includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 if ( !class_exists( 'UtfNormal' ) ) {
   8         require_once( dirname(__FILE__) . '/normal/UtfNormal.php' );
   9 }
  10
  11 define ( 'GAID_FOR_UPDATE', 1 );
  12
  13
  14 /**
  15  * Constants for pr_cascade bitfield
  16  */
  17 define( 'CASCADE', 1 );
  18
  19 /**
  20  * Represents a title within MediaWiki.
  21  * Optionally may contain an interwiki designation or namespace.
  22  * @note This class can fetch various kinds of data from the database;
  23  *       however, it does so inefficiently.
  24  */
  25 class Title {
  26         /** @name Static cache variables */
  27         //@{
  28         static private $titleCache=array();
  29         static private $interwikiCache=array();
  30         //@}
  31
  32         /**
  33          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  34          * commonly used titles. On a batch operation this can become a memory leak
  35          * if not bounded. After hitting this many titles reset the cache.
  36          */
  37         const CACHE_MAX = 1000;
  38
  39
  40         /**
  41          * @name Private member variables
  42          * Please use the accessor functions instead.
  43          * @private
  44          */
  45         //@{
  46
  47         var $mTextform = '';              ///< Text form (spaces not underscores) of the main part
  48         var $mUrlform = '';               ///< URL-encoded form of the main part
  49         var $mDbkeyform = '';             ///< Main part with underscores
  50         var $mUserCaseDBKey;              ///< DB key with the initial letter in the case specified by the user
  51         var $mNamespace = NS_MAIN;        ///< Namespace index, i.e. one of the NS_xxxx constants
  52         var $mInterwiki = '';             ///< Interwiki prefix (or null string)
  53         var $mFragment;                   ///< Title fragment (i.e. the bit after the #)
  54         var $mArticleID = -1;             ///< Article ID, fetched from the link cache on demand
  55         var $mLatestID = false;           ///< ID of most recent revision
  56         var $mRestrictions = array();     ///< Array of groups allowed to edit this article
  57         var $mOldRestrictions = false;
  58         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  59         var $mRestrictionsExpiry = array();       ///< When do the restrictions on this page expire?
  60         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  61         var $mCascadeSources;  ///< Where are the cascading restrictions coming from on this page?
  62         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  63         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  64         # Don't change the following default, NS_MAIN is hardcoded in several
  65         # places.  See bug 696.
  66         var $mDefaultNamespace = NS_MAIN; ///< Namespace index when there is no namespace
  67                                           # Zero except in {{transclusion}} tags
  68         var $mWatched = null;             ///< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  69         var $mLength = -1;                ///< The page length, 0 for special pages
  70         var $mRedirect = null;            ///< Is the article at this title a redirect?
  71         var $mNotificationTimestamp = array(); ///< Associative array of user ID -> timestamp/false
  72         var $mBacklinkCache = null; ///< Cache of links to this title
  73         //@}
  74
  75
  76         /**
  77          * Constructor
  78          * @private
  79          */
  80         /* private */ function __construct() {}
  81
  82         /**
  83          * Create a new Title from a prefixed DB key
  84          * @param $key \type{\string} The database key, which has underscores
  85          *      instead of spaces, possibly including namespace and
  86          *      interwiki prefixes
  87          * @return \type{Title} the new object, or NULL on an error
  88          */
  89         public static function newFromDBkey( $key ) {
  90                 $t = new Title();
  91                 $t->mDbkeyform = $key;
  92                 if( $t->secureAndSplit() )
  93                         return $t;
  94                 else
  95                         return NULL;
  96         }
  97
  98         /**
  99          * Create a new Title from text, such as what one would find in a link. De-
 100          * codes any HTML entities in the text.
 101          *
 102          * @param $text             string  The link text; spaces, prefixes, and an
 103          *   initial ':' indicating the main namespace are accepted.
 104          * @param $defaultNamespace int     The namespace to use if none is speci-
 105          *   fied by a prefix.  If you want to force a specific namespace even if
 106          *   $text might begin with a namespace prefix, use makeTitle() or
 107          *   makeTitleSafe().
 108          * @return Title  The new object, or null on an error.
 109          */
 110         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 111                 if( is_object( $text ) ) {
 112                         throw new MWException( 'Title::newFromText given an object' );
 113                 }
 114
 115                 /**
 116                  * Wiki pages often contain multiple links to the same page.
 117                  * Title normalization and parsing can become expensive on
 118                  * pages with many links, so we can save a little time by
 119                  * caching them.
 120                  *
 121                  * In theory these are value objects and won't get changed...
 122                  */
 123                 if( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 124                         return Title::$titleCache[$text];
 125                 }
 126
 127                 /**
 128                  * Convert things like &eacute; &#257; or &#x3017; into real text...
 129                  */
 130                 $filteredText = Sanitizer::decodeCharReferences( $text );
 131
 132                 $t = new Title();
 133                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 134                 $t->mDefaultNamespace = $defaultNamespace;
 135
 136                 static $cachedcount = 0 ;
 137                 if( $t->secureAndSplit() ) {
 138                         if( $defaultNamespace == NS_MAIN ) {
 139                                 if( $cachedcount >= self::CACHE_MAX ) {
 140                                         # Avoid memory leaks on mass operations...
 141                                         Title::$titleCache = array();
 142                                         $cachedcount=0;
 143                                 }
 144                                 $cachedcount++;
 145                                 Title::$titleCache[$text] =& $t;
 146                         }
 147                         return $t;
 148                 } else {
 149                         $ret = NULL;
 150                         return $ret;
 151                 }
 152         }
 153
 154         /**
 155          * Create a new Title from URL-encoded text. Ensures that
 156          * the given title's length does not exceed the maximum.
 157          * @param $url \type{\string} the title, as might be taken from a URL
 158          * @return \type{Title} the new object, or NULL on an error
 159          */
 160         public static function newFromURL( $url ) {
 161                 global $wgLegalTitleChars;
 162                 $t = new Title();
 163
 164                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 165                 # but some URLs used it as a space replacement and they still come
 166                 # from some external search tools.
 167                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 168                         $url = str_replace( '+', ' ', $url );
 169                 }
 170
 171                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 172                 if( $t->secureAndSplit() ) {
 173                         return $t;
 174                 } else {
 175                         return NULL;
 176                 }
 177         }
 178
 179         /**
 180          * Create a new Title from an article ID
 181          *
 182          * @todo This is inefficiently implemented, the page row is requested
 183          *       but not used for anything else
 184          *
 185          * @param $id \type{\int} the page_id corresponding to the Title to create
 186          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 187          * @return \type{Title} the new object, or NULL on an error
 188          */
 189         public static function newFromID( $id, $flags = 0 ) {
 190                 $fname = 'Title::newFromID';
 191                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 192                 $row = $db->selectRow( 'page', array( 'page_namespace', 'page_title' ),
 193                         array( 'page_id' => $id ), $fname );
 194                 if ( $row !== false ) {
 195                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 196                 } else {
 197                         $title = NULL;
 198                 }
 199                 return $title;
 200         }
 201
 202         /**
 203          * Make an array of titles from an array of IDs
 204          * @param $ids \type{\arrayof{\int}} Array of IDs
 205          * @return \type{\arrayof{Title}} Array of Titles
 206          */
 207         public static function newFromIDs( $ids ) {
 208                 if ( !count( $ids ) ) {
 209                         return array();
 210                 }
 211                 $dbr = wfGetDB( DB_SLAVE );
 212                 $res = $dbr->select( 'page', array( 'page_namespace', 'page_title' ),
 213                         'page_id IN (' . $dbr->makeList( $ids ) . ')', __METHOD__ );
 214
 215                 $titles = array();
 216                 foreach( $res as $row ) {
 217                         $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
 218                 }
 219                 return $titles;
 220         }
 221
 222         /**
 223          * Make a Title object from a DB row
 224          * @param $row \type{Row} (needs at least page_title,page_namespace)
 225          * @return \type{Title} corresponding Title
 226          */
 227         public static function newFromRow( $row ) {
 228                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 229
 230                 $t->mArticleID = isset($row->page_id) ? intval($row->page_id) : -1;
 231                 $t->mLength = isset($row->page_len) ? intval($row->page_len) : -1;
 232                 $t->mRedirect = isset($row->page_is_redirect) ? (bool)$row->page_is_redirect : NULL;
 233                 $t->mLatestID = isset($row->page_latest) ? $row->page_latest : false;
 234
 235                 return $t;
 236         }
 237
 238         /**
 239          * Create a new Title from a namespace index and a DB key.
 240          * It's assumed that $ns and $title are *valid*, for instance when
 241          * they came directly from the database or a special page name.
 242          * For convenience, spaces are converted to underscores so that
 243          * eg user_text fields can be used directly.
 244          *
 245          * @param $ns \type{\int} the namespace of the article
 246          * @param $title \type{\string} the unprefixed database key form
 247          * @param $fragment \type{\string} The link fragment (after the "#")
 248          * @return \type{Title} the new object
 249          */
 250         public static function &makeTitle( $ns, $title, $fragment = '' ) {
 251                 $t = new Title();
 252                 $t->mInterwiki = '';
 253                 $t->mFragment = $fragment;
 254                 $t->mNamespace = $ns = intval( $ns );
 255                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 256                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 257                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 258                 $t->mTextform = str_replace( '_', ' ', $title );
 259                 return $t;
 260         }
 261
 262         /**
 263          * Create a new Title from a namespace index and a DB key.
 264          * The parameters will be checked for validity, which is a bit slower
 265          * than makeTitle() but safer for user-provided data.
 266          *
 267          * @param $ns \type{\int} the namespace of the article
 268          * @param $title \type{\string} the database key form
 269          * @param $fragment \type{\string} The link fragment (after the "#")
 270          * @return \type{Title} the new object, or NULL on an error
 271          */
 272         public static function makeTitleSafe( $ns, $title, $fragment = '' ) {
 273                 $t = new Title();
 274                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment );
 275                 if( $t->secureAndSplit() ) {
 276                         return $t;
 277                 } else {
 278                         return NULL;
 279                 }
 280         }
 281
 282         /**
 283          * Create a new Title for the Main Page
 284          * @return \type{Title} the new object
 285          */
 286         public static function newMainPage() {
 287                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 288                 // Don't give fatal errors if the message is broken
 289                 if ( !$title ) {
 290                         $title = Title::newFromText( 'Main Page' );
 291                 }
 292                 return $title;
 293         }
 294
 295         /**
 296          * Extract a redirect destination from a string and return the
 297          * Title, or null if the text doesn't contain a valid redirect
 298          * This will only return the very next target, useful for
 299          * the redirect table and other checks that don't need full recursion
 300          *
 301          * @param $text \type{\string} Text with possible redirect
 302          * @return \type{Title} The corresponding Title
 303          */
 304         public static function newFromRedirect( $text ) {
 305                 return self::newFromRedirectInternal( $text );
 306         }
 307
 308         /**
 309          * Extract a redirect destination from a string and return the
 310          * Title, or null if the text doesn't contain a valid redirect
 311          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 312          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 313          *
 314          * @param $text \type{\string} Text with possible redirect
 315          * @return \type{Title} The corresponding Title
 316          */
 317         public static function newFromRedirectRecurse( $text ) {
 318                 $titles = self::newFromRedirectArray( $text );
 319                 return $titles ? array_pop( $titles ) : null;
 320         }
 321
 322         /**
 323          * Extract a redirect destination from a string and return an
 324          * array of Titles, or null if the text doesn't contain a valid redirect
 325          * The last element in the array is the final destination after all redirects
 326          * have been resolved (up to $wgMaxRedirects times)
 327          *
 328          * @param $text \type{\string} Text with possible redirect
 329          * @return \type{\array} Array of Titles, with the destination last
 330          */
 331         public static function newFromRedirectArray( $text ) {
 332                 global $wgMaxRedirects;
 333                 // are redirects disabled?
 334                 if( $wgMaxRedirects < 1 )
 335                         return null;
 336                 $title = self::newFromRedirectInternal( $text );
 337                 if( is_null( $title ) )
 338                         return null;
 339                 // recursive check to follow double redirects
 340                 $recurse = $wgMaxRedirects;
 341                 $titles = array( $title );
 342                 while( --$recurse > 0 ) {
 343                         if( $title->isRedirect() ) {
 344                                 $article = new Article( $title, 0 );
 345                                 $newtitle = $article->getRedirectTarget();
 346                         } else {
 347                                 break;
 348                         }
 349                         // Redirects to some special pages are not permitted
 350                         if( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 351                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 352                                 $title = $newtitle;
 353                                 $titles[] = $newtitle;
 354                         } else {
 355                                 break;
 356                         }
 357                 }
 358                 return $titles;
 359         }
 360
 361         /**
 362          * Really extract the redirect destination
 363          * Do not call this function directly, use one of the newFromRedirect* functions above
 364          *
 365          * @param $text \type{\string} Text with possible redirect
 366          * @return \type{Title} The corresponding Title
 367          */
 368         protected static function newFromRedirectInternal( $text ) {
 369                 $redir = MagicWord::get( 'redirect' );
 370                 $text = trim($text);
 371                 if( $redir->matchStartAndRemove( $text ) ) {
 372                         // Extract the first link and see if it's usable
 373                         // Ensure that it really does come directly after #REDIRECT
 374                         // Some older redirects included a colon, so don't freak about that!
 375                         $m = array();
 376                         if( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 377                                 // Strip preceding colon used to "escape" categories, etc.
 378                                 // and URL-decode links
 379                                 if( strpos( $m[1], '%' ) !== false ) {
 380                                         // Match behavior of inline link parsing here;
 381                                         // don't interpret + as " " most of the time!
 382                                         // It might be safe to just use rawurldecode instead, though.
 383                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 384                                 }
 385                                 $title = Title::newFromText( $m[1] );
 386                                 // If the title is a redirect to bad special pages or is invalid, return null
 387                                 if( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 388                                         return null;
 389                                 }
 390                                 return $title;
 391                         }
 392                 }
 393                 return null;
 394         }
 395
 396 #----------------------------------------------------------------------------
 397 #       Static functions
 398 #----------------------------------------------------------------------------
 399
 400         /**
 401          * Get the prefixed DB key associated with an ID
 402          * @param $id \type{\int} the page_id of the article
 403          * @return \type{Title} an object representing the article, or NULL
 404          *      if no such article was found
 405          */
 406         public static function nameOf( $id ) {
 407                 $dbr = wfGetDB( DB_SLAVE );
 408
 409                 $s = $dbr->selectRow( 'page',
 410                         array( 'page_namespace','page_title' ),
 411                         array( 'page_id' => $id ),
 412                         __METHOD__ );
 413                 if ( $s === false ) { return NULL; }
 414
 415                 $n = self::makeName( $s->page_namespace, $s->page_title );
 416                 return $n;
 417         }
 418
 419         /**
 420          * Get a regex character class describing the legal characters in a link
 421          * @return \type{\string} the list of characters, not delimited
 422          */
 423         public static function legalChars() {
 424                 global $wgLegalTitleChars;
 425                 return $wgLegalTitleChars;
 426         }
 427
 428         /**
 429          * Get a string representation of a title suitable for
 430          * including in a search index
 431          *
 432          * @param $ns \type{\int} a namespace index
 433          * @param $title \type{\string} text-form main part
 434          * @return \type{\string} a stripped-down title string ready for the
 435          *      search index
 436          */
 437         public static function indexTitle( $ns, $title ) {
 438                 global $wgContLang;
 439
 440                 $lc = SearchEngine::legalSearchChars() . '&#;';
 441                 $t = $wgContLang->stripForSearch( $title );
 442                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 443                 $t = $wgContLang->lc( $t );
 444
 445                 # Handle 's, s'
 446                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 447                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 448
 449                 $t = preg_replace( "/\\s+/", ' ', $t );
 450
 451                 if ( $ns == NS_FILE ) {
 452                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 453                 }
 454                 return trim( $t );
 455         }
 456
 457         /*
 458          * Make a prefixed DB key from a DB key and a namespace index
 459          * @param $ns \type{\int} numerical representation of the namespace
 460          * @param $title \type{\string} the DB key form the title
 461          * @param $fragment \type{\string} The link fragment (after the "#")
 462          * @return \type{\string} the prefixed form of the title
 463          */
 464         public static function makeName( $ns, $title, $fragment = '' ) {
 465                 global $wgContLang;
 466
 467                 $namespace = $wgContLang->getNsText( $ns );
 468                 $name = $namespace == '' ? $title : "$namespace:$title";
 469                 if ( strval( $fragment ) != '' ) {
 470                         $name .= '#' . $fragment;
 471                 }
 472                 return $name;
 473         }
 474
 475         /**
 476          * Returns the URL associated with an interwiki prefix
 477          * @param $key \type{\string} the interwiki prefix (e.g. "MeatBall")
 478          * @return \type{\string} the associated URL, containing "$1",
 479          *      which should be replaced by an article title
 480          * @static (arguably)
 481          * @deprecated See Interwiki class
 482          */
 483         public function getInterwikiLink( $key )  {
 484                 return Interwiki::fetch( $key )->getURL( );
 485         }
 486
 487         /**
 488          * Determine whether the object refers to a page within
 489          * this project.
 490          *
 491          * @return \type{\bool} TRUE if this is an in-project interwiki link
 492          *      or a wikilink, FALSE otherwise
 493          */
 494         public function isLocal() {
 495                 if ( $this->mInterwiki != '' ) {
 496                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 497                 } else {
 498                         return true;
 499                 }
 500         }
 501
 502         /**
 503          * Determine whether the object refers to a page within
 504          * this project and is transcludable.
 505          *
 506          * @return \type{\bool} TRUE if this is transcludable
 507          */
 508         public function isTrans() {
 509                 if ($this->mInterwiki == '')
 510                         return false;
 511
 512                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 513         }
 514
 515         /**
 516          * Escape a text fragment, say from a link, for a URL
 517          */
 518         static function escapeFragmentForURL( $fragment ) {
 519                 global $wgEnforceHtmlIds;
 520                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 521                 # fragments appear not to work in IE (at least up to 7) or in at least
 522                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 523                 # to care if they aren't encoded.
 524                 return Sanitizer::escapeId( $fragment,
 525                         $wgEnforceHtmlIds ? 'noninitial' : 'xml' );
 526         }
 527
 528 #----------------------------------------------------------------------------
 529 #       Other stuff
 530 #----------------------------------------------------------------------------
 531
 532         /** Simple accessors */
 533         /**
 534          * Get the text form (spaces not underscores) of the main part
 535          * @return \type{\string} Main part of the title
 536          */
 537         public function getText() { return $this->mTextform; }
 538         /**
 539          * Get the URL-encoded form of the main part
 540          * @return \type{\string} Main part of the title, URL-encoded
 541          */
 542         public function getPartialURL() { return $this->mUrlform; }
 543         /**
 544          * Get the main part with underscores
 545          * @return \type{\string} Main part of the title, with underscores
 546          */
 547         public function getDBkey() { return $this->mDbkeyform; }
 548         /**
 549          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 550          * @return \type{\int} Namespace index
 551          */
 552         public function getNamespace() { return $this->mNamespace; }
 553         /**
 554          * Get the namespace text
 555          * @return \type{\string} Namespace text
 556          */
 557         public function getNsText() {
 558                 global $wgContLang, $wgCanonicalNamespaceNames;
 559
 560                 if ( '' != $this->mInterwiki ) {
 561                         // This probably shouldn't even happen. ohh man, oh yuck.
 562                         // But for interwiki transclusion it sometimes does.
 563                         // Shit. Shit shit shit.
 564                         //
 565                         // Use the canonical namespaces if possible to try to
 566                         // resolve a foreign namespace.
 567                         if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
 568                                 return $wgCanonicalNamespaceNames[$this->mNamespace];
 569                         }
 570                 }
 571                 return $wgContLang->getNsText( $this->mNamespace );
 572         }
 573         /**
 574          * Get the DB key with the initial letter case as specified by the user
 575          * @return \type{\string} DB key
 576          */
 577         function getUserCaseDBKey() {
 578                 return $this->mUserCaseDBKey;
 579         }
 580         /**
 581          * Get the namespace text of the subject (rather than talk) page
 582          * @return \type{\string} Namespace text
 583          */
 584         public function getSubjectNsText() {
 585                 global $wgContLang;
 586                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 587         }
 588         /**
 589          * Get the namespace text of the talk page
 590          * @return \type{\string} Namespace text
 591          */
 592         public function getTalkNsText() {
 593                 global $wgContLang;
 594                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 595         }
 596         /**
 597          * Could this title have a corresponding talk page?
 598          * @return \type{\bool} TRUE or FALSE
 599          */
 600         public function canTalk() {
 601                 return( MWNamespace::canTalk( $this->mNamespace ) );
 602         }
 603         /**
 604          * Get the interwiki prefix (or null string)
 605          * @return \type{\string} Interwiki prefix
 606          */
 607         public function getInterwiki() { return $this->mInterwiki; }
 608         /**
 609          * Get the Title fragment (i.e.\ the bit after the #) in text form
 610          * @return \type{\string} Title fragment
 611          */
 612         public function getFragment() { return $this->mFragment; }
 613         /**
 614          * Get the fragment in URL form, including the "#" character if there is one
 615          * @return \type{\string} Fragment in URL form
 616          */
 617         public function getFragmentForURL() {
 618                 if ( $this->mFragment == '' ) {
 619                         return '';
 620                 } else {
 621                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 622                 }
 623         }
 624         /**
 625          * Get the default namespace index, for when there is no namespace
 626          * @return \type{\int} Default namespace index
 627          */
 628         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 629
 630         /**
 631          * Get title for search index
 632          * @return \type{\string} a stripped-down title string ready for the
 633          *      search index
 634          */
 635         public function getIndexTitle() {
 636                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 637         }
 638
 639         /**
 640          * Get the prefixed database key form
 641          * @return \type{\string} the prefixed title, with underscores and
 642          *      any interwiki and namespace prefixes
 643          */
 644         public function getPrefixedDBkey() {
 645                 $s = $this->prefix( $this->mDbkeyform );
 646                 $s = str_replace( ' ', '_', $s );
 647                 return $s;
 648         }
 649
 650         /**
 651          * Get the prefixed title with spaces.
 652          * This is the form usually used for display
 653          * @return \type{\string} the prefixed title, with spaces
 654          */
 655         public function getPrefixedText() {
 656                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 657                         $s = $this->prefix( $this->mTextform );
 658                         $s = str_replace( '_', ' ', $s );
 659                         $this->mPrefixedText = $s;
 660                 }
 661                 return $this->mPrefixedText;
 662         }
 663
 664         /**
 665          * Get the prefixed title with spaces, plus any fragment
 666          * (part beginning with '#')
 667          * @return \type{\string} the prefixed title, with spaces and
 668          *      the fragment, including '#'
 669          */
 670         public function getFullText() {
 671                 $text = $this->getPrefixedText();
 672                 if( '' != $this->mFragment ) {
 673                         $text .= '#' . $this->mFragment;
 674                 }
 675                 return $text;
 676         }
 677
 678         /**
 679          * Get the base name, i.e. the leftmost parts before the /
 680          * @return \type{\string} Base name
 681          */
 682         public function getBaseText() {
 683                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 684                         return $this->getText();
 685                 }
 686
 687                 $parts = explode( '/', $this->getText() );
 688                 # Don't discard the real title if there's no subpage involved
 689                 if( count( $parts ) > 1 )
 690                         unset( $parts[ count( $parts ) - 1 ] );
 691                 return implode( '/', $parts );
 692         }
 693
 694         /**
 695          * Get the lowest-level subpage name, i.e. the rightmost part after /
 696          * @return \type{\string} Subpage name
 697          */
 698         public function getSubpageText() {
 699                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 700                         return( $this->mTextform );
 701                 }
 702                 $parts = explode( '/', $this->mTextform );
 703                 return( $parts[ count( $parts ) - 1 ] );
 704         }
 705
 706         /**
 707          * Get a URL-encoded form of the subpage text
 708          * @return \type{\string} URL-encoded subpage name
 709          */
 710         public function getSubpageUrlForm() {
 711                 $text = $this->getSubpageText();
 712                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 713                 return( $text );
 714         }
 715
 716         /**
 717          * Get a URL-encoded title (not an actual URL) including interwiki
 718          * @return \type{\string} the URL-encoded form
 719          */
 720         public function getPrefixedURL() {
 721                 $s = $this->prefix( $this->mDbkeyform );
 722                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 723                 return $s;
 724         }
 725
 726         /**
 727          * Get a real URL referring to this title, with interwiki link and
 728          * fragment
 729          *
 730          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 731          *   links. Can be specified as an associative array as well, e.g.,
 732          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 733          * @param $variant \type{\string} language variant of url (for sr, zh..)
 734          * @return \type{\string} the URL
 735          */
 736         public function getFullURL( $query = '', $variant = false ) {
 737                 global $wgContLang, $wgServer, $wgRequest;
 738
 739                 if( is_array( $query ) ) {
 740                         $query = wfArrayToCGI( $query );
 741                 }
 742
 743                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 744                 if ( !$interwiki ) {
 745                         $url = $this->getLocalUrl( $query, $variant );
 746
 747                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 748                         // Correct fix would be to move the prepending elsewhere.
 749                         if ($wgRequest->getVal('action') != 'render') {
 750                                 $url = $wgServer . $url;
 751                         }
 752                 } else {
 753                         $baseUrl = $interwiki->getURL( );
 754
 755                         $namespace = wfUrlencode( $this->getNsText() );
 756                         if ( '' != $namespace ) {
 757                                 # Can this actually happen? Interwikis shouldn't be parsed.
 758                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 759                                 $namespace .= ':';
 760                         }
 761                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 762                         $url = wfAppendQuery( $url, $query );
 763                 }
 764
 765                 # Finally, add the fragment.
 766                 $url .= $this->getFragmentForURL();
 767
 768                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 769                 return $url;
 770         }
 771
 772         /**
 773          * Get a URL with no fragment or server name.  If this page is generated
 774          * with action=render, $wgServer is prepended.
 775          * @param mixed $query an optional query string; if not specified,
 776          *       $wgArticlePath will be used.  Can be specified as an associative array
 777          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 778          *   URL-escaped).
 779          * @param $variant \type{\string} language variant of url (for sr, zh..)
 780          * @return \type{\string} the URL
 781          */
 782         public function getLocalURL( $query = '', $variant = false ) {
 783                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 784                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 785
 786                 if( is_array( $query ) ) {
 787                         $query = wfArrayToCGI( $query );
 788                 }
 789
 790                 // internal links should point to same variant as current page (only anonymous users)
 791                 if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
 792                         $pref = $wgContLang->getPreferredVariant(false);
 793                         if($pref != $wgContLang->getCode())
 794                                 $variant = $pref;
 795                 }
 796
 797                 if ( $this->isExternal() ) {
 798                         $url = $this->getFullURL();
 799                         if ( $query ) {
 800                                 // This is currently only used for edit section links in the
 801                                 // context of interwiki transclusion. In theory we should
 802                                 // append the query to the end of any existing query string,
 803                                 // but interwiki transclusion is already broken in that case.
 804                                 $url .= "?$query";
 805                         }
 806                 } else {
 807                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 808                         if ( $query == '' ) {
 809                                 if( $variant != false && $wgContLang->hasVariants() ) {
 810                                         if( $wgVariantArticlePath == false ) {
 811                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 812                                         } else {
 813                                                 $variantArticlePath = $wgVariantArticlePath;
 814                                         }
 815                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 816                                         $url = str_replace( '$1', $dbkey, $url  );
 817                                 } else {
 818                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 819                                 }
 820                         } else {
 821                                 global $wgActionPaths;
 822                                 $url = false;
 823                                 $matches = array();
 824                                 if( !empty( $wgActionPaths ) &&
 825                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 826                                 {
 827                                         $action = urldecode( $matches[2] );
 828                                         if( isset( $wgActionPaths[$action] ) ) {
 829                                                 $query = $matches[1];
 830                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 831                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 832                                                 if( $query != '' ) {
 833                                                         $url = wfAppendQuery( $url, $query );
 834                                                 }
 835                                         }
 836                                 }
 837                                 if ( $url === false ) {
 838                                         if ( $query == '-' ) {
 839                                                 $query = '';
 840                                         }
 841                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 842                                 }
 843                         }
 844
 845                         // FIXME: this causes breakage in various places when we
 846                         // actually expected a local URL and end up with dupe prefixes.
 847                         if ($wgRequest->getVal('action') == 'render') {
 848                                 $url = $wgServer . $url;
 849                         }
 850                 }
 851                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 852                 return $url;
 853         }
 854
 855         /**
 856          * Get a URL that's the simplest URL that will be valid to link, locally,
 857          * to the current Title.  It includes the fragment, but does not include
 858          * the server unless action=render is used (or the link is external).  If
 859          * there's a fragment but the prefixed text is empty, we just return a link
 860          * to the fragment.
 861          *
 862          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 863          *   query string.  Keys and values will be escaped.
 864          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 865          *   for external links.  Default is "false" (same variant as current page,
 866          *   for anonymous users).
 867          * @return \type{\string} the URL
 868          */
 869         public function getLinkUrl( $query = array(), $variant = false ) {
 870                 wfProfileIn( __METHOD__ );
 871                 if( !is_array( $query ) ) {
 872                         wfProfileOut( __METHOD__ );
 873                         throw new MWException( 'Title::getLinkUrl passed a non-array for '.
 874                         '$query' );
 875                 }
 876                 if( $this->isExternal() ) {
 877                         $ret = $this->getFullURL( $query );
 878                 } elseif( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 879                         $ret = $this->getFragmentForURL();
 880                 } else {
 881                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 882                 }
 883                 wfProfileOut( __METHOD__ );
 884                 return $ret;
 885         }
 886
 887         /**
 888          * Get an HTML-escaped version of the URL form, suitable for
 889          * using in a link, without a server name or fragment
 890          * @param $query \type{\string} an optional query string
 891          * @return \type{\string} the URL
 892          */
 893         public function escapeLocalURL( $query = '' ) {
 894                 return htmlspecialchars( $this->getLocalURL( $query ) );
 895         }
 896
 897         /**
 898          * Get an HTML-escaped version of the URL form, suitable for
 899          * using in a link, including the server name and fragment
 900          *
 901          * @param $query \type{\string} an optional query string
 902          * @return \type{\string} the URL
 903          */
 904         public function escapeFullURL( $query = '' ) {
 905                 return htmlspecialchars( $this->getFullURL( $query ) );
 906         }
 907
 908         /**
 909          * Get the URL form for an internal link.
 910          * - Used in various Squid-related code, in case we have a different
 911          * internal hostname for the server from the exposed one.
 912          *
 913          * @param $query \type{\string} an optional query string
 914          * @param $variant \type{\string} language variant of url (for sr, zh..)
 915          * @return \type{\string} the URL
 916          */
 917         public function getInternalURL( $query = '', $variant = false ) {
 918                 global $wgInternalServer;
 919                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 920                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 921                 return $url;
 922         }
 923
 924         /**
 925          * Get the edit URL for this Title
 926          * @return \type{\string} the URL, or a null string if this is an
 927          *      interwiki link
 928          */
 929         public function getEditURL() {
 930                 if ( '' != $this->mInterwiki ) { return ''; }
 931                 $s = $this->getLocalURL( 'action=edit' );
 932
 933                 return $s;
 934         }
 935
 936         /**
 937          * Get the HTML-escaped displayable text form.
 938          * Used for the title field in <a> tags.
 939          * @return \type{\string} the text, including any prefixes
 940          */
 941         public function getEscapedText() {
 942                 return htmlspecialchars( $this->getPrefixedText() );
 943         }
 944
 945         /**
 946          * Is this Title interwiki?
 947          * @return \type{\bool}
 948          */
 949         public function isExternal() { return ( '' != $this->mInterwiki ); }
 950
 951         /**
 952          * Is this page "semi-protected" - the *only* protection is autoconfirm?
 953          *
 954          * @param @action \type{\string} Action to check (default: edit)
 955          * @return \type{\bool}
 956          */
 957         public function isSemiProtected( $action = 'edit' ) {
 958                 if( $this->exists() ) {
 959                         $restrictions = $this->getRestrictions( $action );
 960                         if( count( $restrictions ) > 0 ) {
 961                                 foreach( $restrictions as $restriction ) {
 962                                         if( strtolower( $restriction ) != 'autoconfirmed' )
 963                                                 return false;
 964                                 }
 965                         } else {
 966                                 # Not protected
 967                                 return false;
 968                         }
 969                         return true;
 970                 } else {
 971                         # If it doesn't exist, it can't be protected
 972                         return false;
 973                 }
 974         }
 975
 976         /**
 977          * Does the title correspond to a protected article?
 978          * @param $what \type{\string} the action the page is protected from,
 979          * by default checks move and edit
 980          * @return \type{\bool}
 981          */
 982         public function isProtected( $action = '' ) {
 983                 global $wgRestrictionLevels, $wgRestrictionTypes;
 984
 985                 # Special pages have inherent protection
 986                 if( $this->getNamespace() == NS_SPECIAL )
 987                         return true;
 988
 989                 # Check regular protection levels
 990                 foreach( $wgRestrictionTypes as $type ){
 991                         if( $action == $type || $action == '' ) {
 992                                 $r = $this->getRestrictions( $type );
 993                                 foreach( $wgRestrictionLevels as $level ) {
 994                                         if( in_array( $level, $r ) && $level != '' ) {
 995                                                 return true;
 996                                         }
 997                                 }
 998                         }
 999                 }
1000
1001                 return false;
1002         }
1003
1004         /**
1005          * Is $wgUser watching this page?
1006          * @return \type{\bool}
1007          */
1008         public function userIsWatching() {
1009                 global $wgUser;
1010
1011                 if ( is_null( $this->mWatched ) ) {
1012                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
1013                                 $this->mWatched = false;
1014                         } else {
1015                                 $this->mWatched = $wgUser->isWatched( $this );
1016                         }
1017                 }
1018                 return $this->mWatched;
1019         }
1020
1021         /**
1022          * Can $wgUser perform $action on this page?
1023          * This skips potentially expensive cascading permission checks.
1024          *
1025          * Suitable for use for nonessential UI controls in common cases, but
1026          * _not_ for functional access control.
1027          *
1028          * May provide false positives, but should never provide a false negative.
1029          *
1030          * @param $action \type{\string} action that permission needs to be checked for
1031          * @return \type{\bool}
1032          */
1033         public function quickUserCan( $action ) {
1034                 return $this->userCan( $action, false );
1035         }
1036
1037         /**
1038          * Determines if $wgUser is unable to edit this page because it has been protected
1039          * by $wgNamespaceProtection.
1040          *
1041          * @return \type{\bool}
1042          */
1043         public function isNamespaceProtected() {
1044                 global $wgNamespaceProtection, $wgUser;
1045                 if( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1046                         foreach( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1047                                 if( $right != '' && !$wgUser->isAllowed( $right ) )
1048                                         return true;
1049                         }
1050                 }
1051                 return false;
1052         }
1053
1054         /**
1055          * Can $wgUser perform $action on this page?
1056          * @param $action \type{\string} action that permission needs to be checked for
1057          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1058          * @return \type{\bool}
1059          */
1060         public function userCan( $action, $doExpensiveQueries = true ) {
1061                 global $wgUser;
1062                 return ($this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array());
1063         }
1064
1065         /**
1066          * Can $user perform $action on this page?
1067          *
1068          * FIXME: This *does not* check throttles (User::pingLimiter()).
1069          *
1070          * @param $action \type{\string}action that permission needs to be checked for
1071          * @param $user \type{User} user to check
1072          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1073          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1074          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1075          */
1076         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1077                 if( !StubObject::isRealObject( $user ) ) {
1078                         //Since StubObject is always used on globals, we can unstub $wgUser here and set $user = $wgUser
1079                         global $wgUser;
1080                         $wgUser->_unstub( '', 5 );
1081                         $user = $wgUser;
1082                 }
1083                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1084
1085                 global $wgContLang;
1086                 global $wgLang;
1087                 global $wgEmailConfirmToEdit;
1088
1089                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1090                         $errors[] = array( 'confirmedittext' );
1091                 }
1092
1093                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1094                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1095                         $block = $user->mBlock;
1096
1097                         // This is from OutputPage::blockedPage
1098                         // Copied at r23888 by werdna
1099
1100                         $id = $user->blockedBy();
1101                         $reason = $user->blockedFor();
1102                         if( $reason == '' ) {
1103                                 $reason = wfMsg( 'blockednoreason' );
1104                         }
1105                         $ip = wfGetIP();
1106
1107                         if ( is_numeric( $id ) ) {
1108                                 $name = User::whoIs( $id );
1109                         } else {
1110                                 $name = $id;
1111                         }
1112
1113                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1114                         $blockid = $block->mId;
1115                         $blockExpiry = $user->mBlock->mExpiry;
1116                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1117
1118                         if ( $blockExpiry == 'infinity' ) {
1119                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1120                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1121
1122                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1123                                         if ( strpos( $option, ':' ) == false )
1124                                                 continue;
1125
1126                                         list ($show, $value) = explode( ":", $option );
1127
1128                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1129                                                 $blockExpiry = $show;
1130                                                 break;
1131                                         }
1132                                 }
1133                         } else {
1134                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1135                         }
1136
1137                         $intended = $user->mBlock->mAddress;
1138
1139                         $errors[] = array( ($block->mAuto ? 'autoblockedtext' : 'blockedtext'), $link, $reason, $ip, $name,
1140                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1141                 }
1142
1143                 // Remove the errors being ignored.
1144
1145                 foreach( $errors as $index => $error ) {
1146                         $error_key = is_array($error) ? $error[0] : $error;
1147
1148                         if (in_array( $error_key, $ignoreErrors )) {
1149                                 unset($errors[$index]);
1150                         }
1151                 }
1152
1153                 return $errors;
1154         }
1155
1156         /**
1157          * Can $user perform $action on this page? This is an internal function,
1158          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1159          * checks on wfReadOnly() and blocks)
1160          *
1161          * @param $action \type{\string} action that permission needs to be checked for
1162          * @param $user \type{User} user to check
1163          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1164          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1165          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1166          */
1167         private function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries=true, $short=false ) {
1168                 wfProfileIn( __METHOD__ );
1169
1170                 $errors = array();
1171
1172                 // First stop is permissions checks, which fail most often, and which are easiest to test.
1173                 if ( $action == 'move' ) {
1174                         if( !$user->isAllowed( 'move-rootuserpages' )
1175                                         && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1176                         {
1177                                 // Show user page-specific message only if the user can move other pages
1178                                 $errors[] = array( 'cant-move-user-page' );
1179                         }
1180
1181                         // Check if user is allowed to move files if it's a file
1182                         if( $this->getNamespace() == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1183                                 $errors[] = array( 'movenotallowedfile' );
1184                         }
1185
1186                         if( !$user->isAllowed( 'move' ) ) {
1187                                 // User can't move anything
1188                                 $errors[] = $user->isAnon() ? array ( 'movenologintext' ) : array ('movenotallowed');
1189                         }
1190                 } elseif ( $action == 'create' ) {
1191                         if( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1192                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) )
1193                         {
1194                                 $errors[] = $user->isAnon() ? array ('nocreatetext') : array ('nocreate-loggedin');
1195                         }
1196                 } elseif( $action == 'move-target' ) {
1197                         if( !$user->isAllowed( 'move' ) ) {
1198                                 // User can't move anything
1199                                 $errors[] = $user->isAnon() ? array ( 'movenologintext' ) : array ('movenotallowed');
1200                         } elseif( !$user->isAllowed( 'move-rootuserpages' )
1201                                 && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1202                         {
1203                                 // Show user page-specific message only if the user can move other pages
1204                                 $errors[] = array( 'cant-move-to-user-page' );
1205                         }
1206                 } elseif( !$user->isAllowed( $action ) ) {
1207                         $return = null;
1208                         $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1209                                 User::getGroupsWithPermission( $action ) );
1210                         if( $groups ) {
1211                                 $return = array( 'badaccess-groups',
1212                                         array( implode( ', ', $groups ), count( $groups ) ) );
1213                         } else {
1214                                 $return = array( "badaccess-group0" );
1215                         }
1216                         $errors[] = $return;
1217                 }
1218
1219                 # Short-circuit point
1220                 if( $short && count($errors) > 0 ) {
1221                         wfProfileOut( __METHOD__ );
1222                         return $errors;
1223                 }
1224
1225                 // Use getUserPermissionsErrors instead
1226                 if( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1227                         wfProfileOut( __METHOD__ );
1228                         return $result ? array() : array( array( 'badaccess-group0' ) );
1229                 }
1230                 // Check getUserPermissionsErrors hook
1231                 if( !wfRunHooks( 'getUserPermissionsErrors', array(&$this,&$user,$action,&$result) ) ) {
1232                         if( is_array($result) && count($result) && !is_array($result[0]) )
1233                                 $errors[] = $result; # A single array representing an error
1234                         else if( is_array($result) && is_array($result[0]) )
1235                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1236                         else if( $result !== '' && is_string($result) )
1237                                 $errors[] = array($result); # A string representing a message-id
1238                         else if( $result === false )
1239                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1240                 }
1241                 # Short-circuit point
1242                 if( $short && count($errors) > 0 ) {
1243                         wfProfileOut( __METHOD__ );
1244                         return $errors;
1245                 }
1246                 // Check getUserPermissionsErrorsExpensive hook
1247                 if( $doExpensiveQueries && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array(&$this,&$user,$action,&$result) ) ) {
1248                         if( is_array($result) && count($result) && !is_array($result[0]) )
1249                                 $errors[] = $result; # A single array representing an error
1250                         else if( is_array($result) && is_array($result[0]) )
1251                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1252                         else if( $result !== '' && is_string($result) )
1253                                 $errors[] = array($result); # A string representing a message-id
1254                         else if( $result === false )
1255                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1256                 }
1257                 # Short-circuit point
1258                 if( $short && count($errors) > 0 ) {
1259                         wfProfileOut( __METHOD__ );
1260                         return $errors;
1261                 }
1262
1263                 # Only 'createaccount' and 'execute' can be performed on
1264                 # special pages, which don't actually exist in the DB.
1265                 $specialOKActions = array( 'createaccount', 'execute' );
1266                 if( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions) ) {
1267                         $errors[] = array('ns-specialprotected');
1268                 }
1269
1270                 # Check $wgNamespaceProtection for restricted namespaces
1271                 if( $this->isNamespaceProtected() ) {
1272                         $ns = $this->getNamespace() == NS_MAIN ?
1273                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1274                         $errors[] = NS_MEDIAWIKI == $this->mNamespace ?
1275                                 array('protectedinterface') : array( 'namespaceprotected',  $ns );
1276                 }
1277
1278                 # Protect css/js subpages of user pages
1279                 # XXX: this might be better using restrictions
1280                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
1281                 if( $this->isCssJsSubpage() && !$user->isAllowed('editusercssjs')
1282                         && !preg_match('/^'.preg_quote($user->getName(), '/').'\//', $this->mTextform) )
1283                 {
1284                         $errors[] = array('customcssjsprotected');
1285                 }
1286
1287                 # Check against page_restrictions table requirements on this
1288                 # page. The user must possess all required rights for this action.
1289                 foreach( $this->getRestrictions($action) as $right ) {
1290                         // Backwards compatibility, rewrite sysop -> protect
1291                         if( $right == 'sysop' ) {
1292                                 $right = 'protect';
1293                         }
1294                         if( '' != $right && !$user->isAllowed( $right ) ) {
1295                                 // Users with 'editprotected' permission can edit protected pages
1296                                 if( $action=='edit' && $user->isAllowed( 'editprotected' ) ) {
1297                                         // Users with 'editprotected' permission cannot edit protected pages
1298                                         // with cascading option turned on.
1299                                         if( $this->mCascadeRestriction ) {
1300                                                 $errors[] = array( 'protectedpagetext', $right );
1301                                         }
1302                                 } else {
1303                                         $errors[] = array( 'protectedpagetext', $right );
1304                                 }
1305                         }
1306                 }
1307                 # Short-circuit point
1308                 if( $short && count($errors) > 0 ) {
1309                         wfProfileOut( __METHOD__ );
1310                         return $errors;
1311                 }
1312
1313                 if( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1314                         # We /could/ use the protection level on the source page, but it's fairly ugly
1315                         #  as we have to establish a precedence hierarchy for pages included by multiple
1316                         #  cascade-protected pages. So just restrict it to people with 'protect' permission,
1317                         #  as they could remove the protection anyway.
1318                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1319                         # Cascading protection depends on more than this page...
1320                         # Several cascading protected pages may include this page...
1321                         # Check each cascading level
1322                         # This is only for protection restrictions, not for all actions
1323                         if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
1324                                 foreach( $restrictions[$action] as $right ) {
1325                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1326                                         if( '' != $right && !$user->isAllowed( $right ) ) {
1327                                                 $pages = '';
1328                                                 foreach( $cascadingSources as $page )
1329                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1330                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1331                                         }
1332                                 }
1333                         }
1334                 }
1335                 # Short-circuit point
1336                 if( $short && count($errors) > 0 ) {
1337                         wfProfileOut( __METHOD__ );
1338                         return $errors;
1339                 }
1340
1341                 if( $action == 'protect' ) {
1342                         if( $this->getUserPermissionsErrors('edit', $user) != array() ) {
1343                                 $errors[] = array( 'protect-cantedit' ); // If they can't edit, they shouldn't protect.
1344                         }
1345                 }
1346
1347                 if( $action == 'create' ) {
1348                         $title_protection = $this->getTitleProtection();
1349                         if( is_array($title_protection) ) {
1350                                 extract($title_protection); // is this extract() really needed?
1351
1352                                 if( $pt_create_perm == 'sysop' ) {
1353                                         $pt_create_perm = 'protect'; // B/C
1354                                 }
1355                                 if( $pt_create_perm == '' || !$user->isAllowed($pt_create_perm) ) {
1356                                         $errors[] = array( 'titleprotected', User::whoIs($pt_user), $pt_reason );
1357                                 }
1358                         }
1359                 } elseif( $action == 'move' ) {
1360                         // Check for immobile pages
1361                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1362                                 // Specific message for this case
1363                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1364                         } elseif( !$this->isMovable() ) {
1365                                 // Less specific message for rarer cases
1366                                 $errors[] = array( 'immobile-page' );
1367                         }
1368                 } elseif( $action == 'move-target' ) {
1369                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1370                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1371                         } elseif( !$this->isMovable() ) {
1372                                 $errors[] = array( 'immobile-target-page' );
1373                         }
1374                 }
1375
1376                 wfProfileOut( __METHOD__ );
1377                 return $errors;
1378         }
1379
1380         /**
1381          * Is this title subject to title protection?
1382          * @return \type{\mixed} An associative array representing any existent title
1383          *   protection, or false if there's none.
1384          */
1385         private function getTitleProtection() {
1386                 // Can't protect pages in special namespaces
1387                 if ( $this->getNamespace() < 0 ) {
1388                         return false;
1389                 }
1390
1391                 $dbr = wfGetDB( DB_SLAVE );
1392                 $res = $dbr->select( 'protected_titles', '*',
1393                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1394                         __METHOD__ );
1395
1396                 if ($row = $dbr->fetchRow( $res )) {
1397                         return $row;
1398                 } else {
1399                         return false;
1400                 }
1401         }
1402
1403         /**
1404          * Update the title protection status
1405          * @param $create_perm \type{\string} Permission required for creation
1406          * @param $reason \type{\string} Reason for protection
1407          * @param $expiry \type{\string} Expiry timestamp
1408          */
1409         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1410                 global $wgUser,$wgContLang;
1411
1412                 if ($create_perm == implode(',',$this->getRestrictions('create'))
1413                         && $expiry == $this->mRestrictionsExpiry['create']) {
1414                         // No change
1415                         return true;
1416                 }
1417
1418                 list ($namespace, $title) = array( $this->getNamespace(), $this->getDBkey() );
1419
1420                 $dbw = wfGetDB( DB_MASTER );
1421
1422                 $encodedExpiry = Block::encodeExpiry($expiry, $dbw );
1423
1424                 $expiry_description = '';
1425                 if ( $encodedExpiry != 'infinity' ) {
1426                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ) , $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ).')';
1427                 }
1428                 else {
1429                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ).')';
1430                 }
1431
1432                 # Update protection table
1433                 if ($create_perm != '' ) {
1434                         $dbw->replace( 'protected_titles', array(array('pt_namespace', 'pt_title')),
1435                                 array( 'pt_namespace' => $namespace, 'pt_title' => $title
1436                                         , 'pt_create_perm' => $create_perm
1437                                         , 'pt_timestamp' => Block::encodeExpiry(wfTimestampNow(), $dbw)
1438                                         , 'pt_expiry' => $encodedExpiry
1439                                         , 'pt_user' => $wgUser->getId(), 'pt_reason' => $reason ), __METHOD__  );
1440                 } else {
1441                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1442                                 'pt_title' => $title ), __METHOD__ );
1443                 }
1444                 # Update the protection log
1445                 $log = new LogPage( 'protect' );
1446
1447                 if( $create_perm ) {
1448                         $params = array("[create=$create_perm] $expiry_description",'');
1449                         $log->addEntry( $this->mRestrictions['create'] ? 'modify' : 'protect', $this, trim( $reason ), $params );
1450                 } else {
1451                         $log->addEntry( 'unprotect', $this, $reason );
1452                 }
1453
1454                 return true;
1455         }
1456
1457         /**
1458          * Remove any title protection due to page existing
1459          */
1460         public function deleteTitleProtection() {
1461                 $dbw = wfGetDB( DB_MASTER );
1462
1463                 $dbw->delete( 'protected_titles',
1464                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1465                         __METHOD__ );
1466         }
1467
1468         /**
1469          * Can $wgUser edit this page?
1470          * @return \type{\bool} TRUE or FALSE
1471          * @deprecated use userCan('edit')
1472          */
1473         public function userCanEdit( $doExpensiveQueries = true ) {
1474                 return $this->userCan( 'edit', $doExpensiveQueries );
1475         }
1476
1477         /**
1478          * Can $wgUser create this page?
1479          * @return \type{\bool} TRUE or FALSE
1480          * @deprecated use userCan('create')
1481          */
1482         public function userCanCreate( $doExpensiveQueries = true ) {
1483                 return $this->userCan( 'create', $doExpensiveQueries );
1484         }
1485
1486         /**
1487          * Can $wgUser move this page?
1488          * @return \type{\bool} TRUE or FALSE
1489          * @deprecated use userCan('move')
1490          */
1491         public function userCanMove( $doExpensiveQueries = true ) {
1492                 return $this->userCan( 'move', $doExpensiveQueries );
1493         }
1494
1495         /**
1496          * Would anybody with sufficient privileges be able to move this page?
1497          * Some pages just aren't movable.
1498          *
1499          * @return \type{\bool} TRUE or FALSE
1500          */
1501         public function isMovable() {
1502                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1503         }
1504
1505         /**
1506          * Can $wgUser read this page?
1507          * @return \type{\bool} TRUE or FALSE
1508          * @todo fold these checks into userCan()
1509          */
1510         public function userCanRead() {
1511                 global $wgUser, $wgGroupPermissions;
1512
1513                 $result = null;
1514                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1515                 if ( $result !== null ) {
1516                         return $result;
1517                 }
1518
1519                 # Shortcut for public wikis, allows skipping quite a bit of code
1520                 if ( !empty( $wgGroupPermissions['*']['read'] ) )
1521                         return true;
1522
1523                 if( $wgUser->isAllowed( 'read' ) ) {
1524                         return true;
1525                 } else {
1526                         global $wgWhitelistRead;
1527
1528                         /**
1529                          * Always grant access to the login page.
1530                          * Even anons need to be able to log in.
1531                         */
1532                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1533                                 return true;
1534                         }
1535
1536                         /**
1537                          * Bail out if there isn't whitelist
1538                          */
1539                         if( !is_array($wgWhitelistRead) ) {
1540                                 return false;
1541                         }
1542
1543                         /**
1544                          * Check for explicit whitelisting
1545                          */
1546                         $name = $this->getPrefixedText();
1547                         $dbName = $this->getPrefixedDBKey();
1548                         // Check with and without underscores
1549                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1550                                 return true;
1551
1552                         /**
1553                          * Old settings might have the title prefixed with
1554                          * a colon for main-namespace pages
1555                          */
1556                         if( $this->getNamespace() == NS_MAIN ) {
1557                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1558                                         return true;
1559                         }
1560
1561                         /**
1562                          * If it's a special page, ditch the subpage bit
1563                          * and check again
1564                          */
1565                         if( $this->getNamespace() == NS_SPECIAL ) {
1566                                 $name = $this->getDBkey();
1567                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1568                                 if ( $name === false ) {
1569                                         # Invalid special page, but we show standard login required message
1570                                         return false;
1571                                 }
1572
1573                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1574                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1575                                         return true;
1576                         }
1577
1578                 }
1579                 return false;
1580         }
1581
1582         /**
1583          * Is this a talk page of some sort?
1584          * @return \type{\bool} TRUE or FALSE
1585          */
1586         public function isTalkPage() {
1587                 return MWNamespace::isTalk( $this->getNamespace() );
1588         }
1589
1590         /**
1591          * Is this a subpage?
1592          * @return \type{\bool} TRUE or FALSE
1593          */
1594         public function isSubpage() {
1595                 return MWNamespace::hasSubpages( $this->mNamespace )
1596                         ? strpos( $this->getText(), '/' ) !== false
1597                         : false;
1598         }
1599
1600         /**
1601          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1602          * @return \type{\bool} TRUE or FALSE
1603          */
1604         public function hasSubpages() {
1605                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1606                         # Duh
1607                         return false;
1608                 }
1609
1610                 # We dynamically add a member variable for the purpose of this method
1611                 # alone to cache the result.  There's no point in having it hanging
1612                 # around uninitialized in every Title object; therefore we only add it
1613                 # if needed and don't declare it statically.
1614                 if( isset( $this->mHasSubpages ) ) {
1615                         return $this->mHasSubpages;
1616                 }
1617
1618                 $subpages = $this->getSubpages( 1 );
1619                 if( $subpages instanceof TitleArray )
1620                         return $this->mHasSubpages = (bool)$subpages->count();
1621                 return $this->mHasSubpages = false;
1622         }
1623
1624         /**
1625          * Get all subpages of this page.
1626          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1627          * @return mixed TitleArray, or empty array if this page's namespace
1628          *  doesn't allow subpages
1629          */
1630         public function getSubpages( $limit = -1 ) {
1631                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1632                         return array();
1633
1634                 $dbr = wfGetDB( DB_SLAVE );
1635                 $conds['page_namespace'] = $this->getNamespace();
1636                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1637                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1638                 $options = array();
1639                 if( $limit > -1 )
1640                         $options['LIMIT'] = $limit;
1641                 return $this->mSubpages = TitleArray::newFromResult(
1642                         $dbr->select( 'page',
1643                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1644                                 $conds,
1645                                 __METHOD__,
1646                                 $options
1647                         )
1648                 );
1649         }
1650
1651         /**
1652          * Could this page contain custom CSS or JavaScript, based
1653          * on the title?
1654          *
1655          * @return \type{\bool} TRUE or FALSE
1656          */
1657         public function isCssOrJsPage() {
1658                 return $this->mNamespace == NS_MEDIAWIKI
1659                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1660         }
1661
1662         /**
1663          * Is this a .css or .js subpage of a user page?
1664          * @return \type{\bool} TRUE or FALSE
1665          */
1666         public function isCssJsSubpage() {
1667                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1668         }
1669         /**
1670          * Is this a *valid* .css or .js subpage of a user page?
1671          * Check that the corresponding skin exists
1672          * @return \type{\bool} TRUE or FALSE
1673          */
1674         public function isValidCssJsSubpage() {
1675                 if ( $this->isCssJsSubpage() ) {
1676                         $skinNames = Skin::getSkinNames();
1677                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1678                 } else {
1679                         return false;
1680                 }
1681         }
1682         /**
1683          * Trim down a .css or .js subpage title to get the corresponding skin name
1684          */
1685         public function getSkinFromCssJsSubpage() {
1686                 $subpage = explode( '/', $this->mTextform );
1687                 $subpage = $subpage[ count( $subpage ) - 1 ];
1688                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1689         }
1690         /**
1691          * Is this a .css subpage of a user page?
1692          * @return \type{\bool} TRUE or FALSE
1693          */
1694         public function isCssSubpage() {
1695                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1696         }
1697         /**
1698          * Is this a .js subpage of a user page?
1699          * @return \type{\bool} TRUE or FALSE
1700          */
1701         public function isJsSubpage() {
1702                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1703         }
1704         /**
1705          * Protect css/js subpages of user pages: can $wgUser edit
1706          * this page?
1707          *
1708          * @return \type{\bool} TRUE or FALSE
1709          * @todo XXX: this might be better using restrictions
1710          */
1711         public function userCanEditCssJsSubpage() {
1712                 global $wgUser;
1713                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1714         }
1715
1716         /**
1717          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1718          *
1719          * @return \type{\bool} If the page is subject to cascading restrictions.
1720          */
1721         public function isCascadeProtected() {
1722                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1723                 return ( $sources > 0 );
1724         }
1725
1726         /**
1727          * Cascading protection: Get the source of any cascading restrictions on this page.
1728          *
1729          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1730          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1731          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1732          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1733          */
1734         public function getCascadeProtectionSources( $get_pages = true ) {
1735                 global $wgRestrictionTypes;
1736
1737                 # Define our dimension of restrictions types
1738                 $pagerestrictions = array();
1739                 foreach( $wgRestrictionTypes as $action )
1740                         $pagerestrictions[$action] = array();
1741
1742                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1743                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1744                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1745                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1746                 }
1747
1748                 wfProfileIn( __METHOD__ );
1749
1750                 $dbr = wfGetDB( DB_SLAVE );
1751
1752                 if ( $this->getNamespace() == NS_FILE ) {
1753                         $tables = array ('imagelinks', 'page_restrictions');
1754                         $where_clauses = array(
1755                                 'il_to' => $this->getDBkey(),
1756                                 'il_from=pr_page',
1757                                 'pr_cascade' => 1 );
1758                 } else {
1759                         $tables = array ('templatelinks', 'page_restrictions');
1760                         $where_clauses = array(
1761                                 'tl_namespace' => $this->getNamespace(),
1762                                 'tl_title' => $this->getDBkey(),
1763                                 'tl_from=pr_page',
1764                                 'pr_cascade' => 1 );
1765                 }
1766
1767                 if ( $get_pages ) {
1768                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1769                         $where_clauses[] = 'page_id=pr_page';
1770                         $tables[] = 'page';
1771                 } else {
1772                         $cols = array( 'pr_expiry' );
1773                 }
1774
1775                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1776
1777                 $sources = $get_pages ? array() : false;
1778                 $now = wfTimestampNow();
1779                 $purgeExpired = false;
1780
1781                 foreach( $res as $row ) {
1782                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1783                         if( $expiry > $now ) {
1784                                 if ($get_pages) {
1785                                         $page_id = $row->pr_page;
1786                                         $page_ns = $row->page_namespace;
1787                                         $page_title = $row->page_title;
1788                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1789                                         # Add groups needed for each restriction type if its not already there
1790                                         # Make sure this restriction type still exists
1791                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1792                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1793                                         }
1794                                 } else {
1795                                         $sources = true;
1796                                 }
1797                         } else {
1798                                 // Trigger lazy purge of expired restrictions from the db
1799                                 $purgeExpired = true;
1800                         }
1801                 }
1802                 if( $purgeExpired ) {
1803                         Title::purgeExpiredRestrictions();
1804                 }
1805
1806                 wfProfileOut( __METHOD__ );
1807
1808                 if ( $get_pages ) {
1809                         $this->mCascadeSources = $sources;
1810                         $this->mCascadingRestrictions = $pagerestrictions;
1811                 } else {
1812                         $this->mHasCascadingRestrictions = $sources;
1813                 }
1814                 return array( $sources, $pagerestrictions );
1815         }
1816
1817         function areRestrictionsCascading() {
1818                 if (!$this->mRestrictionsLoaded) {
1819                         $this->loadRestrictions();
1820                 }
1821
1822                 return $this->mCascadeRestriction;
1823         }
1824
1825         /**
1826          * Loads a string into mRestrictions array
1827          * @param $res \type{Resource} restrictions as an SQL result.
1828          */
1829         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1830                 global $wgRestrictionTypes;
1831                 $dbr = wfGetDB( DB_SLAVE );
1832
1833                 foreach( $wgRestrictionTypes as $type ){
1834                         $this->mRestrictions[$type] = array();
1835                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1836                 }
1837
1838                 $this->mCascadeRestriction = false;
1839
1840                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1841
1842                 if ( $oldFashionedRestrictions === NULL ) {
1843                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1844                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1845                 }
1846
1847                 if ($oldFashionedRestrictions != '') {
1848
1849                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1850                                 $temp = explode( '=', trim( $restrict ) );
1851                                 if(count($temp) == 1) {
1852                                         // old old format should be treated as edit/move restriction
1853                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1854                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1855                                 } else {
1856                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1857                                 }
1858                         }
1859
1860                         $this->mOldRestrictions = true;
1861
1862                 }
1863
1864                 if( $dbr->numRows( $res ) ) {
1865                         # Current system - load second to make them override.
1866                         $now = wfTimestampNow();
1867                         $purgeExpired = false;
1868
1869                         foreach( $res as $row ) {
1870                                 # Cycle through all the restrictions.
1871
1872                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1873                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1874                                         continue;
1875
1876                                 // This code should be refactored, now that it's being used more generally,
1877                                 // But I don't really see any harm in leaving it in Block for now -werdna
1878                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1879
1880                                 // Only apply the restrictions if they haven't expired!
1881                                 if ( !$expiry || $expiry > $now ) {
1882                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1883                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1884
1885                                         $this->mCascadeRestriction |= $row->pr_cascade;
1886                                 } else {
1887                                         // Trigger a lazy purge of expired restrictions
1888                                         $purgeExpired = true;
1889                                 }
1890                         }
1891
1892                         if( $purgeExpired ) {
1893                                 Title::purgeExpiredRestrictions();
1894                         }
1895                 }
1896
1897                 $this->mRestrictionsLoaded = true;
1898         }
1899
1900         /**
1901          * Load restrictions from the page_restrictions table
1902          */
1903         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1904                 if( !$this->mRestrictionsLoaded ) {
1905                         if ($this->exists()) {
1906                                 $dbr = wfGetDB( DB_SLAVE );
1907
1908                                 $res = $dbr->select( 'page_restrictions', '*',
1909                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1910
1911                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1912                         } else {
1913                                 $title_protection = $this->getTitleProtection();
1914
1915                                 if (is_array($title_protection)) {
1916                                         extract($title_protection);
1917
1918                                         $now = wfTimestampNow();
1919                                         $expiry = Block::decodeExpiry($pt_expiry);
1920
1921                                         if (!$expiry || $expiry > $now) {
1922                                                 // Apply the restrictions
1923                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1924                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1925                                         } else { // Get rid of the old restrictions
1926                                                 Title::purgeExpiredRestrictions();
1927                                         }
1928                                 } else {
1929                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1930                                 }
1931                                 $this->mRestrictionsLoaded = true;
1932                         }
1933                 }
1934         }
1935
1936         /**
1937          * Purge expired restrictions from the page_restrictions table
1938          */
1939         static function purgeExpiredRestrictions() {
1940                 $dbw = wfGetDB( DB_MASTER );
1941                 $dbw->delete( 'page_restrictions',
1942                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1943                         __METHOD__ );
1944
1945                 $dbw->delete( 'protected_titles',
1946                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1947                         __METHOD__ );
1948         }
1949
1950         /**
1951          * Accessor/initialisation for mRestrictions
1952          *
1953          * @param $action \type{\string} action that permission needs to be checked for
1954          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1955          */
1956         public function getRestrictions( $action ) {
1957                 if( !$this->mRestrictionsLoaded ) {
1958                         $this->loadRestrictions();
1959                 }
1960                 return isset( $this->mRestrictions[$action] )
1961                                 ? $this->mRestrictions[$action]
1962                                 : array();
1963         }
1964
1965         /**
1966          * Get the expiry time for the restriction against a given action
1967          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1968          * or not protected at all, or false if the action is not recognised.
1969          */
1970         public function getRestrictionExpiry( $action ) {
1971                 if( !$this->mRestrictionsLoaded ) {
1972                         $this->loadRestrictions();
1973                 }
1974                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1975         }
1976
1977         /**
1978          * Is there a version of this page in the deletion archive?
1979          * @return \type{\int} the number of archived revisions
1980          */
1981         public function isDeleted() {
1982                 if( $this->getNamespace() < 0 ) {
1983                         $n = 0;
1984                 } else {
1985                         $dbr = wfGetDB( DB_SLAVE );
1986                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
1987                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1988                                 __METHOD__
1989                         );
1990                         if( $this->getNamespace() == NS_FILE ) {
1991                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1992                                         array( 'fa_name' => $this->getDBkey() ),
1993                                         __METHOD__
1994                                 );
1995                         }
1996                 }
1997                 return (int)$n;
1998         }
1999
2000         /**
2001          * Is there a version of this page in the deletion archive?
2002          * @return bool
2003          */
2004         public function isDeletedQuick() {
2005                 if( $this->getNamespace() < 0 ) {
2006                         return false;
2007                 }
2008                 $dbr = wfGetDB( DB_SLAVE );
2009                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2010                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2011                         __METHOD__
2012                 );
2013                 if( !$deleted && $this->getNamespace() == NS_FILE ) {
2014                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2015                                 array( 'fa_name' => $this->getDBkey() ),
2016                                 __METHOD__
2017                         );
2018                 }
2019                 return $deleted;
2020         }
2021
2022         /**
2023          * Get the article ID for this Title from the link cache,
2024          * adding it if necessary
2025          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2026          *      for update
2027          * @return \type{\int} the ID
2028          */
2029         public function getArticleID( $flags = 0 ) {
2030                 if( $this->getNamespace() < 0 ) {
2031                         return $this->mArticleID = 0;
2032                 }
2033                 $linkCache = LinkCache::singleton();
2034                 if( $flags & GAID_FOR_UPDATE ) {
2035                         $oldUpdate = $linkCache->forUpdate( true );
2036                         $linkCache->clearLink( $this );
2037                         $this->mArticleID = $linkCache->addLinkObj( $this );
2038                         $linkCache->forUpdate( $oldUpdate );
2039                 } else {
2040                         if( -1 == $this->mArticleID ) {
2041                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2042                         }
2043                 }
2044                 return $this->mArticleID;
2045         }
2046
2047         /**
2048          * Is this an article that is a redirect page?
2049          * Uses link cache, adding it if necessary
2050          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2051          * @return \type{\bool}
2052          */
2053         public function isRedirect( $flags = 0 ) {
2054                 if( !is_null($this->mRedirect) )
2055                         return $this->mRedirect;
2056                 # Calling getArticleID() loads the field from cache as needed
2057                 if( !$this->getArticleID($flags) ) {
2058                         return $this->mRedirect = false;
2059                 }
2060                 $linkCache = LinkCache::singleton();
2061                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2062
2063                 return $this->mRedirect;
2064         }
2065
2066         /**
2067          * What is the length of this page?
2068          * Uses link cache, adding it if necessary
2069          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2070          * @return \type{\bool}
2071          */
2072         public function getLength( $flags = 0 ) {
2073                 if( $this->mLength != -1 )
2074                         return $this->mLength;
2075                 # Calling getArticleID() loads the field from cache as needed
2076                 if( !$this->getArticleID($flags) ) {
2077                         return $this->mLength = 0;
2078                 }
2079                 $linkCache = LinkCache::singleton();
2080                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2081
2082                 return $this->mLength;
2083         }
2084
2085         /**
2086          * What is the page_latest field for this page?
2087          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2088          * @return \type{\int}
2089          */
2090         public function getLatestRevID( $flags = 0 ) {
2091                 if( $this->mLatestID !== false )
2092                         return $this->mLatestID;
2093
2094                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2095                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2096                 return $this->mLatestID;
2097         }
2098
2099         /**
2100          * This clears some fields in this object, and clears any associated
2101          * keys in the "bad links" section of the link cache.
2102          *
2103          * - This is called from Article::insertNewArticle() to allow
2104          * loading of the new page_id. It's also called from
2105          * Article::doDeleteArticle()
2106          *
2107          * @param $newid \type{\int} the new Article ID
2108          */
2109         public function resetArticleID( $newid ) {
2110                 $linkCache = LinkCache::singleton();
2111                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2112
2113                 if ( $newid === false ) { $this->mArticleID = -1; }
2114                 else { $this->mArticleID = $newid; }
2115                 $this->mRestrictionsLoaded = false;
2116                 $this->mRestrictions = array();
2117         }
2118
2119         /**
2120          * Updates page_touched for this page; called from LinksUpdate.php
2121          * @return \type{\bool} true if the update succeded
2122          */
2123         public function invalidateCache() {
2124                 if( wfReadOnly() ) {
2125                         return;
2126                 }
2127                 $dbw = wfGetDB( DB_MASTER );
2128                 $success = $dbw->update( 'page',
2129                         array( 'page_touched' => $dbw->timestamp() ),
2130                         $this->pageCond(),
2131                         __METHOD__
2132                 );
2133                 HTMLFileCache::clearFileCache( $this );
2134                 return $success;
2135         }
2136
2137         /**
2138          * Prefix some arbitrary text with the namespace or interwiki prefix
2139          * of this object
2140          *
2141          * @param $name \type{\string} the text
2142          * @return \type{\string} the prefixed text
2143          * @private
2144          */
2145         /* private */ function prefix( $name ) {
2146                 $p = '';
2147                 if ( '' != $this->mInterwiki ) {
2148                         $p = $this->mInterwiki . ':';
2149                 }
2150                 if ( 0 != $this->mNamespace ) {
2151                         $p .= $this->getNsText() . ':';
2152                 }
2153                 return $p . $name;
2154         }
2155
2156         /**
2157          * Secure and split - main initialisation function for this object
2158          *
2159          * Assumes that mDbkeyform has been set, and is urldecoded
2160          * and uses underscores, but not otherwise munged.  This function
2161          * removes illegal characters, splits off the interwiki and
2162          * namespace prefixes, sets the other forms, and canonicalizes
2163          * everything.
2164          * @return \type{\bool} true on success
2165          */
2166         private function secureAndSplit() {
2167                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2168
2169                 # Initialisation
2170                 static $rxTc = false;
2171                 if( !$rxTc ) {
2172                         # Matching titles will be held as illegal.
2173                         $rxTc = '/' .
2174                                 # Any character not allowed is forbidden...
2175                                 '[^' . Title::legalChars() . ']' .
2176                                 # URL percent encoding sequences interfere with the ability
2177                                 # to round-trip titles -- you can't link to them consistently.
2178                                 '|%[0-9A-Fa-f]{2}' .
2179                                 # XML/HTML character references produce similar issues.
2180                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2181                                 '|&#[0-9]+;' .
2182                                 '|&#x[0-9A-Fa-f]+;' .
2183                                 '/S';
2184                 }
2185
2186                 $this->mInterwiki = $this->mFragment = '';
2187                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2188
2189                 $dbkey = $this->mDbkeyform;
2190
2191                 # Strip Unicode bidi override characters.
2192                 # Sometimes they slip into cut-n-pasted page titles, where the
2193                 # override chars get included in list displays.
2194                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2195
2196                 # Clean up whitespace
2197                 #
2198                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2199                 $dbkey = trim( $dbkey, '_' );
2200
2201                 # Clean up Arabic harakats (bug 16899)
2202                 $dbkey = preg_replace( '/[\x{064B}-\x{0652}]/Su', '', $dbkey );
2203
2204                 if ( '' == $dbkey ) {
2205                         return false;
2206                 }
2207
2208                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2209                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2210                         return false;
2211                 }
2212
2213                 $this->mDbkeyform = $dbkey;
2214
2215                 # Initial colon indicates main namespace rather than specified default
2216                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2217                 if ( ':' == $dbkey{0} ) {
2218                         $this->mNamespace = NS_MAIN;
2219                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2220                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2221                 }
2222
2223                 # Namespace or interwiki prefix
2224                 $firstPass = true;
2225                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2226                 do {
2227                         $m = array();
2228                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2229                                 $p = $m[1];
2230                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2231                                         # Ordinary namespace
2232                                         $dbkey = $m[2];
2233                                         $this->mNamespace = $ns;
2234                                         # For Talk:X pages, check if X has a "namespace" prefix
2235                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2236                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2237                                                         return false; # Disallow Talk:File:x type titles...
2238                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2239                                                         return false; # Disallow Talk:Interwiki:x type titles...
2240                                         }
2241                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2242                                         if( !$firstPass ) {
2243                                                 # Can't make a local interwiki link to an interwiki link.
2244                                                 # That's just crazy!
2245                                                 return false;
2246                                         }
2247
2248                                         # Interwiki link
2249                                         $dbkey = $m[2];
2250                                         $this->mInterwiki = $wgContLang->lc( $p );
2251
2252                                         # Redundant interwiki prefix to the local wiki
2253                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2254                                                 if( $dbkey == '' ) {
2255                                                         # Can't have an empty self-link
2256                                                         return false;
2257                                                 }
2258                                                 $this->mInterwiki = '';
2259                                                 $firstPass = false;
2260                                                 # Do another namespace split...
2261                                                 continue;
2262                                         }
2263
2264                                         # If there's an initial colon after the interwiki, that also
2265                                         # resets the default namespace
2266                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2267                                                 $this->mNamespace = NS_MAIN;
2268                                                 $dbkey = substr( $dbkey, 1 );
2269                                         }
2270                                 }
2271                                 # If there's no recognized interwiki or namespace,
2272                                 # then let the colon expression be part of the title.
2273                         }
2274                         break;
2275                 } while( true );
2276
2277                 # We already know that some pages won't be in the database!
2278                 #
2279                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2280                         $this->mArticleID = 0;
2281                 }
2282                 $fragment = strstr( $dbkey, '#' );
2283                 if ( false !== $fragment ) {
2284                         $this->setFragment( $fragment );
2285                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2286                         # remove whitespace again: prevents "Foo_bar_#"
2287                         # becoming "Foo_bar_"
2288                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2289                 }
2290
2291                 # Reject illegal characters.
2292                 #
2293                 if( preg_match( $rxTc, $dbkey ) ) {
2294                         return false;
2295                 }
2296
2297                 /**
2298                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2299                  * reachable due to the way web browsers deal with 'relative' URLs.
2300                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2301                  */
2302                 if ( strpos( $dbkey, '.' ) !== false &&
2303                      ( $dbkey === '.' || $dbkey === '..' ||
2304                        strpos( $dbkey, './' ) === 0  ||
2305                        strpos( $dbkey, '../' ) === 0 ||
2306                        strpos( $dbkey, '/./' ) !== false ||
2307                        strpos( $dbkey, '/../' ) !== false  ||
2308                        substr( $dbkey, -2 ) == '/.' ||
2309                        substr( $dbkey, -3 ) == '/..' ) )
2310                 {
2311                         return false;
2312                 }
2313
2314                 /**
2315                  * Magic tilde sequences? Nu-uh!
2316                  */
2317                 if( strpos( $dbkey, '~~~' ) !== false ) {
2318                         return false;
2319                 }
2320
2321                 /**
2322                  * Limit the size of titles to 255 bytes.
2323                  * This is typically the size of the underlying database field.
2324                  * We make an exception for special pages, which don't need to be stored
2325                  * in the database, and may edge over 255 bytes due to subpage syntax
2326                  * for long titles, e.g. [[Special:Block/Long name]]
2327                  */
2328                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2329                   strlen( $dbkey ) > 512 )
2330                 {
2331                         return false;
2332                 }
2333
2334                 /**
2335                  * Normally, all wiki links are forced to have
2336                  * an initial capital letter so [[foo]] and [[Foo]]
2337                  * point to the same place.
2338                  *
2339                  * Don't force it for interwikis, since the other
2340                  * site might be case-sensitive.
2341                  */
2342                 $this->mUserCaseDBKey = $dbkey;
2343                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2344                         $dbkey = $wgContLang->ucfirst( $dbkey );
2345                 }
2346
2347                 /**
2348                  * Can't make a link to a namespace alone...
2349                  * "empty" local links can only be self-links
2350                  * with a fragment identifier.
2351                  */
2352                 if( $dbkey == '' &&
2353                         $this->mInterwiki == '' &&
2354                         $this->mNamespace != NS_MAIN ) {
2355                         return false;
2356                 }
2357                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2358                 // IP names are not allowed for accounts, and can only be referring to
2359                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2360                 // there are numerous ways to present the same IP. Having sp:contribs scan
2361                 // them all is silly and having some show the edits and others not is
2362                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2363                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2364                         IP::sanitizeIP( $dbkey ) : $dbkey;
2365                 // Any remaining initial :s are illegal.
2366                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2367                         return false;
2368                 }
2369
2370                 # Fill fields
2371                 $this->mDbkeyform = $dbkey;
2372                 $this->mUrlform = wfUrlencode( $dbkey );
2373
2374                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2375
2376                 return true;
2377         }
2378
2379         /**
2380          * Set the fragment for this title. Removes the first character from the
2381          * specified fragment before setting, so it assumes you're passing it with
2382          * an initial "#".
2383          *
2384          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2385          * Still in active use privately.
2386          *
2387          * @param $fragment \type{\string} text
2388          */
2389         public function setFragment( $fragment ) {
2390                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2391         }
2392
2393         /**
2394          * Get a Title object associated with the talk page of this article
2395          * @return \type{Title} the object for the talk page
2396          */
2397         public function getTalkPage() {
2398                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2399         }
2400
2401         /**
2402          * Get a title object associated with the subject page of this
2403          * talk page
2404          *
2405          * @return \type{Title} the object for the subject page
2406          */
2407         public function getSubjectPage() {
2408                 // Is this the same title?
2409                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2410                 if( $this->getNamespace() == $subjectNS ) {
2411                         return $this;
2412                 }
2413                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2414         }
2415
2416         /**
2417          * Get an array of Title objects linking to this Title
2418          * Also stores the IDs in the link cache.
2419          *
2420          * WARNING: do not use this function on arbitrary user-supplied titles!
2421          * On heavily-used templates it will max out the memory.
2422          *
2423          * @param array $options may be FOR UPDATE
2424          * @return \type{\arrayof{Title}} the Title objects linking here
2425          */
2426         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2427                 $linkCache = LinkCache::singleton();
2428
2429                 if ( count( $options ) > 0 ) {
2430                         $db = wfGetDB( DB_MASTER );
2431                 } else {
2432                         $db = wfGetDB( DB_SLAVE );
2433                 }
2434
2435                 $res = $db->select( array( 'page', $table ),
2436                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2437                         array(
2438                                 "{$prefix}_from=page_id",
2439                                 "{$prefix}_namespace" => $this->getNamespace(),
2440                                 "{$prefix}_title"     => $this->getDBkey() ),
2441                         __METHOD__,
2442                         $options );
2443
2444                 $retVal = array();
2445                 if ( $db->numRows( $res ) ) {
2446                         foreach( $res as $row ) {
2447                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2448                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2449                                         $retVal[] = $titleObj;
2450                                 }
2451                         }
2452                 }
2453                 $db->freeResult( $res );
2454                 return $retVal;
2455         }
2456
2457         /**
2458          * Get an array of Title objects using this Title as a template
2459          * Also stores the IDs in the link cache.
2460          *
2461          * WARNING: do not use this function on arbitrary user-supplied titles!
2462          * On heavily-used templates it will max out the memory.
2463          *
2464          * @param array $options may be FOR UPDATE
2465          * @return \type{\arrayof{Title}} the Title objects linking here
2466          */
2467         public function getTemplateLinksTo( $options = array() ) {
2468                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2469         }
2470
2471         /**
2472          * Get an array of Title objects referring to non-existent articles linked from this page
2473          *
2474          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2475          * @return \type{\arrayof{Title}} the Title objects
2476          */
2477         public function getBrokenLinksFrom() {
2478                 if ( $this->getArticleId() == 0 ) {
2479                         # All links from article ID 0 are false positives
2480                         return array();
2481                 }
2482
2483                 $dbr = wfGetDB( DB_SLAVE );
2484                 $res = $dbr->select(
2485                         array( 'page', 'pagelinks' ),
2486                         array( 'pl_namespace', 'pl_title' ),
2487                         array(
2488                                 'pl_from' => $this->getArticleId(),
2489                                 'page_namespace IS NULL'
2490                         ),
2491                         __METHOD__, array(),
2492                         array(
2493                                 'page' => array(
2494                                         'LEFT JOIN',
2495                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2496                                 )
2497                         )
2498                 );
2499
2500                 $retVal = array();
2501                 foreach( $res as $row ) {
2502                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2503                 }
2504                 return $retVal;
2505         }
2506
2507
2508         /**
2509          * Get a list of URLs to purge from the Squid cache when this
2510          * page changes
2511          *
2512          * @return \type{\arrayof{\string}} the URLs
2513          */
2514         public function getSquidURLs() {
2515                 global $wgContLang;
2516
2517                 $urls = array(
2518                         $this->getInternalURL(),
2519                         $this->getInternalURL( 'action=history' )
2520                 );
2521
2522                 // purge variant urls as well
2523                 if($wgContLang->hasVariants()){
2524                         $variants = $wgContLang->getVariants();
2525                         foreach($variants as $vCode){
2526                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2527                                 $urls[] = $this->getInternalURL('',$vCode);
2528                         }
2529                 }
2530
2531                 return $urls;
2532         }
2533
2534         /**
2535          * Purge all applicable Squid URLs
2536          */
2537         public function purgeSquid() {
2538                 global $wgUseSquid;
2539                 if ( $wgUseSquid ) {
2540                         $urls = $this->getSquidURLs();
2541                         $u = new SquidUpdate( $urls );
2542                         $u->doUpdate();
2543                 }
2544         }
2545
2546         /**
2547          * Move this page without authentication
2548          * @param &$nt \type{Title} the new page Title
2549          */
2550         public function moveNoAuth( &$nt ) {
2551                 return $this->moveTo( $nt, false );
2552         }
2553
2554         /**
2555          * Check whether a given move operation would be valid.
2556          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2557          * @param &$nt \type{Title} the new title
2558          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2559          *      should be checked
2560          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2561          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2562          */
2563         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2564                 global $wgUser;
2565
2566                 $errors = array();
2567                 if( !$nt ) {
2568                         // Normally we'd add this to $errors, but we'll get
2569                         // lots of syntax errors if $nt is not an object
2570                         return array(array('badtitletext'));
2571                 }
2572                 if( $this->equals( $nt ) ) {
2573                         $errors[] = array('selfmove');
2574                 }
2575                 if( !$this->isMovable() ) {
2576                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2577                 }
2578                 if ( $nt->getInterwiki() != '' ) {
2579                         $errors[] = array( 'immobile-target-namespace-iw' );
2580                 }
2581                 if ( !$nt->isMovable() ) {
2582                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2583                 }
2584
2585                 $oldid = $this->getArticleID();
2586                 $newid = $nt->getArticleID();
2587
2588                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2589                         $errors[] = array('articleexists');
2590                 }
2591                 if ( ( '' == $this->getDBkey() ) ||
2592                          ( !$oldid ) ||
2593                      ( '' == $nt->getDBkey() ) ) {
2594                         $errors[] = array('badarticleerror');
2595                 }
2596
2597                 // Image-specific checks
2598                 if( $this->getNamespace() == NS_FILE ) {
2599                         $file = wfLocalFile( $this );
2600                         if( $file->exists() ) {
2601                                 if( $nt->getNamespace() != NS_FILE ) {
2602                                         $errors[] = array('imagenocrossnamespace');
2603                                 }
2604                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2605                                         $errors[] = array('imageinvalidfilename');
2606                                 }
2607                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBKey() ) ) {
2608                                         $errors[] = array('imagetypemismatch');
2609                                 }
2610                         }
2611                 }
2612
2613                 if ( $auth ) {
2614                         $errors = wfMergeErrorArrays( $errors,
2615                                 $this->getUserPermissionsErrors('move', $wgUser),
2616                                 $this->getUserPermissionsErrors('edit', $wgUser),
2617                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2618                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2619                 }
2620
2621                 $match = EditPage::matchSpamRegex( $reason );
2622                 if( $match !== false ) {
2623                         // This is kind of lame, won't display nice
2624                         $errors[] = array('spamprotectiontext');
2625                 }
2626
2627                 $err = null;
2628                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2629                         $errors[] = array('hookaborted', $err);
2630                 }
2631
2632                 # The move is allowed only if (1) the target doesn't exist, or
2633                 # (2) the target is a redirect to the source, and has no history
2634                 # (so we can undo bad moves right after they're done).
2635
2636                 if ( 0 != $newid ) { # Target exists; check for validity
2637                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2638                                 $errors[] = array('articleexists');
2639                         }
2640                 } else {
2641                         $tp = $nt->getTitleProtection();
2642                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2643                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2644                                 $errors[] = array('cantmove-titleprotected');
2645                         }
2646                 }
2647                 if(empty($errors))
2648                         return true;
2649                 return $errors;
2650         }
2651
2652         /**
2653          * Move a title to a new location
2654          * @param &$nt \type{Title} the new title
2655          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2656          *      should be checked
2657          * @param $reason \type{\string} The reason for the move
2658          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2659          *  Ignored if the user doesn't have the suppressredirect right.
2660          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2661          */
2662         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2663                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2664                 if( is_array( $err ) ) {
2665                         return $err;
2666                 }
2667
2668                 $pageid = $this->getArticleID();
2669                 $protected = $this->isProtected();
2670                 if( $nt->exists() ) {
2671                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2672                         $pageCountChange = ($createRedirect ? 0 : -1);
2673                 } else { # Target didn't exist, do normal move.
2674                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2675                         $pageCountChange = ($createRedirect ? 1 : 0);
2676                 }
2677
2678                 if( is_array( $err ) ) {
2679                         return $err;
2680                 }
2681                 $redirid = $this->getArticleID();
2682
2683                 // Category memberships include a sort key which may be customized.
2684                 // If it's left as the default (the page title), we need to update
2685                 // the sort key to match the new title.
2686                 //
2687                 // Be careful to avoid resetting cl_timestamp, which may disturb
2688                 // time-based lists on some sites.
2689                 //
2690                 // Warning -- if the sort key is *explicitly* set to the old title,
2691                 // we can't actually distinguish it from a default here, and it'll
2692                 // be set to the new title even though it really shouldn't.
2693                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2694                 $dbw = wfGetDB( DB_MASTER );
2695                 $dbw->update( 'categorylinks',
2696                         array(
2697                                 'cl_sortkey' => $nt->getPrefixedText(),
2698                                 'cl_timestamp=cl_timestamp' ),
2699                         array(
2700                                 'cl_from' => $pageid,
2701                                 'cl_sortkey' => $this->getPrefixedText() ),
2702                         __METHOD__ );
2703
2704                 if( $protected ) {
2705                         # Protect the redirect title as the title used to be...
2706                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2707                                 array(
2708                                         'pr_page'    => $redirid,
2709                                         'pr_type'    => 'pr_type',
2710                                         'pr_level'   => 'pr_level',
2711                                         'pr_cascade' => 'pr_cascade',
2712                                         'pr_user'    => 'pr_user',
2713                                         'pr_expiry'  => 'pr_expiry'
2714                                 ),
2715                                 array( 'pr_page' => $pageid ),
2716                                 __METHOD__,
2717                                 array( 'IGNORE' )
2718                         );
2719                         # Update the protection log
2720                         $log = new LogPage( 'protect' );
2721                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2722                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2723                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2724                 }
2725
2726                 # Update watchlists
2727                 $oldnamespace = $this->getNamespace() & ~1;
2728                 $newnamespace = $nt->getNamespace() & ~1;
2729                 $oldtitle = $this->getDBkey();
2730                 $newtitle = $nt->getDBkey();
2731
2732                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2733                         WatchedItem::duplicateEntries( $this, $nt );
2734                 }
2735
2736                 # Update search engine
2737                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2738                 $u->doUpdate();
2739                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2740                 $u->doUpdate();
2741
2742                 # Update site_stats
2743                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2744                         # No longer a content page
2745                         # Not viewed, edited, removing
2746                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2747                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2748                         # Now a content page
2749                         # Not viewed, edited, adding
2750                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2751                 } elseif( $pageCountChange ) {
2752                         # Redirect added
2753                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2754                 } else {
2755                         # Nothing special
2756                         $u = false;
2757                 }
2758                 if( $u )
2759                         $u->doUpdate();
2760                 # Update message cache for interface messages
2761                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2762                         global $wgMessageCache;
2763                         $oldarticle = new Article( $this );
2764                         $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2765                         $newarticle = new Article( $nt );
2766                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2767                 }
2768
2769                 global $wgUser;
2770                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2771                 return true;
2772         }
2773
2774         /**
2775          * Move page to a title which is at present a redirect to the
2776          * source page
2777          *
2778          * @param &$nt \type{Title} the page to move to, which should currently
2779          *      be a redirect
2780          * @param $reason \type{\string} The reason for the move
2781          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2782          *  Ignored if the user doesn't have the suppressredirect right
2783          */
2784         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2785                 global $wgUseSquid, $wgUser;
2786                 $fname = 'Title::moveOverExistingRedirect';
2787                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2788
2789                 if ( $reason ) {
2790                         $comment .= ": $reason";
2791                 }
2792
2793                 $now = wfTimestampNow();
2794                 $newid = $nt->getArticleID();
2795                 $oldid = $this->getArticleID();
2796                 $latest = $this->getLatestRevID();
2797
2798                 $dbw = wfGetDB( DB_MASTER );
2799
2800                 # Delete the old redirect. We don't save it to history since
2801                 # by definition if we've got here it's rather uninteresting.
2802                 # We have to remove it so that the next step doesn't trigger
2803                 # a conflict on the unique namespace+title index...
2804                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2805                 if ( !$dbw->cascadingDeletes() ) {
2806                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2807                         global $wgUseTrackbacks;
2808                         if ($wgUseTrackbacks)
2809                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2810                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2811                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2812                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2813                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2814                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2815                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2816                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2817                 }
2818
2819                 # Save a null revision in the page's history notifying of the move
2820                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2821                 $nullRevId = $nullRevision->insertOn( $dbw );
2822
2823                 $article = new Article( $this );
2824                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2825
2826                 # Change the name of the target page:
2827                 $dbw->update( 'page',
2828                         /* SET */ array(
2829                                 'page_touched'   => $dbw->timestamp($now),
2830                                 'page_namespace' => $nt->getNamespace(),
2831                                 'page_title'     => $nt->getDBkey(),
2832                                 'page_latest'    => $nullRevId,
2833                         ),
2834                         /* WHERE */ array( 'page_id' => $oldid ),
2835                         $fname
2836                 );
2837                 $nt->resetArticleID( $oldid );
2838
2839                 # Recreate the redirect, this time in the other direction.
2840                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2841                         $mwRedir = MagicWord::get( 'redirect' );
2842                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2843                         $redirectArticle = new Article( $this );
2844                         $newid = $redirectArticle->insertOn( $dbw );
2845                         $redirectRevision = new Revision( array(
2846                                 'page'    => $newid,
2847                                 'comment' => $comment,
2848                                 'text'    => $redirectText ) );
2849                         $redirectRevision->insertOn( $dbw );
2850                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2851
2852                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2853
2854                         # Now, we record the link from the redirect to the new title.
2855                         # It should have no other outgoing links...
2856                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2857                         $dbw->insert( 'pagelinks',
2858                                 array(
2859                                         'pl_from'      => $newid,
2860                                         'pl_namespace' => $nt->getNamespace(),
2861                                         'pl_title'     => $nt->getDBkey() ),
2862                                 $fname );
2863                         $redirectSuppressed = false;
2864                 } else {
2865                         $this->resetArticleID( 0 );
2866                         $redirectSuppressed = true;
2867                 }
2868
2869                 # Move an image if this is a file
2870                 if( $this->getNamespace() == NS_FILE ) {
2871                         $file = wfLocalFile( $this );
2872                         if( $file->exists() ) {
2873                                 $status = $file->move( $nt );
2874                                 if( !$status->isOk() ) {
2875                                         $dbw->rollback();
2876                                         return $status->getErrorsArray();
2877                                 }
2878                         }
2879                 }
2880
2881                 # Log the move
2882                 $log = new LogPage( 'move' );
2883                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2884
2885                 # Purge squid
2886                 if ( $wgUseSquid ) {
2887                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2888                         $u = new SquidUpdate( $urls );
2889                         $u->doUpdate();
2890                 }
2891
2892         }
2893
2894         /**
2895          * Move page to non-existing title.
2896          * @param &$nt \type{Title} the new Title
2897          * @param $reason \type{\string} The reason for the move
2898          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2899          *  Ignored if the user doesn't have the suppressredirect right
2900          */
2901         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2902                 global $wgUseSquid, $wgUser;
2903                 $fname = 'MovePageForm::moveToNewTitle';
2904                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2905                 if ( $reason ) {
2906                         $comment .= wfMsgExt( 'colon-separator',
2907                                 array( 'escapenoentities', 'content' ) );
2908                         $comment .= $reason;
2909                 }
2910
2911                 $newid = $nt->getArticleID();
2912                 $oldid = $this->getArticleID();
2913                 $latest = $this->getLatestRevId();
2914
2915                 $dbw = wfGetDB( DB_MASTER );
2916                 $now = $dbw->timestamp();
2917
2918                 # Save a null revision in the page's history notifying of the move
2919                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2920                 $nullRevId = $nullRevision->insertOn( $dbw );
2921
2922                 $article = new Article( $this );
2923                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2924
2925                 # Rename page entry
2926                 $dbw->update( 'page',
2927                         /* SET */ array(
2928                                 'page_touched'   => $now,
2929                                 'page_namespace' => $nt->getNamespace(),
2930                                 'page_title'     => $nt->getDBkey(),
2931                                 'page_latest'    => $nullRevId,
2932                         ),
2933                         /* WHERE */ array( 'page_id' => $oldid ),
2934                         $fname
2935                 );
2936                 $nt->resetArticleID( $oldid );
2937
2938                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2939                         # Insert redirect
2940                         $mwRedir = MagicWord::get( 'redirect' );
2941                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2942                         $redirectArticle = new Article( $this );
2943                         $newid = $redirectArticle->insertOn( $dbw );
2944                         $redirectRevision = new Revision( array(
2945                                 'page'    => $newid,
2946                                 'comment' => $comment,
2947                                 'text'    => $redirectText ) );
2948                         $redirectRevision->insertOn( $dbw );
2949                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2950
2951                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2952
2953                         # Record the just-created redirect's linking to the page
2954                         $dbw->insert( 'pagelinks',
2955                                 array(
2956                                         'pl_from'      => $newid,
2957                                         'pl_namespace' => $nt->getNamespace(),
2958                                         'pl_title'     => $nt->getDBkey() ),
2959                                 $fname );
2960                         $redirectSuppressed = false;
2961                 } else {
2962                         $this->resetArticleID( 0 );
2963                         $redirectSuppressed = true;
2964                 }
2965
2966                 # Move an image if this is a file
2967                 if( $this->getNamespace() == NS_FILE ) {
2968                         $file = wfLocalFile( $this );
2969                         if( $file->exists() ) {
2970                                 $status = $file->move( $nt );
2971                                 if( !$status->isOk() ) {
2972                                         $dbw->rollback();
2973                                         return $status->getErrorsArray();
2974                                 }
2975                         }
2976                 }
2977
2978                 # Log the move
2979                 $log = new LogPage( 'move' );
2980                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2981
2982                 # Purge caches as per article creation
2983                 Article::onArticleCreate( $nt );
2984
2985                 # Purge old title from squid
2986                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2987                 $this->purgeSquid();
2988
2989         }
2990
2991         /**
2992          * Move this page's subpages to be subpages of $nt
2993          * @param $nt Title Move target
2994          * @param $auth bool Whether $wgUser's permissions should be checked
2995          * @param $reason string The reason for the move
2996          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2997          *  Ignored if the user doesn't have the 'suppressredirect' right
2998          * @return mixed array with old page titles as keys, and strings (new page titles) or
2999          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3000          */
3001         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3002                 global $wgUser, $wgMaximumMovedPages;
3003                 // Check permissions
3004                 if( !$this->userCan( 'move-subpages' ) )
3005                         return array( 'cant-move-subpages' );
3006                 // Do the source and target namespaces support subpages?
3007                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
3008                         return array( 'namespace-nosubpages',
3009                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3010                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
3011                         return array( 'namespace-nosubpages',
3012                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3013
3014                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
3015                 $retval = array();
3016                 $count = 0;
3017                 foreach( $subpages as $oldSubpage ) {
3018                         $count++;
3019                         if( $count > $wgMaximumMovedPages ) {
3020                                 $retval[$oldSubpage->getPrefixedTitle()] =
3021                                                 array( 'movepage-max-pages',
3022                                                         $wgMaximumMovedPages );
3023                                 break;
3024                         }
3025
3026                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
3027                                 // When moving a page to a subpage of itself,
3028                                 // don't move it twice
3029                                 continue;
3030                         $newPageName = preg_replace(
3031                                         '#^'.preg_quote( $this->getDBKey(), '#' ).'#',
3032                                         $nt->getDBKey(), $oldSubpage->getDBKey() );
3033                         if( $oldSubpage->isTalkPage() ) {
3034                                 $newNs = $nt->getTalkPage()->getNamespace();
3035                         } else {
3036                                 $newNs = $nt->getSubjectPage()->getNamespace();
3037                         }
3038                         # Bug 14385: we need makeTitleSafe because the new page names may
3039                         # be longer than 255 characters.
3040                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3041
3042                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3043                         if( $success === true ) {
3044                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3045                         } else {
3046                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3047                         }
3048                 }
3049                 return $retval;
3050         }
3051
3052         /**
3053          * Checks if this page is just a one-rev redirect.
3054          * Adds lock, so don't use just for light purposes.
3055          *
3056          * @return \type{\bool} TRUE or FALSE
3057          */
3058         public function isSingleRevRedirect() {
3059                 $dbw = wfGetDB( DB_MASTER );
3060                 # Is it a redirect?
3061                 $row = $dbw->selectRow( 'page',
3062                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3063                         $this->pageCond(),
3064                         __METHOD__,
3065                         array( 'FOR UPDATE' )
3066                 );
3067                 # Cache some fields we may want
3068                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3069                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3070                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3071                 if( !$this->mRedirect ) {
3072                         return false;
3073                 }
3074                 # Does the article have a history?
3075                 $row = $dbw->selectField( array( 'page', 'revision'),
3076                         'rev_id',
3077                         array( 'page_namespace' => $this->getNamespace(),
3078                                 'page_title' => $this->getDBkey(),
3079                                 'page_id=rev_page',
3080                                 'page_latest != rev_id'
3081                         ),
3082                         __METHOD__,
3083                         array( 'FOR UPDATE' )
3084                 );
3085                 # Return true if there was no history
3086                 return ($row === false);
3087         }
3088
3089         /**
3090          * Checks if $this can be moved to a given Title
3091          * - Selects for update, so don't call it unless you mean business
3092          *
3093          * @param &$nt \type{Title} the new title to check
3094          * @return \type{\bool} TRUE or FALSE
3095          */
3096         public function isValidMoveTarget( $nt ) {
3097                 $dbw = wfGetDB( DB_MASTER );
3098                 # Is it an existsing file?
3099                 if( $nt->getNamespace() == NS_FILE ) {
3100                         $file = wfLocalFile( $nt );
3101                         if( $file->exists() ) {
3102                                 wfDebug( __METHOD__ . ": file exists\n" );
3103                                 return false;
3104                         }
3105                 }
3106                 # Is it a redirect with no history?
3107                 if( !$nt->isSingleRevRedirect() ) {
3108                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3109                         return false;
3110                 }
3111                 # Get the article text
3112                 $rev = Revision::newFromTitle( $nt );
3113                 $text = $rev->getText();
3114                 # Does the redirect point to the source?
3115                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3116                 $m = array();
3117                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3118                         $redirTitle = Title::newFromText( $m[1] );
3119                         if( !is_object( $redirTitle ) ||
3120                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3121                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3122                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3123                                 return false;
3124                         }
3125                 } else {
3126                         # Fail safe
3127                         wfDebug( __METHOD__ . ": failsafe\n" );
3128                         return false;
3129                 }
3130                 return true;
3131         }
3132
3133         /**
3134          * Can this title be added to a user's watchlist?
3135          *
3136          * @return \type{\bool} TRUE or FALSE
3137          */
3138         public function isWatchable() {
3139                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3140         }
3141
3142         /**
3143          * Get categories to which this Title belongs and return an array of
3144          * categories' names.
3145          *
3146          * @return \type{\array} array an array of parents in the form:
3147          *      $parent => $currentarticle
3148          */
3149         public function getParentCategories() {
3150                 global $wgContLang;
3151
3152                 $titlekey = $this->getArticleId();
3153                 $dbr = wfGetDB( DB_SLAVE );
3154                 $categorylinks = $dbr->tableName( 'categorylinks' );
3155
3156                 # NEW SQL
3157                 $sql = "SELECT * FROM $categorylinks"
3158                      ." WHERE cl_from='$titlekey'"
3159                          ." AND cl_from <> '0'"
3160                          ." ORDER BY cl_sortkey";
3161
3162                 $res = $dbr->query( $sql );
3163
3164                 if( $dbr->numRows( $res ) > 0 ) {
3165                         foreach( $res as $row )
3166                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3167                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3168                         $dbr->freeResult( $res );
3169                 } else {
3170                         $data = array();
3171                 }
3172                 return $data;
3173         }
3174
3175         /**
3176          * Get a tree of parent categories
3177          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3178          * @return \type{\array} Tree of parent categories
3179          */
3180         public function getParentCategoryTree( $children = array() ) {
3181                 $stack = array();
3182                 $parents = $this->getParentCategories();
3183
3184                 if( $parents ) {
3185                         foreach( $parents as $parent => $current ) {
3186                                 if ( array_key_exists( $parent, $children ) ) {
3187                                         # Circular reference
3188                                         $stack[$parent] = array();
3189                                 } else {
3190                                         $nt = Title::newFromText($parent);
3191                                         if ( $nt ) {
3192                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3193                                         }
3194                                 }
3195                         }
3196                         return $stack;
3197                 } else {
3198                         return array();
3199                 }
3200         }
3201
3202
3203         /**
3204          * Get an associative array for selecting this title from
3205          * the "page" table
3206          *
3207          * @return \type{\array} Selection array
3208          */
3209         public function pageCond() {
3210                 if( $this->mArticleID > 0 ) {
3211                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3212                         return array( 'page_id' => $this->mArticleID );
3213                 } else {
3214                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3215                 }
3216         }
3217
3218         /**
3219          * Get the revision ID of the previous revision
3220          *
3221          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3222          * @param $flags \type{\int} GAID_FOR_UPDATE
3223          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3224          */
3225         public function getPreviousRevisionID( $revId, $flags=0 ) {
3226                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3227                 return $db->selectField( 'revision', 'rev_id',
3228                         array(
3229                                 'rev_page' => $this->getArticleId($flags),
3230                                 'rev_id < ' . intval( $revId )
3231                         ),
3232                         __METHOD__,
3233                         array( 'ORDER BY' => 'rev_id DESC' )
3234                 );
3235         }
3236
3237         /**
3238          * Get the revision ID of the next revision
3239          *
3240          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3241          * @param $flags \type{\int} GAID_FOR_UPDATE
3242          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3243          */
3244         public function getNextRevisionID( $revId, $flags=0 ) {
3245                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3246                 return $db->selectField( 'revision', 'rev_id',
3247                         array(
3248                                 'rev_page' => $this->getArticleId($flags),
3249                                 'rev_id > ' . intval( $revId )
3250                         ),
3251                         __METHOD__,
3252                         array( 'ORDER BY' => 'rev_id' )
3253                 );
3254         }
3255
3256         /**
3257          * Get the first revision of the page
3258          *
3259          * @param $flags \type{\int} GAID_FOR_UPDATE
3260          * @return Revision (or NULL if page doesn't exist)
3261          */
3262         public function getFirstRevision( $flags=0 ) {
3263                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3264                 $pageId = $this->getArticleId($flags);
3265                 if( !$pageId ) return NULL;
3266                 $row = $db->selectRow( 'revision', '*',
3267                         array( 'rev_page' => $pageId ),
3268                         __METHOD__,
3269                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3270                 );
3271                 if( !$row ) {
3272                         return NULL;
3273                 } else {
3274                         return new Revision( $row );
3275                 }
3276         }
3277
3278         /**
3279          * Check if this is a new page
3280          *
3281          * @return bool
3282          */
3283         public function isNewPage() {
3284                 $dbr = wfGetDB( DB_SLAVE );
3285                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3286         }
3287
3288         /**
3289          * Get the oldest revision timestamp of this page
3290          *
3291          * @return string, MW timestamp
3292          */
3293         public function getEarliestRevTime() {
3294                 $dbr = wfGetDB( DB_SLAVE );
3295                 if( $this->exists() ) {
3296                         $min = $dbr->selectField( 'revision',
3297                                 'MIN(rev_timestamp)',
3298                                 array( 'rev_page' => $this->getArticleId() ),
3299                                 __METHOD__ );
3300                         return wfTimestampOrNull( TS_MW, $min );
3301                 }
3302                 return null;
3303         }
3304
3305         /**
3306          * Get the number of revisions between the given revision IDs.
3307          * Used for diffs and other things that really need it.
3308          *
3309          * @param $old \type{\int} Revision ID.
3310          * @param $new \type{\int} Revision ID.
3311          * @return \type{\int} Number of revisions between these IDs.
3312          */
3313         public function countRevisionsBetween( $old, $new ) {
3314                 $dbr = wfGetDB( DB_SLAVE );
3315                 return $dbr->selectField( 'revision', 'count(*)',
3316                         'rev_page = ' . intval( $this->getArticleId() ) .
3317                         ' AND rev_id > ' . intval( $old ) .
3318                         ' AND rev_id < ' . intval( $new ),
3319                         __METHOD__
3320                 );
3321         }
3322
3323         /**
3324          * Compare with another title.
3325          *
3326          * @param \type{Title} $title
3327          * @return \type{\bool} TRUE or FALSE
3328          */
3329         public function equals( Title $title ) {
3330                 // Note: === is necessary for proper matching of number-like titles.
3331                 return $this->getInterwiki() === $title->getInterwiki()
3332                         && $this->getNamespace() == $title->getNamespace()
3333                         && $this->getDBkey() === $title->getDBkey();
3334         }
3335
3336         /**
3337          * Callback for usort() to do title sorts by (namespace, title)
3338          */
3339         public static function compare( $a, $b ) {
3340                 if( $a->getNamespace() == $b->getNamespace() ) {
3341                         return strcmp( $a->getText(), $b->getText() );
3342                 } else {
3343                         return $a->getNamespace() - $b->getNamespace();
3344                 }
3345         }
3346
3347         /**
3348          * Return a string representation of this title
3349          *
3350          * @return \type{\string} String representation of this title
3351          */
3352         public function __toString() {
3353                 return $this->getPrefixedText();
3354         }
3355
3356         /**
3357          * Check if page exists.  For historical reasons, this function simply
3358          * checks for the existence of the title in the page table, and will
3359          * thus return false for interwiki links, special pages and the like.
3360          * If you want to know if a title can be meaningfully viewed, you should
3361          * probably call the isKnown() method instead.
3362          *
3363          * @return \type{\bool} TRUE or FALSE
3364          */
3365         public function exists() {
3366                 return $this->getArticleId() != 0;
3367         }
3368
3369         /**
3370          * Should links to this title be shown as potentially viewable (i.e. as
3371          * "bluelinks"), even if there's no record by this title in the page
3372          * table?
3373          *
3374          * This function is semi-deprecated for public use, as well as somewhat
3375          * misleadingly named.  You probably just want to call isKnown(), which
3376          * calls this function internally.
3377          *
3378          * (ISSUE: Most of these checks are cheap, but the file existence check
3379          * can potentially be quite expensive.  Including it here fixes a lot of
3380          * existing code, but we might want to add an optional parameter to skip
3381          * it and any other expensive checks.)
3382          *
3383          * @return \type{\bool} TRUE or FALSE
3384          */
3385         public function isAlwaysKnown() {
3386                 if( $this->mInterwiki != '' ) {
3387                         return true;  // any interwiki link might be viewable, for all we know
3388                 }
3389                 switch( $this->mNamespace ) {
3390                 case NS_MEDIA:
3391                 case NS_FILE:
3392                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3393                 case NS_SPECIAL:
3394                         return SpecialPage::exists( $this->getDBKey() );  // valid special page
3395                 case NS_MAIN:
3396                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3397                 case NS_MEDIAWIKI:
3398                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3399                         // the full l10n of that language to be loaded. That takes much memory and
3400                         // isn't needed. So we strip the language part away.
3401                         // Also, extension messages which are not loaded, are shown as red, because
3402                         // we don't call MessageCache::loadAllMessages.
3403                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3404                         return wfMsgWeirdKey( $basename );  // known system message
3405                 default:
3406                         return false;
3407                 }
3408         }
3409
3410         /**
3411          * Does this title refer to a page that can (or might) be meaningfully
3412          * viewed?  In particular, this function may be used to determine if
3413          * links to the title should be rendered as "bluelinks" (as opposed to
3414          * "redlinks" to non-existent pages).
3415          *
3416          * @return \type{\bool} TRUE or FALSE
3417          */
3418         public function isKnown() {
3419                 return $this->exists() || $this->isAlwaysKnown();
3420         }
3421
3422         /**
3423         * Is this in a namespace that allows actual pages?
3424         *
3425         * @return \type{\bool} TRUE or FALSE
3426         */
3427         public function canExist() {
3428                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3429         }
3430
3431         /**
3432          * Update page_touched timestamps and send squid purge messages for
3433          * pages linking to this title. May be sent to the job queue depending
3434          * on the number of links. Typically called on create and delete.
3435          */
3436         public function touchLinks() {
3437                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3438                 $u->doUpdate();
3439
3440                 if ( $this->getNamespace() == NS_CATEGORY ) {
3441                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3442                         $u->doUpdate();
3443                 }
3444         }
3445
3446         /**
3447          * Get the last touched timestamp
3448          * @param Database $db, optional db
3449          * @return \type{\string} Last touched timestamp
3450          */
3451         public function getTouched( $db = NULL ) {
3452                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3453                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3454                 return $touched;
3455         }
3456
3457         /**
3458          * Get the timestamp when this page was updated since the user last saw it.
3459          * @param User $user
3460          * @return mixed string/NULL
3461          */
3462         public function getNotificationTimestamp( $user = NULL ) {
3463                 global $wgUser, $wgShowUpdatedMarker;
3464                 // Assume current user if none given
3465                 if( !$user ) $user = $wgUser;
3466                 // Check cache first
3467                 $uid = $user->getId();
3468                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3469                         return $this->mNotificationTimestamp[$uid];
3470                 }
3471                 if( !$uid || !$wgShowUpdatedMarker ) {
3472                         return $this->mNotificationTimestamp[$uid] = false;
3473                 }
3474                 // Don't cache too much!
3475                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3476                         $this->mNotificationTimestamp = array();
3477                 }
3478                 $dbr = wfGetDB( DB_SLAVE );
3479                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3480                         'wl_notificationtimestamp',
3481                         array( 'wl_namespace' => $this->getNamespace(),
3482                                 'wl_title' => $this->getDBkey(),
3483                                 'wl_user' => $user->getId()
3484                         ),
3485                         __METHOD__
3486                 );
3487                 return $this->mNotificationTimestamp[$uid];
3488         }
3489
3490         /**
3491          * Get the trackback URL for this page
3492          * @return \type{\string} Trackback URL
3493          */
3494         public function trackbackURL() {
3495                 global $wgScriptPath, $wgServer;
3496
3497                 return "$wgServer$wgScriptPath/trackback.php?article="
3498                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3499         }
3500
3501         /**
3502          * Get the trackback RDF for this page
3503          * @return \type{\string} Trackback RDF
3504          */
3505         public function trackbackRDF() {
3506                 $url = htmlspecialchars($this->getFullURL());
3507                 $title = htmlspecialchars($this->getText());
3508                 $tburl = $this->trackbackURL();
3509
3510                 // Autodiscovery RDF is placed in comments so HTML validator
3511                 // won't barf. This is a rather icky workaround, but seems
3512                 // frequently used by this kind of RDF thingy.
3513                 //
3514                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3515                 return "<!--
3516 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3517          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3518          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3519 <rdf:Description
3520    rdf:about=\"$url\"
3521    dc:identifier=\"$url\"
3522    dc:title=\"$title\"
3523    trackback:ping=\"$tburl\" />
3524 </rdf:RDF>
3525 -->";
3526         }
3527
3528         /**
3529          * Generate strings used for xml 'id' names in monobook tabs
3530          * @return \type{\string} XML 'id' name
3531          */
3532         public function getNamespaceKey() {
3533                 global $wgContLang;
3534                 switch ($this->getNamespace()) {
3535                         case NS_MAIN:
3536                         case NS_TALK:
3537                                 return 'nstab-main';
3538                         case NS_USER:
3539                         case NS_USER_TALK:
3540                                 return 'nstab-user';
3541                         case NS_MEDIA:
3542                                 return 'nstab-media';
3543                         case NS_SPECIAL:
3544                                 return 'nstab-special';
3545                         case NS_PROJECT:
3546                         case NS_PROJECT_TALK:
3547                                 return 'nstab-project';
3548                         case NS_FILE:
3549                         case NS_FILE_TALK:
3550                                 return 'nstab-image';
3551                         case NS_MEDIAWIKI:
3552                         case NS_MEDIAWIKI_TALK:
3553                                 return 'nstab-mediawiki';
3554                         case NS_TEMPLATE:
3555                         case NS_TEMPLATE_TALK:
3556                                 return 'nstab-template';
3557                         case NS_HELP:
3558                         case NS_HELP_TALK:
3559                                 return 'nstab-help';
3560                         case NS_CATEGORY:
3561                         case NS_CATEGORY_TALK:
3562                                 return 'nstab-category';
3563                         default:
3564                                 return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
3565                 }
3566         }
3567
3568         /**
3569          * Returns true if this title resolves to the named special page
3570          * @param $name \type{\string} The special page name
3571          */
3572         public function isSpecial( $name ) {
3573                 if ( $this->getNamespace() == NS_SPECIAL ) {
3574                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3575                         if ( $name == $thisName ) {
3576                                 return true;
3577                         }
3578                 }
3579                 return false;
3580         }
3581
3582         /**
3583          * If the Title refers to a special page alias which is not the local default,
3584          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3585          */
3586         public function fixSpecialName() {
3587                 if ( $this->getNamespace() == NS_SPECIAL ) {
3588                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3589                         if ( $canonicalName ) {
3590                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3591                                 if ( $localName != $this->mDbkeyform ) {
3592                                         return Title::makeTitle( NS_SPECIAL, $localName );
3593                                 }
3594                         }
3595                 }
3596                 return $this;
3597         }
3598
3599         /**
3600          * Is this Title in a namespace which contains content?
3601          * In other words, is this a content page, for the purposes of calculating
3602          * statistics, etc?
3603          *
3604          * @return \type{\bool} TRUE or FALSE
3605          */
3606         public function isContentPage() {
3607                 return MWNamespace::isContent( $this->getNamespace() );
3608         }
3609
3610         /**
3611          * Get all extant redirects to this Title
3612          *
3613          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3614          *            NULL to consider all namespaces
3615          * @return \type{\arrayof{Title}} Redirects to this title
3616          */
3617         public function getRedirectsHere( $ns = null ) {
3618                 $redirs = array();
3619
3620                 $dbr = wfGetDB( DB_SLAVE );
3621                 $where = array(
3622                         'rd_namespace' => $this->getNamespace(),
3623                         'rd_title' => $this->getDBkey(),
3624                         'rd_from = page_id'
3625                 );
3626                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3627
3628                 $res = $dbr->select(
3629                         array( 'redirect', 'page' ),
3630                         array( 'page_namespace', 'page_title' ),
3631                         $where,
3632                         __METHOD__
3633                 );
3634
3635
3636                 foreach( $res as $row ) {
3637                         $redirs[] = self::newFromRow( $row );
3638                 }
3639                 return $redirs;
3640         }
3641
3642         /**
3643          * Check if this Title is a valid redirect target
3644          *
3645          * @return \type{\bool} TRUE or FALSE
3646          */
3647         public function isValidRedirectTarget() {
3648                 global $wgInvalidRedirectTargets;
3649
3650                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3651                 if( $this->isSpecial( 'Userlogout' ) ) {
3652                         return false;
3653                 }
3654
3655                 foreach( $wgInvalidRedirectTargets as $target ) {
3656                         if( $this->isSpecial( $target ) ) {
3657                                 return false;
3658                         }
3659                 }
3660
3661                 return true;
3662         }
3663
3664         /**
3665          * Get a backlink cache object
3666          */
3667         function getBacklinkCache() {
3668                 if ( is_null( $this->mBacklinkCache ) ) {
3669                         $this->mBacklinkCache = new BacklinkCache( $this );
3670                 }
3671                 return $this->mBacklinkCache;
3672         }
3673 }