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          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 156          *
 157          * Example of wrong and broken code:
 158          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 159          *
 160          * Example of right code:
 161          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 162          *
 163          * Create a new Title from URL-encoded text. Ensures that
 164          * the given title's length does not exceed the maximum.
 165          * @param $url \type{\string} the title, as might be taken from a URL
 166          * @return \type{Title} the new object, or NULL on an error
 167          */
 168         public static function newFromURL( $url ) {
 169                 global $wgLegalTitleChars;
 170                 $t = new Title();
 171
 172                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 173                 # but some URLs used it as a space replacement and they still come
 174                 # from some external search tools.
 175                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 176                         $url = str_replace( '+', ' ', $url );
 177                 }
 178
 179                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 180                 if( $t->secureAndSplit() ) {
 181                         return $t;
 182                 } else {
 183                         return NULL;
 184                 }
 185         }
 186
 187         /**
 188          * Create a new Title from an article ID
 189          *
 190          * @param $id \type{\int} the page_id corresponding to the Title to create
 191          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 192          * @return \type{Title} the new object, or NULL on an error
 193          */
 194         public static function newFromID( $id, $flags = 0 ) {
 195                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 196                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 197                 if( $row !== false ) {
 198                         $title = Title::newFromRow( $row );
 199                 } else {
 200                         $title = NULL;
 201                 }
 202                 return $title;
 203         }
 204
 205         /**
 206          * Make an array of titles from an array of IDs
 207          * @param $ids \type{\arrayof{\int}} Array of IDs
 208          * @return \type{\arrayof{Title}} Array of Titles
 209          */
 210         public static function newFromIDs( $ids ) {
 211                 if ( !count( $ids ) ) {
 212                         return array();
 213                 }
 214                 $dbr = wfGetDB( DB_SLAVE );
 215                 $res = $dbr->select( 'page', array( 'page_namespace', 'page_title' ),
 216                         'page_id IN (' . $dbr->makeList( $ids ) . ')', __METHOD__ );
 217
 218                 $titles = array();
 219                 foreach( $res as $row ) {
 220                         $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
 221                 }
 222                 return $titles;
 223         }
 224
 225         /**
 226          * Make a Title object from a DB row
 227          * @param $row \type{Row} (needs at least page_title,page_namespace)
 228          * @return \type{Title} corresponding Title
 229          */
 230         public static function newFromRow( $row ) {
 231                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 232
 233                 $t->mArticleID = isset($row->page_id) ? intval($row->page_id) : -1;
 234                 $t->mLength = isset($row->page_len) ? intval($row->page_len) : -1;
 235                 $t->mRedirect = isset($row->page_is_redirect) ? (bool)$row->page_is_redirect : NULL;
 236                 $t->mLatestID = isset($row->page_latest) ? $row->page_latest : false;
 237
 238                 return $t;
 239         }
 240
 241         /**
 242          * Create a new Title from a namespace index and a DB key.
 243          * It's assumed that $ns and $title are *valid*, for instance when
 244          * they came directly from the database or a special page name.
 245          * For convenience, spaces are converted to underscores so that
 246          * eg user_text fields can be used directly.
 247          *
 248          * @param $ns \type{\int} the namespace of the article
 249          * @param $title \type{\string} the unprefixed database key form
 250          * @param $fragment \type{\string} The link fragment (after the "#")
 251          * @return \type{Title} the new object
 252          */
 253         public static function &makeTitle( $ns, $title, $fragment = '' ) {
 254                 $t = new Title();
 255                 $t->mInterwiki = '';
 256                 $t->mFragment = $fragment;
 257                 $t->mNamespace = $ns = intval( $ns );
 258                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 259                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 260                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 261                 $t->mTextform = str_replace( '_', ' ', $title );
 262                 return $t;
 263         }
 264
 265         /**
 266          * Create a new Title from a namespace index and a DB key.
 267          * The parameters will be checked for validity, which is a bit slower
 268          * than makeTitle() but safer for user-provided data.
 269          *
 270          * @param $ns \type{\int} the namespace of the article
 271          * @param $title \type{\string} the database key form
 272          * @param $fragment \type{\string} The link fragment (after the "#")
 273          * @return \type{Title} the new object, or NULL on an error
 274          */
 275         public static function makeTitleSafe( $ns, $title, $fragment = '' ) {
 276                 $t = new Title();
 277                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment );
 278                 if( $t->secureAndSplit() ) {
 279                         return $t;
 280                 } else {
 281                         return NULL;
 282                 }
 283         }
 284
 285         /**
 286          * Create a new Title for the Main Page
 287          * @return \type{Title} the new object
 288          */
 289         public static function newMainPage() {
 290                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 291                 // Don't give fatal errors if the message is broken
 292                 if ( !$title ) {
 293                         $title = Title::newFromText( 'Main Page' );
 294                 }
 295                 return $title;
 296         }
 297
 298         /**
 299          * Extract a redirect destination from a string and return the
 300          * Title, or null if the text doesn't contain a valid redirect
 301          * This will only return the very next target, useful for
 302          * the redirect table and other checks that don't need full recursion
 303          *
 304          * @param $text \type{\string} Text with possible redirect
 305          * @return \type{Title} The corresponding Title
 306          */
 307         public static function newFromRedirect( $text ) {
 308                 return self::newFromRedirectInternal( $text );
 309         }
 310
 311         /**
 312          * Extract a redirect destination from a string and return the
 313          * Title, or null if the text doesn't contain a valid redirect
 314          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 315          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 316          *
 317          * @param $text \type{\string} Text with possible redirect
 318          * @return \type{Title} The corresponding Title
 319          */
 320         public static function newFromRedirectRecurse( $text ) {
 321                 $titles = self::newFromRedirectArray( $text );
 322                 return $titles ? array_pop( $titles ) : null;
 323         }
 324
 325         /**
 326          * Extract a redirect destination from a string and return an
 327          * array of Titles, or null if the text doesn't contain a valid redirect
 328          * The last element in the array is the final destination after all redirects
 329          * have been resolved (up to $wgMaxRedirects times)
 330          *
 331          * @param $text \type{\string} Text with possible redirect
 332          * @return \type{\array} Array of Titles, with the destination last
 333          */
 334         public static function newFromRedirectArray( $text ) {
 335                 global $wgMaxRedirects;
 336                 // are redirects disabled?
 337                 if( $wgMaxRedirects < 1 )
 338                         return null;
 339                 $title = self::newFromRedirectInternal( $text );
 340                 if( is_null( $title ) )
 341                         return null;
 342                 // recursive check to follow double redirects
 343                 $recurse = $wgMaxRedirects;
 344                 $titles = array( $title );
 345                 while( --$recurse > 0 ) {
 346                         if( $title->isRedirect() ) {
 347                                 $article = new Article( $title, 0 );
 348                                 $newtitle = $article->getRedirectTarget();
 349                         } else {
 350                                 break;
 351                         }
 352                         // Redirects to some special pages are not permitted
 353                         if( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 354                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 355                                 $title = $newtitle;
 356                                 $titles[] = $newtitle;
 357                         } else {
 358                                 break;
 359                         }
 360                 }
 361                 return $titles;
 362         }
 363
 364         /**
 365          * Really extract the redirect destination
 366          * Do not call this function directly, use one of the newFromRedirect* functions above
 367          *
 368          * @param $text \type{\string} Text with possible redirect
 369          * @return \type{Title} The corresponding Title
 370          */
 371         protected static function newFromRedirectInternal( $text ) {
 372                 $redir = MagicWord::get( 'redirect' );
 373                 $text = trim($text);
 374                 if( $redir->matchStartAndRemove( $text ) ) {
 375                         // Extract the first link and see if it's usable
 376                         // Ensure that it really does come directly after #REDIRECT
 377                         // Some older redirects included a colon, so don't freak about that!
 378                         $m = array();
 379                         if( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 380                                 // Strip preceding colon used to "escape" categories, etc.
 381                                 // and URL-decode links
 382                                 if( strpos( $m[1], '%' ) !== false ) {
 383                                         // Match behavior of inline link parsing here;
 384                                         // don't interpret + as " " most of the time!
 385                                         // It might be safe to just use rawurldecode instead, though.
 386                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 387                                 }
 388                                 $title = Title::newFromText( $m[1] );
 389                                 // If the title is a redirect to bad special pages or is invalid, return null
 390                                 if( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 391                                         return null;
 392                                 }
 393                                 return $title;
 394                         }
 395                 }
 396                 return null;
 397         }
 398
 399 #----------------------------------------------------------------------------
 400 #       Static functions
 401 #----------------------------------------------------------------------------
 402
 403         /**
 404          * Get the prefixed DB key associated with an ID
 405          * @param $id \type{\int} the page_id of the article
 406          * @return \type{Title} an object representing the article, or NULL
 407          *      if no such article was found
 408          */
 409         public static function nameOf( $id ) {
 410                 $dbr = wfGetDB( DB_SLAVE );
 411
 412                 $s = $dbr->selectRow( 'page',
 413                         array( 'page_namespace','page_title' ),
 414                         array( 'page_id' => $id ),
 415                         __METHOD__ );
 416                 if ( $s === false ) { return NULL; }
 417
 418                 $n = self::makeName( $s->page_namespace, $s->page_title );
 419                 return $n;
 420         }
 421
 422         /**
 423          * Get a regex character class describing the legal characters in a link
 424          * @return \type{\string} the list of characters, not delimited
 425          */
 426         public static function legalChars() {
 427                 global $wgLegalTitleChars;
 428                 return $wgLegalTitleChars;
 429         }
 430
 431         /**
 432          * Get a string representation of a title suitable for
 433          * including in a search index
 434          *
 435          * @param $ns \type{\int} a namespace index
 436          * @param $title \type{\string} text-form main part
 437          * @return \type{\string} a stripped-down title string ready for the
 438          *      search index
 439          */
 440         public static function indexTitle( $ns, $title ) {
 441                 global $wgContLang;
 442
 443                 $lc = SearchEngine::legalSearchChars() . '&#;';
 444                 $t = $wgContLang->stripForSearch( $title );
 445                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 446                 $t = $wgContLang->lc( $t );
 447
 448                 # Handle 's, s'
 449                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 450                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 451
 452                 $t = preg_replace( "/\\s+/", ' ', $t );
 453
 454                 if ( $ns == NS_FILE ) {
 455                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 456                 }
 457                 return trim( $t );
 458         }
 459
 460         /**
 461          * Make a prefixed DB key from a DB key and a namespace index
 462          * @param $ns \type{\int} numerical representation of the namespace
 463          * @param $title \type{\string} the DB key form the title
 464          * @param $fragment \type{\string} The link fragment (after the "#")
 465          * @return \type{\string} the prefixed form of the title
 466          */
 467         public static function makeName( $ns, $title, $fragment = '' ) {
 468                 global $wgContLang;
 469
 470                 $namespace = $wgContLang->getNsText( $ns );
 471                 $name = $namespace == '' ? $title : "$namespace:$title";
 472                 if ( strval( $fragment ) != '' ) {
 473                         $name .= '#' . $fragment;
 474                 }
 475                 return $name;
 476         }
 477
 478         /**
 479          * Determine whether the object refers to a page within
 480          * this project.
 481          *
 482          * @return \type{\bool} TRUE if this is an in-project interwiki link
 483          *      or a wikilink, FALSE otherwise
 484          */
 485         public function isLocal() {
 486                 if ( $this->mInterwiki != '' ) {
 487                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 488                 } else {
 489                         return true;
 490                 }
 491         }
 492
 493         /**
 494          * Determine whether the object refers to a page within
 495          * this project and is transcludable.
 496          *
 497          * @return \type{\bool} TRUE if this is transcludable
 498          */
 499         public function isTrans() {
 500                 if ($this->mInterwiki == '')
 501                         return false;
 502
 503                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 504         }
 505
 506         /**
 507          * Escape a text fragment, say from a link, for a URL
 508          */
 509         static function escapeFragmentForURL( $fragment ) {
 510                 global $wgEnforceHtmlIds;
 511                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 512                 # fragments appear not to work in IE (at least up to 7) or in at least
 513                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 514                 # to care if they aren't encoded.
 515                 return Sanitizer::escapeId( $fragment,
 516                         $wgEnforceHtmlIds ? 'noninitial' : 'xml' );
 517         }
 518
 519 #----------------------------------------------------------------------------
 520 #       Other stuff
 521 #----------------------------------------------------------------------------
 522
 523         /** Simple accessors */
 524         /**
 525          * Get the text form (spaces not underscores) of the main part
 526          * @return \type{\string} Main part of the title
 527          */
 528         public function getText() { return $this->mTextform; }
 529         /**
 530          * Get the URL-encoded form of the main part
 531          * @return \type{\string} Main part of the title, URL-encoded
 532          */
 533         public function getPartialURL() { return $this->mUrlform; }
 534         /**
 535          * Get the main part with underscores
 536          * @return \type{\string} Main part of the title, with underscores
 537          */
 538         public function getDBkey() { return $this->mDbkeyform; }
 539         /**
 540          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 541          * @return \type{\int} Namespace index
 542          */
 543         public function getNamespace() { return $this->mNamespace; }
 544         /**
 545          * Get the namespace text
 546          * @return \type{\string} Namespace text
 547          */
 548         public function getNsText() {
 549                 global $wgContLang, $wgCanonicalNamespaceNames;
 550
 551                 if ( '' != $this->mInterwiki ) {
 552                         // This probably shouldn't even happen. ohh man, oh yuck.
 553                         // But for interwiki transclusion it sometimes does.
 554                         // Shit. Shit shit shit.
 555                         //
 556                         // Use the canonical namespaces if possible to try to
 557                         // resolve a foreign namespace.
 558                         if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
 559                                 return $wgCanonicalNamespaceNames[$this->mNamespace];
 560                         }
 561                 }
 562                 return $wgContLang->getNsText( $this->mNamespace );
 563         }
 564         /**
 565          * Get the DB key with the initial letter case as specified by the user
 566          * @return \type{\string} DB key
 567          */
 568         function getUserCaseDBKey() {
 569                 return $this->mUserCaseDBKey;
 570         }
 571         /**
 572          * Get the namespace text of the subject (rather than talk) page
 573          * @return \type{\string} Namespace text
 574          */
 575         public function getSubjectNsText() {
 576                 global $wgContLang;
 577                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 578         }
 579         /**
 580          * Get the namespace text of the talk page
 581          * @return \type{\string} Namespace text
 582          */
 583         public function getTalkNsText() {
 584                 global $wgContLang;
 585                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 586         }
 587         /**
 588          * Could this title have a corresponding talk page?
 589          * @return \type{\bool} TRUE or FALSE
 590          */
 591         public function canTalk() {
 592                 return( MWNamespace::canTalk( $this->mNamespace ) );
 593         }
 594         /**
 595          * Get the interwiki prefix (or null string)
 596          * @return \type{\string} Interwiki prefix
 597          */
 598         public function getInterwiki() { return $this->mInterwiki; }
 599         /**
 600          * Get the Title fragment (i.e.\ the bit after the #) in text form
 601          * @return \type{\string} Title fragment
 602          */
 603         public function getFragment() { return $this->mFragment; }
 604         /**
 605          * Get the fragment in URL form, including the "#" character if there is one
 606          * @return \type{\string} Fragment in URL form
 607          */
 608         public function getFragmentForURL() {
 609                 if ( $this->mFragment == '' ) {
 610                         return '';
 611                 } else {
 612                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 613                 }
 614         }
 615         /**
 616          * Get the default namespace index, for when there is no namespace
 617          * @return \type{\int} Default namespace index
 618          */
 619         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 620
 621         /**
 622          * Get title for search index
 623          * @return \type{\string} a stripped-down title string ready for the
 624          *      search index
 625          */
 626         public function getIndexTitle() {
 627                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 628         }
 629
 630         /**
 631          * Get the prefixed database key form
 632          * @return \type{\string} the prefixed title, with underscores and
 633          *      any interwiki and namespace prefixes
 634          */
 635         public function getPrefixedDBkey() {
 636                 $s = $this->prefix( $this->mDbkeyform );
 637                 $s = str_replace( ' ', '_', $s );
 638                 return $s;
 639         }
 640
 641         /**
 642          * Get the prefixed title with spaces.
 643          * This is the form usually used for display
 644          * @return \type{\string} the prefixed title, with spaces
 645          */
 646         public function getPrefixedText() {
 647                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 648                         $s = $this->prefix( $this->mTextform );
 649                         $s = str_replace( '_', ' ', $s );
 650                         $this->mPrefixedText = $s;
 651                 }
 652                 return $this->mPrefixedText;
 653         }
 654
 655         /**
 656          * Get the prefixed title with spaces, plus any fragment
 657          * (part beginning with '#')
 658          * @return \type{\string} the prefixed title, with spaces and
 659          *      the fragment, including '#'
 660          */
 661         public function getFullText() {
 662                 $text = $this->getPrefixedText();
 663                 if( '' != $this->mFragment ) {
 664                         $text .= '#' . $this->mFragment;
 665                 }
 666                 return $text;
 667         }
 668
 669         /**
 670          * Get the base name, i.e. the leftmost parts before the /
 671          * @return \type{\string} Base name
 672          */
 673         public function getBaseText() {
 674                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 675                         return $this->getText();
 676                 }
 677
 678                 $parts = explode( '/', $this->getText() );
 679                 # Don't discard the real title if there's no subpage involved
 680                 if( count( $parts ) > 1 )
 681                         unset( $parts[ count( $parts ) - 1 ] );
 682                 return implode( '/', $parts );
 683         }
 684
 685         /**
 686          * Get the lowest-level subpage name, i.e. the rightmost part after /
 687          * @return \type{\string} Subpage name
 688          */
 689         public function getSubpageText() {
 690                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 691                         return( $this->mTextform );
 692                 }
 693                 $parts = explode( '/', $this->mTextform );
 694                 return( $parts[ count( $parts ) - 1 ] );
 695         }
 696
 697         /**
 698          * Get a URL-encoded form of the subpage text
 699          * @return \type{\string} URL-encoded subpage name
 700          */
 701         public function getSubpageUrlForm() {
 702                 $text = $this->getSubpageText();
 703                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 704                 return( $text );
 705         }
 706
 707         /**
 708          * Get a URL-encoded title (not an actual URL) including interwiki
 709          * @return \type{\string} the URL-encoded form
 710          */
 711         public function getPrefixedURL() {
 712                 $s = $this->prefix( $this->mDbkeyform );
 713                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 714                 return $s;
 715         }
 716
 717         /**
 718          * Get a real URL referring to this title, with interwiki link and
 719          * fragment
 720          *
 721          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 722          *   links. Can be specified as an associative array as well, e.g.,
 723          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 724          * @param $variant \type{\string} language variant of url (for sr, zh..)
 725          * @return \type{\string} the URL
 726          */
 727         public function getFullURL( $query = '', $variant = false ) {
 728                 global $wgContLang, $wgServer, $wgRequest;
 729
 730                 if( is_array( $query ) ) {
 731                         $query = wfArrayToCGI( $query );
 732                 }
 733
 734                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 735                 if ( !$interwiki ) {
 736                         $url = $this->getLocalUrl( $query, $variant );
 737
 738                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 739                         // Correct fix would be to move the prepending elsewhere.
 740                         if ($wgRequest->getVal('action') != 'render') {
 741                                 $url = $wgServer . $url;
 742                         }
 743                 } else {
 744                         $baseUrl = $interwiki->getURL( );
 745
 746                         $namespace = wfUrlencode( $this->getNsText() );
 747                         if ( '' != $namespace ) {
 748                                 # Can this actually happen? Interwikis shouldn't be parsed.
 749                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 750                                 $namespace .= ':';
 751                         }
 752                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 753                         $url = wfAppendQuery( $url, $query );
 754                 }
 755
 756                 # Finally, add the fragment.
 757                 $url .= $this->getFragmentForURL();
 758
 759                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 760                 return $url;
 761         }
 762
 763         /**
 764          * Get a URL with no fragment or server name.  If this page is generated
 765          * with action=render, $wgServer is prepended.
 766          * @param mixed $query an optional query string; if not specified,
 767          *       $wgArticlePath will be used.  Can be specified as an associative array
 768          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 769          *   URL-escaped).
 770          * @param $variant \type{\string} language variant of url (for sr, zh..)
 771          * @return \type{\string} the URL
 772          */
 773         public function getLocalURL( $query = '', $variant = false ) {
 774                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 775                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 776
 777                 if( is_array( $query ) ) {
 778                         $query = wfArrayToCGI( $query );
 779                 }
 780
 781                 // internal links should point to same variant as current page (only anonymous users)
 782                 if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
 783                         $pref = $wgContLang->getPreferredVariant(false);
 784                         if($pref != $wgContLang->getCode())
 785                                 $variant = $pref;
 786                 }
 787
 788                 if ( $this->isExternal() ) {
 789                         $url = $this->getFullURL();
 790                         if ( $query ) {
 791                                 // This is currently only used for edit section links in the
 792                                 // context of interwiki transclusion. In theory we should
 793                                 // append the query to the end of any existing query string,
 794                                 // but interwiki transclusion is already broken in that case.
 795                                 $url .= "?$query";
 796                         }
 797                 } else {
 798                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 799                         if ( $query == '' ) {
 800                                 if( $variant != false && $wgContLang->hasVariants() ) {
 801                                         if( $wgVariantArticlePath == false ) {
 802                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 803                                         } else {
 804                                                 $variantArticlePath = $wgVariantArticlePath;
 805                                         }
 806                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 807                                         $url = str_replace( '$1', $dbkey, $url  );
 808                                 } else {
 809                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 810                                 }
 811                         } else {
 812                                 global $wgActionPaths;
 813                                 $url = false;
 814                                 $matches = array();
 815                                 if( !empty( $wgActionPaths ) &&
 816                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 817                                 {
 818                                         $action = urldecode( $matches[2] );
 819                                         if( isset( $wgActionPaths[$action] ) ) {
 820                                                 $query = $matches[1];
 821                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 822                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 823                                                 if( $query != '' ) {
 824                                                         $url = wfAppendQuery( $url, $query );
 825                                                 }
 826                                         }
 827                                 }
 828                                 if ( $url === false ) {
 829                                         if ( $query == '-' ) {
 830                                                 $query = '';
 831                                         }
 832                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 833                                 }
 834                         }
 835
 836                         // FIXME: this causes breakage in various places when we
 837                         // actually expected a local URL and end up with dupe prefixes.
 838                         if ($wgRequest->getVal('action') == 'render') {
 839                                 $url = $wgServer . $url;
 840                         }
 841                 }
 842                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 843                 return $url;
 844         }
 845
 846         /**
 847          * Get a URL that's the simplest URL that will be valid to link, locally,
 848          * to the current Title.  It includes the fragment, but does not include
 849          * the server unless action=render is used (or the link is external).  If
 850          * there's a fragment but the prefixed text is empty, we just return a link
 851          * to the fragment.
 852          *
 853          * The result obviously should not be URL-escaped, but does need to be
 854          * HTML-escaped if it's being output in HTML.
 855          *
 856          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 857          *   query string.  Keys and values will be escaped.
 858          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 859          *   for external links.  Default is "false" (same variant as current page,
 860          *   for anonymous users).
 861          * @return \type{\string} the URL
 862          */
 863         public function getLinkUrl( $query = array(), $variant = false ) {
 864                 wfProfileIn( __METHOD__ );
 865                 if( $this->isExternal() ) {
 866                         $ret = $this->getFullURL( $query );
 867                 } elseif( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 868                         $ret = $this->getFragmentForURL();
 869                 } else {
 870                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 871                 }
 872                 wfProfileOut( __METHOD__ );
 873                 return $ret;
 874         }
 875
 876         /**
 877          * Get an HTML-escaped version of the URL form, suitable for
 878          * using in a link, without a server name or fragment
 879          * @param $query \type{\string} an optional query string
 880          * @return \type{\string} the URL
 881          */
 882         public function escapeLocalURL( $query = '' ) {
 883                 return htmlspecialchars( $this->getLocalURL( $query ) );
 884         }
 885
 886         /**
 887          * Get an HTML-escaped version of the URL form, suitable for
 888          * using in a link, including the server name and fragment
 889          *
 890          * @param $query \type{\string} an optional query string
 891          * @return \type{\string} the URL
 892          */
 893         public function escapeFullURL( $query = '' ) {
 894                 return htmlspecialchars( $this->getFullURL( $query ) );
 895         }
 896
 897         /**
 898          * Get the URL form for an internal link.
 899          * - Used in various Squid-related code, in case we have a different
 900          * internal hostname for the server from the exposed one.
 901          *
 902          * @param $query \type{\string} an optional query string
 903          * @param $variant \type{\string} language variant of url (for sr, zh..)
 904          * @return \type{\string} the URL
 905          */
 906         public function getInternalURL( $query = '', $variant = false ) {
 907                 global $wgInternalServer;
 908                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 909                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 910                 return $url;
 911         }
 912
 913         /**
 914          * Get the edit URL for this Title
 915          * @return \type{\string} the URL, or a null string if this is an
 916          *      interwiki link
 917          */
 918         public function getEditURL() {
 919                 if ( '' != $this->mInterwiki ) { return ''; }
 920                 $s = $this->getLocalURL( 'action=edit' );
 921
 922                 return $s;
 923         }
 924
 925         /**
 926          * Get the HTML-escaped displayable text form.
 927          * Used for the title field in <a> tags.
 928          * @return \type{\string} the text, including any prefixes
 929          */
 930         public function getEscapedText() {
 931                 return htmlspecialchars( $this->getPrefixedText() );
 932         }
 933
 934         /**
 935          * Is this Title interwiki?
 936          * @return \type{\bool}
 937          */
 938         public function isExternal() { return ( '' != $this->mInterwiki ); }
 939
 940         /**
 941          * Is this page "semi-protected" - the *only* protection is autoconfirm?
 942          *
 943          * @param @action \type{\string} Action to check (default: edit)
 944          * @return \type{\bool}
 945          */
 946         public function isSemiProtected( $action = 'edit' ) {
 947                 if( $this->exists() ) {
 948                         $restrictions = $this->getRestrictions( $action );
 949                         if( count( $restrictions ) > 0 ) {
 950                                 foreach( $restrictions as $restriction ) {
 951                                         if( strtolower( $restriction ) != 'autoconfirmed' )
 952                                                 return false;
 953                                 }
 954                         } else {
 955                                 # Not protected
 956                                 return false;
 957                         }
 958                         return true;
 959                 } else {
 960                         # If it doesn't exist, it can't be protected
 961                         return false;
 962                 }
 963         }
 964
 965         /**
 966          * Does the title correspond to a protected article?
 967          * @param $what \type{\string} the action the page is protected from,
 968          * by default checks move and edit
 969          * @return \type{\bool}
 970          */
 971         public function isProtected( $action = '' ) {
 972                 global $wgRestrictionLevels, $wgRestrictionTypes;
 973
 974                 # Special pages have inherent protection
 975                 if( $this->getNamespace() == NS_SPECIAL )
 976                         return true;
 977
 978                 # Check regular protection levels
 979                 foreach( $wgRestrictionTypes as $type ){
 980                         if( $action == $type || $action == '' ) {
 981                                 $r = $this->getRestrictions( $type );
 982                                 foreach( $wgRestrictionLevels as $level ) {
 983                                         if( in_array( $level, $r ) && $level != '' ) {
 984                                                 return true;
 985                                         }
 986                                 }
 987                         }
 988                 }
 989
 990                 return false;
 991         }
 992
 993         /**
 994          * Is $wgUser watching this page?
 995          * @return \type{\bool}
 996          */
 997         public function userIsWatching() {
 998                 global $wgUser;
 999
1000                 if ( is_null( $this->mWatched ) ) {
1001                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
1002                                 $this->mWatched = false;
1003                         } else {
1004                                 $this->mWatched = $wgUser->isWatched( $this );
1005                         }
1006                 }
1007                 return $this->mWatched;
1008         }
1009
1010         /**
1011          * Can $wgUser perform $action on this page?
1012          * This skips potentially expensive cascading permission checks.
1013          *
1014          * Suitable for use for nonessential UI controls in common cases, but
1015          * _not_ for functional access control.
1016          *
1017          * May provide false positives, but should never provide a false negative.
1018          *
1019          * @param $action \type{\string} action that permission needs to be checked for
1020          * @return \type{\bool}
1021          */
1022         public function quickUserCan( $action ) {
1023                 return $this->userCan( $action, false );
1024         }
1025
1026         /**
1027          * Determines if $wgUser is unable to edit this page because it has been protected
1028          * by $wgNamespaceProtection.
1029          *
1030          * @return \type{\bool}
1031          */
1032         public function isNamespaceProtected() {
1033                 global $wgNamespaceProtection, $wgUser;
1034                 if( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1035                         foreach( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1036                                 if( $right != '' && !$wgUser->isAllowed( $right ) )
1037                                         return true;
1038                         }
1039                 }
1040                 return false;
1041         }
1042
1043         /**
1044          * Can $wgUser perform $action on this page?
1045          * @param $action \type{\string} action that permission needs to be checked for
1046          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1047          * @return \type{\bool}
1048          */
1049         public function userCan( $action, $doExpensiveQueries = true ) {
1050                 global $wgUser;
1051                 return ($this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array());
1052         }
1053
1054         /**
1055          * Can $user perform $action on this page?
1056          *
1057          * FIXME: This *does not* check throttles (User::pingLimiter()).
1058          *
1059          * @param $action \type{\string}action that permission needs to be checked for
1060          * @param $user \type{User} user to check
1061          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1062          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1063          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1064          */
1065         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1066                 if( !StubObject::isRealObject( $user ) ) {
1067                         //Since StubObject is always used on globals, we can unstub $wgUser here and set $user = $wgUser
1068                         global $wgUser;
1069                         $wgUser->_unstub( '', 5 );
1070                         $user = $wgUser;
1071                 }
1072                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1073
1074                 global $wgContLang;
1075                 global $wgLang;
1076                 global $wgEmailConfirmToEdit;
1077
1078                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1079                         $errors[] = array( 'confirmedittext' );
1080                 }
1081
1082                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1083                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1084                         $block = $user->mBlock;
1085
1086                         // This is from OutputPage::blockedPage
1087                         // Copied at r23888 by werdna
1088
1089                         $id = $user->blockedBy();
1090                         $reason = $user->blockedFor();
1091                         if( $reason == '' ) {
1092                                 $reason = wfMsg( 'blockednoreason' );
1093                         }
1094                         $ip = wfGetIP();
1095
1096                         if ( is_numeric( $id ) ) {
1097                                 $name = User::whoIs( $id );
1098                         } else {
1099                                 $name = $id;
1100                         }
1101
1102                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1103                         $blockid = $block->mId;
1104                         $blockExpiry = $user->mBlock->mExpiry;
1105                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1106
1107                         if ( $blockExpiry == 'infinity' ) {
1108                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1109                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1110
1111                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1112                                         if ( strpos( $option, ':' ) == false )
1113                                                 continue;
1114
1115                                         list ($show, $value) = explode( ":", $option );
1116
1117                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1118                                                 $blockExpiry = $show;
1119                                                 break;
1120                                         }
1121                                 }
1122                         } else {
1123                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1124                         }
1125
1126                         $intended = $user->mBlock->mAddress;
1127
1128                         $errors[] = array( ($block->mAuto ? 'autoblockedtext' : 'blockedtext'), $link, $reason, $ip, $name,
1129                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1130                 }
1131
1132                 // Remove the errors being ignored.
1133
1134                 foreach( $errors as $index => $error ) {
1135                         $error_key = is_array($error) ? $error[0] : $error;
1136
1137                         if (in_array( $error_key, $ignoreErrors )) {
1138                                 unset($errors[$index]);
1139                         }
1140                 }
1141
1142                 return $errors;
1143         }
1144
1145         /**
1146          * Can $user perform $action on this page? This is an internal function,
1147          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1148          * checks on wfReadOnly() and blocks)
1149          *
1150          * @param $action \type{\string} action that permission needs to be checked for
1151          * @param $user \type{User} user to check
1152          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1153          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1154          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1155          */
1156         private function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries=true, $short=false ) {
1157                 wfProfileIn( __METHOD__ );
1158
1159                 $errors = array();
1160
1161                 // First stop is permissions checks, which fail most often, and which are easiest to test.
1162                 if ( $action == 'move' ) {
1163                         if( !$user->isAllowed( 'move-rootuserpages' )
1164                                         && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1165                         {
1166                                 // Show user page-specific message only if the user can move other pages
1167                                 $errors[] = array( 'cant-move-user-page' );
1168                         }
1169
1170                         // Check if user is allowed to move files if it's a file
1171                         if( $this->getNamespace() == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1172                                 $errors[] = array( 'movenotallowedfile' );
1173                         }
1174
1175                         if( !$user->isAllowed( 'move' ) ) {
1176                                 // User can't move anything
1177                                 global $wgGroupPermissions;
1178                                 $userCanMove = false;
1179                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1180                                         $userCanMove = $wgGroupPermissions['user']['move'];
1181                                 }
1182                                 $autoconfirmedCanMove = false;
1183                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1184                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1185                                 }
1186                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1187                                         // custom message if logged-in users without any special rights can move
1188                                         $errors[] = array ( 'movenologintext' );
1189                                 } else {
1190                                         $errors[] = array ('movenotallowed');
1191                                 }
1192                         }
1193                 } elseif ( $action == 'create' ) {
1194                         if( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1195                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) )
1196                         {
1197                                 $errors[] = $user->isAnon() ? array ('nocreatetext') : array ('nocreate-loggedin');
1198                         }
1199                 } elseif( $action == 'move-target' ) {
1200                         if( !$user->isAllowed( 'move' ) ) {
1201                                 // User can't move anything
1202                                 $errors[] = array ('movenotallowed');
1203                         } elseif( !$user->isAllowed( 'move-rootuserpages' )
1204                                 && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1205                         {
1206                                 // Show user page-specific message only if the user can move other pages
1207                                 $errors[] = array( 'cant-move-to-user-page' );
1208                         }
1209                 } elseif( !$user->isAllowed( $action ) ) {
1210                         $return = null;
1211                         $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1212                                 User::getGroupsWithPermission( $action ) );
1213                         if( $groups ) {
1214                                 $return = array( 'badaccess-groups',
1215                                         array( implode( ', ', $groups ), count( $groups ) ) );
1216                         } else {
1217                                 $return = array( "badaccess-group0" );
1218                         }
1219                         $errors[] = $return;
1220                 }
1221
1222                 # Short-circuit point
1223                 if( $short && count($errors) > 0 ) {
1224                         wfProfileOut( __METHOD__ );
1225                         return $errors;
1226                 }
1227
1228                 // Use getUserPermissionsErrors instead
1229                 if( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1230                         wfProfileOut( __METHOD__ );
1231                         return $result ? array() : array( array( 'badaccess-group0' ) );
1232                 }
1233                 // Check getUserPermissionsErrors hook
1234                 if( !wfRunHooks( 'getUserPermissionsErrors', array(&$this,&$user,$action,&$result) ) ) {
1235                         if( is_array($result) && count($result) && !is_array($result[0]) )
1236                                 $errors[] = $result; # A single array representing an error
1237                         else if( is_array($result) && is_array($result[0]) )
1238                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1239                         else if( $result !== '' && is_string($result) )
1240                                 $errors[] = array($result); # A string representing a message-id
1241                         else if( $result === false )
1242                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1243                 }
1244                 # Short-circuit point
1245                 if( $short && count($errors) > 0 ) {
1246                         wfProfileOut( __METHOD__ );
1247                         return $errors;
1248                 }
1249                 // Check getUserPermissionsErrorsExpensive hook
1250                 if( $doExpensiveQueries && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array(&$this,&$user,$action,&$result) ) ) {
1251                         if( is_array($result) && count($result) && !is_array($result[0]) )
1252                                 $errors[] = $result; # A single array representing an error
1253                         else if( is_array($result) && is_array($result[0]) )
1254                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1255                         else if( $result !== '' && is_string($result) )
1256                                 $errors[] = array($result); # A string representing a message-id
1257                         else if( $result === false )
1258                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1259                 }
1260                 # Short-circuit point
1261                 if( $short && count($errors) > 0 ) {
1262                         wfProfileOut( __METHOD__ );
1263                         return $errors;
1264                 }
1265
1266                 # Only 'createaccount' and 'execute' can be performed on
1267                 # special pages, which don't actually exist in the DB.
1268                 $specialOKActions = array( 'createaccount', 'execute' );
1269                 if( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions) ) {
1270                         $errors[] = array('ns-specialprotected');
1271                 }
1272
1273                 # Check $wgNamespaceProtection for restricted namespaces
1274                 if( $this->isNamespaceProtected() ) {
1275                         $ns = $this->getNamespace() == NS_MAIN ?
1276                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1277                         $errors[] = NS_MEDIAWIKI == $this->mNamespace ?
1278                                 array('protectedinterface') : array( 'namespaceprotected',  $ns );
1279                 }
1280
1281                 # Protect css/js subpages of user pages
1282                 # XXX: this might be better using restrictions
1283                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
1284                 if( $this->isCssJsSubpage() && !$user->isAllowed('editusercssjs')
1285                         && !preg_match('/^'.preg_quote($user->getName(), '/').'\//', $this->mTextform) )
1286                 {
1287                         $errors[] = array('customcssjsprotected');
1288                 }
1289
1290                 # Check against page_restrictions table requirements on this
1291                 # page. The user must possess all required rights for this action.
1292                 foreach( $this->getRestrictions($action) as $right ) {
1293                         // Backwards compatibility, rewrite sysop -> protect
1294                         if( $right == 'sysop' ) {
1295                                 $right = 'protect';
1296                         }
1297                         if( '' != $right && !$user->isAllowed( $right ) ) {
1298                                 // Users with 'editprotected' permission can edit protected pages
1299                                 if( $action=='edit' && $user->isAllowed( 'editprotected' ) ) {
1300                                         // Users with 'editprotected' permission cannot edit protected pages
1301                                         // with cascading option turned on.
1302                                         if( $this->mCascadeRestriction ) {
1303                                                 $errors[] = array( 'protectedpagetext', $right );
1304                                         }
1305                                 } else {
1306                                         $errors[] = array( 'protectedpagetext', $right );
1307                                 }
1308                         }
1309                 }
1310                 # Short-circuit point
1311                 if( $short && count($errors) > 0 ) {
1312                         wfProfileOut( __METHOD__ );
1313                         return $errors;
1314                 }
1315
1316                 if( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1317                         # We /could/ use the protection level on the source page, but it's fairly ugly
1318                         #  as we have to establish a precedence hierarchy for pages included by multiple
1319                         #  cascade-protected pages. So just restrict it to people with 'protect' permission,
1320                         #  as they could remove the protection anyway.
1321                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1322                         # Cascading protection depends on more than this page...
1323                         # Several cascading protected pages may include this page...
1324                         # Check each cascading level
1325                         # This is only for protection restrictions, not for all actions
1326                         if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
1327                                 foreach( $restrictions[$action] as $right ) {
1328                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1329                                         if( '' != $right && !$user->isAllowed( $right ) ) {
1330                                                 $pages = '';
1331                                                 foreach( $cascadingSources as $page )
1332                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1333                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1334                                         }
1335                                 }
1336                         }
1337                 }
1338                 # Short-circuit point
1339                 if( $short && count($errors) > 0 ) {
1340                         wfProfileOut( __METHOD__ );
1341                         return $errors;
1342                 }
1343
1344                 if( $action == 'protect' ) {
1345                         if( $this->getUserPermissionsErrors('edit', $user) != array() ) {
1346                                 $errors[] = array( 'protect-cantedit' ); // If they can't edit, they shouldn't protect.
1347                         }
1348                 }
1349
1350                 if( $action == 'create' ) {
1351                         $title_protection = $this->getTitleProtection();
1352                         if( is_array($title_protection) ) {
1353                                 extract($title_protection); // is this extract() really needed?
1354
1355                                 if( $pt_create_perm == 'sysop' ) {
1356                                         $pt_create_perm = 'protect'; // B/C
1357                                 }
1358                                 if( $pt_create_perm == '' || !$user->isAllowed($pt_create_perm) ) {
1359                                         $errors[] = array( 'titleprotected', User::whoIs($pt_user), $pt_reason );
1360                                 }
1361                         }
1362                 } elseif( $action == 'move' ) {
1363                         // Check for immobile pages
1364                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1365                                 // Specific message for this case
1366                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1367                         } elseif( !$this->isMovable() ) {
1368                                 // Less specific message for rarer cases
1369                                 $errors[] = array( 'immobile-page' );
1370                         }
1371                 } elseif( $action == 'move-target' ) {
1372                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1373                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1374                         } elseif( !$this->isMovable() ) {
1375                                 $errors[] = array( 'immobile-target-page' );
1376                         }
1377                 }
1378
1379                 wfProfileOut( __METHOD__ );
1380                 return $errors;
1381         }
1382
1383         /**
1384          * Is this title subject to title protection?
1385          * @return \type{\mixed} An associative array representing any existent title
1386          *   protection, or false if there's none.
1387          */
1388         private function getTitleProtection() {
1389                 // Can't protect pages in special namespaces
1390                 if ( $this->getNamespace() < 0 ) {
1391                         return false;
1392                 }
1393
1394                 $dbr = wfGetDB( DB_SLAVE );
1395                 $res = $dbr->select( 'protected_titles', '*',
1396                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1397                         __METHOD__ );
1398
1399                 if ($row = $dbr->fetchRow( $res )) {
1400                         return $row;
1401                 } else {
1402                         return false;
1403                 }
1404         }
1405
1406         /**
1407          * Update the title protection status
1408          * @param $create_perm \type{\string} Permission required for creation
1409          * @param $reason \type{\string} Reason for protection
1410          * @param $expiry \type{\string} Expiry timestamp
1411          */
1412         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1413                 global $wgUser,$wgContLang;
1414
1415                 if ($create_perm == implode(',',$this->getRestrictions('create'))
1416                         && $expiry == $this->mRestrictionsExpiry['create']) {
1417                         // No change
1418                         return true;
1419                 }
1420
1421                 list ($namespace, $title) = array( $this->getNamespace(), $this->getDBkey() );
1422
1423                 $dbw = wfGetDB( DB_MASTER );
1424
1425                 $encodedExpiry = Block::encodeExpiry($expiry, $dbw );
1426
1427                 $expiry_description = '';
1428                 if ( $encodedExpiry != 'infinity' ) {
1429                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ) , $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ).')';
1430                 }
1431                 else {
1432                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ).')';
1433                 }
1434
1435                 # Update protection table
1436                 if ($create_perm != '' ) {
1437                         $dbw->replace( 'protected_titles', array(array('pt_namespace', 'pt_title')),
1438                                 array( 'pt_namespace' => $namespace, 'pt_title' => $title
1439                                         , 'pt_create_perm' => $create_perm
1440                                         , 'pt_timestamp' => Block::encodeExpiry(wfTimestampNow(), $dbw)
1441                                         , 'pt_expiry' => $encodedExpiry
1442                                         , 'pt_user' => $wgUser->getId(), 'pt_reason' => $reason ), __METHOD__  );
1443                 } else {
1444                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1445                                 'pt_title' => $title ), __METHOD__ );
1446                 }
1447                 # Update the protection log
1448                 $log = new LogPage( 'protect' );
1449
1450                 if( $create_perm ) {
1451                         $params = array("[create=$create_perm] $expiry_description",'');
1452                         $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1453                 } else {
1454                         $log->addEntry( 'unprotect', $this, $reason );
1455                 }
1456
1457                 return true;
1458         }
1459
1460         /**
1461          * Remove any title protection due to page existing
1462          */
1463         public function deleteTitleProtection() {
1464                 $dbw = wfGetDB( DB_MASTER );
1465
1466                 $dbw->delete( 'protected_titles',
1467                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1468                         __METHOD__ );
1469         }
1470
1471         /**
1472          * Would anybody with sufficient privileges be able to move this page?
1473          * Some pages just aren't movable.
1474          *
1475          * @return \type{\bool} TRUE or FALSE
1476          */
1477         public function isMovable() {
1478                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1479         }
1480
1481         /**
1482          * Can $wgUser read this page?
1483          * @return \type{\bool} TRUE or FALSE
1484          * @todo fold these checks into userCan()
1485          */
1486         public function userCanRead() {
1487                 global $wgUser, $wgGroupPermissions;
1488
1489                 static $useShortcut = null;
1490
1491                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1492                 if( is_null( $useShortcut ) ) {
1493                         global $wgRevokePermissions;
1494                         $useShortcut = true;
1495                         if( empty( $wgGroupPermissions['*']['read'] ) ) {
1496                                 # Not a public wiki, so no shortcut
1497                                 $useShortcut = false;
1498                         } elseif( !empty( $wgRevokePermissions ) ) {
1499                                 /*
1500                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1501                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1502                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1503                                  * reading is allowed.
1504                                  */
1505                                 foreach( $wgRevokePermissions as $perms ) {
1506                                         if( !empty( $perms['read'] ) ) {
1507                                                 # We might be removing the read right from the user, so no shortcut
1508                                                 $useShortcut = false;
1509                                                 break;
1510                                         }
1511                                 }
1512                         }
1513                 }
1514
1515                 $result = null;
1516                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1517                 if ( $result !== null ) {
1518                         return $result;
1519                 }
1520
1521                 # Shortcut for public wikis, allows skipping quite a bit of code
1522                 if ( $useShortcut )
1523                         return true;
1524
1525                 if( $wgUser->isAllowed( 'read' ) ) {
1526                         return true;
1527                 } else {
1528                         global $wgWhitelistRead;
1529
1530                         /**
1531                          * Always grant access to the login page.
1532                          * Even anons need to be able to log in.
1533                         */
1534                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1535                                 return true;
1536                         }
1537
1538                         /**
1539                          * Bail out if there isn't whitelist
1540                          */
1541                         if( !is_array($wgWhitelistRead) ) {
1542                                 return false;
1543                         }
1544
1545                         /**
1546                          * Check for explicit whitelisting
1547                          */
1548                         $name = $this->getPrefixedText();
1549                         $dbName = $this->getPrefixedDBKey();
1550                         // Check with and without underscores
1551                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1552                                 return true;
1553
1554                         /**
1555                          * Old settings might have the title prefixed with
1556                          * a colon for main-namespace pages
1557                          */
1558                         if( $this->getNamespace() == NS_MAIN ) {
1559                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1560                                         return true;
1561                         }
1562
1563                         /**
1564                          * If it's a special page, ditch the subpage bit
1565                          * and check again
1566                          */
1567                         if( $this->getNamespace() == NS_SPECIAL ) {
1568                                 $name = $this->getDBkey();
1569                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1570                                 if ( $name === false ) {
1571                                         # Invalid special page, but we show standard login required message
1572                                         return false;
1573                                 }
1574
1575                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1576                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1577                                         return true;
1578                         }
1579
1580                 }
1581                 return false;
1582         }
1583
1584         /**
1585          * Is this a talk page of some sort?
1586          * @return \type{\bool} TRUE or FALSE
1587          */
1588         public function isTalkPage() {
1589                 return MWNamespace::isTalk( $this->getNamespace() );
1590         }
1591
1592         /**
1593          * Is this a subpage?
1594          * @return \type{\bool} TRUE or FALSE
1595          */
1596         public function isSubpage() {
1597                 return MWNamespace::hasSubpages( $this->mNamespace )
1598                         ? strpos( $this->getText(), '/' ) !== false
1599                         : false;
1600         }
1601
1602         /**
1603          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1604          * @return \type{\bool} TRUE or FALSE
1605          */
1606         public function hasSubpages() {
1607                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1608                         # Duh
1609                         return false;
1610                 }
1611
1612                 # We dynamically add a member variable for the purpose of this method
1613                 # alone to cache the result.  There's no point in having it hanging
1614                 # around uninitialized in every Title object; therefore we only add it
1615                 # if needed and don't declare it statically.
1616                 if( isset( $this->mHasSubpages ) ) {
1617                         return $this->mHasSubpages;
1618                 }
1619
1620                 $subpages = $this->getSubpages( 1 );
1621                 if( $subpages instanceof TitleArray )
1622                         return $this->mHasSubpages = (bool)$subpages->count();
1623                 return $this->mHasSubpages = false;
1624         }
1625
1626         /**
1627          * Get all subpages of this page.
1628          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1629          * @return mixed TitleArray, or empty array if this page's namespace
1630          *  doesn't allow subpages
1631          */
1632         public function getSubpages( $limit = -1 ) {
1633                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1634                         return array();
1635
1636                 $dbr = wfGetDB( DB_SLAVE );
1637                 $conds['page_namespace'] = $this->getNamespace();
1638                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1639                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1640                 $options = array();
1641                 if( $limit > -1 )
1642                         $options['LIMIT'] = $limit;
1643                 return $this->mSubpages = TitleArray::newFromResult(
1644                         $dbr->select( 'page',
1645                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1646                                 $conds,
1647                                 __METHOD__,
1648                                 $options
1649                         )
1650                 );
1651         }
1652
1653         /**
1654          * Could this page contain custom CSS or JavaScript, based
1655          * on the title?
1656          *
1657          * @return \type{\bool} TRUE or FALSE
1658          */
1659         public function isCssOrJsPage() {
1660                 return $this->mNamespace == NS_MEDIAWIKI
1661                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1662         }
1663
1664         /**
1665          * Is this a .css or .js subpage of a user page?
1666          * @return \type{\bool} TRUE or FALSE
1667          */
1668         public function isCssJsSubpage() {
1669                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1670         }
1671         /**
1672          * Is this a *valid* .css or .js subpage of a user page?
1673          * Check that the corresponding skin exists
1674          * @return \type{\bool} TRUE or FALSE
1675          */
1676         public function isValidCssJsSubpage() {
1677                 if ( $this->isCssJsSubpage() ) {
1678                         $skinNames = Skin::getSkinNames();
1679                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1680                 } else {
1681                         return false;
1682                 }
1683         }
1684         /**
1685          * Trim down a .css or .js subpage title to get the corresponding skin name
1686          */
1687         public function getSkinFromCssJsSubpage() {
1688                 $subpage = explode( '/', $this->mTextform );
1689                 $subpage = $subpage[ count( $subpage ) - 1 ];
1690                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1691         }
1692         /**
1693          * Is this a .css subpage of a user page?
1694          * @return \type{\bool} TRUE or FALSE
1695          */
1696         public function isCssSubpage() {
1697                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1698         }
1699         /**
1700          * Is this a .js subpage of a user page?
1701          * @return \type{\bool} TRUE or FALSE
1702          */
1703         public function isJsSubpage() {
1704                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1705         }
1706         /**
1707          * Protect css/js subpages of user pages: can $wgUser edit
1708          * this page?
1709          *
1710          * @return \type{\bool} TRUE or FALSE
1711          * @todo XXX: this might be better using restrictions
1712          */
1713         public function userCanEditCssJsSubpage() {
1714                 global $wgUser;
1715                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1716         }
1717
1718         /**
1719          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1720          *
1721          * @return \type{\bool} If the page is subject to cascading restrictions.
1722          */
1723         public function isCascadeProtected() {
1724                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1725                 return ( $sources > 0 );
1726         }
1727
1728         /**
1729          * Cascading protection: Get the source of any cascading restrictions on this page.
1730          *
1731          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1732          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1733          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1734          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1735          */
1736         public function getCascadeProtectionSources( $get_pages = true ) {
1737                 global $wgRestrictionTypes;
1738
1739                 # Define our dimension of restrictions types
1740                 $pagerestrictions = array();
1741                 foreach( $wgRestrictionTypes as $action )
1742                         $pagerestrictions[$action] = array();
1743
1744                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1745                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1746                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1747                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1748                 }
1749
1750                 wfProfileIn( __METHOD__ );
1751
1752                 $dbr = wfGetDB( DB_SLAVE );
1753
1754                 if ( $this->getNamespace() == NS_FILE ) {
1755                         $tables = array ('imagelinks', 'page_restrictions');
1756                         $where_clauses = array(
1757                                 'il_to' => $this->getDBkey(),
1758                                 'il_from=pr_page',
1759                                 'pr_cascade' => 1 );
1760                 } else {
1761                         $tables = array ('templatelinks', 'page_restrictions');
1762                         $where_clauses = array(
1763                                 'tl_namespace' => $this->getNamespace(),
1764                                 'tl_title' => $this->getDBkey(),
1765                                 'tl_from=pr_page',
1766                                 'pr_cascade' => 1 );
1767                 }
1768
1769                 if ( $get_pages ) {
1770                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1771                         $where_clauses[] = 'page_id=pr_page';
1772                         $tables[] = 'page';
1773                 } else {
1774                         $cols = array( 'pr_expiry' );
1775                 }
1776
1777                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1778
1779                 $sources = $get_pages ? array() : false;
1780                 $now = wfTimestampNow();
1781                 $purgeExpired = false;
1782
1783                 foreach( $res as $row ) {
1784                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1785                         if( $expiry > $now ) {
1786                                 if ($get_pages) {
1787                                         $page_id = $row->pr_page;
1788                                         $page_ns = $row->page_namespace;
1789                                         $page_title = $row->page_title;
1790                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1791                                         # Add groups needed for each restriction type if its not already there
1792                                         # Make sure this restriction type still exists
1793                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1794                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1795                                         }
1796                                 } else {
1797                                         $sources = true;
1798                                 }
1799                         } else {
1800                                 // Trigger lazy purge of expired restrictions from the db
1801                                 $purgeExpired = true;
1802                         }
1803                 }
1804                 if( $purgeExpired ) {
1805                         Title::purgeExpiredRestrictions();
1806                 }
1807
1808                 wfProfileOut( __METHOD__ );
1809
1810                 if ( $get_pages ) {
1811                         $this->mCascadeSources = $sources;
1812                         $this->mCascadingRestrictions = $pagerestrictions;
1813                 } else {
1814                         $this->mHasCascadingRestrictions = $sources;
1815                 }
1816                 return array( $sources, $pagerestrictions );
1817         }
1818
1819         function areRestrictionsCascading() {
1820                 if (!$this->mRestrictionsLoaded) {
1821                         $this->loadRestrictions();
1822                 }
1823
1824                 return $this->mCascadeRestriction;
1825         }
1826
1827         /**
1828          * Loads a string into mRestrictions array
1829          * @param $res \type{Resource} restrictions as an SQL result.
1830          */
1831         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1832                 global $wgRestrictionTypes;
1833                 $dbr = wfGetDB( DB_SLAVE );
1834
1835                 foreach( $wgRestrictionTypes as $type ){
1836                         $this->mRestrictions[$type] = array();
1837                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1838                 }
1839
1840                 $this->mCascadeRestriction = false;
1841
1842                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1843
1844                 if ( $oldFashionedRestrictions === NULL ) {
1845                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1846                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1847                 }
1848
1849                 if ($oldFashionedRestrictions != '') {
1850
1851                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1852                                 $temp = explode( '=', trim( $restrict ) );
1853                                 if(count($temp) == 1) {
1854                                         // old old format should be treated as edit/move restriction
1855                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1856                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1857                                 } else {
1858                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1859                                 }
1860                         }
1861
1862                         $this->mOldRestrictions = true;
1863
1864                 }
1865
1866                 if( $dbr->numRows( $res ) ) {
1867                         # Current system - load second to make them override.
1868                         $now = wfTimestampNow();
1869                         $purgeExpired = false;
1870
1871                         foreach( $res as $row ) {
1872                                 # Cycle through all the restrictions.
1873
1874                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1875                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1876                                         continue;
1877
1878                                 // This code should be refactored, now that it's being used more generally,
1879                                 // But I don't really see any harm in leaving it in Block for now -werdna
1880                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1881
1882                                 // Only apply the restrictions if they haven't expired!
1883                                 if ( !$expiry || $expiry > $now ) {
1884                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1885                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1886
1887                                         $this->mCascadeRestriction |= $row->pr_cascade;
1888                                 } else {
1889                                         // Trigger a lazy purge of expired restrictions
1890                                         $purgeExpired = true;
1891                                 }
1892                         }
1893
1894                         if( $purgeExpired ) {
1895                                 Title::purgeExpiredRestrictions();
1896                         }
1897                 }
1898
1899                 $this->mRestrictionsLoaded = true;
1900         }
1901
1902         /**
1903          * Load restrictions from the page_restrictions table
1904          */
1905         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1906                 if( !$this->mRestrictionsLoaded ) {
1907                         if ($this->exists()) {
1908                                 $dbr = wfGetDB( DB_SLAVE );
1909
1910                                 $res = $dbr->select( 'page_restrictions', '*',
1911                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1912
1913                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1914                         } else {
1915                                 $title_protection = $this->getTitleProtection();
1916
1917                                 if (is_array($title_protection)) {
1918                                         extract($title_protection);
1919
1920                                         $now = wfTimestampNow();
1921                                         $expiry = Block::decodeExpiry($pt_expiry);
1922
1923                                         if (!$expiry || $expiry > $now) {
1924                                                 // Apply the restrictions
1925                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1926                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1927                                         } else { // Get rid of the old restrictions
1928                                                 Title::purgeExpiredRestrictions();
1929                                         }
1930                                 } else {
1931                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1932                                 }
1933                                 $this->mRestrictionsLoaded = true;
1934                         }
1935                 }
1936         }
1937
1938         /**
1939          * Purge expired restrictions from the page_restrictions table
1940          */
1941         static function purgeExpiredRestrictions() {
1942                 $dbw = wfGetDB( DB_MASTER );
1943                 $dbw->delete( 'page_restrictions',
1944                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1945                         __METHOD__ );
1946
1947                 $dbw->delete( 'protected_titles',
1948                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1949                         __METHOD__ );
1950         }
1951
1952         /**
1953          * Accessor/initialisation for mRestrictions
1954          *
1955          * @param $action \type{\string} action that permission needs to be checked for
1956          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1957          */
1958         public function getRestrictions( $action ) {
1959                 if( !$this->mRestrictionsLoaded ) {
1960                         $this->loadRestrictions();
1961                 }
1962                 return isset( $this->mRestrictions[$action] )
1963                                 ? $this->mRestrictions[$action]
1964                                 : array();
1965         }
1966
1967         /**
1968          * Get the expiry time for the restriction against a given action
1969          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1970          * or not protected at all, or false if the action is not recognised.
1971          */
1972         public function getRestrictionExpiry( $action ) {
1973                 if( !$this->mRestrictionsLoaded ) {
1974                         $this->loadRestrictions();
1975                 }
1976                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1977         }
1978
1979         /**
1980          * Is there a version of this page in the deletion archive?
1981          * @return \type{\int} the number of archived revisions
1982          */
1983         public function isDeleted() {
1984                 if( $this->getNamespace() < 0 ) {
1985                         $n = 0;
1986                 } else {
1987                         $dbr = wfGetDB( DB_SLAVE );
1988                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
1989                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1990                                 __METHOD__
1991                         );
1992                         if( $this->getNamespace() == NS_FILE ) {
1993                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1994                                         array( 'fa_name' => $this->getDBkey() ),
1995                                         __METHOD__
1996                                 );
1997                         }
1998                 }
1999                 return (int)$n;
2000         }
2001
2002         /**
2003          * Is there a version of this page in the deletion archive?
2004          * @return bool
2005          */
2006         public function isDeletedQuick() {
2007                 if( $this->getNamespace() < 0 ) {
2008                         return false;
2009                 }
2010                 $dbr = wfGetDB( DB_SLAVE );
2011                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2012                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2013                         __METHOD__
2014                 );
2015                 if( !$deleted && $this->getNamespace() == NS_FILE ) {
2016                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2017                                 array( 'fa_name' => $this->getDBkey() ),
2018                                 __METHOD__
2019                         );
2020                 }
2021                 return $deleted;
2022         }
2023
2024         /**
2025          * Get the article ID for this Title from the link cache,
2026          * adding it if necessary
2027          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2028          *      for update
2029          * @return \type{\int} the ID
2030          */
2031         public function getArticleID( $flags = 0 ) {
2032                 if( $this->getNamespace() < 0 ) {
2033                         return $this->mArticleID = 0;
2034                 }
2035                 $linkCache = LinkCache::singleton();
2036                 if( $flags & GAID_FOR_UPDATE ) {
2037                         $oldUpdate = $linkCache->forUpdate( true );
2038                         $linkCache->clearLink( $this );
2039                         $this->mArticleID = $linkCache->addLinkObj( $this );
2040                         $linkCache->forUpdate( $oldUpdate );
2041                 } else {
2042                         if( -1 == $this->mArticleID ) {
2043                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2044                         }
2045                 }
2046                 return $this->mArticleID;
2047         }
2048
2049         /**
2050          * Is this an article that is a redirect page?
2051          * Uses link cache, adding it if necessary
2052          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2053          * @return \type{\bool}
2054          */
2055         public function isRedirect( $flags = 0 ) {
2056                 if( !is_null($this->mRedirect) )
2057                         return $this->mRedirect;
2058                 # Calling getArticleID() loads the field from cache as needed
2059                 if( !$this->getArticleID($flags) ) {
2060                         return $this->mRedirect = false;
2061                 }
2062                 $linkCache = LinkCache::singleton();
2063                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2064
2065                 return $this->mRedirect;
2066         }
2067
2068         /**
2069          * What is the length of this page?
2070          * Uses link cache, adding it if necessary
2071          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2072          * @return \type{\bool}
2073          */
2074         public function getLength( $flags = 0 ) {
2075                 if( $this->mLength != -1 )
2076                         return $this->mLength;
2077                 # Calling getArticleID() loads the field from cache as needed
2078                 if( !$this->getArticleID($flags) ) {
2079                         return $this->mLength = 0;
2080                 }
2081                 $linkCache = LinkCache::singleton();
2082                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2083
2084                 return $this->mLength;
2085         }
2086
2087         /**
2088          * What is the page_latest field for this page?
2089          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2090          * @return \type{\int}
2091          */
2092         public function getLatestRevID( $flags = 0 ) {
2093                 if( $this->mLatestID !== false )
2094                         return $this->mLatestID;
2095
2096                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2097                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2098                 return $this->mLatestID;
2099         }
2100
2101         /**
2102          * This clears some fields in this object, and clears any associated
2103          * keys in the "bad links" section of the link cache.
2104          *
2105          * - This is called from Article::insertNewArticle() to allow
2106          * loading of the new page_id. It's also called from
2107          * Article::doDeleteArticle()
2108          *
2109          * @param $newid \type{\int} the new Article ID
2110          */
2111         public function resetArticleID( $newid ) {
2112                 $linkCache = LinkCache::singleton();
2113                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2114
2115                 if ( $newid === false ) { $this->mArticleID = -1; }
2116                 else { $this->mArticleID = $newid; }
2117                 $this->mRestrictionsLoaded = false;
2118                 $this->mRestrictions = array();
2119         }
2120
2121         /**
2122          * Updates page_touched for this page; called from LinksUpdate.php
2123          * @return \type{\bool} true if the update succeded
2124          */
2125         public function invalidateCache() {
2126                 if( wfReadOnly() ) {
2127                         return;
2128                 }
2129                 $dbw = wfGetDB( DB_MASTER );
2130                 $success = $dbw->update( 'page',
2131                         array( 'page_touched' => $dbw->timestamp() ),
2132                         $this->pageCond(),
2133                         __METHOD__
2134                 );
2135                 HTMLFileCache::clearFileCache( $this );
2136                 return $success;
2137         }
2138
2139         /**
2140          * Prefix some arbitrary text with the namespace or interwiki prefix
2141          * of this object
2142          *
2143          * @param $name \type{\string} the text
2144          * @return \type{\string} the prefixed text
2145          * @private
2146          */
2147         /* private */ function prefix( $name ) {
2148                 $p = '';
2149                 if ( '' != $this->mInterwiki ) {
2150                         $p = $this->mInterwiki . ':';
2151                 }
2152                 if ( 0 != $this->mNamespace ) {
2153                         $p .= $this->getNsText() . ':';
2154                 }
2155                 return $p . $name;
2156         }
2157
2158         /**
2159          * Secure and split - main initialisation function for this object
2160          *
2161          * Assumes that mDbkeyform has been set, and is urldecoded
2162          * and uses underscores, but not otherwise munged.  This function
2163          * removes illegal characters, splits off the interwiki and
2164          * namespace prefixes, sets the other forms, and canonicalizes
2165          * everything.
2166          * @return \type{\bool} true on success
2167          */
2168         private function secureAndSplit() {
2169                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2170
2171                 # Initialisation
2172                 static $rxTc = false;
2173                 if( !$rxTc ) {
2174                         # Matching titles will be held as illegal.
2175                         $rxTc = '/' .
2176                                 # Any character not allowed is forbidden...
2177                                 '[^' . Title::legalChars() . ']' .
2178                                 # URL percent encoding sequences interfere with the ability
2179                                 # to round-trip titles -- you can't link to them consistently.
2180                                 '|%[0-9A-Fa-f]{2}' .
2181                                 # XML/HTML character references produce similar issues.
2182                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2183                                 '|&#[0-9]+;' .
2184                                 '|&#x[0-9A-Fa-f]+;' .
2185                                 '/S';
2186                 }
2187
2188                 $this->mInterwiki = $this->mFragment = '';
2189                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2190
2191                 $dbkey = $this->mDbkeyform;
2192
2193                 # Strip Unicode bidi override characters.
2194                 # Sometimes they slip into cut-n-pasted page titles, where the
2195                 # override chars get included in list displays.
2196                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2197
2198                 # Clean up whitespace
2199                 #
2200                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2201                 $dbkey = trim( $dbkey, '_' );
2202
2203                 if ( '' == $dbkey ) {
2204                         return false;
2205                 }
2206
2207                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2208                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2209                         return false;
2210                 }
2211
2212                 $this->mDbkeyform = $dbkey;
2213
2214                 # Initial colon indicates main namespace rather than specified default
2215                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2216                 if ( ':' == $dbkey{0} ) {
2217                         $this->mNamespace = NS_MAIN;
2218                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2219                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2220                 }
2221
2222                 # Namespace or interwiki prefix
2223                 $firstPass = true;
2224                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2225                 do {
2226                         $m = array();
2227                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2228                                 $p = $m[1];
2229                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2230                                         # Ordinary namespace
2231                                         $dbkey = $m[2];
2232                                         $this->mNamespace = $ns;
2233                                         # For Talk:X pages, check if X has a "namespace" prefix
2234                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2235                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2236                                                         return false; # Disallow Talk:File:x type titles...
2237                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2238                                                         return false; # Disallow Talk:Interwiki:x type titles...
2239                                         }
2240                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2241                                         if( !$firstPass ) {
2242                                                 # Can't make a local interwiki link to an interwiki link.
2243                                                 # That's just crazy!
2244                                                 return false;
2245                                         }
2246
2247                                         # Interwiki link
2248                                         $dbkey = $m[2];
2249                                         $this->mInterwiki = $wgContLang->lc( $p );
2250
2251                                         # Redundant interwiki prefix to the local wiki
2252                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2253                                                 if( $dbkey == '' ) {
2254                                                         # Can't have an empty self-link
2255                                                         return false;
2256                                                 }
2257                                                 $this->mInterwiki = '';
2258                                                 $firstPass = false;
2259                                                 # Do another namespace split...
2260                                                 continue;
2261                                         }
2262
2263                                         # If there's an initial colon after the interwiki, that also
2264                                         # resets the default namespace
2265                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2266                                                 $this->mNamespace = NS_MAIN;
2267                                                 $dbkey = substr( $dbkey, 1 );
2268                                         }
2269                                 }
2270                                 # If there's no recognized interwiki or namespace,
2271                                 # then let the colon expression be part of the title.
2272                         }
2273                         break;
2274                 } while( true );
2275
2276                 # We already know that some pages won't be in the database!
2277                 #
2278                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2279                         $this->mArticleID = 0;
2280                 }
2281                 $fragment = strstr( $dbkey, '#' );
2282                 if ( false !== $fragment ) {
2283                         $this->setFragment( $fragment );
2284                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2285                         # remove whitespace again: prevents "Foo_bar_#"
2286                         # becoming "Foo_bar_"
2287                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2288                 }
2289
2290                 # Reject illegal characters.
2291                 #
2292                 if( preg_match( $rxTc, $dbkey ) ) {
2293                         return false;
2294                 }
2295
2296                 /**
2297                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2298                  * reachable due to the way web browsers deal with 'relative' URLs.
2299                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2300                  */
2301                 if ( strpos( $dbkey, '.' ) !== false &&
2302                      ( $dbkey === '.' || $dbkey === '..' ||
2303                        strpos( $dbkey, './' ) === 0  ||
2304                        strpos( $dbkey, '../' ) === 0 ||
2305                        strpos( $dbkey, '/./' ) !== false ||
2306                        strpos( $dbkey, '/../' ) !== false  ||
2307                        substr( $dbkey, -2 ) == '/.' ||
2308                        substr( $dbkey, -3 ) == '/..' ) )
2309                 {
2310                         return false;
2311                 }
2312
2313                 /**
2314                  * Magic tilde sequences? Nu-uh!
2315                  */
2316                 if( strpos( $dbkey, '~~~' ) !== false ) {
2317                         return false;
2318                 }
2319
2320                 /**
2321                  * Limit the size of titles to 255 bytes.
2322                  * This is typically the size of the underlying database field.
2323                  * We make an exception for special pages, which don't need to be stored
2324                  * in the database, and may edge over 255 bytes due to subpage syntax
2325                  * for long titles, e.g. [[Special:Block/Long name]]
2326                  */
2327                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2328                   strlen( $dbkey ) > 512 )
2329                 {
2330                         return false;
2331                 }
2332
2333                 /**
2334                  * Normally, all wiki links are forced to have
2335                  * an initial capital letter so [[foo]] and [[Foo]]
2336                  * point to the same place.
2337                  *
2338                  * Don't force it for interwikis, since the other
2339                  * site might be case-sensitive.
2340                  */
2341                 $this->mUserCaseDBKey = $dbkey;
2342                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2343                         $dbkey = $wgContLang->ucfirst( $dbkey );
2344                 }
2345
2346                 /**
2347                  * Can't make a link to a namespace alone...
2348                  * "empty" local links can only be self-links
2349                  * with a fragment identifier.
2350                  */
2351                 if( $dbkey == '' &&
2352                         $this->mInterwiki == '' &&
2353                         $this->mNamespace != NS_MAIN ) {
2354                         return false;
2355                 }
2356                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2357                 // IP names are not allowed for accounts, and can only be referring to
2358                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2359                 // there are numerous ways to present the same IP. Having sp:contribs scan
2360                 // them all is silly and having some show the edits and others not is
2361                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2362                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2363                         IP::sanitizeIP( $dbkey ) : $dbkey;
2364                 // Any remaining initial :s are illegal.
2365                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2366                         return false;
2367                 }
2368
2369                 # Fill fields
2370                 $this->mDbkeyform = $dbkey;
2371                 $this->mUrlform = wfUrlencode( $dbkey );
2372
2373                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2374
2375                 return true;
2376         }
2377
2378         /**
2379          * Set the fragment for this title. Removes the first character from the
2380          * specified fragment before setting, so it assumes you're passing it with
2381          * an initial "#".
2382          *
2383          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2384          * Still in active use privately.
2385          *
2386          * @param $fragment \type{\string} text
2387          */
2388         public function setFragment( $fragment ) {
2389                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2390         }
2391
2392         /**
2393          * Get a Title object associated with the talk page of this article
2394          * @return \type{Title} the object for the talk page
2395          */
2396         public function getTalkPage() {
2397                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2398         }
2399
2400         /**
2401          * Get a title object associated with the subject page of this
2402          * talk page
2403          *
2404          * @return \type{Title} the object for the subject page
2405          */
2406         public function getSubjectPage() {
2407                 // Is this the same title?
2408                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2409                 if( $this->getNamespace() == $subjectNS ) {
2410                         return $this;
2411                 }
2412                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2413         }
2414
2415         /**
2416          * Get an array of Title objects linking to this Title
2417          * Also stores the IDs in the link cache.
2418          *
2419          * WARNING: do not use this function on arbitrary user-supplied titles!
2420          * On heavily-used templates it will max out the memory.
2421          *
2422          * @param array $options may be FOR UPDATE
2423          * @return \type{\arrayof{Title}} the Title objects linking here
2424          */
2425         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2426                 $linkCache = LinkCache::singleton();
2427
2428                 if ( count( $options ) > 0 ) {
2429                         $db = wfGetDB( DB_MASTER );
2430                 } else {
2431                         $db = wfGetDB( DB_SLAVE );
2432                 }
2433
2434                 $res = $db->select( array( 'page', $table ),
2435                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2436                         array(
2437                                 "{$prefix}_from=page_id",
2438                                 "{$prefix}_namespace" => $this->getNamespace(),
2439                                 "{$prefix}_title"     => $this->getDBkey() ),
2440                         __METHOD__,
2441                         $options );
2442
2443                 $retVal = array();
2444                 if ( $db->numRows( $res ) ) {
2445                         foreach( $res as $row ) {
2446                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2447                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2448                                         $retVal[] = $titleObj;
2449                                 }
2450                         }
2451                 }
2452                 $db->freeResult( $res );
2453                 return $retVal;
2454         }
2455
2456         /**
2457          * Get an array of Title objects using this Title as a template
2458          * Also stores the IDs in the link cache.
2459          *
2460          * WARNING: do not use this function on arbitrary user-supplied titles!
2461          * On heavily-used templates it will max out the memory.
2462          *
2463          * @param array $options may be FOR UPDATE
2464          * @return \type{\arrayof{Title}} the Title objects linking here
2465          */
2466         public function getTemplateLinksTo( $options = array() ) {
2467                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2468         }
2469
2470         /**
2471          * Get an array of Title objects referring to non-existent articles linked from this page
2472          *
2473          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2474          * @return \type{\arrayof{Title}} the Title objects
2475          */
2476         public function getBrokenLinksFrom() {
2477                 if ( $this->getArticleId() == 0 ) {
2478                         # All links from article ID 0 are false positives
2479                         return array();
2480                 }
2481
2482                 $dbr = wfGetDB( DB_SLAVE );
2483                 $res = $dbr->select(
2484                         array( 'page', 'pagelinks' ),
2485                         array( 'pl_namespace', 'pl_title' ),
2486                         array(
2487                                 'pl_from' => $this->getArticleId(),
2488                                 'page_namespace IS NULL'
2489                         ),
2490                         __METHOD__, array(),
2491                         array(
2492                                 'page' => array(
2493                                         'LEFT JOIN',
2494                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2495                                 )
2496                         )
2497                 );
2498
2499                 $retVal = array();
2500                 foreach( $res as $row ) {
2501                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2502                 }
2503                 return $retVal;
2504         }
2505
2506
2507         /**
2508          * Get a list of URLs to purge from the Squid cache when this
2509          * page changes
2510          *
2511          * @return \type{\arrayof{\string}} the URLs
2512          */
2513         public function getSquidURLs() {
2514                 global $wgContLang;
2515
2516                 $urls = array(
2517                         $this->getInternalURL(),
2518                         $this->getInternalURL( 'action=history' )
2519                 );
2520
2521                 // purge variant urls as well
2522                 if($wgContLang->hasVariants()){
2523                         $variants = $wgContLang->getVariants();
2524                         foreach($variants as $vCode){
2525                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2526                                 $urls[] = $this->getInternalURL('',$vCode);
2527                         }
2528                 }
2529
2530                 return $urls;
2531         }
2532
2533         /**
2534          * Purge all applicable Squid URLs
2535          */
2536         public function purgeSquid() {
2537                 global $wgUseSquid;
2538                 if ( $wgUseSquid ) {
2539                         $urls = $this->getSquidURLs();
2540                         $u = new SquidUpdate( $urls );
2541                         $u->doUpdate();
2542                 }
2543         }
2544
2545         /**
2546          * Move this page without authentication
2547          * @param &$nt \type{Title} the new page Title
2548          */
2549         public function moveNoAuth( &$nt ) {
2550                 return $this->moveTo( $nt, false );
2551         }
2552
2553         /**
2554          * Check whether a given move operation would be valid.
2555          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2556          * @param &$nt \type{Title} the new title
2557          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2558          *      should be checked
2559          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2560          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2561          */
2562         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2563                 global $wgUser;
2564
2565                 $errors = array();
2566                 if( !$nt ) {
2567                         // Normally we'd add this to $errors, but we'll get
2568                         // lots of syntax errors if $nt is not an object
2569                         return array(array('badtitletext'));
2570                 }
2571                 if( $this->equals( $nt ) ) {
2572                         $errors[] = array('selfmove');
2573                 }
2574                 if( !$this->isMovable() ) {
2575                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2576                 }
2577                 if ( $nt->getInterwiki() != '' ) {
2578                         $errors[] = array( 'immobile-target-namespace-iw' );
2579                 }
2580                 if ( !$nt->isMovable() ) {
2581                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2582                 }
2583
2584                 $oldid = $this->getArticleID();
2585                 $newid = $nt->getArticleID();
2586
2587                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2588                         $errors[] = array('articleexists');
2589                 }
2590                 if ( ( '' == $this->getDBkey() ) ||
2591                          ( !$oldid ) ||
2592                      ( '' == $nt->getDBkey() ) ) {
2593                         $errors[] = array('badarticleerror');
2594                 }
2595
2596                 // Image-specific checks
2597                 if( $this->getNamespace() == NS_FILE ) {
2598                         $file = wfLocalFile( $this );
2599                         if( $file->exists() ) {
2600                                 if( $nt->getNamespace() != NS_FILE ) {
2601                                         $errors[] = array('imagenocrossnamespace');
2602                                 }
2603                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2604                                         $errors[] = array('imageinvalidfilename');
2605                                 }
2606                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2607                                         $errors[] = array('imagetypemismatch');
2608                                 }
2609                         }
2610                 }
2611
2612                 if ( $auth ) {
2613                         $errors = wfMergeErrorArrays( $errors,
2614                                 $this->getUserPermissionsErrors('move', $wgUser),
2615                                 $this->getUserPermissionsErrors('edit', $wgUser),
2616                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2617                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2618                 }
2619
2620                 $match = EditPage::matchSummarySpamRegex( $reason );
2621                 if( $match !== false ) {
2622                         // This is kind of lame, won't display nice
2623                         $errors[] = array('spamprotectiontext');
2624                 }
2625
2626                 $err = null;
2627                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2628                         $errors[] = array('hookaborted', $err);
2629                 }
2630
2631                 # The move is allowed only if (1) the target doesn't exist, or
2632                 # (2) the target is a redirect to the source, and has no history
2633                 # (so we can undo bad moves right after they're done).
2634
2635                 if ( 0 != $newid ) { # Target exists; check for validity
2636                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2637                                 $errors[] = array('articleexists');
2638                         }
2639                 } else {
2640                         $tp = $nt->getTitleProtection();
2641                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2642                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2643                                 $errors[] = array('cantmove-titleprotected');
2644                         }
2645                 }
2646                 if(empty($errors))
2647                         return true;
2648                 return $errors;
2649         }
2650
2651         /**
2652          * Move a title to a new location
2653          * @param &$nt \type{Title} the new title
2654          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2655          *      should be checked
2656          * @param $reason \type{\string} The reason for the move
2657          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2658          *  Ignored if the user doesn't have the suppressredirect right.
2659          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2660          */
2661         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2662                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2663                 if( is_array( $err ) ) {
2664                         return $err;
2665                 }
2666
2667                 // If it is a file, more it first. It is done before all other moving stuff is done because it's hard to revert
2668                 $dbw = wfGetDB( DB_MASTER );
2669                 if( $this->getNamespace() == NS_FILE ) {
2670                         $file = wfLocalFile( $this );
2671                         if( $file->exists() ) {
2672                                 $status = $file->move( $nt );
2673                                 if( !$status->isOk() ) {
2674                                         return $status->getErrorsArray();
2675                                 }
2676                         }
2677                 }
2678
2679                 $pageid = $this->getArticleID();
2680                 $protected = $this->isProtected();
2681                 if( $nt->exists() ) {
2682                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2683                         $pageCountChange = ($createRedirect ? 0 : -1);
2684                 } else { # Target didn't exist, do normal move.
2685                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2686                         $pageCountChange = ($createRedirect ? 1 : 0);
2687                 }
2688
2689                 if( is_array( $err ) ) {
2690                         return $err;
2691                 }
2692                 $redirid = $this->getArticleID();
2693
2694                 // Category memberships include a sort key which may be customized.
2695                 // If it's left as the default (the page title), we need to update
2696                 // the sort key to match the new title.
2697                 //
2698                 // Be careful to avoid resetting cl_timestamp, which may disturb
2699                 // time-based lists on some sites.
2700                 //
2701                 // Warning -- if the sort key is *explicitly* set to the old title,
2702                 // we can't actually distinguish it from a default here, and it'll
2703                 // be set to the new title even though it really shouldn't.
2704                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2705                 $dbw->update( 'categorylinks',
2706                         array(
2707                                 'cl_sortkey' => $nt->getPrefixedText(),
2708                                 'cl_timestamp=cl_timestamp' ),
2709                         array(
2710                                 'cl_from' => $pageid,
2711                                 'cl_sortkey' => $this->getPrefixedText() ),
2712                         __METHOD__ );
2713
2714                 if( $protected ) {
2715                         # Protect the redirect title as the title used to be...
2716                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2717                                 array(
2718                                         'pr_page'    => $redirid,
2719                                         'pr_type'    => 'pr_type',
2720                                         'pr_level'   => 'pr_level',
2721                                         'pr_cascade' => 'pr_cascade',
2722                                         'pr_user'    => 'pr_user',
2723                                         'pr_expiry'  => 'pr_expiry'
2724                                 ),
2725                                 array( 'pr_page' => $pageid ),
2726                                 __METHOD__,
2727                                 array( 'IGNORE' )
2728                         );
2729                         # Update the protection log
2730                         $log = new LogPage( 'protect' );
2731                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2732                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2733                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2734                 }
2735
2736                 # Update watchlists
2737                 $oldnamespace = $this->getNamespace() & ~1;
2738                 $newnamespace = $nt->getNamespace() & ~1;
2739                 $oldtitle = $this->getDBkey();
2740                 $newtitle = $nt->getDBkey();
2741
2742                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2743                         WatchedItem::duplicateEntries( $this, $nt );
2744                 }
2745
2746                 # Update search engine
2747                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2748                 $u->doUpdate();
2749                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2750                 $u->doUpdate();
2751
2752                 # Update site_stats
2753                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2754                         # No longer a content page
2755                         # Not viewed, edited, removing
2756                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2757                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2758                         # Now a content page
2759                         # Not viewed, edited, adding
2760                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2761                 } elseif( $pageCountChange ) {
2762                         # Redirect added
2763                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2764                 } else {
2765                         # Nothing special
2766                         $u = false;
2767                 }
2768                 if( $u )
2769                         $u->doUpdate();
2770                 # Update message cache for interface messages
2771                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2772                         global $wgMessageCache;
2773
2774                         # @bug 17860: old article can be deleted, if this the case,
2775                         # delete it from message cache
2776                         if ( $this->getArticleID() === 0 ) {
2777                                 $wgMessageCache->replace( $this->getDBkey(), false );
2778                         } else {
2779                                 $oldarticle = new Article( $this );
2780                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2781                         }
2782
2783                         $newarticle = new Article( $nt );
2784                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2785                 }
2786
2787                 global $wgUser;
2788                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2789                 return true;
2790         }
2791
2792         /**
2793          * Move page to a title which is at present a redirect to the
2794          * source page
2795          *
2796          * @param &$nt \type{Title} the page to move to, which should currently
2797          *      be a redirect
2798          * @param $reason \type{\string} The reason for the move
2799          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2800          *  Ignored if the user doesn't have the suppressredirect right
2801          */
2802         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2803                 global $wgUseSquid, $wgUser;
2804                 $fname = 'Title::moveOverExistingRedirect';
2805                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2806
2807                 if ( $reason ) {
2808                         $comment .= ": $reason";
2809                 }
2810
2811                 $now = wfTimestampNow();
2812                 $newid = $nt->getArticleID();
2813                 $oldid = $this->getArticleID();
2814                 $latest = $this->getLatestRevID();
2815
2816                 $dbw = wfGetDB( DB_MASTER );
2817
2818                 # Delete the old redirect. We don't save it to history since
2819                 # by definition if we've got here it's rather uninteresting.
2820                 # We have to remove it so that the next step doesn't trigger
2821                 # a conflict on the unique namespace+title index...
2822                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2823                 if ( !$dbw->cascadingDeletes() ) {
2824                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2825                         global $wgUseTrackbacks;
2826                         if ($wgUseTrackbacks)
2827                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2828                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2829                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2830                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2831                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2832                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2833                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2834                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2835                 }
2836
2837                 # Save a null revision in the page's history notifying of the move
2838                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2839                 $nullRevId = $nullRevision->insertOn( $dbw );
2840
2841                 $article = new Article( $this );
2842                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2843
2844                 # Change the name of the target page:
2845                 $dbw->update( 'page',
2846                         /* SET */ array(
2847                                 'page_touched'   => $dbw->timestamp($now),
2848                                 'page_namespace' => $nt->getNamespace(),
2849                                 'page_title'     => $nt->getDBkey(),
2850                                 'page_latest'    => $nullRevId,
2851                         ),
2852                         /* WHERE */ array( 'page_id' => $oldid ),
2853                         $fname
2854                 );
2855                 $nt->resetArticleID( $oldid );
2856
2857                 # Recreate the redirect, this time in the other direction.
2858                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2859                         $mwRedir = MagicWord::get( 'redirect' );
2860                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2861                         $redirectArticle = new Article( $this );
2862                         $newid = $redirectArticle->insertOn( $dbw );
2863                         $redirectRevision = new Revision( array(
2864                                 'page'    => $newid,
2865                                 'comment' => $comment,
2866                                 'text'    => $redirectText ) );
2867                         $redirectRevision->insertOn( $dbw );
2868                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2869
2870                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2871
2872                         # Now, we record the link from the redirect to the new title.
2873                         # It should have no other outgoing links...
2874                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2875                         $dbw->insert( 'pagelinks',
2876                                 array(
2877                                         'pl_from'      => $newid,
2878                                         'pl_namespace' => $nt->getNamespace(),
2879                                         'pl_title'     => $nt->getDBkey() ),
2880                                 $fname );
2881                         $redirectSuppressed = false;
2882                 } else {
2883                         $this->resetArticleID( 0 );
2884                         $redirectSuppressed = true;
2885                 }
2886
2887                 # Log the move
2888                 $log = new LogPage( 'move' );
2889                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2890
2891                 # Purge squid
2892                 if ( $wgUseSquid ) {
2893                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2894                         $u = new SquidUpdate( $urls );
2895                         $u->doUpdate();
2896                 }
2897
2898         }
2899
2900         /**
2901          * Move page to non-existing title.
2902          * @param &$nt \type{Title} the new Title
2903          * @param $reason \type{\string} The reason for the move
2904          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2905          *  Ignored if the user doesn't have the suppressredirect right
2906          */
2907         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2908                 global $wgUseSquid, $wgUser;
2909                 $fname = 'MovePageForm::moveToNewTitle';
2910                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2911                 if ( $reason ) {
2912                         $comment .= wfMsgExt( 'colon-separator',
2913                                 array( 'escapenoentities', 'content' ) );
2914                         $comment .= $reason;
2915                 }
2916
2917                 $newid = $nt->getArticleID();
2918                 $oldid = $this->getArticleID();
2919                 $latest = $this->getLatestRevId();
2920
2921                 $dbw = wfGetDB( DB_MASTER );
2922                 $now = $dbw->timestamp();
2923
2924                 # Save a null revision in the page's history notifying of the move
2925                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2926                 $nullRevId = $nullRevision->insertOn( $dbw );
2927
2928                 $article = new Article( $this );
2929                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2930
2931                 # Rename page entry
2932                 $dbw->update( 'page',
2933                         /* SET */ array(
2934                                 'page_touched'   => $now,
2935                                 'page_namespace' => $nt->getNamespace(),
2936                                 'page_title'     => $nt->getDBkey(),
2937                                 'page_latest'    => $nullRevId,
2938                         ),
2939                         /* WHERE */ array( 'page_id' => $oldid ),
2940                         $fname
2941                 );
2942                 $nt->resetArticleID( $oldid );
2943
2944                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2945                         # Insert redirect
2946                         $mwRedir = MagicWord::get( 'redirect' );
2947                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2948                         $redirectArticle = new Article( $this );
2949                         $newid = $redirectArticle->insertOn( $dbw );
2950                         $redirectRevision = new Revision( array(
2951                                 'page'    => $newid,
2952                                 'comment' => $comment,
2953                                 'text'    => $redirectText ) );
2954                         $redirectRevision->insertOn( $dbw );
2955                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2956
2957                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2958
2959                         # Record the just-created redirect's linking to the page
2960                         $dbw->insert( 'pagelinks',
2961                                 array(
2962                                         'pl_from'      => $newid,
2963                                         'pl_namespace' => $nt->getNamespace(),
2964                                         'pl_title'     => $nt->getDBkey() ),
2965                                 $fname );
2966                         $redirectSuppressed = false;
2967                 } else {
2968                         $this->resetArticleID( 0 );
2969                         $redirectSuppressed = true;
2970                 }
2971
2972                 # Log the move
2973                 $log = new LogPage( 'move' );
2974                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2975
2976                 # Purge caches as per article creation
2977                 Article::onArticleCreate( $nt );
2978
2979                 # Purge old title from squid
2980                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2981                 $this->purgeSquid();
2982
2983         }
2984
2985         /**
2986          * Move this page's subpages to be subpages of $nt
2987          * @param $nt Title Move target
2988          * @param $auth bool Whether $wgUser's permissions should be checked
2989          * @param $reason string The reason for the move
2990          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2991          *  Ignored if the user doesn't have the 'suppressredirect' right
2992          * @return mixed array with old page titles as keys, and strings (new page titles) or
2993          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
2994          */
2995         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
2996                 global $wgMaximumMovedPages;
2997                 // Check permissions
2998                 if( !$this->userCan( 'move-subpages' ) )
2999                         return array( 'cant-move-subpages' );
3000                 // Do the source and target namespaces support subpages?
3001                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
3002                         return array( 'namespace-nosubpages',
3003                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3004                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
3005                         return array( 'namespace-nosubpages',
3006                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3007
3008                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
3009                 $retval = array();
3010                 $count = 0;
3011                 foreach( $subpages as $oldSubpage ) {
3012                         $count++;
3013                         if( $count > $wgMaximumMovedPages ) {
3014                                 $retval[$oldSubpage->getPrefixedTitle()] =
3015                                                 array( 'movepage-max-pages',
3016                                                         $wgMaximumMovedPages );
3017                                 break;
3018                         }
3019
3020                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
3021                                 // When moving a page to a subpage of itself,
3022                                 // don't move it twice
3023                                 continue;
3024                         $newPageName = preg_replace(
3025                                         '#^'.preg_quote( $this->getDBkey(), '#' ).'#',
3026                                         $nt->getDBkey(), $oldSubpage->getDBkey() );
3027                         if( $oldSubpage->isTalkPage() ) {
3028                                 $newNs = $nt->getTalkPage()->getNamespace();
3029                         } else {
3030                                 $newNs = $nt->getSubjectPage()->getNamespace();
3031                         }
3032                         # Bug 14385: we need makeTitleSafe because the new page names may
3033                         # be longer than 255 characters.
3034                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3035
3036                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3037                         if( $success === true ) {
3038                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3039                         } else {
3040                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3041                         }
3042                 }
3043                 return $retval;
3044         }
3045
3046         /**
3047          * Checks if this page is just a one-rev redirect.
3048          * Adds lock, so don't use just for light purposes.
3049          *
3050          * @return \type{\bool} TRUE or FALSE
3051          */
3052         public function isSingleRevRedirect() {
3053                 $dbw = wfGetDB( DB_MASTER );
3054                 # Is it a redirect?
3055                 $row = $dbw->selectRow( 'page',
3056                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3057                         $this->pageCond(),
3058                         __METHOD__,
3059                         array( 'FOR UPDATE' )
3060                 );
3061                 # Cache some fields we may want
3062                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3063                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3064                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3065                 if( !$this->mRedirect ) {
3066                         return false;
3067                 }
3068                 # Does the article have a history?
3069                 $row = $dbw->selectField( array( 'page', 'revision'),
3070                         'rev_id',
3071                         array( 'page_namespace' => $this->getNamespace(),
3072                                 'page_title' => $this->getDBkey(),
3073                                 'page_id=rev_page',
3074                                 'page_latest != rev_id'
3075                         ),
3076                         __METHOD__,
3077                         array( 'FOR UPDATE' )
3078                 );
3079                 # Return true if there was no history
3080                 return ($row === false);
3081         }
3082
3083         /**
3084          * Checks if $this can be moved to a given Title
3085          * - Selects for update, so don't call it unless you mean business
3086          *
3087          * @param &$nt \type{Title} the new title to check
3088          * @return \type{\bool} TRUE or FALSE
3089          */
3090         public function isValidMoveTarget( $nt ) {
3091                 $dbw = wfGetDB( DB_MASTER );
3092                 # Is it an existsing file?
3093                 if( $nt->getNamespace() == NS_FILE ) {
3094                         $file = wfLocalFile( $nt );
3095                         if( $file->exists() ) {
3096                                 wfDebug( __METHOD__ . ": file exists\n" );
3097                                 return false;
3098                         }
3099                 }
3100                 # Is it a redirect with no history?
3101                 if( !$nt->isSingleRevRedirect() ) {
3102                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3103                         return false;
3104                 }
3105                 # Get the article text
3106                 $rev = Revision::newFromTitle( $nt );
3107                 $text = $rev->getText();
3108                 # Does the redirect point to the source?
3109                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3110                 $m = array();
3111                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3112                         $redirTitle = Title::newFromText( $m[1] );
3113                         if( !is_object( $redirTitle ) ||
3114                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3115                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3116                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3117                                 return false;
3118                         }
3119                 } else {
3120                         # Fail safe
3121                         wfDebug( __METHOD__ . ": failsafe\n" );
3122                         return false;
3123                 }
3124                 return true;
3125         }
3126
3127         /**
3128          * Can this title be added to a user's watchlist?
3129          *
3130          * @return \type{\bool} TRUE or FALSE
3131          */
3132         public function isWatchable() {
3133                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3134         }
3135
3136         /**
3137          * Get categories to which this Title belongs and return an array of
3138          * categories' names.
3139          *
3140          * @return \type{\array} array an array of parents in the form:
3141          *      $parent => $currentarticle
3142          */
3143         public function getParentCategories() {
3144                 global $wgContLang;
3145
3146                 $titlekey = $this->getArticleId();
3147                 $dbr = wfGetDB( DB_SLAVE );
3148                 $categorylinks = $dbr->tableName( 'categorylinks' );
3149
3150                 # NEW SQL
3151                 $sql = "SELECT * FROM $categorylinks"
3152                      ." WHERE cl_from='$titlekey'"
3153                          ." AND cl_from <> '0'"
3154                          ." ORDER BY cl_sortkey";
3155
3156                 $res = $dbr->query( $sql );
3157
3158                 if( $dbr->numRows( $res ) > 0 ) {
3159                         foreach( $res as $row )
3160                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3161                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3162                         $dbr->freeResult( $res );
3163                 } else {
3164                         $data = array();
3165                 }
3166                 return $data;
3167         }
3168
3169         /**
3170          * Get a tree of parent categories
3171          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3172          * @return \type{\array} Tree of parent categories
3173          */
3174         public function getParentCategoryTree( $children = array() ) {
3175                 $stack = array();
3176                 $parents = $this->getParentCategories();
3177
3178                 if( $parents ) {
3179                         foreach( $parents as $parent => $current ) {
3180                                 if ( array_key_exists( $parent, $children ) ) {
3181                                         # Circular reference
3182                                         $stack[$parent] = array();
3183                                 } else {
3184                                         $nt = Title::newFromText($parent);
3185                                         if ( $nt ) {
3186                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3187                                         }
3188                                 }
3189                         }
3190                         return $stack;
3191                 } else {
3192                         return array();
3193                 }
3194         }
3195
3196
3197         /**
3198          * Get an associative array for selecting this title from
3199          * the "page" table
3200          *
3201          * @return \type{\array} Selection array
3202          */
3203         public function pageCond() {
3204                 if( $this->mArticleID > 0 ) {
3205                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3206                         return array( 'page_id' => $this->mArticleID );
3207                 } else {
3208                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3209                 }
3210         }
3211
3212         /**
3213          * Get the revision ID of the previous revision
3214          *
3215          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3216          * @param $flags \type{\int} GAID_FOR_UPDATE
3217          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3218          */
3219         public function getPreviousRevisionID( $revId, $flags=0 ) {
3220                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3221                 return $db->selectField( 'revision', 'rev_id',
3222                         array(
3223                                 'rev_page' => $this->getArticleId($flags),
3224                                 'rev_id < ' . intval( $revId )
3225                         ),
3226                         __METHOD__,
3227                         array( 'ORDER BY' => 'rev_id DESC' )
3228                 );
3229         }
3230
3231         /**
3232          * Get the revision ID of the next revision
3233          *
3234          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3235          * @param $flags \type{\int} GAID_FOR_UPDATE
3236          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3237          */
3238         public function getNextRevisionID( $revId, $flags=0 ) {
3239                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3240                 return $db->selectField( 'revision', 'rev_id',
3241                         array(
3242                                 'rev_page' => $this->getArticleId($flags),
3243                                 'rev_id > ' . intval( $revId )
3244                         ),
3245                         __METHOD__,
3246                         array( 'ORDER BY' => 'rev_id' )
3247                 );
3248         }
3249
3250         /**
3251          * Get the first revision of the page
3252          *
3253          * @param $flags \type{\int} GAID_FOR_UPDATE
3254          * @return Revision (or NULL if page doesn't exist)
3255          */
3256         public function getFirstRevision( $flags=0 ) {
3257                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3258                 $pageId = $this->getArticleId($flags);
3259                 if( !$pageId ) return NULL;
3260                 $row = $db->selectRow( 'revision', '*',
3261                         array( 'rev_page' => $pageId ),
3262                         __METHOD__,
3263                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3264                 );
3265                 if( !$row ) {
3266                         return NULL;
3267                 } else {
3268                         return new Revision( $row );
3269                 }
3270         }
3271
3272         /**
3273          * Check if this is a new page
3274          *
3275          * @return bool
3276          */
3277         public function isNewPage() {
3278                 $dbr = wfGetDB( DB_SLAVE );
3279                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3280         }
3281
3282         /**
3283          * Get the oldest revision timestamp of this page
3284          *
3285          * @return string, MW timestamp
3286          */
3287         public function getEarliestRevTime() {
3288                 $dbr = wfGetDB( DB_SLAVE );
3289                 if( $this->exists() ) {
3290                         $min = $dbr->selectField( 'revision',
3291                                 'MIN(rev_timestamp)',
3292                                 array( 'rev_page' => $this->getArticleId() ),
3293                                 __METHOD__ );
3294                         return wfTimestampOrNull( TS_MW, $min );
3295                 }
3296                 return null;
3297         }
3298
3299         /**
3300          * Get the number of revisions between the given revision IDs.
3301          * Used for diffs and other things that really need it.
3302          *
3303          * @param $old \type{\int} Revision ID.
3304          * @param $new \type{\int} Revision ID.
3305          * @return \type{\int} Number of revisions between these IDs.
3306          */
3307         public function countRevisionsBetween( $old, $new ) {
3308                 $dbr = wfGetDB( DB_SLAVE );
3309                 return $dbr->selectField( 'revision', 'count(*)',
3310                         'rev_page = ' . intval( $this->getArticleId() ) .
3311                         ' AND rev_id > ' . intval( $old ) .
3312                         ' AND rev_id < ' . intval( $new ),
3313                         __METHOD__
3314                 );
3315         }
3316
3317         /**
3318          * Compare with another title.
3319          *
3320          * @param \type{Title} $title
3321          * @return \type{\bool} TRUE or FALSE
3322          */
3323         public function equals( Title $title ) {
3324                 // Note: === is necessary for proper matching of number-like titles.
3325                 return $this->getInterwiki() === $title->getInterwiki()
3326                         && $this->getNamespace() == $title->getNamespace()
3327                         && $this->getDBkey() === $title->getDBkey();
3328         }
3329
3330         /**
3331          * Callback for usort() to do title sorts by (namespace, title)
3332          */
3333         public static function compare( $a, $b ) {
3334                 if( $a->getNamespace() == $b->getNamespace() ) {
3335                         return strcmp( $a->getText(), $b->getText() );
3336                 } else {
3337                         return $a->getNamespace() - $b->getNamespace();
3338                 }
3339         }
3340
3341         /**
3342          * Return a string representation of this title
3343          *
3344          * @return \type{\string} String representation of this title
3345          */
3346         public function __toString() {
3347                 return $this->getPrefixedText();
3348         }
3349
3350         /**
3351          * Check if page exists.  For historical reasons, this function simply
3352          * checks for the existence of the title in the page table, and will
3353          * thus return false for interwiki links, special pages and the like.
3354          * If you want to know if a title can be meaningfully viewed, you should
3355          * probably call the isKnown() method instead.
3356          *
3357          * @return \type{\bool} TRUE or FALSE
3358          */
3359         public function exists() {
3360                 return $this->getArticleId() != 0;
3361         }
3362
3363         /**
3364          * Should links to this title be shown as potentially viewable (i.e. as
3365          * "bluelinks"), even if there's no record by this title in the page
3366          * table?
3367          *
3368          * This function is semi-deprecated for public use, as well as somewhat
3369          * misleadingly named.  You probably just want to call isKnown(), which
3370          * calls this function internally.
3371          *
3372          * (ISSUE: Most of these checks are cheap, but the file existence check
3373          * can potentially be quite expensive.  Including it here fixes a lot of
3374          * existing code, but we might want to add an optional parameter to skip
3375          * it and any other expensive checks.)
3376          *
3377          * @return \type{\bool} TRUE or FALSE
3378          */
3379         public function isAlwaysKnown() {
3380                 if( $this->mInterwiki != '' ) {
3381                         return true;  // any interwiki link might be viewable, for all we know
3382                 }
3383                 switch( $this->mNamespace ) {
3384                 case NS_MEDIA:
3385                 case NS_FILE:
3386                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3387                 case NS_SPECIAL:
3388                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3389                 case NS_MAIN:
3390                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3391                 case NS_MEDIAWIKI:
3392                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3393                         // the full l10n of that language to be loaded. That takes much memory and
3394                         // isn't needed. So we strip the language part away.
3395                         // Also, extension messages which are not loaded, are shown as red, because
3396                         // we don't call MessageCache::loadAllMessages.
3397                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3398                         return wfMsgWeirdKey( $basename );  // known system message
3399                 default:
3400                         return false;
3401                 }
3402         }
3403
3404         /**
3405          * Does this title refer to a page that can (or might) be meaningfully
3406          * viewed?  In particular, this function may be used to determine if
3407          * links to the title should be rendered as "bluelinks" (as opposed to
3408          * "redlinks" to non-existent pages).
3409          *
3410          * @return \type{\bool} TRUE or FALSE
3411          */
3412         public function isKnown() {
3413                 return $this->exists() || $this->isAlwaysKnown();
3414         }
3415
3416         /**
3417         * Is this in a namespace that allows actual pages?
3418         *
3419         * @return \type{\bool} TRUE or FALSE
3420         */
3421         public function canExist() {
3422                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3423         }
3424
3425         /**
3426          * Update page_touched timestamps and send squid purge messages for
3427          * pages linking to this title. May be sent to the job queue depending
3428          * on the number of links. Typically called on create and delete.
3429          */
3430         public function touchLinks() {
3431                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3432                 $u->doUpdate();
3433
3434                 if ( $this->getNamespace() == NS_CATEGORY ) {
3435                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3436                         $u->doUpdate();
3437                 }
3438         }
3439
3440         /**
3441          * Get the last touched timestamp
3442          * @param Database $db, optional db
3443          * @return \type{\string} Last touched timestamp
3444          */
3445         public function getTouched( $db = NULL ) {
3446                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3447                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3448                 return $touched;
3449         }
3450
3451         /**
3452          * Get the timestamp when this page was updated since the user last saw it.
3453          * @param User $user
3454          * @return mixed string/NULL
3455          */
3456         public function getNotificationTimestamp( $user = NULL ) {
3457                 global $wgUser, $wgShowUpdatedMarker;
3458                 // Assume current user if none given
3459                 if( !$user ) $user = $wgUser;
3460                 // Check cache first
3461                 $uid = $user->getId();
3462                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3463                         return $this->mNotificationTimestamp[$uid];
3464                 }
3465                 if( !$uid || !$wgShowUpdatedMarker ) {
3466                         return $this->mNotificationTimestamp[$uid] = false;
3467                 }
3468                 // Don't cache too much!
3469                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3470                         $this->mNotificationTimestamp = array();
3471                 }
3472                 $dbr = wfGetDB( DB_SLAVE );
3473                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3474                         'wl_notificationtimestamp',
3475                         array( 'wl_namespace' => $this->getNamespace(),
3476                                 'wl_title' => $this->getDBkey(),
3477                                 'wl_user' => $user->getId()
3478                         ),
3479                         __METHOD__
3480                 );
3481                 return $this->mNotificationTimestamp[$uid];
3482         }
3483
3484         /**
3485          * Get the trackback URL for this page
3486          * @return \type{\string} Trackback URL
3487          */
3488         public function trackbackURL() {
3489                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3490
3491                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3492                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3493         }
3494
3495         /**
3496          * Get the trackback RDF for this page
3497          * @return \type{\string} Trackback RDF
3498          */
3499         public function trackbackRDF() {
3500                 $url = htmlspecialchars($this->getFullURL());
3501                 $title = htmlspecialchars($this->getText());
3502                 $tburl = $this->trackbackURL();
3503
3504                 // Autodiscovery RDF is placed in comments so HTML validator
3505                 // won't barf. This is a rather icky workaround, but seems
3506                 // frequently used by this kind of RDF thingy.
3507                 //
3508                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3509                 return "<!--
3510 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3511          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3512          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3513 <rdf:Description
3514    rdf:about=\"$url\"
3515    dc:identifier=\"$url\"
3516    dc:title=\"$title\"
3517    trackback:ping=\"$tburl\" />
3518 </rdf:RDF>
3519 -->";
3520         }
3521
3522         /**
3523          * Generate strings used for xml 'id' names in monobook tabs
3524          * @return \type{\string} XML 'id' name
3525          */
3526         public function getNamespaceKey( $prepend = 'nstab-' ) {
3527                 global $wgContLang, $wgCanonicalNamespaceNames;
3528                 // Gets the subject namespace if this title
3529                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3530                 // Checks if cononical namespace name exists for namespace
3531                 if ( isset( $wgCanonicalNamespaceNames[$namespace] ) ) {
3532                         // Uses canonical namespace name
3533                         $namespaceKey = $wgCanonicalNamespaceNames[$namespace];
3534                 } else {
3535                         // Uses text of namespace
3536                         $namespaceKey = $this->getSubjectNsText();
3537                 }
3538                 // Makes namespace key lowercase
3539                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3540                 // Uses main
3541                 if ( $namespaceKey == '' ) {
3542                         $namespaceKey = 'main';
3543                 }
3544                 // Changes file to image for backwards compatibility
3545                 if ( $namespaceKey == 'file' ) {
3546                         $namespaceKey = 'image';
3547                 }
3548                 return $prepend . $namespaceKey;
3549         }
3550
3551         /**
3552          * Returns true if this title resolves to the named special page
3553          * @param $name \type{\string} The special page name
3554          */
3555         public function isSpecial( $name ) {
3556                 if ( $this->getNamespace() == NS_SPECIAL ) {
3557                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3558                         if ( $name == $thisName ) {
3559                                 return true;
3560                         }
3561                 }
3562                 return false;
3563         }
3564
3565         /**
3566          * If the Title refers to a special page alias which is not the local default,
3567          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3568          */
3569         public function fixSpecialName() {
3570                 if ( $this->getNamespace() == NS_SPECIAL ) {
3571                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3572                         if ( $canonicalName ) {
3573                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3574                                 if ( $localName != $this->mDbkeyform ) {
3575                                         return Title::makeTitle( NS_SPECIAL, $localName );
3576                                 }
3577                         }
3578                 }
3579                 return $this;
3580         }
3581
3582         /**
3583          * Is this Title in a namespace which contains content?
3584          * In other words, is this a content page, for the purposes of calculating
3585          * statistics, etc?
3586          *
3587          * @return \type{\bool} TRUE or FALSE
3588          */
3589         public function isContentPage() {
3590                 return MWNamespace::isContent( $this->getNamespace() );
3591         }
3592
3593         /**
3594          * Get all extant redirects to this Title
3595          *
3596          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3597          *            NULL to consider all namespaces
3598          * @return \type{\arrayof{Title}} Redirects to this title
3599          */
3600         public function getRedirectsHere( $ns = null ) {
3601                 $redirs = array();
3602
3603                 $dbr = wfGetDB( DB_SLAVE );
3604                 $where = array(
3605                         'rd_namespace' => $this->getNamespace(),
3606                         'rd_title' => $this->getDBkey(),
3607                         'rd_from = page_id'
3608                 );
3609                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3610
3611                 $res = $dbr->select(
3612                         array( 'redirect', 'page' ),
3613                         array( 'page_namespace', 'page_title' ),
3614                         $where,
3615                         __METHOD__
3616                 );
3617
3618
3619                 foreach( $res as $row ) {
3620                         $redirs[] = self::newFromRow( $row );
3621                 }
3622                 return $redirs;
3623         }
3624
3625         /**
3626          * Check if this Title is a valid redirect target
3627          *
3628          * @return \type{\bool} TRUE or FALSE
3629          */
3630         public function isValidRedirectTarget() {
3631                 global $wgInvalidRedirectTargets;
3632
3633                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3634                 if( $this->isSpecial( 'Userlogout' ) ) {
3635                         return false;
3636                 }
3637
3638                 foreach( $wgInvalidRedirectTargets as $target ) {
3639                         if( $this->isSpecial( $target ) ) {
3640                                 return false;
3641                         }
3642                 }
3643
3644                 return true;
3645         }
3646
3647         /**
3648          * Get a backlink cache object
3649          */
3650         function getBacklinkCache() {
3651                 if ( is_null( $this->mBacklinkCache ) ) {
3652                         $this->mBacklinkCache = new BacklinkCache( $this );
3653                 }
3654                 return $this->mBacklinkCache;
3655         }
3656 }