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( !is_array( $query ) ) {
 866                         wfProfileOut( __METHOD__ );
 867                         throw new MWException( 'Title::getLinkUrl passed a non-array for '.
 868                         '$query' );
 869                 }
 870                 if( $this->isExternal() ) {
 871                         $ret = $this->getFullURL( $query );
 872                 } elseif( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 873                         $ret = $this->getFragmentForURL();
 874                 } else {
 875                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 876                 }
 877                 wfProfileOut( __METHOD__ );
 878                 return $ret;
 879         }
 880
 881         /**
 882          * Get an HTML-escaped version of the URL form, suitable for
 883          * using in a link, without a server name or fragment
 884          * @param $query \type{\string} an optional query string
 885          * @return \type{\string} the URL
 886          */
 887         public function escapeLocalURL( $query = '' ) {
 888                 return htmlspecialchars( $this->getLocalURL( $query ) );
 889         }
 890
 891         /**
 892          * Get an HTML-escaped version of the URL form, suitable for
 893          * using in a link, including the server name and fragment
 894          *
 895          * @param $query \type{\string} an optional query string
 896          * @return \type{\string} the URL
 897          */
 898         public function escapeFullURL( $query = '' ) {
 899                 return htmlspecialchars( $this->getFullURL( $query ) );
 900         }
 901
 902         /**
 903          * Get the URL form for an internal link.
 904          * - Used in various Squid-related code, in case we have a different
 905          * internal hostname for the server from the exposed one.
 906          *
 907          * @param $query \type{\string} an optional query string
 908          * @param $variant \type{\string} language variant of url (for sr, zh..)
 909          * @return \type{\string} the URL
 910          */
 911         public function getInternalURL( $query = '', $variant = false ) {
 912                 global $wgInternalServer;
 913                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 914                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 915                 return $url;
 916         }
 917
 918         /**
 919          * Get the edit URL for this Title
 920          * @return \type{\string} the URL, or a null string if this is an
 921          *      interwiki link
 922          */
 923         public function getEditURL() {
 924                 if ( '' != $this->mInterwiki ) { return ''; }
 925                 $s = $this->getLocalURL( 'action=edit' );
 926
 927                 return $s;
 928         }
 929
 930         /**
 931          * Get the HTML-escaped displayable text form.
 932          * Used for the title field in <a> tags.
 933          * @return \type{\string} the text, including any prefixes
 934          */
 935         public function getEscapedText() {
 936                 return htmlspecialchars( $this->getPrefixedText() );
 937         }
 938
 939         /**
 940          * Is this Title interwiki?
 941          * @return \type{\bool}
 942          */
 943         public function isExternal() { return ( '' != $this->mInterwiki ); }
 944
 945         /**
 946          * Is this page "semi-protected" - the *only* protection is autoconfirm?
 947          *
 948          * @param @action \type{\string} Action to check (default: edit)
 949          * @return \type{\bool}
 950          */
 951         public function isSemiProtected( $action = 'edit' ) {
 952                 if( $this->exists() ) {
 953                         $restrictions = $this->getRestrictions( $action );
 954                         if( count( $restrictions ) > 0 ) {
 955                                 foreach( $restrictions as $restriction ) {
 956                                         if( strtolower( $restriction ) != 'autoconfirmed' )
 957                                                 return false;
 958                                 }
 959                         } else {
 960                                 # Not protected
 961                                 return false;
 962                         }
 963                         return true;
 964                 } else {
 965                         # If it doesn't exist, it can't be protected
 966                         return false;
 967                 }
 968         }
 969
 970         /**
 971          * Does the title correspond to a protected article?
 972          * @param $what \type{\string} the action the page is protected from,
 973          * by default checks move and edit
 974          * @return \type{\bool}
 975          */
 976         public function isProtected( $action = '' ) {
 977                 global $wgRestrictionLevels, $wgRestrictionTypes;
 978
 979                 # Special pages have inherent protection
 980                 if( $this->getNamespace() == NS_SPECIAL )
 981                         return true;
 982
 983                 # Check regular protection levels
 984                 foreach( $wgRestrictionTypes as $type ){
 985                         if( $action == $type || $action == '' ) {
 986                                 $r = $this->getRestrictions( $type );
 987                                 foreach( $wgRestrictionLevels as $level ) {
 988                                         if( in_array( $level, $r ) && $level != '' ) {
 989                                                 return true;
 990                                         }
 991                                 }
 992                         }
 993                 }
 994
 995                 return false;
 996         }
 997
 998         /**
 999          * Is $wgUser watching this page?
1000          * @return \type{\bool}
1001          */
1002         public function userIsWatching() {
1003                 global $wgUser;
1004
1005                 if ( is_null( $this->mWatched ) ) {
1006                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
1007                                 $this->mWatched = false;
1008                         } else {
1009                                 $this->mWatched = $wgUser->isWatched( $this );
1010                         }
1011                 }
1012                 return $this->mWatched;
1013         }
1014
1015         /**
1016          * Can $wgUser perform $action on this page?
1017          * This skips potentially expensive cascading permission checks.
1018          *
1019          * Suitable for use for nonessential UI controls in common cases, but
1020          * _not_ for functional access control.
1021          *
1022          * May provide false positives, but should never provide a false negative.
1023          *
1024          * @param $action \type{\string} action that permission needs to be checked for
1025          * @return \type{\bool}
1026          */
1027         public function quickUserCan( $action ) {
1028                 return $this->userCan( $action, false );
1029         }
1030
1031         /**
1032          * Determines if $wgUser is unable to edit this page because it has been protected
1033          * by $wgNamespaceProtection.
1034          *
1035          * @return \type{\bool}
1036          */
1037         public function isNamespaceProtected() {
1038                 global $wgNamespaceProtection, $wgUser;
1039                 if( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1040                         foreach( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1041                                 if( $right != '' && !$wgUser->isAllowed( $right ) )
1042                                         return true;
1043                         }
1044                 }
1045                 return false;
1046         }
1047
1048         /**
1049          * Can $wgUser perform $action on this page?
1050          * @param $action \type{\string} action that permission needs to be checked for
1051          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1052          * @return \type{\bool}
1053          */
1054         public function userCan( $action, $doExpensiveQueries = true ) {
1055                 global $wgUser;
1056                 return ($this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array());
1057         }
1058
1059         /**
1060          * Can $user perform $action on this page?
1061          *
1062          * FIXME: This *does not* check throttles (User::pingLimiter()).
1063          *
1064          * @param $action \type{\string}action that permission needs to be checked for
1065          * @param $user \type{User} user to check
1066          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1067          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1068          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1069          */
1070         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1071                 if( !StubObject::isRealObject( $user ) ) {
1072                         //Since StubObject is always used on globals, we can unstub $wgUser here and set $user = $wgUser
1073                         global $wgUser;
1074                         $wgUser->_unstub( '', 5 );
1075                         $user = $wgUser;
1076                 }
1077                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1078
1079                 global $wgContLang;
1080                 global $wgLang;
1081                 global $wgEmailConfirmToEdit;
1082
1083                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1084                         $errors[] = array( 'confirmedittext' );
1085                 }
1086
1087                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1088                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1089                         $block = $user->mBlock;
1090
1091                         // This is from OutputPage::blockedPage
1092                         // Copied at r23888 by werdna
1093
1094                         $id = $user->blockedBy();
1095                         $reason = $user->blockedFor();
1096                         if( $reason == '' ) {
1097                                 $reason = wfMsg( 'blockednoreason' );
1098                         }
1099                         $ip = wfGetIP();
1100
1101                         if ( is_numeric( $id ) ) {
1102                                 $name = User::whoIs( $id );
1103                         } else {
1104                                 $name = $id;
1105                         }
1106
1107                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1108                         $blockid = $block->mId;
1109                         $blockExpiry = $user->mBlock->mExpiry;
1110                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1111
1112                         if ( $blockExpiry == 'infinity' ) {
1113                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1114                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1115
1116                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1117                                         if ( strpos( $option, ':' ) == false )
1118                                                 continue;
1119
1120                                         list ($show, $value) = explode( ":", $option );
1121
1122                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1123                                                 $blockExpiry = $show;
1124                                                 break;
1125                                         }
1126                                 }
1127                         } else {
1128                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1129                         }
1130
1131                         $intended = $user->mBlock->mAddress;
1132
1133                         $errors[] = array( ($block->mAuto ? 'autoblockedtext' : 'blockedtext'), $link, $reason, $ip, $name,
1134                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1135                 }
1136
1137                 // Remove the errors being ignored.
1138
1139                 foreach( $errors as $index => $error ) {
1140                         $error_key = is_array($error) ? $error[0] : $error;
1141
1142                         if (in_array( $error_key, $ignoreErrors )) {
1143                                 unset($errors[$index]);
1144                         }
1145                 }
1146
1147                 return $errors;
1148         }
1149
1150         /**
1151          * Can $user perform $action on this page? This is an internal function,
1152          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1153          * checks on wfReadOnly() and blocks)
1154          *
1155          * @param $action \type{\string} action that permission needs to be checked for
1156          * @param $user \type{User} user to check
1157          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1158          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1159          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1160          */
1161         private function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries=true, $short=false ) {
1162                 wfProfileIn( __METHOD__ );
1163
1164                 $errors = array();
1165
1166                 // First stop is permissions checks, which fail most often, and which are easiest to test.
1167                 if ( $action == 'move' ) {
1168                         if( !$user->isAllowed( 'move-rootuserpages' )
1169                                         && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1170                         {
1171                                 // Show user page-specific message only if the user can move other pages
1172                                 $errors[] = array( 'cant-move-user-page' );
1173                         }
1174
1175                         // Check if user is allowed to move files if it's a file
1176                         if( $this->getNamespace() == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1177                                 $errors[] = array( 'movenotallowedfile' );
1178                         }
1179
1180                         if( !$user->isAllowed( 'move' ) ) {
1181                                 // User can't move anything
1182                                 global $wgGroupPermissions;
1183                                 if( $user->isAnon() && ( $wgGroupPermissions['user']['move']
1184                                 || $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1185                                         // custom message if logged-in users without any special rights can move
1186                                         $errors[] = array ( 'movenologintext' );
1187                                 } else {
1188                                         $errors[] = array ('movenotallowed');
1189                                 }
1190                         }
1191                 } elseif ( $action == 'create' ) {
1192                         if( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1193                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) )
1194                         {
1195                                 $errors[] = $user->isAnon() ? array ('nocreatetext') : array ('nocreate-loggedin');
1196                         }
1197                 } elseif( $action == 'move-target' ) {
1198                         if( !$user->isAllowed( 'move' ) ) {
1199                                 // User can't move anything
1200                                 $errors[] = array ('movenotallowed');
1201                         } elseif( !$user->isAllowed( 'move-rootuserpages' )
1202                                 && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1203                         {
1204                                 // Show user page-specific message only if the user can move other pages
1205                                 $errors[] = array( 'cant-move-to-user-page' );
1206                         }
1207                 } elseif( !$user->isAllowed( $action ) ) {
1208                         $return = null;
1209                         $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1210                                 User::getGroupsWithPermission( $action ) );
1211                         if( $groups ) {
1212                                 $return = array( 'badaccess-groups',
1213                                         array( implode( ', ', $groups ), count( $groups ) ) );
1214                         } else {
1215                                 $return = array( "badaccess-group0" );
1216                         }
1217                         $errors[] = $return;
1218                 }
1219
1220                 # Short-circuit point
1221                 if( $short && count($errors) > 0 ) {
1222                         wfProfileOut( __METHOD__ );
1223                         return $errors;
1224                 }
1225
1226                 // Use getUserPermissionsErrors instead
1227                 if( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1228                         wfProfileOut( __METHOD__ );
1229                         return $result ? array() : array( array( 'badaccess-group0' ) );
1230                 }
1231                 // Check getUserPermissionsErrors hook
1232                 if( !wfRunHooks( 'getUserPermissionsErrors', array(&$this,&$user,$action,&$result) ) ) {
1233                         if( is_array($result) && count($result) && !is_array($result[0]) )
1234                                 $errors[] = $result; # A single array representing an error
1235                         else if( is_array($result) && is_array($result[0]) )
1236                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1237                         else if( $result !== '' && is_string($result) )
1238                                 $errors[] = array($result); # A string representing a message-id
1239                         else if( $result === false )
1240                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1241                 }
1242                 # Short-circuit point
1243                 if( $short && count($errors) > 0 ) {
1244                         wfProfileOut( __METHOD__ );
1245                         return $errors;
1246                 }
1247                 // Check getUserPermissionsErrorsExpensive hook
1248                 if( $doExpensiveQueries && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array(&$this,&$user,$action,&$result) ) ) {
1249                         if( is_array($result) && count($result) && !is_array($result[0]) )
1250                                 $errors[] = $result; # A single array representing an error
1251                         else if( is_array($result) && is_array($result[0]) )
1252                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1253                         else if( $result !== '' && is_string($result) )
1254                                 $errors[] = array($result); # A string representing a message-id
1255                         else if( $result === false )
1256                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1257                 }
1258                 # Short-circuit point
1259                 if( $short && count($errors) > 0 ) {
1260                         wfProfileOut( __METHOD__ );
1261                         return $errors;
1262                 }
1263
1264                 # Only 'createaccount' and 'execute' can be performed on
1265                 # special pages, which don't actually exist in the DB.
1266                 $specialOKActions = array( 'createaccount', 'execute' );
1267                 if( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions) ) {
1268                         $errors[] = array('ns-specialprotected');
1269                 }
1270
1271                 # Check $wgNamespaceProtection for restricted namespaces
1272                 if( $this->isNamespaceProtected() ) {
1273                         $ns = $this->getNamespace() == NS_MAIN ?
1274                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1275                         $errors[] = NS_MEDIAWIKI == $this->mNamespace ?
1276                                 array('protectedinterface') : array( 'namespaceprotected',  $ns );
1277                 }
1278
1279                 # Protect css/js subpages of user pages
1280                 # XXX: this might be better using restrictions
1281                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
1282                 if( $this->isCssJsSubpage() && !$user->isAllowed('editusercssjs')
1283                         && !preg_match('/^'.preg_quote($user->getName(), '/').'\//', $this->mTextform) )
1284                 {
1285                         $errors[] = array('customcssjsprotected');
1286                 }
1287
1288                 # Check against page_restrictions table requirements on this
1289                 # page. The user must possess all required rights for this action.
1290                 foreach( $this->getRestrictions($action) as $right ) {
1291                         // Backwards compatibility, rewrite sysop -> protect
1292                         if( $right == 'sysop' ) {
1293                                 $right = 'protect';
1294                         }
1295                         if( '' != $right && !$user->isAllowed( $right ) ) {
1296                                 // Users with 'editprotected' permission can edit protected pages
1297                                 if( $action=='edit' && $user->isAllowed( 'editprotected' ) ) {
1298                                         // Users with 'editprotected' permission cannot edit protected pages
1299                                         // with cascading option turned on.
1300                                         if( $this->mCascadeRestriction ) {
1301                                                 $errors[] = array( 'protectedpagetext', $right );
1302                                         }
1303                                 } else {
1304                                         $errors[] = array( 'protectedpagetext', $right );
1305                                 }
1306                         }
1307                 }
1308                 # Short-circuit point
1309                 if( $short && count($errors) > 0 ) {
1310                         wfProfileOut( __METHOD__ );
1311                         return $errors;
1312                 }
1313
1314                 if( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1315                         # We /could/ use the protection level on the source page, but it's fairly ugly
1316                         #  as we have to establish a precedence hierarchy for pages included by multiple
1317                         #  cascade-protected pages. So just restrict it to people with 'protect' permission,
1318                         #  as they could remove the protection anyway.
1319                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1320                         # Cascading protection depends on more than this page...
1321                         # Several cascading protected pages may include this page...
1322                         # Check each cascading level
1323                         # This is only for protection restrictions, not for all actions
1324                         if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
1325                                 foreach( $restrictions[$action] as $right ) {
1326                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1327                                         if( '' != $right && !$user->isAllowed( $right ) ) {
1328                                                 $pages = '';
1329                                                 foreach( $cascadingSources as $page )
1330                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1331                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1332                                         }
1333                                 }
1334                         }
1335                 }
1336                 # Short-circuit point
1337                 if( $short && count($errors) > 0 ) {
1338                         wfProfileOut( __METHOD__ );
1339                         return $errors;
1340                 }
1341
1342                 if( $action == 'protect' ) {
1343                         if( $this->getUserPermissionsErrors('edit', $user) != array() ) {
1344                                 $errors[] = array( 'protect-cantedit' ); // If they can't edit, they shouldn't protect.
1345                         }
1346                 }
1347
1348                 if( $action == 'create' ) {
1349                         $title_protection = $this->getTitleProtection();
1350                         if( is_array($title_protection) ) {
1351                                 extract($title_protection); // is this extract() really needed?
1352
1353                                 if( $pt_create_perm == 'sysop' ) {
1354                                         $pt_create_perm = 'protect'; // B/C
1355                                 }
1356                                 if( $pt_create_perm == '' || !$user->isAllowed($pt_create_perm) ) {
1357                                         $errors[] = array( 'titleprotected', User::whoIs($pt_user), $pt_reason );
1358                                 }
1359                         }
1360                 } elseif( $action == 'move' ) {
1361                         // Check for immobile pages
1362                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1363                                 // Specific message for this case
1364                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1365                         } elseif( !$this->isMovable() ) {
1366                                 // Less specific message for rarer cases
1367                                 $errors[] = array( 'immobile-page' );
1368                         }
1369                 } elseif( $action == 'move-target' ) {
1370                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1371                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1372                         } elseif( !$this->isMovable() ) {
1373                                 $errors[] = array( 'immobile-target-page' );
1374                         }
1375                 }
1376
1377                 wfProfileOut( __METHOD__ );
1378                 return $errors;
1379         }
1380
1381         /**
1382          * Is this title subject to title protection?
1383          * @return \type{\mixed} An associative array representing any existent title
1384          *   protection, or false if there's none.
1385          */
1386         private function getTitleProtection() {
1387                 // Can't protect pages in special namespaces
1388                 if ( $this->getNamespace() < 0 ) {
1389                         return false;
1390                 }
1391
1392                 $dbr = wfGetDB( DB_SLAVE );
1393                 $res = $dbr->select( 'protected_titles', '*',
1394                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1395                         __METHOD__ );
1396
1397                 if ($row = $dbr->fetchRow( $res )) {
1398                         return $row;
1399                 } else {
1400                         return false;
1401                 }
1402         }
1403
1404         /**
1405          * Update the title protection status
1406          * @param $create_perm \type{\string} Permission required for creation
1407          * @param $reason \type{\string} Reason for protection
1408          * @param $expiry \type{\string} Expiry timestamp
1409          */
1410         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1411                 global $wgUser,$wgContLang;
1412
1413                 if ($create_perm == implode(',',$this->getRestrictions('create'))
1414                         && $expiry == $this->mRestrictionsExpiry['create']) {
1415                         // No change
1416                         return true;
1417                 }
1418
1419                 list ($namespace, $title) = array( $this->getNamespace(), $this->getDBkey() );
1420
1421                 $dbw = wfGetDB( DB_MASTER );
1422
1423                 $encodedExpiry = Block::encodeExpiry($expiry, $dbw );
1424
1425                 $expiry_description = '';
1426                 if ( $encodedExpiry != 'infinity' ) {
1427                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ) , $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ).')';
1428                 }
1429                 else {
1430                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ).')';
1431                 }
1432
1433                 # Update protection table
1434                 if ($create_perm != '' ) {
1435                         $dbw->replace( 'protected_titles', array(array('pt_namespace', 'pt_title')),
1436                                 array( 'pt_namespace' => $namespace, 'pt_title' => $title
1437                                         , 'pt_create_perm' => $create_perm
1438                                         , 'pt_timestamp' => Block::encodeExpiry(wfTimestampNow(), $dbw)
1439                                         , 'pt_expiry' => $encodedExpiry
1440                                         , 'pt_user' => $wgUser->getId(), 'pt_reason' => $reason ), __METHOD__  );
1441                 } else {
1442                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1443                                 'pt_title' => $title ), __METHOD__ );
1444                 }
1445                 # Update the protection log
1446                 $log = new LogPage( 'protect' );
1447
1448                 if( $create_perm ) {
1449                         $params = array("[create=$create_perm] $expiry_description",'');
1450                         $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1451                 } else {
1452                         $log->addEntry( 'unprotect', $this, $reason );
1453                 }
1454
1455                 return true;
1456         }
1457
1458         /**
1459          * Remove any title protection due to page existing
1460          */
1461         public function deleteTitleProtection() {
1462                 $dbw = wfGetDB( DB_MASTER );
1463
1464                 $dbw->delete( 'protected_titles',
1465                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1466                         __METHOD__ );
1467         }
1468
1469         /**
1470          * Would anybody with sufficient privileges be able to move this page?
1471          * Some pages just aren't movable.
1472          *
1473          * @return \type{\bool} TRUE or FALSE
1474          */
1475         public function isMovable() {
1476                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1477         }
1478
1479         /**
1480          * Can $wgUser read this page?
1481          * @return \type{\bool} TRUE or FALSE
1482          * @todo fold these checks into userCan()
1483          */
1484         public function userCanRead() {
1485                 global $wgUser, $wgGroupPermissions;
1486
1487                 static $useShortcut = null;
1488
1489                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1490                 if( is_null( $useShortcut ) ) {
1491                         global $wgRevokePermissions;
1492                         $useShortcut = true;
1493                         if( empty( $wgGroupPermissions['*']['read'] ) ) {
1494                                 # Not a public wiki, so no shortcut
1495                                 $useShortcut = false;
1496                         } elseif( !empty( $wgRevokePermissions ) ) {
1497                                 foreach( array_keys( $wgRevokePermissions ) as $group ) {
1498                                         if( !empty( $wgRevokePermissions[$group]['read'] ) ) {
1499                                                 # We might be removing the read right from the user, so no shortcut
1500                                                 $useShortcut = false;
1501                                                 break;
1502                                         }
1503                                 }
1504                         }
1505                 }
1506
1507                 $result = null;
1508                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1509                 if ( $result !== null ) {
1510                         return $result;
1511                 }
1512
1513                 # Shortcut for public wikis, allows skipping quite a bit of code
1514                 if ( $useShortcut )
1515                         return true;
1516
1517                 if( $wgUser->isAllowed( 'read' ) ) {
1518                         return true;
1519                 } else {
1520                         global $wgWhitelistRead;
1521
1522                         /**
1523                          * Always grant access to the login page.
1524                          * Even anons need to be able to log in.
1525                         */
1526                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1527                                 return true;
1528                         }
1529
1530                         /**
1531                          * Bail out if there isn't whitelist
1532                          */
1533                         if( !is_array($wgWhitelistRead) ) {
1534                                 return false;
1535                         }
1536
1537                         /**
1538                          * Check for explicit whitelisting
1539                          */
1540                         $name = $this->getPrefixedText();
1541                         $dbName = $this->getPrefixedDBKey();
1542                         // Check with and without underscores
1543                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1544                                 return true;
1545
1546                         /**
1547                          * Old settings might have the title prefixed with
1548                          * a colon for main-namespace pages
1549                          */
1550                         if( $this->getNamespace() == NS_MAIN ) {
1551                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1552                                         return true;
1553                         }
1554
1555                         /**
1556                          * If it's a special page, ditch the subpage bit
1557                          * and check again
1558                          */
1559                         if( $this->getNamespace() == NS_SPECIAL ) {
1560                                 $name = $this->getDBkey();
1561                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1562                                 if ( $name === false ) {
1563                                         # Invalid special page, but we show standard login required message
1564                                         return false;
1565                                 }
1566
1567                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1568                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1569                                         return true;
1570                         }
1571
1572                 }
1573                 return false;
1574         }
1575
1576         /**
1577          * Is this a talk page of some sort?
1578          * @return \type{\bool} TRUE or FALSE
1579          */
1580         public function isTalkPage() {
1581                 return MWNamespace::isTalk( $this->getNamespace() );
1582         }
1583
1584         /**
1585          * Is this a subpage?
1586          * @return \type{\bool} TRUE or FALSE
1587          */
1588         public function isSubpage() {
1589                 return MWNamespace::hasSubpages( $this->mNamespace )
1590                         ? strpos( $this->getText(), '/' ) !== false
1591                         : false;
1592         }
1593
1594         /**
1595          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1596          * @return \type{\bool} TRUE or FALSE
1597          */
1598         public function hasSubpages() {
1599                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1600                         # Duh
1601                         return false;
1602                 }
1603
1604                 # We dynamically add a member variable for the purpose of this method
1605                 # alone to cache the result.  There's no point in having it hanging
1606                 # around uninitialized in every Title object; therefore we only add it
1607                 # if needed and don't declare it statically.
1608                 if( isset( $this->mHasSubpages ) ) {
1609                         return $this->mHasSubpages;
1610                 }
1611
1612                 $subpages = $this->getSubpages( 1 );
1613                 if( $subpages instanceof TitleArray )
1614                         return $this->mHasSubpages = (bool)$subpages->count();
1615                 return $this->mHasSubpages = false;
1616         }
1617
1618         /**
1619          * Get all subpages of this page.
1620          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1621          * @return mixed TitleArray, or empty array if this page's namespace
1622          *  doesn't allow subpages
1623          */
1624         public function getSubpages( $limit = -1 ) {
1625                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1626                         return array();
1627
1628                 $dbr = wfGetDB( DB_SLAVE );
1629                 $conds['page_namespace'] = $this->getNamespace();
1630                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1631                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1632                 $options = array();
1633                 if( $limit > -1 )
1634                         $options['LIMIT'] = $limit;
1635                 return $this->mSubpages = TitleArray::newFromResult(
1636                         $dbr->select( 'page',
1637                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1638                                 $conds,
1639                                 __METHOD__,
1640                                 $options
1641                         )
1642                 );
1643         }
1644
1645         /**
1646          * Could this page contain custom CSS or JavaScript, based
1647          * on the title?
1648          *
1649          * @return \type{\bool} TRUE or FALSE
1650          */
1651         public function isCssOrJsPage() {
1652                 return $this->mNamespace == NS_MEDIAWIKI
1653                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1654         }
1655
1656         /**
1657          * Is this a .css or .js subpage of a user page?
1658          * @return \type{\bool} TRUE or FALSE
1659          */
1660         public function isCssJsSubpage() {
1661                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1662         }
1663         /**
1664          * Is this a *valid* .css or .js subpage of a user page?
1665          * Check that the corresponding skin exists
1666          * @return \type{\bool} TRUE or FALSE
1667          */
1668         public function isValidCssJsSubpage() {
1669                 if ( $this->isCssJsSubpage() ) {
1670                         $skinNames = Skin::getSkinNames();
1671                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1672                 } else {
1673                         return false;
1674                 }
1675         }
1676         /**
1677          * Trim down a .css or .js subpage title to get the corresponding skin name
1678          */
1679         public function getSkinFromCssJsSubpage() {
1680                 $subpage = explode( '/', $this->mTextform );
1681                 $subpage = $subpage[ count( $subpage ) - 1 ];
1682                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1683         }
1684         /**
1685          * Is this a .css subpage of a user page?
1686          * @return \type{\bool} TRUE or FALSE
1687          */
1688         public function isCssSubpage() {
1689                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1690         }
1691         /**
1692          * Is this a .js subpage of a user page?
1693          * @return \type{\bool} TRUE or FALSE
1694          */
1695         public function isJsSubpage() {
1696                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1697         }
1698         /**
1699          * Protect css/js subpages of user pages: can $wgUser edit
1700          * this page?
1701          *
1702          * @return \type{\bool} TRUE or FALSE
1703          * @todo XXX: this might be better using restrictions
1704          */
1705         public function userCanEditCssJsSubpage() {
1706                 global $wgUser;
1707                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1708         }
1709
1710         /**
1711          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1712          *
1713          * @return \type{\bool} If the page is subject to cascading restrictions.
1714          */
1715         public function isCascadeProtected() {
1716                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1717                 return ( $sources > 0 );
1718         }
1719
1720         /**
1721          * Cascading protection: Get the source of any cascading restrictions on this page.
1722          *
1723          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1724          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1725          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1726          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1727          */
1728         public function getCascadeProtectionSources( $get_pages = true ) {
1729                 global $wgRestrictionTypes;
1730
1731                 # Define our dimension of restrictions types
1732                 $pagerestrictions = array();
1733                 foreach( $wgRestrictionTypes as $action )
1734                         $pagerestrictions[$action] = array();
1735
1736                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1737                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1738                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1739                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1740                 }
1741
1742                 wfProfileIn( __METHOD__ );
1743
1744                 $dbr = wfGetDB( DB_SLAVE );
1745
1746                 if ( $this->getNamespace() == NS_FILE ) {
1747                         $tables = array ('imagelinks', 'page_restrictions');
1748                         $where_clauses = array(
1749                                 'il_to' => $this->getDBkey(),
1750                                 'il_from=pr_page',
1751                                 'pr_cascade' => 1 );
1752                 } else {
1753                         $tables = array ('templatelinks', 'page_restrictions');
1754                         $where_clauses = array(
1755                                 'tl_namespace' => $this->getNamespace(),
1756                                 'tl_title' => $this->getDBkey(),
1757                                 'tl_from=pr_page',
1758                                 'pr_cascade' => 1 );
1759                 }
1760
1761                 if ( $get_pages ) {
1762                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1763                         $where_clauses[] = 'page_id=pr_page';
1764                         $tables[] = 'page';
1765                 } else {
1766                         $cols = array( 'pr_expiry' );
1767                 }
1768
1769                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1770
1771                 $sources = $get_pages ? array() : false;
1772                 $now = wfTimestampNow();
1773                 $purgeExpired = false;
1774
1775                 foreach( $res as $row ) {
1776                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1777                         if( $expiry > $now ) {
1778                                 if ($get_pages) {
1779                                         $page_id = $row->pr_page;
1780                                         $page_ns = $row->page_namespace;
1781                                         $page_title = $row->page_title;
1782                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1783                                         # Add groups needed for each restriction type if its not already there
1784                                         # Make sure this restriction type still exists
1785                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1786                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1787                                         }
1788                                 } else {
1789                                         $sources = true;
1790                                 }
1791                         } else {
1792                                 // Trigger lazy purge of expired restrictions from the db
1793                                 $purgeExpired = true;
1794                         }
1795                 }
1796                 if( $purgeExpired ) {
1797                         Title::purgeExpiredRestrictions();
1798                 }
1799
1800                 wfProfileOut( __METHOD__ );
1801
1802                 if ( $get_pages ) {
1803                         $this->mCascadeSources = $sources;
1804                         $this->mCascadingRestrictions = $pagerestrictions;
1805                 } else {
1806                         $this->mHasCascadingRestrictions = $sources;
1807                 }
1808                 return array( $sources, $pagerestrictions );
1809         }
1810
1811         function areRestrictionsCascading() {
1812                 if (!$this->mRestrictionsLoaded) {
1813                         $this->loadRestrictions();
1814                 }
1815
1816                 return $this->mCascadeRestriction;
1817         }
1818
1819         /**
1820          * Loads a string into mRestrictions array
1821          * @param $res \type{Resource} restrictions as an SQL result.
1822          */
1823         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1824                 global $wgRestrictionTypes;
1825                 $dbr = wfGetDB( DB_SLAVE );
1826
1827                 foreach( $wgRestrictionTypes as $type ){
1828                         $this->mRestrictions[$type] = array();
1829                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1830                 }
1831
1832                 $this->mCascadeRestriction = false;
1833
1834                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1835
1836                 if ( $oldFashionedRestrictions === NULL ) {
1837                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1838                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1839                 }
1840
1841                 if ($oldFashionedRestrictions != '') {
1842
1843                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1844                                 $temp = explode( '=', trim( $restrict ) );
1845                                 if(count($temp) == 1) {
1846                                         // old old format should be treated as edit/move restriction
1847                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1848                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1849                                 } else {
1850                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1851                                 }
1852                         }
1853
1854                         $this->mOldRestrictions = true;
1855
1856                 }
1857
1858                 if( $dbr->numRows( $res ) ) {
1859                         # Current system - load second to make them override.
1860                         $now = wfTimestampNow();
1861                         $purgeExpired = false;
1862
1863                         foreach( $res as $row ) {
1864                                 # Cycle through all the restrictions.
1865
1866                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1867                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1868                                         continue;
1869
1870                                 // This code should be refactored, now that it's being used more generally,
1871                                 // But I don't really see any harm in leaving it in Block for now -werdna
1872                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1873
1874                                 // Only apply the restrictions if they haven't expired!
1875                                 if ( !$expiry || $expiry > $now ) {
1876                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1877                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1878
1879                                         $this->mCascadeRestriction |= $row->pr_cascade;
1880                                 } else {
1881                                         // Trigger a lazy purge of expired restrictions
1882                                         $purgeExpired = true;
1883                                 }
1884                         }
1885
1886                         if( $purgeExpired ) {
1887                                 Title::purgeExpiredRestrictions();
1888                         }
1889                 }
1890
1891                 $this->mRestrictionsLoaded = true;
1892         }
1893
1894         /**
1895          * Load restrictions from the page_restrictions table
1896          */
1897         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1898                 if( !$this->mRestrictionsLoaded ) {
1899                         if ($this->exists()) {
1900                                 $dbr = wfGetDB( DB_SLAVE );
1901
1902                                 $res = $dbr->select( 'page_restrictions', '*',
1903                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1904
1905                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1906                         } else {
1907                                 $title_protection = $this->getTitleProtection();
1908
1909                                 if (is_array($title_protection)) {
1910                                         extract($title_protection);
1911
1912                                         $now = wfTimestampNow();
1913                                         $expiry = Block::decodeExpiry($pt_expiry);
1914
1915                                         if (!$expiry || $expiry > $now) {
1916                                                 // Apply the restrictions
1917                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1918                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1919                                         } else { // Get rid of the old restrictions
1920                                                 Title::purgeExpiredRestrictions();
1921                                         }
1922                                 } else {
1923                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1924                                 }
1925                                 $this->mRestrictionsLoaded = true;
1926                         }
1927                 }
1928         }
1929
1930         /**
1931          * Purge expired restrictions from the page_restrictions table
1932          */
1933         static function purgeExpiredRestrictions() {
1934                 $dbw = wfGetDB( DB_MASTER );
1935                 $dbw->delete( 'page_restrictions',
1936                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1937                         __METHOD__ );
1938
1939                 $dbw->delete( 'protected_titles',
1940                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1941                         __METHOD__ );
1942         }
1943
1944         /**
1945          * Accessor/initialisation for mRestrictions
1946          *
1947          * @param $action \type{\string} action that permission needs to be checked for
1948          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1949          */
1950         public function getRestrictions( $action ) {
1951                 if( !$this->mRestrictionsLoaded ) {
1952                         $this->loadRestrictions();
1953                 }
1954                 return isset( $this->mRestrictions[$action] )
1955                                 ? $this->mRestrictions[$action]
1956                                 : array();
1957         }
1958
1959         /**
1960          * Get the expiry time for the restriction against a given action
1961          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1962          * or not protected at all, or false if the action is not recognised.
1963          */
1964         public function getRestrictionExpiry( $action ) {
1965                 if( !$this->mRestrictionsLoaded ) {
1966                         $this->loadRestrictions();
1967                 }
1968                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1969         }
1970
1971         /**
1972          * Is there a version of this page in the deletion archive?
1973          * @return \type{\int} the number of archived revisions
1974          */
1975         public function isDeleted() {
1976                 if( $this->getNamespace() < 0 ) {
1977                         $n = 0;
1978                 } else {
1979                         $dbr = wfGetDB( DB_SLAVE );
1980                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
1981                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1982                                 __METHOD__
1983                         );
1984                         if( $this->getNamespace() == NS_FILE ) {
1985                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1986                                         array( 'fa_name' => $this->getDBkey() ),
1987                                         __METHOD__
1988                                 );
1989                         }
1990                 }
1991                 return (int)$n;
1992         }
1993
1994         /**
1995          * Is there a version of this page in the deletion archive?
1996          * @return bool
1997          */
1998         public function isDeletedQuick() {
1999                 if( $this->getNamespace() < 0 ) {
2000                         return false;
2001                 }
2002                 $dbr = wfGetDB( DB_SLAVE );
2003                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2004                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2005                         __METHOD__
2006                 );
2007                 if( !$deleted && $this->getNamespace() == NS_FILE ) {
2008                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2009                                 array( 'fa_name' => $this->getDBkey() ),
2010                                 __METHOD__
2011                         );
2012                 }
2013                 return $deleted;
2014         }
2015
2016         /**
2017          * Get the article ID for this Title from the link cache,
2018          * adding it if necessary
2019          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2020          *      for update
2021          * @return \type{\int} the ID
2022          */
2023         public function getArticleID( $flags = 0 ) {
2024                 if( $this->getNamespace() < 0 ) {
2025                         return $this->mArticleID = 0;
2026                 }
2027                 $linkCache = LinkCache::singleton();
2028                 if( $flags & GAID_FOR_UPDATE ) {
2029                         $oldUpdate = $linkCache->forUpdate( true );
2030                         $linkCache->clearLink( $this );
2031                         $this->mArticleID = $linkCache->addLinkObj( $this );
2032                         $linkCache->forUpdate( $oldUpdate );
2033                 } else {
2034                         if( -1 == $this->mArticleID ) {
2035                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2036                         }
2037                 }
2038                 return $this->mArticleID;
2039         }
2040
2041         /**
2042          * Is this an article that is a redirect page?
2043          * Uses link cache, adding it if necessary
2044          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2045          * @return \type{\bool}
2046          */
2047         public function isRedirect( $flags = 0 ) {
2048                 if( !is_null($this->mRedirect) )
2049                         return $this->mRedirect;
2050                 # Calling getArticleID() loads the field from cache as needed
2051                 if( !$this->getArticleID($flags) ) {
2052                         return $this->mRedirect = false;
2053                 }
2054                 $linkCache = LinkCache::singleton();
2055                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2056
2057                 return $this->mRedirect;
2058         }
2059
2060         /**
2061          * What is the length of this page?
2062          * Uses link cache, adding it if necessary
2063          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2064          * @return \type{\bool}
2065          */
2066         public function getLength( $flags = 0 ) {
2067                 if( $this->mLength != -1 )
2068                         return $this->mLength;
2069                 # Calling getArticleID() loads the field from cache as needed
2070                 if( !$this->getArticleID($flags) ) {
2071                         return $this->mLength = 0;
2072                 }
2073                 $linkCache = LinkCache::singleton();
2074                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2075
2076                 return $this->mLength;
2077         }
2078
2079         /**
2080          * What is the page_latest field for this page?
2081          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2082          * @return \type{\int}
2083          */
2084         public function getLatestRevID( $flags = 0 ) {
2085                 if( $this->mLatestID !== false )
2086                         return $this->mLatestID;
2087
2088                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2089                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2090                 return $this->mLatestID;
2091         }
2092
2093         /**
2094          * This clears some fields in this object, and clears any associated
2095          * keys in the "bad links" section of the link cache.
2096          *
2097          * - This is called from Article::insertNewArticle() to allow
2098          * loading of the new page_id. It's also called from
2099          * Article::doDeleteArticle()
2100          *
2101          * @param $newid \type{\int} the new Article ID
2102          */
2103         public function resetArticleID( $newid ) {
2104                 $linkCache = LinkCache::singleton();
2105                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2106
2107                 if ( $newid === false ) { $this->mArticleID = -1; }
2108                 else { $this->mArticleID = $newid; }
2109                 $this->mRestrictionsLoaded = false;
2110                 $this->mRestrictions = array();
2111         }
2112
2113         /**
2114          * Updates page_touched for this page; called from LinksUpdate.php
2115          * @return \type{\bool} true if the update succeded
2116          */
2117         public function invalidateCache() {
2118                 if( wfReadOnly() ) {
2119                         return;
2120                 }
2121                 $dbw = wfGetDB( DB_MASTER );
2122                 $success = $dbw->update( 'page',
2123                         array( 'page_touched' => $dbw->timestamp() ),
2124                         $this->pageCond(),
2125                         __METHOD__
2126                 );
2127                 HTMLFileCache::clearFileCache( $this );
2128                 return $success;
2129         }
2130
2131         /**
2132          * Prefix some arbitrary text with the namespace or interwiki prefix
2133          * of this object
2134          *
2135          * @param $name \type{\string} the text
2136          * @return \type{\string} the prefixed text
2137          * @private
2138          */
2139         /* private */ function prefix( $name ) {
2140                 $p = '';
2141                 if ( '' != $this->mInterwiki ) {
2142                         $p = $this->mInterwiki . ':';
2143                 }
2144                 if ( 0 != $this->mNamespace ) {
2145                         $p .= $this->getNsText() . ':';
2146                 }
2147                 return $p . $name;
2148         }
2149
2150         /**
2151          * Secure and split - main initialisation function for this object
2152          *
2153          * Assumes that mDbkeyform has been set, and is urldecoded
2154          * and uses underscores, but not otherwise munged.  This function
2155          * removes illegal characters, splits off the interwiki and
2156          * namespace prefixes, sets the other forms, and canonicalizes
2157          * everything.
2158          * @return \type{\bool} true on success
2159          */
2160         private function secureAndSplit() {
2161                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2162
2163                 # Initialisation
2164                 static $rxTc = false;
2165                 if( !$rxTc ) {
2166                         # Matching titles will be held as illegal.
2167                         $rxTc = '/' .
2168                                 # Any character not allowed is forbidden...
2169                                 '[^' . Title::legalChars() . ']' .
2170                                 # URL percent encoding sequences interfere with the ability
2171                                 # to round-trip titles -- you can't link to them consistently.
2172                                 '|%[0-9A-Fa-f]{2}' .
2173                                 # XML/HTML character references produce similar issues.
2174                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2175                                 '|&#[0-9]+;' .
2176                                 '|&#x[0-9A-Fa-f]+;' .
2177                                 '/S';
2178                 }
2179
2180                 $this->mInterwiki = $this->mFragment = '';
2181                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2182
2183                 $dbkey = $this->mDbkeyform;
2184
2185                 # Strip Unicode bidi override characters.
2186                 # Sometimes they slip into cut-n-pasted page titles, where the
2187                 # override chars get included in list displays.
2188                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2189
2190                 # Clean up whitespace
2191                 #
2192                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2193                 $dbkey = trim( $dbkey, '_' );
2194
2195                 if ( '' == $dbkey ) {
2196                         return false;
2197                 }
2198
2199                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2200                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2201                         return false;
2202                 }
2203
2204                 $this->mDbkeyform = $dbkey;
2205
2206                 # Initial colon indicates main namespace rather than specified default
2207                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2208                 if ( ':' == $dbkey{0} ) {
2209                         $this->mNamespace = NS_MAIN;
2210                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2211                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2212                 }
2213
2214                 # Namespace or interwiki prefix
2215                 $firstPass = true;
2216                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2217                 do {
2218                         $m = array();
2219                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2220                                 $p = $m[1];
2221                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2222                                         # Ordinary namespace
2223                                         $dbkey = $m[2];
2224                                         $this->mNamespace = $ns;
2225                                         # For Talk:X pages, check if X has a "namespace" prefix
2226                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2227                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2228                                                         return false; # Disallow Talk:File:x type titles...
2229                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2230                                                         return false; # Disallow Talk:Interwiki:x type titles...
2231                                         }
2232                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2233                                         if( !$firstPass ) {
2234                                                 # Can't make a local interwiki link to an interwiki link.
2235                                                 # That's just crazy!
2236                                                 return false;
2237                                         }
2238
2239                                         # Interwiki link
2240                                         $dbkey = $m[2];
2241                                         $this->mInterwiki = $wgContLang->lc( $p );
2242
2243                                         # Redundant interwiki prefix to the local wiki
2244                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2245                                                 if( $dbkey == '' ) {
2246                                                         # Can't have an empty self-link
2247                                                         return false;
2248                                                 }
2249                                                 $this->mInterwiki = '';
2250                                                 $firstPass = false;
2251                                                 # Do another namespace split...
2252                                                 continue;
2253                                         }
2254
2255                                         # If there's an initial colon after the interwiki, that also
2256                                         # resets the default namespace
2257                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2258                                                 $this->mNamespace = NS_MAIN;
2259                                                 $dbkey = substr( $dbkey, 1 );
2260                                         }
2261                                 }
2262                                 # If there's no recognized interwiki or namespace,
2263                                 # then let the colon expression be part of the title.
2264                         }
2265                         break;
2266                 } while( true );
2267
2268                 # We already know that some pages won't be in the database!
2269                 #
2270                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2271                         $this->mArticleID = 0;
2272                 }
2273                 $fragment = strstr( $dbkey, '#' );
2274                 if ( false !== $fragment ) {
2275                         $this->setFragment( $fragment );
2276                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2277                         # remove whitespace again: prevents "Foo_bar_#"
2278                         # becoming "Foo_bar_"
2279                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2280                 }
2281
2282                 # Reject illegal characters.
2283                 #
2284                 if( preg_match( $rxTc, $dbkey ) ) {
2285                         return false;
2286                 }
2287
2288                 /**
2289                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2290                  * reachable due to the way web browsers deal with 'relative' URLs.
2291                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2292                  */
2293                 if ( strpos( $dbkey, '.' ) !== false &&
2294                      ( $dbkey === '.' || $dbkey === '..' ||
2295                        strpos( $dbkey, './' ) === 0  ||
2296                        strpos( $dbkey, '../' ) === 0 ||
2297                        strpos( $dbkey, '/./' ) !== false ||
2298                        strpos( $dbkey, '/../' ) !== false  ||
2299                        substr( $dbkey, -2 ) == '/.' ||
2300                        substr( $dbkey, -3 ) == '/..' ) )
2301                 {
2302                         return false;
2303                 }
2304
2305                 /**
2306                  * Magic tilde sequences? Nu-uh!
2307                  */
2308                 if( strpos( $dbkey, '~~~' ) !== false ) {
2309                         return false;
2310                 }
2311
2312                 /**
2313                  * Limit the size of titles to 255 bytes.
2314                  * This is typically the size of the underlying database field.
2315                  * We make an exception for special pages, which don't need to be stored
2316                  * in the database, and may edge over 255 bytes due to subpage syntax
2317                  * for long titles, e.g. [[Special:Block/Long name]]
2318                  */
2319                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2320                   strlen( $dbkey ) > 512 )
2321                 {
2322                         return false;
2323                 }
2324
2325                 /**
2326                  * Normally, all wiki links are forced to have
2327                  * an initial capital letter so [[foo]] and [[Foo]]
2328                  * point to the same place.
2329                  *
2330                  * Don't force it for interwikis, since the other
2331                  * site might be case-sensitive.
2332                  */
2333                 $this->mUserCaseDBKey = $dbkey;
2334                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2335                         $dbkey = $wgContLang->ucfirst( $dbkey );
2336                 }
2337
2338                 /**
2339                  * Can't make a link to a namespace alone...
2340                  * "empty" local links can only be self-links
2341                  * with a fragment identifier.
2342                  */
2343                 if( $dbkey == '' &&
2344                         $this->mInterwiki == '' &&
2345                         $this->mNamespace != NS_MAIN ) {
2346                         return false;
2347                 }
2348                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2349                 // IP names are not allowed for accounts, and can only be referring to
2350                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2351                 // there are numerous ways to present the same IP. Having sp:contribs scan
2352                 // them all is silly and having some show the edits and others not is
2353                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2354                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2355                         IP::sanitizeIP( $dbkey ) : $dbkey;
2356                 // Any remaining initial :s are illegal.
2357                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2358                         return false;
2359                 }
2360
2361                 # Fill fields
2362                 $this->mDbkeyform = $dbkey;
2363                 $this->mUrlform = wfUrlencode( $dbkey );
2364
2365                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2366
2367                 return true;
2368         }
2369
2370         /**
2371          * Set the fragment for this title. Removes the first character from the
2372          * specified fragment before setting, so it assumes you're passing it with
2373          * an initial "#".
2374          *
2375          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2376          * Still in active use privately.
2377          *
2378          * @param $fragment \type{\string} text
2379          */
2380         public function setFragment( $fragment ) {
2381                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2382         }
2383
2384         /**
2385          * Get a Title object associated with the talk page of this article
2386          * @return \type{Title} the object for the talk page
2387          */
2388         public function getTalkPage() {
2389                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2390         }
2391
2392         /**
2393          * Get a title object associated with the subject page of this
2394          * talk page
2395          *
2396          * @return \type{Title} the object for the subject page
2397          */
2398         public function getSubjectPage() {
2399                 // Is this the same title?
2400                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2401                 if( $this->getNamespace() == $subjectNS ) {
2402                         return $this;
2403                 }
2404                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2405         }
2406
2407         /**
2408          * Get an array of Title objects linking to this Title
2409          * Also stores the IDs in the link cache.
2410          *
2411          * WARNING: do not use this function on arbitrary user-supplied titles!
2412          * On heavily-used templates it will max out the memory.
2413          *
2414          * @param array $options may be FOR UPDATE
2415          * @return \type{\arrayof{Title}} the Title objects linking here
2416          */
2417         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2418                 $linkCache = LinkCache::singleton();
2419
2420                 if ( count( $options ) > 0 ) {
2421                         $db = wfGetDB( DB_MASTER );
2422                 } else {
2423                         $db = wfGetDB( DB_SLAVE );
2424                 }
2425
2426                 $res = $db->select( array( 'page', $table ),
2427                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2428                         array(
2429                                 "{$prefix}_from=page_id",
2430                                 "{$prefix}_namespace" => $this->getNamespace(),
2431                                 "{$prefix}_title"     => $this->getDBkey() ),
2432                         __METHOD__,
2433                         $options );
2434
2435                 $retVal = array();
2436                 if ( $db->numRows( $res ) ) {
2437                         foreach( $res as $row ) {
2438                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2439                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2440                                         $retVal[] = $titleObj;
2441                                 }
2442                         }
2443                 }
2444                 $db->freeResult( $res );
2445                 return $retVal;
2446         }
2447
2448         /**
2449          * Get an array of Title objects using this Title as a template
2450          * Also stores the IDs in the link cache.
2451          *
2452          * WARNING: do not use this function on arbitrary user-supplied titles!
2453          * On heavily-used templates it will max out the memory.
2454          *
2455          * @param array $options may be FOR UPDATE
2456          * @return \type{\arrayof{Title}} the Title objects linking here
2457          */
2458         public function getTemplateLinksTo( $options = array() ) {
2459                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2460         }
2461
2462         /**
2463          * Get an array of Title objects referring to non-existent articles linked from this page
2464          *
2465          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2466          * @return \type{\arrayof{Title}} the Title objects
2467          */
2468         public function getBrokenLinksFrom() {
2469                 if ( $this->getArticleId() == 0 ) {
2470                         # All links from article ID 0 are false positives
2471                         return array();
2472                 }
2473
2474                 $dbr = wfGetDB( DB_SLAVE );
2475                 $res = $dbr->select(
2476                         array( 'page', 'pagelinks' ),
2477                         array( 'pl_namespace', 'pl_title' ),
2478                         array(
2479                                 'pl_from' => $this->getArticleId(),
2480                                 'page_namespace IS NULL'
2481                         ),
2482                         __METHOD__, array(),
2483                         array(
2484                                 'page' => array(
2485                                         'LEFT JOIN',
2486                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2487                                 )
2488                         )
2489                 );
2490
2491                 $retVal = array();
2492                 foreach( $res as $row ) {
2493                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2494                 }
2495                 return $retVal;
2496         }
2497
2498
2499         /**
2500          * Get a list of URLs to purge from the Squid cache when this
2501          * page changes
2502          *
2503          * @return \type{\arrayof{\string}} the URLs
2504          */
2505         public function getSquidURLs() {
2506                 global $wgContLang;
2507
2508                 $urls = array(
2509                         $this->getInternalURL(),
2510                         $this->getInternalURL( 'action=history' )
2511                 );
2512
2513                 // purge variant urls as well
2514                 if($wgContLang->hasVariants()){
2515                         $variants = $wgContLang->getVariants();
2516                         foreach($variants as $vCode){
2517                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2518                                 $urls[] = $this->getInternalURL('',$vCode);
2519                         }
2520                 }
2521
2522                 return $urls;
2523         }
2524
2525         /**
2526          * Purge all applicable Squid URLs
2527          */
2528         public function purgeSquid() {
2529                 global $wgUseSquid;
2530                 if ( $wgUseSquid ) {
2531                         $urls = $this->getSquidURLs();
2532                         $u = new SquidUpdate( $urls );
2533                         $u->doUpdate();
2534                 }
2535         }
2536
2537         /**
2538          * Move this page without authentication
2539          * @param &$nt \type{Title} the new page Title
2540          */
2541         public function moveNoAuth( &$nt ) {
2542                 return $this->moveTo( $nt, false );
2543         }
2544
2545         /**
2546          * Check whether a given move operation would be valid.
2547          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2548          * @param &$nt \type{Title} the new title
2549          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2550          *      should be checked
2551          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2552          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2553          */
2554         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2555                 global $wgUser;
2556
2557                 $errors = array();
2558                 if( !$nt ) {
2559                         // Normally we'd add this to $errors, but we'll get
2560                         // lots of syntax errors if $nt is not an object
2561                         return array(array('badtitletext'));
2562                 }
2563                 if( $this->equals( $nt ) ) {
2564                         $errors[] = array('selfmove');
2565                 }
2566                 if( !$this->isMovable() ) {
2567                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2568                 }
2569                 if ( $nt->getInterwiki() != '' ) {
2570                         $errors[] = array( 'immobile-target-namespace-iw' );
2571                 }
2572                 if ( !$nt->isMovable() ) {
2573                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2574                 }
2575
2576                 $oldid = $this->getArticleID();
2577                 $newid = $nt->getArticleID();
2578
2579                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2580                         $errors[] = array('articleexists');
2581                 }
2582                 if ( ( '' == $this->getDBkey() ) ||
2583                          ( !$oldid ) ||
2584                      ( '' == $nt->getDBkey() ) ) {
2585                         $errors[] = array('badarticleerror');
2586                 }
2587
2588                 // Image-specific checks
2589                 if( $this->getNamespace() == NS_FILE ) {
2590                         $file = wfLocalFile( $this );
2591                         if( $file->exists() ) {
2592                                 if( $nt->getNamespace() != NS_FILE ) {
2593                                         $errors[] = array('imagenocrossnamespace');
2594                                 }
2595                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2596                                         $errors[] = array('imageinvalidfilename');
2597                                 }
2598                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2599                                         $errors[] = array('imagetypemismatch');
2600                                 }
2601                         }
2602                 }
2603
2604                 if ( $auth ) {
2605                         $errors = wfMergeErrorArrays( $errors,
2606                                 $this->getUserPermissionsErrors('move', $wgUser),
2607                                 $this->getUserPermissionsErrors('edit', $wgUser),
2608                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2609                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2610                 }
2611
2612                 $match = EditPage::matchSummarySpamRegex( $reason );
2613                 if( $match !== false ) {
2614                         // This is kind of lame, won't display nice
2615                         $errors[] = array('spamprotectiontext');
2616                 }
2617
2618                 $err = null;
2619                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2620                         $errors[] = array('hookaborted', $err);
2621                 }
2622
2623                 # The move is allowed only if (1) the target doesn't exist, or
2624                 # (2) the target is a redirect to the source, and has no history
2625                 # (so we can undo bad moves right after they're done).
2626
2627                 if ( 0 != $newid ) { # Target exists; check for validity
2628                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2629                                 $errors[] = array('articleexists');
2630                         }
2631                 } else {
2632                         $tp = $nt->getTitleProtection();
2633                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2634                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2635                                 $errors[] = array('cantmove-titleprotected');
2636                         }
2637                 }
2638                 if(empty($errors))
2639                         return true;
2640                 return $errors;
2641         }
2642
2643         /**
2644          * Move a title to a new location
2645          * @param &$nt \type{Title} the new title
2646          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2647          *      should be checked
2648          * @param $reason \type{\string} The reason for the move
2649          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2650          *  Ignored if the user doesn't have the suppressredirect right.
2651          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2652          */
2653         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2654                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2655                 if( is_array( $err ) ) {
2656                         return $err;
2657                 }
2658
2659                 // If it is a file, more it first. It is done before all other moving stuff is done because it's hard to revert
2660                 $dbw = wfGetDB( DB_MASTER );
2661                 if( $this->getNamespace() == NS_FILE ) {
2662                         $file = wfLocalFile( $this );
2663                         if( $file->exists() ) {
2664                                 $status = $file->move( $nt );
2665                                 if( !$status->isOk() ) {
2666                                         return $status->getErrorsArray();
2667                                 }
2668                         }
2669                 }
2670
2671                 $pageid = $this->getArticleID();
2672                 $protected = $this->isProtected();
2673                 if( $nt->exists() ) {
2674                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2675                         $pageCountChange = ($createRedirect ? 0 : -1);
2676                 } else { # Target didn't exist, do normal move.
2677                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2678                         $pageCountChange = ($createRedirect ? 1 : 0);
2679                 }
2680
2681                 if( is_array( $err ) ) {
2682                         return $err;
2683                 }
2684                 $redirid = $this->getArticleID();
2685
2686                 // Category memberships include a sort key which may be customized.
2687                 // If it's left as the default (the page title), we need to update
2688                 // the sort key to match the new title.
2689                 //
2690                 // Be careful to avoid resetting cl_timestamp, which may disturb
2691                 // time-based lists on some sites.
2692                 //
2693                 // Warning -- if the sort key is *explicitly* set to the old title,
2694                 // we can't actually distinguish it from a default here, and it'll
2695                 // be set to the new title even though it really shouldn't.
2696                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2697                 $dbw->update( 'categorylinks',
2698                         array(
2699                                 'cl_sortkey' => $nt->getPrefixedText(),
2700                                 'cl_timestamp=cl_timestamp' ),
2701                         array(
2702                                 'cl_from' => $pageid,
2703                                 'cl_sortkey' => $this->getPrefixedText() ),
2704                         __METHOD__ );
2705
2706                 if( $protected ) {
2707                         # Protect the redirect title as the title used to be...
2708                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2709                                 array(
2710                                         'pr_page'    => $redirid,
2711                                         'pr_type'    => 'pr_type',
2712                                         'pr_level'   => 'pr_level',
2713                                         'pr_cascade' => 'pr_cascade',
2714                                         'pr_user'    => 'pr_user',
2715                                         'pr_expiry'  => 'pr_expiry'
2716                                 ),
2717                                 array( 'pr_page' => $pageid ),
2718                                 __METHOD__,
2719                                 array( 'IGNORE' )
2720                         );
2721                         # Update the protection log
2722                         $log = new LogPage( 'protect' );
2723                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2724                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2725                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2726                 }
2727
2728                 # Update watchlists
2729                 $oldnamespace = $this->getNamespace() & ~1;
2730                 $newnamespace = $nt->getNamespace() & ~1;
2731                 $oldtitle = $this->getDBkey();
2732                 $newtitle = $nt->getDBkey();
2733
2734                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2735                         WatchedItem::duplicateEntries( $this, $nt );
2736                 }
2737
2738                 # Update search engine
2739                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2740                 $u->doUpdate();
2741                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2742                 $u->doUpdate();
2743
2744                 # Update site_stats
2745                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2746                         # No longer a content page
2747                         # Not viewed, edited, removing
2748                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2749                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2750                         # Now a content page
2751                         # Not viewed, edited, adding
2752                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2753                 } elseif( $pageCountChange ) {
2754                         # Redirect added
2755                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2756                 } else {
2757                         # Nothing special
2758                         $u = false;
2759                 }
2760                 if( $u )
2761                         $u->doUpdate();
2762                 # Update message cache for interface messages
2763                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2764                         global $wgMessageCache;
2765
2766                         # @bug 17860: old article can be deleted, if this the case,
2767                         # delete it from message cache
2768                         if ( $this->getArticleID() === 0 ) {
2769                                 $wgMessageCache->replace( $this->getDBkey(), false );
2770                         } else {
2771                                 $oldarticle = new Article( $this );
2772                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2773                         }
2774
2775                         $newarticle = new Article( $nt );
2776                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2777                 }
2778
2779                 global $wgUser;
2780                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2781                 return true;
2782         }
2783
2784         /**
2785          * Move page to a title which is at present a redirect to the
2786          * source page
2787          *
2788          * @param &$nt \type{Title} the page to move to, which should currently
2789          *      be a redirect
2790          * @param $reason \type{\string} The reason for the move
2791          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2792          *  Ignored if the user doesn't have the suppressredirect right
2793          */
2794         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2795                 global $wgUseSquid, $wgUser;
2796                 $fname = 'Title::moveOverExistingRedirect';
2797                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2798
2799                 if ( $reason ) {
2800                         $comment .= ": $reason";
2801                 }
2802
2803                 $now = wfTimestampNow();
2804                 $newid = $nt->getArticleID();
2805                 $oldid = $this->getArticleID();
2806                 $latest = $this->getLatestRevID();
2807
2808                 $dbw = wfGetDB( DB_MASTER );
2809
2810                 # Delete the old redirect. We don't save it to history since
2811                 # by definition if we've got here it's rather uninteresting.
2812                 # We have to remove it so that the next step doesn't trigger
2813                 # a conflict on the unique namespace+title index...
2814                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2815                 if ( !$dbw->cascadingDeletes() ) {
2816                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2817                         global $wgUseTrackbacks;
2818                         if ($wgUseTrackbacks)
2819                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2820                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2821                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2822                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2823                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2824                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2825                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2826                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2827                 }
2828
2829                 # Save a null revision in the page's history notifying of the move
2830                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2831                 $nullRevId = $nullRevision->insertOn( $dbw );
2832
2833                 $article = new Article( $this );
2834                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2835
2836                 # Change the name of the target page:
2837                 $dbw->update( 'page',
2838                         /* SET */ array(
2839                                 'page_touched'   => $dbw->timestamp($now),
2840                                 'page_namespace' => $nt->getNamespace(),
2841                                 'page_title'     => $nt->getDBkey(),
2842                                 'page_latest'    => $nullRevId,
2843                         ),
2844                         /* WHERE */ array( 'page_id' => $oldid ),
2845                         $fname
2846                 );
2847                 $nt->resetArticleID( $oldid );
2848
2849                 # Recreate the redirect, this time in the other direction.
2850                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2851                         $mwRedir = MagicWord::get( 'redirect' );
2852                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2853                         $redirectArticle = new Article( $this );
2854                         $newid = $redirectArticle->insertOn( $dbw );
2855                         $redirectRevision = new Revision( array(
2856                                 'page'    => $newid,
2857                                 'comment' => $comment,
2858                                 'text'    => $redirectText ) );
2859                         $redirectRevision->insertOn( $dbw );
2860                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2861
2862                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2863
2864                         # Now, we record the link from the redirect to the new title.
2865                         # It should have no other outgoing links...
2866                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2867                         $dbw->insert( 'pagelinks',
2868                                 array(
2869                                         'pl_from'      => $newid,
2870                                         'pl_namespace' => $nt->getNamespace(),
2871                                         'pl_title'     => $nt->getDBkey() ),
2872                                 $fname );
2873                         $redirectSuppressed = false;
2874                 } else {
2875                         $this->resetArticleID( 0 );
2876                         $redirectSuppressed = true;
2877                 }
2878
2879                 # Log the move
2880                 $log = new LogPage( 'move' );
2881                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2882
2883                 # Purge squid
2884                 if ( $wgUseSquid ) {
2885                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2886                         $u = new SquidUpdate( $urls );
2887                         $u->doUpdate();
2888                 }
2889
2890         }
2891
2892         /**
2893          * Move page to non-existing title.
2894          * @param &$nt \type{Title} the new Title
2895          * @param $reason \type{\string} The reason for the move
2896          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2897          *  Ignored if the user doesn't have the suppressredirect right
2898          */
2899         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2900                 global $wgUseSquid, $wgUser;
2901                 $fname = 'MovePageForm::moveToNewTitle';
2902                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2903                 if ( $reason ) {
2904                         $comment .= wfMsgExt( 'colon-separator',
2905                                 array( 'escapenoentities', 'content' ) );
2906                         $comment .= $reason;
2907                 }
2908
2909                 $newid = $nt->getArticleID();
2910                 $oldid = $this->getArticleID();
2911                 $latest = $this->getLatestRevId();
2912
2913                 $dbw = wfGetDB( DB_MASTER );
2914                 $now = $dbw->timestamp();
2915
2916                 # Save a null revision in the page's history notifying of the move
2917                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2918                 $nullRevId = $nullRevision->insertOn( $dbw );
2919
2920                 $article = new Article( $this );
2921                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2922
2923                 # Rename page entry
2924                 $dbw->update( 'page',
2925                         /* SET */ array(
2926                                 'page_touched'   => $now,
2927                                 'page_namespace' => $nt->getNamespace(),
2928                                 'page_title'     => $nt->getDBkey(),
2929                                 'page_latest'    => $nullRevId,
2930                         ),
2931                         /* WHERE */ array( 'page_id' => $oldid ),
2932                         $fname
2933                 );
2934                 $nt->resetArticleID( $oldid );
2935
2936                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2937                         # Insert redirect
2938                         $mwRedir = MagicWord::get( 'redirect' );
2939                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2940                         $redirectArticle = new Article( $this );
2941                         $newid = $redirectArticle->insertOn( $dbw );
2942                         $redirectRevision = new Revision( array(
2943                                 'page'    => $newid,
2944                                 'comment' => $comment,
2945                                 'text'    => $redirectText ) );
2946                         $redirectRevision->insertOn( $dbw );
2947                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2948
2949                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2950
2951                         # Record the just-created redirect's linking to the page
2952                         $dbw->insert( 'pagelinks',
2953                                 array(
2954                                         'pl_from'      => $newid,
2955                                         'pl_namespace' => $nt->getNamespace(),
2956                                         'pl_title'     => $nt->getDBkey() ),
2957                                 $fname );
2958                         $redirectSuppressed = false;
2959                 } else {
2960                         $this->resetArticleID( 0 );
2961                         $redirectSuppressed = true;
2962                 }
2963
2964                 # Log the move
2965                 $log = new LogPage( 'move' );
2966                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2967
2968                 # Purge caches as per article creation
2969                 Article::onArticleCreate( $nt );
2970
2971                 # Purge old title from squid
2972                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2973                 $this->purgeSquid();
2974
2975         }
2976
2977         /**
2978          * Move this page's subpages to be subpages of $nt
2979          * @param $nt Title Move target
2980          * @param $auth bool Whether $wgUser's permissions should be checked
2981          * @param $reason string The reason for the move
2982          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2983          *  Ignored if the user doesn't have the 'suppressredirect' right
2984          * @return mixed array with old page titles as keys, and strings (new page titles) or
2985          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
2986          */
2987         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
2988                 global $wgMaximumMovedPages;
2989                 // Check permissions
2990                 if( !$this->userCan( 'move-subpages' ) )
2991                         return array( 'cant-move-subpages' );
2992                 // Do the source and target namespaces support subpages?
2993                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
2994                         return array( 'namespace-nosubpages',
2995                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
2996                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
2997                         return array( 'namespace-nosubpages',
2998                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
2999
3000                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
3001                 $retval = array();
3002                 $count = 0;
3003                 foreach( $subpages as $oldSubpage ) {
3004                         $count++;
3005                         if( $count > $wgMaximumMovedPages ) {
3006                                 $retval[$oldSubpage->getPrefixedTitle()] =
3007                                                 array( 'movepage-max-pages',
3008                                                         $wgMaximumMovedPages );
3009                                 break;
3010                         }
3011
3012                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
3013                                 // When moving a page to a subpage of itself,
3014                                 // don't move it twice
3015                                 continue;
3016                         $newPageName = preg_replace(
3017                                         '#^'.preg_quote( $this->getDBkey(), '#' ).'#',
3018                                         $nt->getDBkey(), $oldSubpage->getDBkey() );
3019                         if( $oldSubpage->isTalkPage() ) {
3020                                 $newNs = $nt->getTalkPage()->getNamespace();
3021                         } else {
3022                                 $newNs = $nt->getSubjectPage()->getNamespace();
3023                         }
3024                         # Bug 14385: we need makeTitleSafe because the new page names may
3025                         # be longer than 255 characters.
3026                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3027
3028                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3029                         if( $success === true ) {
3030                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3031                         } else {
3032                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3033                         }
3034                 }
3035                 return $retval;
3036         }
3037
3038         /**
3039          * Checks if this page is just a one-rev redirect.
3040          * Adds lock, so don't use just for light purposes.
3041          *
3042          * @return \type{\bool} TRUE or FALSE
3043          */
3044         public function isSingleRevRedirect() {
3045                 $dbw = wfGetDB( DB_MASTER );
3046                 # Is it a redirect?
3047                 $row = $dbw->selectRow( 'page',
3048                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3049                         $this->pageCond(),
3050                         __METHOD__,
3051                         array( 'FOR UPDATE' )
3052                 );
3053                 # Cache some fields we may want
3054                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3055                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3056                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3057                 if( !$this->mRedirect ) {
3058                         return false;
3059                 }
3060                 # Does the article have a history?
3061                 $row = $dbw->selectField( array( 'page', 'revision'),
3062                         'rev_id',
3063                         array( 'page_namespace' => $this->getNamespace(),
3064                                 'page_title' => $this->getDBkey(),
3065                                 'page_id=rev_page',
3066                                 'page_latest != rev_id'
3067                         ),
3068                         __METHOD__,
3069                         array( 'FOR UPDATE' )
3070                 );
3071                 # Return true if there was no history
3072                 return ($row === false);
3073         }
3074
3075         /**
3076          * Checks if $this can be moved to a given Title
3077          * - Selects for update, so don't call it unless you mean business
3078          *
3079          * @param &$nt \type{Title} the new title to check
3080          * @return \type{\bool} TRUE or FALSE
3081          */
3082         public function isValidMoveTarget( $nt ) {
3083                 $dbw = wfGetDB( DB_MASTER );
3084                 # Is it an existsing file?
3085                 if( $nt->getNamespace() == NS_FILE ) {
3086                         $file = wfLocalFile( $nt );
3087                         if( $file->exists() ) {
3088                                 wfDebug( __METHOD__ . ": file exists\n" );
3089                                 return false;
3090                         }
3091                 }
3092                 # Is it a redirect with no history?
3093                 if( !$nt->isSingleRevRedirect() ) {
3094                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3095                         return false;
3096                 }
3097                 # Get the article text
3098                 $rev = Revision::newFromTitle( $nt );
3099                 $text = $rev->getText();
3100                 # Does the redirect point to the source?
3101                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3102                 $m = array();
3103                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3104                         $redirTitle = Title::newFromText( $m[1] );
3105                         if( !is_object( $redirTitle ) ||
3106                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3107                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3108                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3109                                 return false;
3110                         }
3111                 } else {
3112                         # Fail safe
3113                         wfDebug( __METHOD__ . ": failsafe\n" );
3114                         return false;
3115                 }
3116                 return true;
3117         }
3118
3119         /**
3120          * Can this title be added to a user's watchlist?
3121          *
3122          * @return \type{\bool} TRUE or FALSE
3123          */
3124         public function isWatchable() {
3125                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3126         }
3127
3128         /**
3129          * Get categories to which this Title belongs and return an array of
3130          * categories' names.
3131          *
3132          * @return \type{\array} array an array of parents in the form:
3133          *      $parent => $currentarticle
3134          */
3135         public function getParentCategories() {
3136                 global $wgContLang;
3137
3138                 $titlekey = $this->getArticleId();
3139                 $dbr = wfGetDB( DB_SLAVE );
3140                 $categorylinks = $dbr->tableName( 'categorylinks' );
3141
3142                 # NEW SQL
3143                 $sql = "SELECT * FROM $categorylinks"
3144                      ." WHERE cl_from='$titlekey'"
3145                          ." AND cl_from <> '0'"
3146                          ." ORDER BY cl_sortkey";
3147
3148                 $res = $dbr->query( $sql );
3149
3150                 if( $dbr->numRows( $res ) > 0 ) {
3151                         foreach( $res as $row )
3152                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3153                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3154                         $dbr->freeResult( $res );
3155                 } else {
3156                         $data = array();
3157                 }
3158                 return $data;
3159         }
3160
3161         /**
3162          * Get a tree of parent categories
3163          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3164          * @return \type{\array} Tree of parent categories
3165          */
3166         public function getParentCategoryTree( $children = array() ) {
3167                 $stack = array();
3168                 $parents = $this->getParentCategories();
3169
3170                 if( $parents ) {
3171                         foreach( $parents as $parent => $current ) {
3172                                 if ( array_key_exists( $parent, $children ) ) {
3173                                         # Circular reference
3174                                         $stack[$parent] = array();
3175                                 } else {
3176                                         $nt = Title::newFromText($parent);
3177                                         if ( $nt ) {
3178                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3179                                         }
3180                                 }
3181                         }
3182                         return $stack;
3183                 } else {
3184                         return array();
3185                 }
3186         }
3187
3188
3189         /**
3190          * Get an associative array for selecting this title from
3191          * the "page" table
3192          *
3193          * @return \type{\array} Selection array
3194          */
3195         public function pageCond() {
3196                 if( $this->mArticleID > 0 ) {
3197                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3198                         return array( 'page_id' => $this->mArticleID );
3199                 } else {
3200                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3201                 }
3202         }
3203
3204         /**
3205          * Get the revision ID of the previous revision
3206          *
3207          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3208          * @param $flags \type{\int} GAID_FOR_UPDATE
3209          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3210          */
3211         public function getPreviousRevisionID( $revId, $flags=0 ) {
3212                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3213                 return $db->selectField( 'revision', 'rev_id',
3214                         array(
3215                                 'rev_page' => $this->getArticleId($flags),
3216                                 'rev_id < ' . intval( $revId )
3217                         ),
3218                         __METHOD__,
3219                         array( 'ORDER BY' => 'rev_id DESC' )
3220                 );
3221         }
3222
3223         /**
3224          * Get the revision ID of the next revision
3225          *
3226          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3227          * @param $flags \type{\int} GAID_FOR_UPDATE
3228          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3229          */
3230         public function getNextRevisionID( $revId, $flags=0 ) {
3231                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3232                 return $db->selectField( 'revision', 'rev_id',
3233                         array(
3234                                 'rev_page' => $this->getArticleId($flags),
3235                                 'rev_id > ' . intval( $revId )
3236                         ),
3237                         __METHOD__,
3238                         array( 'ORDER BY' => 'rev_id' )
3239                 );
3240         }
3241
3242         /**
3243          * Get the first revision of the page
3244          *
3245          * @param $flags \type{\int} GAID_FOR_UPDATE
3246          * @return Revision (or NULL if page doesn't exist)
3247          */
3248         public function getFirstRevision( $flags=0 ) {
3249                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3250                 $pageId = $this->getArticleId($flags);
3251                 if( !$pageId ) return NULL;
3252                 $row = $db->selectRow( 'revision', '*',
3253                         array( 'rev_page' => $pageId ),
3254                         __METHOD__,
3255                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3256                 );
3257                 if( !$row ) {
3258                         return NULL;
3259                 } else {
3260                         return new Revision( $row );
3261                 }
3262         }
3263
3264         /**
3265          * Check if this is a new page
3266          *
3267          * @return bool
3268          */
3269         public function isNewPage() {
3270                 $dbr = wfGetDB( DB_SLAVE );
3271                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3272         }
3273
3274         /**
3275          * Get the oldest revision timestamp of this page
3276          *
3277          * @return string, MW timestamp
3278          */
3279         public function getEarliestRevTime() {
3280                 $dbr = wfGetDB( DB_SLAVE );
3281                 if( $this->exists() ) {
3282                         $min = $dbr->selectField( 'revision',
3283                                 'MIN(rev_timestamp)',
3284                                 array( 'rev_page' => $this->getArticleId() ),
3285                                 __METHOD__ );
3286                         return wfTimestampOrNull( TS_MW, $min );
3287                 }
3288                 return null;
3289         }
3290
3291         /**
3292          * Get the number of revisions between the given revision IDs.
3293          * Used for diffs and other things that really need it.
3294          *
3295          * @param $old \type{\int} Revision ID.
3296          * @param $new \type{\int} Revision ID.
3297          * @return \type{\int} Number of revisions between these IDs.
3298          */
3299         public function countRevisionsBetween( $old, $new ) {
3300                 $dbr = wfGetDB( DB_SLAVE );
3301                 return $dbr->selectField( 'revision', 'count(*)',
3302                         'rev_page = ' . intval( $this->getArticleId() ) .
3303                         ' AND rev_id > ' . intval( $old ) .
3304                         ' AND rev_id < ' . intval( $new ),
3305                         __METHOD__
3306                 );
3307         }
3308
3309         /**
3310          * Compare with another title.
3311          *
3312          * @param \type{Title} $title
3313          * @return \type{\bool} TRUE or FALSE
3314          */
3315         public function equals( Title $title ) {
3316                 // Note: === is necessary for proper matching of number-like titles.
3317                 return $this->getInterwiki() === $title->getInterwiki()
3318                         && $this->getNamespace() == $title->getNamespace()
3319                         && $this->getDBkey() === $title->getDBkey();
3320         }
3321
3322         /**
3323          * Callback for usort() to do title sorts by (namespace, title)
3324          */
3325         public static function compare( $a, $b ) {
3326                 if( $a->getNamespace() == $b->getNamespace() ) {
3327                         return strcmp( $a->getText(), $b->getText() );
3328                 } else {
3329                         return $a->getNamespace() - $b->getNamespace();
3330                 }
3331         }
3332
3333         /**
3334          * Return a string representation of this title
3335          *
3336          * @return \type{\string} String representation of this title
3337          */
3338         public function __toString() {
3339                 return $this->getPrefixedText();
3340         }
3341
3342         /**
3343          * Check if page exists.  For historical reasons, this function simply
3344          * checks for the existence of the title in the page table, and will
3345          * thus return false for interwiki links, special pages and the like.
3346          * If you want to know if a title can be meaningfully viewed, you should
3347          * probably call the isKnown() method instead.
3348          *
3349          * @return \type{\bool} TRUE or FALSE
3350          */
3351         public function exists() {
3352                 return $this->getArticleId() != 0;
3353         }
3354
3355         /**
3356          * Should links to this title be shown as potentially viewable (i.e. as
3357          * "bluelinks"), even if there's no record by this title in the page
3358          * table?
3359          *
3360          * This function is semi-deprecated for public use, as well as somewhat
3361          * misleadingly named.  You probably just want to call isKnown(), which
3362          * calls this function internally.
3363          *
3364          * (ISSUE: Most of these checks are cheap, but the file existence check
3365          * can potentially be quite expensive.  Including it here fixes a lot of
3366          * existing code, but we might want to add an optional parameter to skip
3367          * it and any other expensive checks.)
3368          *
3369          * @return \type{\bool} TRUE or FALSE
3370          */
3371         public function isAlwaysKnown() {
3372                 if( $this->mInterwiki != '' ) {
3373                         return true;  // any interwiki link might be viewable, for all we know
3374                 }
3375                 switch( $this->mNamespace ) {
3376                 case NS_MEDIA:
3377                 case NS_FILE:
3378                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3379                 case NS_SPECIAL:
3380                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3381                 case NS_MAIN:
3382                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3383                 case NS_MEDIAWIKI:
3384                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3385                         // the full l10n of that language to be loaded. That takes much memory and
3386                         // isn't needed. So we strip the language part away.
3387                         // Also, extension messages which are not loaded, are shown as red, because
3388                         // we don't call MessageCache::loadAllMessages.
3389                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3390                         return wfMsgWeirdKey( $basename );  // known system message
3391                 default:
3392                         return false;
3393                 }
3394         }
3395
3396         /**
3397          * Does this title refer to a page that can (or might) be meaningfully
3398          * viewed?  In particular, this function may be used to determine if
3399          * links to the title should be rendered as "bluelinks" (as opposed to
3400          * "redlinks" to non-existent pages).
3401          *
3402          * @return \type{\bool} TRUE or FALSE
3403          */
3404         public function isKnown() {
3405                 return $this->exists() || $this->isAlwaysKnown();
3406         }
3407
3408         /**
3409         * Is this in a namespace that allows actual pages?
3410         *
3411         * @return \type{\bool} TRUE or FALSE
3412         */
3413         public function canExist() {
3414                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3415         }
3416
3417         /**
3418          * Update page_touched timestamps and send squid purge messages for
3419          * pages linking to this title. May be sent to the job queue depending
3420          * on the number of links. Typically called on create and delete.
3421          */
3422         public function touchLinks() {
3423                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3424                 $u->doUpdate();
3425
3426                 if ( $this->getNamespace() == NS_CATEGORY ) {
3427                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3428                         $u->doUpdate();
3429                 }
3430         }
3431
3432         /**
3433          * Get the last touched timestamp
3434          * @param Database $db, optional db
3435          * @return \type{\string} Last touched timestamp
3436          */
3437         public function getTouched( $db = NULL ) {
3438                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3439                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3440                 return $touched;
3441         }
3442
3443         /**
3444          * Get the timestamp when this page was updated since the user last saw it.
3445          * @param User $user
3446          * @return mixed string/NULL
3447          */
3448         public function getNotificationTimestamp( $user = NULL ) {
3449                 global $wgUser, $wgShowUpdatedMarker;
3450                 // Assume current user if none given
3451                 if( !$user ) $user = $wgUser;
3452                 // Check cache first
3453                 $uid = $user->getId();
3454                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3455                         return $this->mNotificationTimestamp[$uid];
3456                 }
3457                 if( !$uid || !$wgShowUpdatedMarker ) {
3458                         return $this->mNotificationTimestamp[$uid] = false;
3459                 }
3460                 // Don't cache too much!
3461                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3462                         $this->mNotificationTimestamp = array();
3463                 }
3464                 $dbr = wfGetDB( DB_SLAVE );
3465                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3466                         'wl_notificationtimestamp',
3467                         array( 'wl_namespace' => $this->getNamespace(),
3468                                 'wl_title' => $this->getDBkey(),
3469                                 'wl_user' => $user->getId()
3470                         ),
3471                         __METHOD__
3472                 );
3473                 return $this->mNotificationTimestamp[$uid];
3474         }
3475
3476         /**
3477          * Get the trackback URL for this page
3478          * @return \type{\string} Trackback URL
3479          */
3480         public function trackbackURL() {
3481                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3482
3483                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3484                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3485         }
3486
3487         /**
3488          * Get the trackback RDF for this page
3489          * @return \type{\string} Trackback RDF
3490          */
3491         public function trackbackRDF() {
3492                 $url = htmlspecialchars($this->getFullURL());
3493                 $title = htmlspecialchars($this->getText());
3494                 $tburl = $this->trackbackURL();
3495
3496                 // Autodiscovery RDF is placed in comments so HTML validator
3497                 // won't barf. This is a rather icky workaround, but seems
3498                 // frequently used by this kind of RDF thingy.
3499                 //
3500                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3501                 return "<!--
3502 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3503          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3504          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3505 <rdf:Description
3506    rdf:about=\"$url\"
3507    dc:identifier=\"$url\"
3508    dc:title=\"$title\"
3509    trackback:ping=\"$tburl\" />
3510 </rdf:RDF>
3511 -->";
3512         }
3513
3514         /**
3515          * Generate strings used for xml 'id' names in monobook tabs
3516          * @return \type{\string} XML 'id' name
3517          */
3518         public function getNamespaceKey() {
3519                 global $wgContLang;
3520                 switch ($this->getNamespace()) {
3521                         case NS_MAIN:
3522                         case NS_TALK:
3523                                 return 'nstab-main';
3524                         case NS_USER:
3525                         case NS_USER_TALK:
3526                                 return 'nstab-user';
3527                         case NS_MEDIA:
3528                                 return 'nstab-media';
3529                         case NS_SPECIAL:
3530                                 return 'nstab-special';
3531                         case NS_PROJECT:
3532                         case NS_PROJECT_TALK:
3533                                 return 'nstab-project';
3534                         case NS_FILE:
3535                         case NS_FILE_TALK:
3536                                 return 'nstab-image';
3537                         case NS_MEDIAWIKI:
3538                         case NS_MEDIAWIKI_TALK:
3539                                 return 'nstab-mediawiki';
3540                         case NS_TEMPLATE:
3541                         case NS_TEMPLATE_TALK:
3542                                 return 'nstab-template';
3543                         case NS_HELP:
3544                         case NS_HELP_TALK:
3545                                 return 'nstab-help';
3546                         case NS_CATEGORY:
3547                         case NS_CATEGORY_TALK:
3548                                 return 'nstab-category';
3549                         default:
3550                                 return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
3551                 }
3552         }
3553
3554         /**
3555          * Returns true if this title resolves to the named special page
3556          * @param $name \type{\string} The special page name
3557          */
3558         public function isSpecial( $name ) {
3559                 if ( $this->getNamespace() == NS_SPECIAL ) {
3560                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3561                         if ( $name == $thisName ) {
3562                                 return true;
3563                         }
3564                 }
3565                 return false;
3566         }
3567
3568         /**
3569          * If the Title refers to a special page alias which is not the local default,
3570          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3571          */
3572         public function fixSpecialName() {
3573                 if ( $this->getNamespace() == NS_SPECIAL ) {
3574                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3575                         if ( $canonicalName ) {
3576                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3577                                 if ( $localName != $this->mDbkeyform ) {
3578                                         return Title::makeTitle( NS_SPECIAL, $localName );
3579                                 }
3580                         }
3581                 }
3582                 return $this;
3583         }
3584
3585         /**
3586          * Is this Title in a namespace which contains content?
3587          * In other words, is this a content page, for the purposes of calculating
3588          * statistics, etc?
3589          *
3590          * @return \type{\bool} TRUE or FALSE
3591          */
3592         public function isContentPage() {
3593                 return MWNamespace::isContent( $this->getNamespace() );
3594         }
3595
3596         /**
3597          * Get all extant redirects to this Title
3598          *
3599          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3600          *            NULL to consider all namespaces
3601          * @return \type{\arrayof{Title}} Redirects to this title
3602          */
3603         public function getRedirectsHere( $ns = null ) {
3604                 $redirs = array();
3605
3606                 $dbr = wfGetDB( DB_SLAVE );
3607                 $where = array(
3608                         'rd_namespace' => $this->getNamespace(),
3609                         'rd_title' => $this->getDBkey(),
3610                         'rd_from = page_id'
3611                 );
3612                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3613
3614                 $res = $dbr->select(
3615                         array( 'redirect', 'page' ),
3616                         array( 'page_namespace', 'page_title' ),
3617                         $where,
3618                         __METHOD__
3619                 );
3620
3621
3622                 foreach( $res as $row ) {
3623                         $redirs[] = self::newFromRow( $row );
3624                 }
3625                 return $redirs;
3626         }
3627
3628         /**
3629          * Check if this Title is a valid redirect target
3630          *
3631          * @return \type{\bool} TRUE or FALSE
3632          */
3633         public function isValidRedirectTarget() {
3634                 global $wgInvalidRedirectTargets;
3635
3636                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3637                 if( $this->isSpecial( 'Userlogout' ) ) {
3638                         return false;
3639                 }
3640
3641                 foreach( $wgInvalidRedirectTargets as $target ) {
3642                         if( $this->isSpecial( $target ) ) {
3643                                 return false;
3644                         }
3645                 }
3646
3647                 return true;
3648         }
3649
3650         /**
3651          * Get a backlink cache object
3652          */
3653         function getBacklinkCache() {
3654                 if ( is_null( $this->mBacklinkCache ) ) {
3655                         $this->mBacklinkCache = new BacklinkCache( $this );
3656                 }
3657                 return $this->mBacklinkCache;
3658         }
3659 }