeleted() {
1948                 if( $this->getNamespace() < 0 ) {
1949                         $n = 0;
1950                 } else {
1951                         $dbr = wfGetDB( DB_SLAVE );
1952                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
1953                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1954                                 __METHOD__
1955                         );
1956                         if( $this->getNamespace() == NS_FILE ) {
1957                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1958                                         array( 'fa_name' => $this->getDBkey() ),
1959                                         __METHOD__
1960                                 );
1961                         }
1962                 }
1963                 return (int)$n;
1964         }
1965
1966         /**
1967          * Is there a version of this page in the deletion archive?
1968          * @return bool
1969          */
1970         public function isDeletedQuick() {
1971                 if( $this->getNamespace() < 0 ) {
1972                         return false;
1973                 }
1974                 $dbr = wfGetDB( DB_SLAVE );
1975                 $deleted = (bool)$dbr->selectField( 'archive', '1',
1976                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1977                         __METHOD__
1978                 );
1979                 if( !$deleted && $this->getNamespace() == NS_FILE ) {
1980                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
1981                                 array( 'fa_name' => $this->getDBkey() ),
1982                                 __METHOD__
1983                         );
1984                 }
1985                 return $deleted;
1986         }
1987
1988         /**
1989          * Get the article ID for this Title from the link cache,
1990          * adding it if necessary
1991          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
1992          *      for update
1993          * @return \type{\int} the ID
1994          */
1995         public function getArticleID( $flags = 0 ) {
1996                 if( $this->getNamespace() < 0 ) {
1997                         return $this->mArticleID = 0;
1998                 }
1999                 $linkCache = LinkCache::singleton();
2000                 if( $flags & GAID_FOR_UPDATE ) {
2001                         $oldUpdate = $linkCache->forUpdate( true );
2002                         $linkCache->clearLink( $this );
2003                         $this->mArticleID = $linkCache->addLinkObj( $this );
2004                         $linkCache->forUpdate( $oldUpdate );
2005                 } else {
2006                         if( -1 == $this->mArticleID ) {
2007                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2008                         }
2009                 }
2010                 return $this->mArticleID;
2011         }
2012
2013         /**
2014          * Is this an article that is a redirect page?
2015          * Uses link cache, adding it if necessary
2016          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2017          * @return \type{\bool}
2018          */
2019         public function isRedirect( $flags = 0 ) {
2020                 if( !is_null($this->mRedirect) )
2021                         return $this->mRedirect;
2022                 # Calling getArticleID() loads the field from cache as needed
2023                 if( !$this->getArticleID($flags) ) {
2024                         return $this->mRedirect = false;
2025                 }
2026                 $linkCache = LinkCache::singleton();
2027                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2028
2029                 return $this->mRedirect;
2030         }
2031
2032         /**
2033          * What is the length of this page?
2034          * Uses link cache, adding it if necessary
2035          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2036          * @return \type{\bool}
2037          */
2038         public function getLength( $flags = 0 ) {
2039                 if( $this->mLength != -1 )
2040                         return $this->mLength;
2041                 # Calling getArticleID() loads the field from cache as needed
2042                 if( !$this->getArticleID($flags) ) {
2043                         return $this->mLength = 0;
2044                 }
2045                 $linkCache = LinkCache::singleton();
2046                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2047
2048                 return $this->mLength;
2049         }
2050
2051         /**
2052          * What is the page_latest field for this page?
2053          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2054          * @return \type{\int}
2055          */
2056         public function getLatestRevID( $flags = 0 ) {
2057                 if( $this->mLatestID !== false )
2058                         return $this->mLatestID;
2059
2060                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2061                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2062                 return $this->mLatestID;
2063         }
2064
2065         /**
2066          * This clears some fields in this object, and clears any associated
2067          * keys in the "bad links" section of the link cache.
2068          *
2069          * - This is called from Article::insertNewArticle() to allow
2070          * loading of the new page_id. It's also called from
2071          * Article::doDeleteArticle()
2072          *
2073          * @param $newid \type{\int} the new Article ID
2074          */
2075         public function resetArticleID( $newid ) {
2076                 $linkCache = LinkCache::singleton();
2077                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2078
2079                 if ( $newid === false ) { $this->mArticleID = -1; }
2080                 else { $this->mArticleID = $newid; }
2081                 $this->mRestrictionsLoaded = false;
2082                 $this->mRestrictions = array();
2083         }
2084
2085         /**
2086          * Updates page_touched for this page; called from LinksUpdate.php
2087          * @return \type{\bool} true if the update succeded
2088          */
2089         public function invalidateCache() {
2090                 if( wfReadOnly() ) {
2091                         return;
2092                 }
2093                 $dbw = wfGetDB( DB_MASTER );
2094                 $success = $dbw->update( 'page',
2095                         array( 'page_touched' => $dbw->timestamp() ),
2096                         $this->pageCond(),
2097                         __METHOD__
2098                 );
2099                 HTMLFileCache::clearFileCache( $this );
2100                 return $success;
2101         }
2102
2103         /**
2104          * Prefix some arbitrary text with the namespace or interwiki prefix
2105          * of this object
2106          *
2107          * @param $name \type{\string} the text
2108          * @return \type{\string} the prefixed text
2109          * @private
2110          */
2111         /* private */ function prefix( $name ) {
2112                 $p = '';
2113                 if ( '' != $this->mInterwiki ) {
2114                         $p = $this->mInterwiki . ':';
2115                 }
2116                 if ( 0 != $this->mNamespace ) {
2117                         $p .= $this->getNsText() . ':';
2118                 }
2119                 return $p . $name;
2120         }
2121
2122         /**
2123          * Secure and split - main initialisation function for this object
2124          *
2125          * Assumes that mDbkeyform has been set, and is urldecoded
2126          * and uses underscores, but not otherwise munged.  This function
2127          * removes illegal characters, splits off the interwiki and
2128          * namespace prefixes, sets the other forms, and canonicalizes
2129          * everything.
2130          * @return \type{\bool} true on success
2131          */
2132         private function secureAndSplit() {
2133                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2134
2135                 # Initialisation
2136                 static $rxTc = false;
2137                 if( !$rxTc ) {
2138                         # Matching titles will be held as illegal.
2139                         $rxTc = '/' .
2140                                 # Any character not allowed is forbidden...
2141                                 '[^' . Title::legalChars() . ']' .
2142                                 # URL percent encoding sequences interfere with the ability
2143                                 # to round-trip titles -- you can't link to them consistently.
2144                                 '|%[0-9A-Fa-f]{2}' .
2145                                 # XML/HTML character references produce similar issues.
2146                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2147                                 '|&#[0-9]+;' .
2148                                 '|&#x[0-9A-Fa-f]+;' .
2149                                 '/S';
2150                 }
2151
2152                 $this->mInterwiki = $this->mFragment = '';
2153                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2154
2155                 $dbkey = $this->mDbkeyform;
2156
2157                 # Strip Unicode bidi override characters.
2158                 # Sometimes they slip into cut-n-pasted page titles, where the
2159                 # override chars get included in list displays.
2160                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2161
2162                 # Clean up whitespace
2163                 #
2164                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2165                 $dbkey = trim( $dbkey, '_' );
2166
2167                 if ( '' == $dbkey ) {
2168                         return false;
2169                 }
2170
2171                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2172                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2173                         return false;
2174                 }
2175
2176                 $this->mDbkeyform = $dbkey;
2177
2178                 # Initial colon indicates main namespace rather than specified default
2179                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2180                 if ( ':' == $dbkey{0} ) {
2181                         $this->mNamespace = NS_MAIN;
2182                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2183                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2184                 }
2185
2186                 # Namespace or interwiki prefix
2187                 $firstPass = true;
2188                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2189                 do {
2190                         $m = array();
2191                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2192                                 $p = $m[1];
2193                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2194                                         # Ordinary namespace
2195                                         $dbkey = $m[2];
2196                                         $this->mNamespace = $ns;
2197                                         # For Talk:X pages, check if X has a "namespace" prefix
2198                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2199                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2200                                                         return false; # Disallow Talk:File:x type titles...
2201                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2202                                                         return false; # Disallow Talk:Interwiki:x type titles...
2203                                         }
2204                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2205                                         if( !$firstPass ) {
2206                                                 # Can't make a local interwiki link to an interwiki link.
2207                                                 # That's just crazy!
2208                                                 return false;
2209                                         }
2210
2211                                         # Interwiki link
2212                                         $dbkey = $m[2];
2213                                         $this->mInterwiki = $wgContLang->lc( $p );
2214
2215                                         # Redundant interwiki prefix to the local wiki
2216                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2217                                                 if( $dbkey == '' ) {
2218                                                         # Can't have an empty self-link
2219                                                         return false;
2220                                                 }
2221                                                 $this->mInterwiki = '';
2222                                                 $firstPass = false;
2223                                                 # Do another namespace split...
2224                                                 continue;
2225                                         }
2226
2227                                         # If there's an initial colon after the interwiki, that also
2228                                         # resets the default namespace
2229                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2230                                                 $this->mNamespace = NS_MAIN;
2231                                                 $dbkey = substr( $dbkey, 1 );
2232                                         }
2233                                 }
2234                                 # If there's no recognized interwiki or namespace,
2235                                 # then let the colon expression be part of the title.
2236                         }
2237                         break;
2238                 } while( true );
2239
2240                 # We already know that some pages won't be in the database!
2241                 #
2242                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2243                         $this->mArticleID = 0;
2244                 }
2245                 $fragment = strstr( $dbkey, '#' );
2246                 if ( false !== $fragment ) {
2247                         $this->setFragment( $fragment );
2248                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2249                         # remove whitespace again: prevents "Foo_bar_#"
2250                         # becoming "Foo_bar_"
2251                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2252                 }
2253
2254                 # Reject illegal characters.
2255                 #
2256                 if( preg_match( $rxTc, $dbkey ) ) {
2257                         return false;
2258                 }
2259
2260                 /**
2261                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2262                  * reachable due to the way web browsers deal with 'relative' URLs.
2263                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2264                  */
2265                 if ( strpos( $dbkey, '.' ) !== false &&
2266                      ( $dbkey === '.' || $dbkey === '..' ||
2267                        strpos( $dbkey, './' ) === 0  ||
2268                        strpos( $dbkey, '../' ) === 0 ||
2269                        strpos( $dbkey, '/./' ) !== false ||
2270                        strpos( $dbkey, '/../' ) !== false  ||
2271                        substr( $dbkey, -2 ) == '/.' ||
2272                        substr( $dbkey, -3 ) == '/..' ) )
2273                 {
2274                         return false;
2275                 }
2276
2277                 /**
2278                  * Magic tilde sequences? Nu-uh!
2279                  */
2280                 if( strpos( $dbkey, '~~~' ) !== false ) {
2281                         return false;
2282                 }
2283
2284                 /**
2285                  * Limit the size of titles to 255 bytes.
2286                  * This is typically the size of the underlying database field.
2287                  * We make an exception for special pages, which don't need to be stored
2288                  * in the database, and may edge over 255 bytes due to subpage syntax
2289                  * for long titles, e.g. [[Special:Block/Long name]]
2290                  */
2291                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2292                   strlen( $dbkey ) > 512 )
2293                 {
2294                         return false;
2295                 }
2296
2297                 /**
2298                  * Normally, all wiki links are forced to have
2299                  * an initial capital letter so [[foo]] and [[Foo]]
2300                  * point to the same place.
2301                  *
2302                  * Don't force it for interwikis, since the other
2303                  * site might be case-sensitive.
2304                  */
2305                 $this->mUserCaseDBKey = $dbkey;
2306                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2307                         $dbkey = $wgContLang->ucfirst( $dbkey );
2308                 }
2309
2310                 /**
2311                  * Can't make a link to a namespace alone...
2312                  * "empty" local links can only be self-links
2313                  * with a fragment identifier.
2314                  */
2315                 if( $dbkey == '' &&
2316                         $this->mInterwiki == '' &&
2317                         $this->mNamespace != NS_MAIN ) {
2318                         return false;
2319                 }
2320                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2321                 // IP names are not allowed for accounts, and can only be referring to
2322                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2323                 // there are numerous ways to present the same IP. Having sp:contribs scan
2324                 // them all is silly and having some show the edits and others not is
2325                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2326                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2327                         IP::sanitizeIP( $dbkey ) : $dbkey;
2328                 // Any remaining initial :s are illegal.
2329                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2330                         return false;
2331                 }
2332
2333                 # Fill fields
2334                 $this->mDbkeyform = $dbkey;
2335                 $this->mUrlform = wfUrlencode( $dbkey );
2336
2337                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2338
2339                 return true;
2340         }
2341
2342         /**
2343          * Set the fragment for this title. Removes the first character from the
2344          * specified fragment before setting, so it assumes you're passing it with
2345          * an initial "#".
2346          *
2347          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2348          * Still in active use privately.
2349          *
2350          * @param $fragment \type{\string} text
2351          */
2352         public function setFragment( $fragment ) {
2353                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2354         }
2355
2356         /**
2357          * Get a Title object associated with the talk page of this article
2358          * @return \type{Title} the object for the talk page
2359          */
2360         public function getTalkPage() {
2361                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2362         }
2363
2364         /**
2365          * Get a title object associated with the subject page of this
2366          * talk page
2367          *
2368          * @return \type{Title} the object for the subject page
2369          */
2370         public function getSubjectPage() {
2371                 // Is this the same title?
2372                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2373                 if( $this->getNamespace() == $subjectNS ) {
2374                         return $this;
2375                 }
2376                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2377         }
2378
2379         /**
2380          * Get an array of Title objects linking to this Title
2381          * Also stores the IDs in the link cache.
2382          *
2383          * WARNING: do not use this function on arbitrary user-supplied titles!
2384          * On heavily-used templates it will max out the memory.
2385          *
2386          * @param array $options may be FOR UPDATE
2387          * @return \type{\arrayof{Title}} the Title objects linking here
2388          */
2389         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2390                 $linkCache = LinkCache::singleton();
2391
2392                 if ( count( $options ) > 0 ) {
2393                         $db = wfGetDB( DB_MASTER );
2394                 } else {
2395                         $db = wfGetDB( DB_SLAVE );
2396                 }
2397
2398                 $res = $db->select( array( 'page', $table ),
2399                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2400                         array(
2401                                 "{$prefix}_from=page_id",
2402                                 "{$prefix}_namespace" => $this->getNamespace(),
2403                                 "{$prefix}_title"     => $this->getDBkey() ),
2404                         __METHOD__,
2405                         $options );
2406
2407                 $retVal = array();
2408                 if ( $db->numRows( $res ) ) {
2409                         foreach( $res as $row ) {
2410                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2411                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2412                                         $retVal[] = $titleObj;
2413                                 }
2414                         }
2415                 }
2416                 $db->freeResult( $res );
2417                 return $retVal;
2418         }
2419
2420         /**
2421          * Get an array of Title objects using this Title as a template
2422          * Also stores the IDs in the link cache.
2423          *
2424          * WARNING: do not use this function on arbitrary user-supplied titles!
2425          * On heavily-used templates it will max out the memory.
2426          *
2427          * @param array $options may be FOR UPDATE
2428          * @return \type{\arrayof{Title}} the Title objects linking here
2429          */
2430         public function getTemplateLinksTo( $options = array() ) {
2431                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2432         }
2433
2434         /**
2435          * Get an array of Title objects referring to non-existent articles linked from this page
2436          *
2437          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2438          * @return \type{\arrayof{Title}} the Title objects
2439          */
2440         public function getBrokenLinksFrom() {
2441                 if ( $this->getArticleId() == 0 ) {
2442                         # All links from article ID 0 are false positives
2443                         return array();
2444                 }
2445
2446                 $dbr = wfGetDB( DB_SLAVE );
2447                 $res = $dbr->select(
2448                         array( 'page', 'pagelinks' ),
2449                         array( 'pl_namespace', 'pl_title' ),
2450                         array(
2451                                 'pl_from' => $this->getArticleId(),
2452                                 'page_namespace IS NULL'
2453                         ),
2454                         __METHOD__, array(),
2455                         array(
2456                                 'page' => array(
2457                                         'LEFT JOIN',
2458                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2459                                 )
2460                         )
2461                 );
2462
2463                 $retVal = array();
2464                 foreach( $res as $row ) {
2465                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2466                 }
2467                 return $retVal;
2468         }
2469
2470
2471         /**
2472          * Get a list of URLs to purge from the Squid cache when this
2473          * page changes
2474          *
2475          * @return \type{\arrayof{\string}} the URLs
2476          */
2477         public function getSquidURLs() {
2478                 global $wgContLang;
2479
2480                 $urls = array(
2481                         $this->getInternalURL(),
2482                         $this->getInternalURL( 'action=history' )
2483                 );
2484
2485                 // purge variant urls as well
2486                 if($wgContLang->hasVariants()){
2487                         $variants = $wgContLang->getVariants();
2488                         foreach($variants as $vCode){
2489                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2490                                 $urls[] = $this->getInternalURL('',$vCode);
2491                         }
2492                 }
2493
2494                 return $urls;
2495         }
2496
2497         /**
2498          * Purge all applicable Squid URLs
2499          */
2500         public function purgeSquid() {
2501                 global $wgUseSquid;
2502                 if ( $wgUseSquid ) {
2503                         $urls = $this->getSquidURLs();
2504                         $u = new SquidUpdate( $urls );
2505                         $u->doUpdate();
2506                 }
2507         }
2508
2509         /**
2510          * Move this page without authentication
2511          * @param &$nt \type{Title} the new page Title
2512          */
2513         public function moveNoAuth( &$nt ) {
2514                 return $this->moveTo( $nt, false );
2515         }
2516
2517         /**
2518          * Check whether a given move operation would be valid.
2519          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2520          * @param &$nt \type{Title} the new title
2521          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2522          *      should be checked
2523          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2524          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2525          */
2526         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2527                 global $wgUser;
2528
2529                 $errors = array();
2530                 if( !$nt ) {
2531                         // Normally we'd add this to $errors, but we'll get
2532                         // lots of syntax errors if $nt is not an object
2533                         return array(array('badtitletext'));
2534                 }
2535                 if( $this->equals( $nt ) ) {
2536                         $errors[] = array('selfmove');
2537                 }
2538                 if( !$this->isMovable() ) {
2539                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2540                 }
2541                 if ( $nt->getInterwiki() != '' ) {
2542                         $errors[] = array( 'immobile-target-namespace-iw' );
2543                 }
2544                 if ( !$nt->isMovable() ) {
2545                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2546                 }
2547
2548                 $oldid = $this->getArticleID();
2549                 $newid = $nt->getArticleID();
2550
2551                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2552                         $errors[] = array('articleexists');
2553                 }
2554                 if ( ( '' == $this->getDBkey() ) ||
2555                          ( !$oldid ) ||
2556                      ( '' == $nt->getDBkey() ) ) {
2557                         $errors[] = array('badarticleerror');
2558                 }
2559
2560                 // Image-specific checks
2561                 if( $this->getNamespace() == NS_FILE ) {
2562                         $file = wfLocalFile( $this );
2563                         if( $file->exists() ) {
2564                                 if( $nt->getNamespace() != NS_FILE ) {
2565                                         $errors[] = array('imagenocrossnamespace');
2566                                 }
2567                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2568                                         $errors[] = array('imageinvalidfilename');
2569                                 }
2570                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2571                                         $errors[] = array('imagetypemismatch');
2572                                 }
2573                         }
2574                 }
2575
2576                 if ( $auth ) {
2577                         $errors = wfMergeErrorArrays( $errors,
2578                                 $this->getUserPermissionsErrors('move', $wgUser),
2579                                 $this->getUserPermissionsErrors('edit', $wgUser),
2580                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2581                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2582                 }
2583
2584                 $match = EditPage::matchSummarySpamRegex( $reason );
2585                 if( $match !== false ) {
2586                         // This is kind of lame, won't display nice
2587                         $errors[] = array('spamprotectiontext');
2588                 }
2589
2590                 $err = null;
2591                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2592                         $errors[] = array('hookaborted', $err);
2593                 }
2594
2595                 # The move is allowed only if (1) the target doesn't exist, or
2596                 # (2) the target is a redirect to the source, and has no history
2597                 # (so we can undo bad moves right after they're done).
2598
2599                 if ( 0 != $newid ) { # Target exists; check for validity
2600                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2601                                 $errors[] = array('articleexists');
2602                         }
2603                 } else {
2604                         $tp = $nt->getTitleProtection();
2605                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2606                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2607                                 $errors[] = array('cantmove-titleprotected');
2608                         }
2609                 }
2610                 if(empty($errors))
2611                         return true;
2612                 return $errors;
2613         }
2614
2615         /**
2616          * Move a title to a new location
2617          * @param &$nt \type{Title} the new title
2618          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2619          *      should be checked
2620          * @param $reason \type{\string} The reason for the move
2621          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2622          *  Ignored if the user doesn't have the suppressredirect right.
2623          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2624          */
2625         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2626                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2627                 if( is_array( $err ) ) {
2628                         return $err;
2629                 }
2630
2631                 // If it is a file, more it first. It is done before all other moving stuff is done because it's hard to revert
2632                 $dbw = wfGetDB( DB_MASTER );
2633                 if( $this->getNamespace() == NS_FILE ) {
2634                         $file = wfLocalFile( $this );
2635                         if( $file->exists() ) {
2636                                 $status = $file->move( $nt );
2637                                 if( !$status->isOk() ) {
2638                                         return $status->getErrorsArray();
2639                                 }
2640                         }
2641                 }
2642
2643                 $pageid = $this->getArticleID();
2644                 $protected = $this->isProtected();
2645                 if( $nt->exists() ) {
2646                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2647                         $pageCountChange = ($createRedirect ? 0 : -1);
2648                 } else { # Target didn't exist, do normal move.
2649                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2650                         $pageCountChange = ($createRedirect ? 1 : 0);
2651                 }
2652
2653                 if( is_array( $err ) ) {
2654                         return $err;
2655                 }
2656                 $redirid = $this->getArticleID();
2657
2658                 // Category memberships include a sort key which may be customized.
2659                 // If it's left as the default (the page title), we need to update
2660                 // the sort key to match the new title.
2661                 //
2662                 // Be careful to avoid resetting cl_timestamp, which may disturb
2663                 // time-based lists on some sites.
2664                 //
2665                 // Warning -- if the sort key is *explicitly* set to the old title,
2666                 // we can't actually distinguish it from a default here, and it'll
2667                 // be set to the new title even though it really shouldn't.
2668                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2669                 $dbw->update( 'categorylinks',
2670                         array(
2671                                 'cl_sortkey' => $nt->getPrefixedText(),
2672                                 'cl_timestamp=cl_timestamp' ),
2673                         array(
2674                                 'cl_from' => $pageid,
2675                                 'cl_sortkey' => $this->getPrefixedText() ),
2676                         __METHOD__ );
2677
2678                 if( $protected ) {
2679                         # Protect the redirect title as the title used to be...
2680                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2681                                 array(
2682                                         'pr_page'    => $redirid,
2683                                         'pr_type'    => 'pr_type',
2684                                         'pr_level'   => 'pr_level',
2685                                         'pr_cascade' => 'pr_cascade',
2686                                         'pr_user'    => 'pr_user',
2687                                         'pr_expiry'  => 'pr_expiry'
2688                                 ),
2689                                 array( 'pr_page' => $pageid ),
2690                                 __METHOD__,
2691                                 array( 'IGNORE' )
2692                         );
2693                         # Update the protection log
2694                         $log = new LogPage( 'protect' );
2695                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2696                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2697                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2698                 }
2699
2700                 # Update watchlists
2701                 $oldnamespace = $this->getNamespace() & ~1;
2702                 $newnamespace = $nt->getNamespace() & ~1;
2703                 $oldtitle = $this->getDBkey();
2704                 $newtitle = $nt->getDBkey();
2705
2706                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2707                         WatchedItem::duplicateEntries( $this, $nt );
2708                 }
2709
2710                 # Update search engine
2711                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2712                 $u->doUpdate();
2713                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2714                 $u->doUpdate();
2715
2716                 # Update site_stats
2717                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2718                         # No longer a content page
2719                         # Not viewed, edited, removing
2720                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2721                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2722                         # Now a content page
2723                         # Not viewed, edited, adding
2724                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2725                 } elseif( $pageCountChange ) {
2726                         # Redirect added
2727                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2728                 } else {
2729                         # Nothing special
2730                         $u = false;
2731                 }
2732                 if( $u )
2733                         $u->doUpdate();
2734                 # Update message cache for interface messages
2735                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2736                         global $wgMessageCache;
2737
2738                         # @bug 17860: old article can be deleted, if this the case,
2739                         # delete it from message cache
2740                         if ( $this->getArticleID() === 0 ) {
2741                                 $wgMessageCache->replace( $this->getDBkey(), false );
2742                         } else {
2743                                 $oldarticle = new Article( $this );
2744                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2745                         }
2746
2747                         $newarticle = new Article( $nt );
2748                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2749                 }
2750
2751                 global $wgUser;
2752                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2753                 return true;
2754         }
2755
2756         /**
2757          * Move page to a title which is at present a redirect to the
2758          * source page
2759          *
2760          * @param &$nt \type{Title} the page to move to, which should currently
2761          *      be a redirect
2762          * @param $reason \type{\string} The reason for the move
2763          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2764          *  Ignored if the user doesn't have the suppressredirect right
2765          */
2766         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2767                 global $wgUseSquid, $wgUser;
2768                 $fname = 'Title::moveOverExistingRedirect';
2769                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2770
2771                 if ( $reason ) {
2772                         $comment .= ": $reason";
2773                 }
2774
2775                 $now = wfTimestampNow();
2776                 $newid = $nt->getArticleID();
2777                 $oldid = $this->getArticleID();
2778                 $latest = $this->getLatestRevID();
2779
2780                 $dbw = wfGetDB( DB_MASTER );
2781
2782                 # Delete the old redirect. We don't save it to history since
2783                 # by definition if we've got here it's rather uninteresting.
2784                 # We have to remove it so that the next step doesn't trigger
2785                 # a conflict on the unique namespace+title index...
2786                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2787                 if ( !$dbw->cascadingDeletes() ) {
2788                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2789                         global $wgUseTrackbacks;
2790                         if ($wgUseTrackbacks)
2791                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2792                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2793                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2794                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2795                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2796                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2797                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2798                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2799                 }
2800
2801                 # Save a null revision in the page's history notifying of the move
2802                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2803                 $nullRevId = $nullRevision->insertOn( $dbw );
2804
2805                 $article = new Article( $this );
2806                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2807
2808                 # Change the name of the target page:
2809                 $dbw->update( 'page',
2810                         /* SET */ array(
2811                                 'page_touched'   => $dbw->timestamp($now),
2812                                 'page_namespace' => $nt->getNamespace(),
2813                                 'page_title'     => $nt->getDBkey(),
2814                                 'page_latest'    => $nullRevId,
2815                         ),
2816                         /* WHERE */ array( 'page_id' => $oldid ),
2817                         $fname
2818                 );
2819                 $nt->resetArticleID( $oldid );
2820
2821                 # Recreate the redirect, this time in the other direction.
2822                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2823                         $mwRedir = MagicWord::get( 'redirect' );
2824                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2825                         $redirectArticle = new Article( $this );
2826                         $newid = $redirectArticle->insertOn( $dbw );
2827                         $redirectRevision = new Revision( array(
2828                                 'page'    => $newid,
2829                                 'comment' => $comment,
2830                                 'text'    => $redirectText ) );
2831                         $redirectRevision->insertOn( $dbw );
2832                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2833
2834                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2835
2836                         # Now, we record the link from the redirect to the new title.
2837                         # It should have no other outgoing links...
2838                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2839                         $dbw->insert( 'pagelinks',
2840                                 array(
2841                                         'pl_from'      => $newid,
2842                                         'pl_namespace' => $nt->getNamespace(),
2843                                         'pl_title'     => $nt->getDBkey() ),
2844                                 $fname );
2845                         $redirectSuppressed = false;
2846                 } else {
2847                         $this->resetArticleID( 0 );
2848                         $redirectSuppressed = true;
2849                 }
2850
2851                 # Log the move
2852                 $log = new LogPage( 'move' );
2853                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2854
2855                 # Purge squid
2856                 if ( $wgUseSquid ) {
2857                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2858                         $u = new SquidUpdate( $urls );
2859                         $u->doUpdate();
2860                 }
2861
2862         }
2863
2864         /**
2865          * Move page to non-existing title.
2866          * @param &$nt \type{Title} the new Title
2867          * @param $reason \type{\string} The reason for the move
2868          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2869          *  Ignored if the user doesn't have the suppressredirect right
2870          */
2871         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2872                 global $wgUseSquid, $wgUser;
2873                 $fname = 'MovePageForm::moveToNewTitle';
2874                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2875                 if ( $reason ) {
2876                         $comment .= wfMsgExt( 'colon-separator',
2877                                 array( 'escapenoentities', 'content' ) );
2878                         $comment .= $reason;
2879                 }
2880
2881                 $newid = $nt->getArticleID();
2882                 $oldid = $this->getArticleID();
2883                 $latest = $this->getLatestRevId();
2884
2885                 $dbw = wfGetDB( DB_MASTER );
2886                 $now = $dbw->timestamp();
2887
2888                 # Save a null revision in the page's history notifying of the move
2889                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2890                 $nullRevId = $nullRevision->insertOn( $dbw );
2891
2892                 $article = new Article( $this );
2893                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2894
2895                 # Rename page entry
2896                 $dbw->update( 'page',
2897                         /* SET */ array(
2898                                 'page_touched'   => $now,
2899                                 'page_namespace' => $nt->getNamespace(),
2900                                 'page_title'     => $nt->getDBkey(),
2901                                 'page_latest'    => $nullRevId,
2902                         ),
2903                         /* WHERE */ array( 'page_id' => $oldid ),
2904                         $fname
2905                 );
2906                 $nt->resetArticleID( $oldid );
2907
2908                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2909                         # Insert redirect
2910                         $mwRedir = MagicWord::get( 'redirect' );
2911                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2912                         $redirectArticle = new Article( $this );
2913                         $newid = $redirectArticle->insertOn( $dbw );
2914                         $redirectRevision = new Revision( array(
2915                                 'page'    => $newid,
2916                                 'comment' => $comment,
2917                                 'text'    => $redirectText ) );
2918                         $redirectRevision->insertOn( $dbw );
2919                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2920
2921                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2922
2923                         # Record the just-created redirect's linking to the page
2924                         $dbw->insert( 'pagelinks',
2925                                 array(
2926                                         'pl_from'      => $newid,
2927                                         'pl_namespace' => $nt->getNamespace(),
2928                                         'pl_title'     => $nt->getDBkey() ),
2929                                 $fname );
2930                         $redirectSuppressed = false;
2931                 } else {
2932                         $this->resetArticleID( 0 );
2933                         $redirectSuppressed = true;
2934                 }
2935
2936                 # Log the move
2937                 $log = new LogPage( 'move' );
2938                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2939
2940                 # Purge caches as per article creation
2941                 Article::onArticleCreate( $nt );
2942
2943                 # Purge old title from squid
2944                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2945                 $this->purgeSquid();
2946
2947         }
2948
2949         /**
2950          * Move this page's subpages to be subpages of $nt
2951          * @param $nt Title Move target
2952          * @param $auth bool Whether $wgUser's permissions should be checked
2953          * @param $reason string The reason for the move
2954          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2955          *  Ignored if the user doesn't have the 'suppressredirect' right
2956          * @return mixed array with old page titles as keys, and strings (new page titles) or
2957          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
2958          */
2959         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
2960                 global $wgMaximumMovedPages;
2961                 // Check permissions
2962                 if( !$this->userCan( 'move-subpages' ) )
2963                         return array( 'cant-move-subpages' );
2964                 // Do the source and target namespaces support subpages?
2965                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
2966                         return array( 'namespace-nosubpages',
2967                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
2968                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
2969                         return array( 'namespace-nosubpages',
2970                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
2971
2972                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
2973                 $retval = array();
2974                 $count = 0;
2975                 foreach( $subpages as $oldSubpage ) {
2976                         $count++;
2977                         if( $count > $wgMaximumMovedPages ) {
2978                                 $retval[$oldSubpage->getPrefixedTitle()] =
2979                                                 array( 'movepage-max-pages',
2980                                                         $wgMaximumMovedPages );
2981                                 break;
2982                         }
2983
2984                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
2985                                 // When moving a page to a subpage of itself,
2986                                 // don't move it twice
2987                                 continue;
2988                         $newPageName = preg_replace(
2989                                         '#^'.preg_quote( $this->getDBkey(), '#' ).'#',
2990                                         $nt->getDBkey(), $oldSubpage->getDBkey() );
2991                         if( $oldSubpage->isTalkPage() ) {
2992                                 $newNs = $nt->getTalkPage()->getNamespace();
2993                         } else {
2994                                 $newNs = $nt->getSubjectPage()->getNamespace();
2995                         }
2996                         # Bug 14385: we need makeTitleSafe because the new page names may
2997                         # be longer than 255 characters.
2998                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
2999
3000                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3001                         if( $success === true ) {
3002                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3003                         } else {
3004                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3005                         }
3006                 }
3007                 return $retval;
3008         }
3009
3010         /**
3011          * Checks if this page is just a one-rev redirect.
3012          * Adds lock, so don't use just for light purposes.
3013          *
3014          * @return \type{\bool} TRUE or FALSE
3015          */
3016         public function isSingleRevRedirect() {
3017                 $dbw = wfGetDB( DB_MASTER );
3018                 # Is it a redirect?
3019                 $row = $dbw->selectRow( 'page',
3020                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3021                         $this->pageCond(),
3022                         __METHOD__,
3023                         array( 'FOR UPDATE' )
3024                 );
3025                 # Cache some fields we may want
3026                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3027                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3028                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3029                 if( !$this->mRedirect ) {
3030                         return false;
3031                 }
3032                 # Does the article have a history?
3033                 $row = $dbw->selectField( array( 'page', 'revision'),
3034                         'rev_id',
3035                         array( 'page_namespace' => $this->getNamespace(),
3036                                 'page_title' => $this->getDBkey(),
3037                                 'page_id=rev_page',
3038                                 'page_latest != rev_id'
3039                         ),
3040                         __METHOD__,
3041                         array( 'FOR UPDATE' )
3042                 );
3043                 # Return true if there was no history
3044                 return ($row === false);
3045         }
3046
3047         /**
3048          * Checks if $this can be moved to a given Title
3049          * - Selects for update, so don't call it unless you mean business
3050          *
3051          * @param &$nt \type{Title} the new title to check
3052          * @return \type{\bool} TRUE or FALSE
3053          */
3054         public function isValidMoveTarget( $nt ) {
3055                 $dbw = wfGetDB( DB_MASTER );
3056                 # Is it an existsing file?
3057                 if( $nt->getNamespace() == NS_FILE ) {
3058                         $file = wfLocalFile( $nt );
3059                         if( $file->exists() ) {
3060                                 wfDebug( __METHOD__ . ": file exists\n" );
3061                                 return false;
3062                         }
3063                 }
3064                 # Is it a redirect with no history?
3065                 if( !$nt->isSingleRevRedirect() ) {
3066                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3067                         return false;
3068                 }
3069                 # Get the article text
3070                 $rev = Revision::newFromTitle( $nt );
3071                 $text = $rev->getText();
3072                 # Does the redirect point to the source?
3073                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3074                 $m = array();
3075                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3076                         $redirTitle = Title::newFromText( $m[1] );
3077                         if( !is_object( $redirTitle ) ||
3078                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3079                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3080                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3081                                 return false;
3082                         }
3083                 } else {
3084                         # Fail safe
3085                         wfDebug( __METHOD__ . ": failsafe\n" );
3086                         return false;
3087                 }
3088                 return true;
3089         }
3090
3091         /**
3092          * Can this title be added to a user's watchlist?
3093          *
3094          * @return \type{\bool} TRUE or FALSE
3095          */
3096         public function isWatchable() {
3097                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3098         }
3099
3100         /**
3101          * Get categories to which this Title belongs and return an array of
3102          * categories' names.
3103          *
3104          * @return \type{\array} array an array of parents in the form:
3105          *      $parent => $currentarticle
3106          */
3107         public function getParentCategories() {
3108                 global $wgContLang;
3109
3110                 $titlekey = $this->getArticleId();
3111                 $dbr = wfGetDB( DB_SLAVE );
3112                 $categorylinks = $dbr->tableName( 'categorylinks' );
3113
3114                 # NEW SQL
3115                 $sql = "SELECT * FROM $categorylinks"
3116                      ." WHERE cl_from='$titlekey'"
3117                          ." AND cl_from <> '0'"
3118                          ." ORDER BY cl_sortkey";
3119
3120                 $res = $dbr->query( $sql );
3121
3122                 if( $dbr->numRows( $res ) > 0 ) {
3123                         foreach( $res as $row )
3124                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3125                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3126                         $dbr->freeResult( $res );
3127                 } else {
3128                         $data = array();
3129                 }
3130                 return $data;
3131         }
3132
3133         /**
3134          * Get a tree of parent categories
3135          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3136          * @return \type{\array} Tree of parent categories
3137          */
3138         public function getParentCategoryTree( $children = array() ) {
3139                 $stack = array();
3140                 $parents = $this->getParentCategories();
3141
3142                 if( $parents ) {
3143                         foreach( $parents as $parent => $current ) {
3144                                 if ( array_key_exists( $parent, $children ) ) {
3145                                         # Circular reference
3146                                         $stack[$parent] = array();
3147                                 } else {
3148                                         $nt = Title::newFromText($parent);
3149                                         if ( $nt ) {
3150                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3151                                         }
3152                                 }
3153                         }
3154                         return $stack;
3155                 } else {
3156                         return array();
3157                 }
3158         }
3159
3160
3161         /**
3162          * Get an associative array for selecting this title from
3163          * the "page" table
3164          *
3165          * @return \type{\array} Selection array
3166          */
3167         public function pageCond() {
3168                 if( $this->mArticleID > 0 ) {
3169                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3170                         return array( 'page_id' => $this->mArticleID );
3171                 } else {
3172                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3173                 }
3174         }
3175
3176         /**
3177          * Get the revision ID of the previous revision
3178          *
3179          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3180          * @param $flags \type{\int} GAID_FOR_UPDATE
3181          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3182          */
3183         public function getPreviousRevisionID( $revId, $flags=0 ) {
3184                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3185                 return $db->selectField( 'revision', 'rev_id',
3186                         array(
3187                                 'rev_page' => $this->getArticleId($flags),
3188                                 'rev_id < ' . intval( $revId )
3189                         ),
3190                         __METHOD__,
3191                         array( 'ORDER BY' => 'rev_id DESC' )
3192                 );
3193         }
3194
3195         /**
3196          * Get the revision ID of the next revision
3197          *
3198          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3199          * @param $flags \type{\int} GAID_FOR_UPDATE
3200          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3201          */
3202         public function getNextRevisionID( $revId, $flags=0 ) {
3203                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3204                 return $db->selectField( 'revision', 'rev_id',
3205                         array(
3206                                 'rev_page' => $this->getArticleId($flags),
3207                                 'rev_id > ' . intval( $revId )
3208                         ),
3209                         __METHOD__,
3210                         array( 'ORDER BY' => 'rev_id' )
3211                 );
3212         }
3213
3214         /**
3215          * Get the first revision of the page
3216          *
3217          * @param $flags \type{\int} GAID_FOR_UPDATE
3218          * @return Revision (or NULL if page doesn't exist)
3219          */
3220         public function getFirstRevision( $flags=0 ) {
3221                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3222                 $pageId = $this->getArticleId($flags);
3223                 if( !$pageId ) return NULL;
3224                 $row = $db->selectRow( 'revision', '*',
3225                         array( 'rev_page' => $pageId ),
3226                         __METHOD__,
3227                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3228                 );
3229                 if( !$row ) {
3230                         return NULL;
3231                 } else {
3232                         return new Revision( $row );
3233                 }
3234         }
3235
3236         /**
3237          * Check if this is a new page
3238          *
3239          * @return bool
3240          */
3241         public function isNewPage() {
3242                 $dbr = wfGetDB( DB_SLAVE );
3243                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3244         }
3245
3246         /**
3247          * Get the oldest revision timestamp of this page
3248          *
3249          * @return string, MW timestamp
3250          */
3251         public function getEarliestRevTime() {
3252                 $dbr = wfGetDB( DB_SLAVE );
3253                 if( $this->exists() ) {
3254                         $min = $dbr->selectField( 'revision',
3255                                 'MIN(rev_timestamp)',
3256                                 array( 'rev_page' => $this->getArticleId() ),
3257                                 __METHOD__ );
3258                         return wfTimestampOrNull( TS_MW, $min );
3259                 }
3260                 return null;
3261         }
3262
3263         /**
3264          * Get the number of revisions between the given revision IDs.
3265          * Used for diffs and other things that really need it.
3266          *
3267          * @param $old \type{\int} Revision ID.
3268          * @param $new \type{\int} Revision ID.
3269          * @return \type{\int} Number of revisions between these IDs.
3270          */
3271         public function countRevisionsBetween( $old, $new ) {
3272                 $dbr = wfGetDB( DB_SLAVE );
3273                 return $dbr->selectField( 'revision', 'count(*)',
3274                         'rev_page = ' . intval( $this->getArticleId() ) .
3275                         ' AND rev_id > ' . intval( $old ) .
3276                         ' AND rev_id < ' . intval( $new ),
3277                         __METHOD__
3278                 );
3279         }
3280
3281         /**
3282          * Compare with another title.
3283          *
3284          * @param \type{Title} $title
3285          * @return \type{\bool} TRUE or FALSE
3286          */
3287         public function equals( Title $title ) {
3288                 // Note: === is necessary for proper matching of number-like titles.
3289                 return $this->getInterwiki() === $title->getInterwiki()
3290                         && $this->getNamespace() == $title->getNamespace()
3291                         && $this->getDBkey() === $title->getDBkey();
3292         }
3293
3294         /**
3295          * Callback for usort() to do title sorts by (namespace, title)
3296          */
3297         public static function compare( $a, $b ) {
3298                 if( $a->getNamespace() == $b->getNamespace() ) {
3299                         return strcmp( $a->getText(), $b->getText() );
3300                 } else {
3301                         return $a->getNamespace() - $b->getNamespace();
3302                 }
3303         }
3304
3305         /**
3306          * Return a string representation of this title
3307          *
3308          * @return \type{\string} String representation of this title
3309          */
3310         public function __toString() {
3311                 return $this->getPrefixedText();
3312         }
3313
3314         /**
3315          * Check if page exists.  For historical reasons, this function simply
3316          * checks for the existence of the title in the page table, and will
3317          * thus return false for interwiki links, special pages and the like.
3318          * If you want to know if a title can be meaningfully viewed, you should
3319          * probably call the isKnown() method instead.
3320          *
3321          * @return \type{\bool} TRUE or FALSE
3322          */
3323         public function exists() {
3324                 return $this->getArticleId() != 0;
3325         }
3326
3327         /**
3328          * Should links to this title be shown as potentially viewable (i.e. as
3329          * "bluelinks"), even if there's no record by this title in the page
3330          * table?
3331          *
3332          * This function is semi-deprecated for public use, as well as somewhat
3333          * misleadingly named.  You probably just want to call isKnown(), which
3334          * calls this function internally.
3335          *
3336          * (ISSUE: Most of these checks are cheap, but the file existence check
3337          * can potentially be quite expensive.  Including it here fixes a lot of
3338          * existing code, but we might want to add an optional parameter to skip
3339          * it and any other expensive checks.)
3340          *
3341          * @return \type{\bool} TRUE or FALSE
3342          */
3343         public function isAlwaysKnown() {
3344                 if( $this->mInterwiki != '' ) {
3345                         return true;  // any interwiki link might be viewable, for all we know
3346                 }
3347                 switch( $this->mNamespace ) {
3348                 case NS_MEDIA:
3349                 case NS_FILE:
3350                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3351                 case NS_SPECIAL:
3352                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3353                 case NS_MAIN:
3354                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3355                 case NS_MEDIAWIKI:
3356                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3357                         // the full l10n of that language to be loaded. That takes much memory and
3358                         // isn't needed. So we strip the language part away.
3359                         // Also, extension messages which are not loaded, are shown as red, because
3360                         // we don't call MessageCache::loadAllMessages.
3361                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3362                         return wfMsgWeirdKey( $basename );  // known system message
3363                 default:
3364                         return false;
3365                 }
3366         }
3367
3368         /**
3369          * Does this title refer to a page that can (or might) be meaningfully
3370          * viewed?  In particular, this function may be used to determine if
3371          * links to the title should be rendered as "bluelinks" (as opposed to
3372          * "redlinks" to non-existent pages).
3373          *
3374          * @return \type{\bool} TRUE or FALSE
3375          */
3376         public function isKnown() {
3377                 return $this->exists() || $this->isAlwaysKnown();
3378         }
3379
3380         /**
3381         * Is this in a namespace that allows actual pages?
3382         *
3383         * @return \type{\bool} TRUE or FALSE
3384         */
3385         public function canExist() {
3386                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3387         }
3388
3389         /**
3390          * Update page_touched timestamps and send squid purge messages for
3391          * pages linking to this title. May be sent to the job queue depending
3392          * on the number of links. Typically called on create and delete.
3393          */
3394         public function touchLinks() {
3395                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3396                 $u->doUpdate();
3397
3398                 if ( $this->getNamespace() == NS_CATEGORY ) {
3399                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3400                         $u->doUpdate();
3401                 }
3402         }
3403
3404         /**
3405          * Get the last touched timestamp
3406          * @param Database $db, optional db
3407          * @return \type{\string} Last touched timestamp
3408          */
3409         public function getTouched( $db = NULL ) {
3410                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3411                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3412                 return $touched;
3413         }
3414
3415         /**
3416          * Get the timestamp when this page was updated since the user last saw it.
3417          * @param User $user
3418          * @return mixed string/NULL
3419          */
3420         public function getNotificationTimestamp( $user = NULL ) {
3421                 global $wgUser, $wgShowUpdatedMarker;
3422                 // Assume current user if none given
3423                 if( !$user ) $user = $wgUser;
3424                 // Check cache first
3425                 $uid = $user->getId();
3426                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3427                         return $this->mNotificationTimestamp[$uid];
3428                 }
3429                 if( !$uid || !$wgShowUpdatedMarker ) {
3430                         return $this->mNotificationTimestamp[$uid] = false;
3431                 }
3432                 // Don't cache too much!
3433                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3434                         $this->mNotificationTimestamp = array();
3435                 }
3436                 $dbr = wfGetDB( DB_SLAVE );
3437                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3438                         'wl_notificationtimestamp',
3439                         array( 'wl_namespace' => $this->getNamespace(),
3440                                 'wl_title' => $this->getDBkey(),
3441                                 'wl_user' => $user->getId()
3442                         ),
3443                         __METHOD__
3444                 );
3445                 return $this->mNotificationTimestamp[$uid];
3446         }
3447
3448         /**
3449          * Get the trackback URL for this page
3450          * @return \type{\string} Trackback URL
3451          */
3452         public function trackbackURL() {
3453                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3454
3455                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3456                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3457         }
3458
3459         /**
3460          * Get the trackback RDF for this page
3461          * @return \type{\string} Trackback RDF
3462          */
3463         public function trackbackRDF() {
3464                 $url = htmlspecialchars($this->getFullURL());
3465                 $title = htmlspecialchars($this->getText());
3466                 $tburl = $this->trackbackURL();
3467
3468                 // Autodiscovery RDF is placed in comments so HTML validator
3469                 // won't barf. This is a rather icky workaround, but seems
3470                 // frequently used by this kind of RDF thingy.
3471                 //
3472                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3473                 return "<!--
3474 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3475          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3476          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3477 <rdf:Description
3478    rdf:about=\"$url\"
3479    dc:identifier=\"$url\"
3480    dc:title=\"$title\"
3481    trackback:ping=\"$tburl\" />
3482 </rdf:RDF>
3483 -->";
3484         }
3485
3486         /**
3487          * Generate strings used for xml 'id' names in monobook tabs
3488          * @return \type{\string} XML 'id' name
3489          */
3490         public function getNamespaceKey() {
3491                 global $wgContLang;
3492                 switch ($this->getNamespace()) {
3493                         case NS_MAIN:
3494                         case NS_TALK:
3495                                 return 'nstab-main';
3496                         case NS_USER:
3497                         case NS_USER_TALK:
3498                                 return 'nstab-user';
3499                         case NS_MEDIA:
3500                                 return 'nstab-media';
3501                         case NS_SPECIAL:
3502                                 return 'nstab-special';
3503                         case NS_PROJECT:
3504                         case NS_PROJECT_TALK:
3505                                 return 'nstab-project';
3506                         case NS_FILE:
3507                         case NS_FILE_TALK:
3508                                 return 'nstab-image';
3509                         case NS_MEDIAWIKI:
3510                         case NS_MEDIAWIKI_TALK:
3511                                 return 'nstab-mediawiki';
3512                         case NS_TEMPLATE:
3513                         case NS_TEMPLATE_TALK:
3514                                 return 'nstab-template';
3515                         case NS_HELP:
3516                         case NS_HELP_TALK:
3517                                 return 'nstab-help';
3518                         case NS_CATEGORY:
3519                         case NS_CATEGORY_TALK:
3520                                 return 'nstab-category';
3521                         default:
3522                                 return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
3523                 }
3524         }
3525
3526         /**
3527          * Returns true if this title resolves to the named special page
3528          * @param $name \type{\string} The special page name
3529          */
3530         public function isSpecial( $name ) {
3531                 if ( $this->getNamespace() == NS_SPECIAL ) {
3532                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3533                         if ( $name == $thisName ) {
3534                                 return true;
3535                         }
3536                 }
3537                 return false;
3538         }
3539
3540         /**
3541          * If the Title refers to a special page alias which is not the local default,
3542          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3543          */
3544         public function fixSpecialName() {
3545                 if ( $this->getNamespace() == NS_SPECIAL ) {
3546                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3547                         if ( $canonicalName ) {
3548                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3549                                 if ( $localName != $this->mDbkeyform ) {
3550                                         return Title::makeTitle( NS_SPECIAL, $localName );
3551                                 }
3552                         }
3553                 }
3554                 return $this;
3555         }
3556
3557         /**
3558          * Is this Title in a namespace which contains content?
3559          * In other words, is this a content page, for the purposes of calculating
3560          * statistics, etc?
3561          *
3562          * @return \type{\bool} TRUE or FALSE
3563          */
3564         public function isContentPage() {
3565                 return MWNamespace::isContent( $this->getNamespace() );
3566         }
3567
3568         /**
3569          * Get all extant redirects to this Title
3570          *
3571          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3572          *            NULL to consider all namespaces
3573          * @return \type{\arrayof{Title}} Redirects to this title
3574          */
3575         public function getRedirectsHere( $ns = null ) {
3576                 $redirs = array();
3577
3578                 $dbr = wfGetDB( DB_SLAVE );
3579                 $where = array(
3580                         'rd_namespace' => $this->getNamespace(),
3581                         'rd_title' => $this->getDBkey(),
3582                         'rd_from = page_id'
3583                 );
3584                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3585
3586                 $res = $dbr->select(
3587                         array( 'redirect', 'page' ),
3588                         array( 'page_namespace', 'page_title' ),
3589                         $where,
3590                         __METHOD__
3591                 );
3592
3593
3594                 foreach( $res as $row ) {
3595                         $redirs[] = self::newFromRow( $row );
3596                 }
3597                 return $redirs;
3598         }
3599
3600         /**
3601          * Check if this Title is a valid redirect target
3602          *
3603          * @return \type{\bool} TRUE or FALSE
3604          */
3605         public function isValidRedirectTarget() {
3606                 global $wgInvalidRedirectTargets;
3607
3608                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3609                 if( $this->isSpecial( 'Userlogout' ) ) {
3610                         return false;
3611                 }
3612
3613                 foreach( $wgInvalidRedirectTargets as $target ) {
3614                         if( $this->isSpecial( $target ) ) {
3615                                 return false;
3616                         }
3617                 }
3618
3619                 return true;
3620         }
3621
3622         /**
3623          * Get a backlink cache object
3624          */
3625         function getBacklinkCache() {
3626                 if ( is_null( $this->mBacklinkCache ) ) {
3627                         $this->mBacklinkCache = new BacklinkCache( $this );
3628                 }
3629                 return $this->mBacklinkCache;
3630         }
3631 }