includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 if ( !class_exists( 'UtfNormal' ) ) {
   8         require_once( dirname(__FILE__) . '/normal/UtfNormal.php' );
   9 }
  10
  11 define ( 'GAID_FOR_UPDATE', 1 );
  12
  13
  14 /**
  15  * Constants for pr_cascade bitfield
  16  */
  17 define( 'CASCADE', 1 );
  18
  19 /**
  20  * Represents a title within MediaWiki.
  21  * Optionally may contain an interwiki designation or namespace.
  22  * @note This class can fetch various kinds of data from the database;
  23  *       however, it does so inefficiently.
  24  */
  25 class Title {
  26         /** @name Static cache variables */
  27         //@{
  28         static private $titleCache=array();
  29         static private $interwikiCache=array();
  30         //@}
  31
  32         /**
  33          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  34          * commonly used titles. On a batch operation this can become a memory leak
  35          * if not bounded. After hitting this many titles reset the cache.
  36          */
  37         const CACHE_MAX = 1000;
  38
  39
  40         /**
  41          * @name Private member variables
  42          * Please use the accessor functions instead.
  43          * @private
  44          */
  45         //@{
  46
  47         var $mTextform = '';              ///< Text form (spaces not underscores) of the main part
  48         var $mUrlform = '';               ///< URL-encoded form of the main part
  49         var $mDbkeyform = '';             ///< Main part with underscores
  50         var $mUserCaseDBKey;              ///< DB key with the initial letter in the case specified by the user
  51         var $mNamespace = NS_MAIN;        ///< Namespace index, i.e. one of the NS_xxxx constants
  52         var $mInterwiki = '';             ///< Interwiki prefix (or null string)
  53         var $mFragment;                   ///< Title fragment (i.e. the bit after the #)
  54         var $mArticleID = -1;             ///< Article ID, fetched from the link cache on demand
  55         var $mLatestID = false;           ///< ID of most recent revision
  56         var $mRestrictions = array();     ///< Array of groups allowed to edit this article
  57         var $mOldRestrictions = false;
  58         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  59         var $mRestrictionsExpiry = array();       ///< When do the restrictions on this page expire?
  60         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  61         var $mCascadeSources;  ///< Where are the cascading restrictions coming from on this page?
  62         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  63         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  64         # Don't change the following default, NS_MAIN is hardcoded in several
  65         # places.  See bug 696.
  66         var $mDefaultNamespace = NS_MAIN; ///< Namespace index when there is no namespace
  67                                           # Zero except in {{transclusion}} tags
  68         var $mWatched = null;             ///< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  69         var $mLength = -1;                ///< The page length, 0 for special pages
  70         var $mRedirect = null;            ///< Is the article at this title a redirect?
  71         var $mNotificationTimestamp = array(); ///< Associative array of user ID -> timestamp/false
  72         var $mBacklinkCache = null; ///< Cache of links to this title
  73         //@}
  74
  75
  76         /**
  77          * Constructor
  78          * @private
  79          */
  80         /* private */ function __construct() {}
  81
  82         /**
  83          * Create a new Title from a prefixed DB key
  84          * @param $key \type{\string} The database key, which has underscores
  85          *      instead of spaces, possibly including namespace and
  86          *      interwiki prefixes
  87          * @return \type{Title} the new object, or NULL on an error
  88          */
  89         public static function newFromDBkey( $key ) {
  90                 $t = new Title();
  91                 $t->mDbkeyform = $key;
  92                 if( $t->secureAndSplit() )
  93                         return $t;
  94                 else
  95                         return NULL;
  96         }
  97
  98         /**
  99          * Create a new Title from text, such as what one would find in a link. De-
 100          * codes any HTML entities in the text.
 101          *
 102          * @param $text             string  The link text; spaces, prefixes, and an
 103          *   initial ':' indicating the main namespace are accepted.
 104          * @param $defaultNamespace int     The namespace to use if none is speci-
 105          *   fied by a prefix.  If you want to force a specific namespace even if
 106          *   $text might begin with a namespace prefix, use makeTitle() or
 107          *   makeTitleSafe().
 108          * @return Title  The new object, or null on an error.
 109          */
 110         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 111                 if( is_object( $text ) ) {
 112                         throw new MWException( 'Title::newFromText given an object' );
 113                 }
 114
 115                 /**
 116                  * Wiki pages often contain multiple links to the same page.
 117                  * Title normalization and parsing can become expensive on
 118                  * pages with many links, so we can save a little time by
 119                  * caching them.
 120                  *
 121                  * In theory these are value objects and won't get changed...
 122                  */
 123                 if( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 124                         return Title::$titleCache[$text];
 125                 }
 126
 127                 /**
 128                  * Convert things like &eacute; &#257; or &#x3017; into real text...
 129                  */
 130                 $filteredText = Sanitizer::decodeCharReferences( $text );
 131
 132                 $t = new Title();
 133                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 134                 $t->mDefaultNamespace = $defaultNamespace;
 135
 136                 static $cachedcount = 0 ;
 137                 if( $t->secureAndSplit() ) {
 138                         if( $defaultNamespace == NS_MAIN ) {
 139                                 if( $cachedcount >= self::CACHE_MAX ) {
 140                                         # Avoid memory leaks on mass operations...
 141                                         Title::$titleCache = array();
 142                                         $cachedcount=0;
 143                                 }
 144                                 $cachedcount++;
 145                                 Title::$titleCache[$text] =& $t;
 146                         }
 147                         return $t;
 148                 } else {
 149                         $ret = NULL;
 150                         return $ret;
 151                 }
 152         }
 153
 154         /**
 155          * Create a new Title from URL-encoded text. Ensures that
 156          * the given title's length does not exceed the maximum.
 157          * @param $url \type{\string} the title, as might be taken from a URL
 158          * @return \type{Title} the new object, or NULL on an error
 159          */
 160         public static function newFromURL( $url ) {
 161                 global $wgLegalTitleChars;
 162                 $t = new Title();
 163
 164                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 165                 # but some URLs used it as a space replacement and they still come
 166                 # from some external search tools.
 167                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 168                         $url = str_replace( '+', ' ', $url );
 169                 }
 170
 171                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 172                 if( $t->secureAndSplit() ) {
 173                         return $t;
 174                 } else {
 175                         return NULL;
 176                 }
 177         }
 178
 179         /**
 180          * Create a new Title from an article ID
 181          *
 182          * @param $id \type{\int} the page_id corresponding to the Title to create
 183          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 184          * @return \type{Title} the new object, or NULL on an error
 185          */
 186         public static function newFromID( $id, $flags = 0 ) {
 187                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 188                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 189                 if( $row !== false ) {
 190                         $title = Title::newFromRow( $row );
 191                 } else {
 192                         $title = NULL;
 193                 }
 194                 return $title;
 195         }
 196
 197         /**
 198          * Make an array of titles from an array of IDs
 199          * @param $ids \type{\arrayof{\int}} Array of IDs
 200          * @return \type{\arrayof{Title}} Array of Titles
 201          */
 202         public static function newFromIDs( $ids ) {
 203                 if ( !count( $ids ) ) {
 204                         return array();
 205                 }
 206                 $dbr = wfGetDB( DB_SLAVE );
 207                 $res = $dbr->select( 'page', array( 'page_namespace', 'page_title' ),
 208                         'page_id IN (' . $dbr->makeList( $ids ) . ')', __METHOD__ );
 209
 210                 $titles = array();
 211                 foreach( $res as $row ) {
 212                         $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
 213                 }
 214                 return $titles;
 215         }
 216
 217         /**
 218          * Make a Title object from a DB row
 219          * @param $row \type{Row} (needs at least page_title,page_namespace)
 220          * @return \type{Title} corresponding Title
 221          */
 222         public static function newFromRow( $row ) {
 223                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 224
 225                 $t->mArticleID = isset($row->page_id) ? intval($row->page_id) : -1;
 226                 $t->mLength = isset($row->page_len) ? intval($row->page_len) : -1;
 227                 $t->mRedirect = isset($row->page_is_redirect) ? (bool)$row->page_is_redirect : NULL;
 228                 $t->mLatestID = isset($row->page_latest) ? $row->page_latest : false;
 229
 230                 return $t;
 231         }
 232
 233         /**
 234          * Create a new Title from a namespace index and a DB key.
 235          * It's assumed that $ns and $title are *valid*, for instance when
 236          * they came directly from the database or a special page name.
 237          * For convenience, spaces are converted to underscores so that
 238          * eg user_text fields can be used directly.
 239          *
 240          * @param $ns \type{\int} the namespace of the article
 241          * @param $title \type{\string} the unprefixed database key form
 242          * @param $fragment \type{\string} The link fragment (after the "#")
 243          * @return \type{Title} the new object
 244          */
 245         public static function &makeTitle( $ns, $title, $fragment = '' ) {
 246                 $t = new Title();
 247                 $t->mInterwiki = '';
 248                 $t->mFragment = $fragment;
 249                 $t->mNamespace = $ns = intval( $ns );
 250                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 251                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 252                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 253                 $t->mTextform = str_replace( '_', ' ', $title );
 254                 return $t;
 255         }
 256
 257         /**
 258          * Create a new Title from a namespace index and a DB key.
 259          * The parameters will be checked for validity, which is a bit slower
 260          * than makeTitle() but safer for user-provided data.
 261          *
 262          * @param $ns \type{\int} the namespace of the article
 263          * @param $title \type{\string} the database key form
 264          * @param $fragment \type{\string} The link fragment (after the "#")
 265          * @return \type{Title} the new object, or NULL on an error
 266          */
 267         public static function makeTitleSafe( $ns, $title, $fragment = '' ) {
 268                 $t = new Title();
 269                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment );
 270                 if( $t->secureAndSplit() ) {
 271                         return $t;
 272                 } else {
 273                         return NULL;
 274                 }
 275         }
 276
 277         /**
 278          * Create a new Title for the Main Page
 279          * @return \type{Title} the new object
 280          */
 281         public static function newMainPage() {
 282                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 283                 // Don't give fatal errors if the message is broken
 284                 if ( !$title ) {
 285                         $title = Title::newFromText( 'Main Page' );
 286                 }
 287                 return $title;
 288         }
 289
 290         /**
 291          * Extract a redirect destination from a string and return the
 292          * Title, or null if the text doesn't contain a valid redirect
 293          * This will only return the very next target, useful for
 294          * the redirect table and other checks that don't need full recursion
 295          *
 296          * @param $text \type{\string} Text with possible redirect
 297          * @return \type{Title} The corresponding Title
 298          */
 299         public static function newFromRedirect( $text ) {
 300                 return self::newFromRedirectInternal( $text );
 301         }
 302
 303         /**
 304          * Extract a redirect destination from a string and return the
 305          * Title, or null if the text doesn't contain a valid redirect
 306          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 307          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 308          *
 309          * @param $text \type{\string} Text with possible redirect
 310          * @return \type{Title} The corresponding Title
 311          */
 312         public static function newFromRedirectRecurse( $text ) {
 313                 $titles = self::newFromRedirectArray( $text );
 314                 return $titles ? array_pop( $titles ) : null;
 315         }
 316
 317         /**
 318          * Extract a redirect destination from a string and return an
 319          * array of Titles, or null if the text doesn't contain a valid redirect
 320          * The last element in the array is the final destination after all redirects
 321          * have been resolved (up to $wgMaxRedirects times)
 322          *
 323          * @param $text \type{\string} Text with possible redirect
 324          * @return \type{\array} Array of Titles, with the destination last
 325          */
 326         public static function newFromRedirectArray( $text ) {
 327                 global $wgMaxRedirects;
 328                 // are redirects disabled?
 329                 if( $wgMaxRedirects < 1 )
 330                         return null;
 331                 $title = self::newFromRedirectInternal( $text );
 332                 if( is_null( $title ) )
 333                         return null;
 334                 // recursive check to follow double redirects
 335                 $recurse = $wgMaxRedirects;
 336                 $titles = array( $title );
 337                 while( --$recurse > 0 ) {
 338                         if( $title->isRedirect() ) {
 339                                 $article = new Article( $title, 0 );
 340                                 $newtitle = $article->getRedirectTarget();
 341                         } else {
 342                                 break;
 343                         }
 344                         // Redirects to some special pages are not permitted
 345                         if( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 346                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 347                                 $title = $newtitle;
 348                                 $titles[] = $newtitle;
 349                         } else {
 350                                 break;
 351                         }
 352                 }
 353                 return $titles;
 354         }
 355
 356         /**
 357          * Really extract the redirect destination
 358          * Do not call this function directly, use one of the newFromRedirect* functions above
 359          *
 360          * @param $text \type{\string} Text with possible redirect
 361          * @return \type{Title} The corresponding Title
 362          */
 363         protected static function newFromRedirectInternal( $text ) {
 364                 $redir = MagicWord::get( 'redirect' );
 365                 $text = trim($text);
 366                 if( $redir->matchStartAndRemove( $text ) ) {
 367                         // Extract the first link and see if it's usable
 368                         // Ensure that it really does come directly after #REDIRECT
 369                         // Some older redirects included a colon, so don't freak about that!
 370                         $m = array();
 371                         if( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 372                                 // Strip preceding colon used to "escape" categories, etc.
 373                                 // and URL-decode links
 374                                 if( strpos( $m[1], '%' ) !== false ) {
 375                                         // Match behavior of inline link parsing here;
 376                                         // don't interpret + as " " most of the time!
 377                                         // It might be safe to just use rawurldecode instead, though.
 378                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 379                                 }
 380                                 $title = Title::newFromText( $m[1] );
 381                                 // If the title is a redirect to bad special pages or is invalid, return null
 382                                 if( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 383                                         return null;
 384                                 }
 385                                 return $title;
 386                         }
 387                 }
 388                 return null;
 389         }
 390
 391 #----------------------------------------------------------------------------
 392 #       Static functions
 393 #----------------------------------------------------------------------------
 394
 395         /**
 396          * Get the prefixed DB key associated with an ID
 397          * @param $id \type{\int} the page_id of the article
 398          * @return \type{Title} an object representing the article, or NULL
 399          *      if no such article was found
 400          */
 401         public static function nameOf( $id ) {
 402                 $dbr = wfGetDB( DB_SLAVE );
 403
 404                 $s = $dbr->selectRow( 'page',
 405                         array( 'page_namespace','page_title' ),
 406                         array( 'page_id' => $id ),
 407                         __METHOD__ );
 408                 if ( $s === false ) { return NULL; }
 409
 410                 $n = self::makeName( $s->page_namespace, $s->page_title );
 411                 return $n;
 412         }
 413
 414         /**
 415          * Get a regex character class describing the legal characters in a link
 416          * @return \type{\string} the list of characters, not delimited
 417          */
 418         public static function legalChars() {
 419                 global $wgLegalTitleChars;
 420                 return $wgLegalTitleChars;
 421         }
 422
 423         /**
 424          * Get a string representation of a title suitable for
 425          * including in a search index
 426          *
 427          * @param $ns \type{\int} a namespace index
 428          * @param $title \type{\string} text-form main part
 429          * @return \type{\string} a stripped-down title string ready for the
 430          *      search index
 431          */
 432         public static function indexTitle( $ns, $title ) {
 433                 global $wgContLang;
 434
 435                 $lc = SearchEngine::legalSearchChars() . '&#;';
 436                 $t = $wgContLang->stripForSearch( $title );
 437                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 438                 $t = $wgContLang->lc( $t );
 439
 440                 # Handle 's, s'
 441                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 442                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 443
 444                 $t = preg_replace( "/\\s+/", ' ', $t );
 445
 446                 if ( $ns == NS_FILE ) {
 447                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 448                 }
 449                 return trim( $t );
 450         }
 451
 452         /*
 453          * Make a prefixed DB key from a DB key and a namespace index
 454          * @param $ns \type{\int} numerical representation of the namespace
 455          * @param $title \type{\string} the DB key form the title
 456          * @param $fragment \type{\string} The link fragment (after the "#")
 457          * @return \type{\string} the prefixed form of the title
 458          */
 459         public static function makeName( $ns, $title, $fragment = '' ) {
 460                 global $wgContLang;
 461
 462                 $namespace = $wgContLang->getNsText( $ns );
 463                 $name = $namespace == '' ? $title : "$namespace:$title";
 464                 if ( strval( $fragment ) != '' ) {
 465                         $name .= '#' . $fragment;
 466                 }
 467                 return $name;
 468         }
 469
 470         /**
 471          * Returns the URL associated with an interwiki prefix
 472          * @param $key \type{\string} the interwiki prefix (e.g. "MeatBall")
 473          * @return \type{\string} the associated URL, containing "$1",
 474          *      which should be replaced by an article title
 475          * @static (arguably)
 476          * @deprecated See Interwiki class
 477          */
 478         public function getInterwikiLink( $key )  {
 479                 return Interwiki::fetch( $key )->getURL( );
 480         }
 481
 482         /**
 483          * Determine whether the object refers to a page within
 484          * this project.
 485          *
 486          * @return \type{\bool} TRUE if this is an in-project interwiki link
 487          *      or a wikilink, FALSE otherwise
 488          */
 489         public function isLocal() {
 490                 if ( $this->mInterwiki != '' ) {
 491                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 492                 } else {
 493                         return true;
 494                 }
 495         }
 496
 497         /**
 498          * Determine whether the object refers to a page within
 499          * this project and is transcludable.
 500          *
 501          * @return \type{\bool} TRUE if this is transcludable
 502          */
 503         public function isTrans() {
 504                 if ($this->mInterwiki == '')
 505                         return false;
 506
 507                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 508         }
 509
 510         /**
 511          * Escape a text fragment, say from a link, for a URL
 512          */
 513         static function escapeFragmentForURL( $fragment ) {
 514                 global $wgEnforceHtmlIds;
 515                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 516                 # fragments appear not to work in IE (at least up to 7) or in at least
 517                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 518                 # to care if they aren't encoded.
 519                 return Sanitizer::escapeId( $fragment,
 520                         $wgEnforceHtmlIds ? 'noninitial' : 'xml' );
 521         }
 522
 523 #----------------------------------------------------------------------------
 524 #       Other stuff
 525 #----------------------------------------------------------------------------
 526
 527         /** Simple accessors */
 528         /**
 529          * Get the text form (spaces not underscores) of the main part
 530          * @return \type{\string} Main part of the title
 531          */
 532         public function getText() { return $this->mTextform; }
 533         /**
 534          * Get the URL-encoded form of the main part
 535          * @return \type{\string} Main part of the title, URL-encoded
 536          */
 537         public function getPartialURL() { return $this->mUrlform; }
 538         /**
 539          * Get the main part with underscores
 540          * @return \type{\string} Main part of the title, with underscores
 541          */
 542         public function getDBkey() { return $this->mDbkeyform; }
 543         /**
 544          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 545          * @return \type{\int} Namespace index
 546          */
 547         public function getNamespace() { return $this->mNamespace; }
 548         /**
 549          * Get the namespace text
 550          * @return \type{\string} Namespace text
 551          */
 552         public function getNsText() {
 553                 global $wgContLang, $wgCanonicalNamespaceNames;
 554
 555                 if ( '' != $this->mInterwiki ) {
 556                         // This probably shouldn't even happen. ohh man, oh yuck.
 557                         // But for interwiki transclusion it sometimes does.
 558                         // Shit. Shit shit shit.
 559                         //
 560                         // Use the canonical namespaces if possible to try to
 561                         // resolve a foreign namespace.
 562                         if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
 563                                 return $wgCanonicalNamespaceNames[$this->mNamespace];
 564                         }
 565                 }
 566                 return $wgContLang->getNsText( $this->mNamespace );
 567         }
 568         /**
 569          * Get the DB key with the initial letter case as specified by the user
 570          * @return \type{\string} DB key
 571          */
 572         function getUserCaseDBKey() {
 573                 return $this->mUserCaseDBKey;
 574         }
 575         /**
 576          * Get the namespace text of the subject (rather than talk) page
 577          * @return \type{\string} Namespace text
 578          */
 579         public function getSubjectNsText() {
 580                 global $wgContLang;
 581                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 582         }
 583         /**
 584          * Get the namespace text of the talk page
 585          * @return \type{\string} Namespace text
 586          */
 587         public function getTalkNsText() {
 588                 global $wgContLang;
 589                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 590         }
 591         /**
 592          * Could this title have a corresponding talk page?
 593          * @return \type{\bool} TRUE or FALSE
 594          */
 595         public function canTalk() {
 596                 return( MWNamespace::canTalk( $this->mNamespace ) );
 597         }
 598         /**
 599          * Get the interwiki prefix (or null string)
 600          * @return \type{\string} Interwiki prefix
 601          */
 602         public function getInterwiki() { return $this->mInterwiki; }
 603         /**
 604          * Get the Title fragment (i.e.\ the bit after the #) in text form
 605          * @return \type{\string} Title fragment
 606          */
 607         public function getFragment() { return $this->mFragment; }
 608         /**
 609          * Get the fragment in URL form, including the "#" character if there is one
 610          * @return \type{\string} Fragment in URL form
 611          */
 612         public function getFragmentForURL() {
 613                 if ( $this->mFragment == '' ) {
 614                         return '';
 615                 } else {
 616                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 617                 }
 618         }
 619         /**
 620          * Get the default namespace index, for when there is no namespace
 621          * @return \type{\int} Default namespace index
 622          */
 623         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 624
 625         /**
 626          * Get title for search index
 627          * @return \type{\string} a stripped-down title string ready for the
 628          *      search index
 629          */
 630         public function getIndexTitle() {
 631                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 632         }
 633
 634         /**
 635          * Get the prefixed database key form
 636          * @return \type{\string} the prefixed title, with underscores and
 637          *      any interwiki and namespace prefixes
 638          */
 639         public function getPrefixedDBkey() {
 640                 $s = $this->prefix( $this->mDbkeyform );
 641                 $s = str_replace( ' ', '_', $s );
 642                 return $s;
 643         }
 644
 645         /**
 646          * Get the prefixed title with spaces.
 647          * This is the form usually used for display
 648          * @return \type{\string} the prefixed title, with spaces
 649          */
 650         public function getPrefixedText() {
 651                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 652                         $s = $this->prefix( $this->mTextform );
 653                         $s = str_replace( '_', ' ', $s );
 654                         $this->mPrefixedText = $s;
 655                 }
 656                 return $this->mPrefixedText;
 657         }
 658
 659         /**
 660          * Get the prefixed title with spaces, plus any fragment
 661          * (part beginning with '#')
 662          * @return \type{\string} the prefixed title, with spaces and
 663          *      the fragment, including '#'
 664          */
 665         public function getFullText() {
 666                 $text = $this->getPrefixedText();
 667                 if( '' != $this->mFragment ) {
 668                         $text .= '#' . $this->mFragment;
 669                 }
 670                 return $text;
 671         }
 672
 673         /**
 674          * Get the base name, i.e. the leftmost parts before the /
 675          * @return \type{\string} Base name
 676          */
 677         public function getBaseText() {
 678                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 679                         return $this->getText();
 680                 }
 681
 682                 $parts = explode( '/', $this->getText() );
 683                 # Don't discard the real title if there's no subpage involved
 684                 if( count( $parts ) > 1 )
 685                         unset( $parts[ count( $parts ) - 1 ] );
 686                 return implode( '/', $parts );
 687         }
 688
 689         /**
 690          * Get the lowest-level subpage name, i.e. the rightmost part after /
 691          * @return \type{\string} Subpage name
 692          */
 693         public function getSubpageText() {
 694                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 695                         return( $this->mTextform );
 696                 }
 697                 $parts = explode( '/', $this->mTextform );
 698                 return( $parts[ count( $parts ) - 1 ] );
 699         }
 700
 701         /**
 702          * Get a URL-encoded form of the subpage text
 703          * @return \type{\string} URL-encoded subpage name
 704          */
 705         public function getSubpageUrlForm() {
 706                 $text = $this->getSubpageText();
 707                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 708                 return( $text );
 709         }
 710
 711         /**
 712          * Get a URL-encoded title (not an actual URL) including interwiki
 713          * @return \type{\string} the URL-encoded form
 714          */
 715         public function getPrefixedURL() {
 716                 $s = $this->prefix( $this->mDbkeyform );
 717                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 718                 return $s;
 719         }
 720
 721         /**
 722          * Get a real URL referring to this title, with interwiki link and
 723          * fragment
 724          *
 725          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 726          *   links. Can be specified as an associative array as well, e.g.,
 727          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 728          * @param $variant \type{\string} language variant of url (for sr, zh..)
 729          * @return \type{\string} the URL
 730          */
 731         public function getFullURL( $query = '', $variant = false ) {
 732                 global $wgContLang, $wgServer, $wgRequest;
 733
 734                 if( is_array( $query ) ) {
 735                         $query = wfArrayToCGI( $query );
 736                 }
 737
 738                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 739                 if ( !$interwiki ) {
 740                         $url = $this->getLocalUrl( $query, $variant );
 741
 742                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 743                         // Correct fix would be to move the prepending elsewhere.
 744                         if ($wgRequest->getVal('action') != 'render') {
 745                                 $url = $wgServer . $url;
 746                         }
 747                 } else {
 748                         $baseUrl = $interwiki->getURL( );
 749
 750                         $namespace = wfUrlencode( $this->getNsText() );
 751                         if ( '' != $namespace ) {
 752                                 # Can this actually happen? Interwikis shouldn't be parsed.
 753                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 754                                 $namespace .= ':';
 755                         }
 756                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 757                         $url = wfAppendQuery( $url, $query );
 758                 }
 759
 760                 # Finally, add the fragment.
 761                 $url .= $this->getFragmentForURL();
 762
 763                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 764                 return $url;
 765         }
 766
 767         /**
 768          * Get a URL with no fragment or server name.  If this page is generated
 769          * with action=render, $wgServer is prepended.
 770          * @param mixed $query an optional query string; if not specified,
 771          *       $wgArticlePath will be used.  Can be specified as an associative array
 772          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 773          *   URL-escaped).
 774          * @param $variant \type{\string} language variant of url (for sr, zh..)
 775          * @return \type{\string} the URL
 776          */
 777         public function getLocalURL( $query = '', $variant = false ) {
 778                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 779                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 780
 781                 if( is_array( $query ) ) {
 782                         $query = wfArrayToCGI( $query );
 783                 }
 784
 785                 // internal links should point to same variant as current page (only anonymous users)
 786                 if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
 787                         $pref = $wgContLang->getPreferredVariant(false);
 788                         if($pref != $wgContLang->getCode())
 789                                 $variant = $pref;
 790                 }
 791
 792                 if ( $this->isExternal() ) {
 793                         $url = $this->getFullURL();
 794                         if ( $query ) {
 795                                 // This is currently only used for edit section links in the
 796                                 // context of interwiki transclusion. In theory we should
 797                                 // append the query to the end of any existing query string,
 798                                 // but interwiki transclusion is already broken in that case.
 799                                 $url .= "?$query";
 800                         }
 801                 } else {
 802                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 803                         if ( $query == '' ) {
 804                                 if( $variant != false && $wgContLang->hasVariants() ) {
 805                                         if( $wgVariantArticlePath == false ) {
 806                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 807                                         } else {
 808                                                 $variantArticlePath = $wgVariantArticlePath;
 809                                         }
 810                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 811                                         $url = str_replace( '$1', $dbkey, $url  );
 812                                 } else {
 813                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 814                                 }
 815                         } else {
 816                                 global $wgActionPaths;
 817                                 $url = false;
 818                                 $matches = array();
 819                                 if( !empty( $wgActionPaths ) &&
 820                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 821                                 {
 822                                         $action = urldecode( $matches[2] );
 823                                         if( isset( $wgActionPaths[$action] ) ) {
 824                                                 $query = $matches[1];
 825                                                 if( isset( $matches[4] ) ) $query .= $matches[4];
 826                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 827                                                 if( $query != '' ) {
 828                                                         $url = wfAppendQuery( $url, $query );
 829                                                 }
 830                                         }
 831                                 }
 832                                 if ( $url === false ) {
 833                                         if ( $query == '-' ) {
 834                                                 $query = '';
 835                                         }
 836                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 837                                 }
 838                         }
 839
 840                         // FIXME: this causes breakage in various places when we
 841                         // actually expected a local URL and end up with dupe prefixes.
 842                         if ($wgRequest->getVal('action') == 'render') {
 843                                 $url = $wgServer . $url;
 844                         }
 845                 }
 846                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 847                 return $url;
 848         }
 849
 850         /**
 851          * Get a URL that's the simplest URL that will be valid to link, locally,
 852          * to the current Title.  It includes the fragment, but does not include
 853          * the server unless action=render is used (or the link is external).  If
 854          * there's a fragment but the prefixed text is empty, we just return a link
 855          * to the fragment.
 856          *
 857          * The result obviously should not be URL-escaped, but does need to be
 858          * HTML-escaped if it's being output in HTML.
 859          *
 860          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 861          *   query string.  Keys and values will be escaped.
 862          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 863          *   for external links.  Default is "false" (same variant as current page,
 864          *   for anonymous users).
 865          * @return \type{\string} the URL
 866          */
 867         public function getLinkUrl( $query = array(), $variant = false ) {
 868                 wfProfileIn( __METHOD__ );
 869                 if( !is_array( $query ) ) {
 870                         wfProfileOut( __METHOD__ );
 871                         throw new MWException( 'Title::getLinkUrl passed a non-array for '.
 872                         '$query' );
 873                 }
 874                 if( $this->isExternal() ) {
 875                         $ret = $this->getFullURL( $query );
 876                 } elseif( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 877                         $ret = $this->getFragmentForURL();
 878                 } else {
 879                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 880                 }
 881                 wfProfileOut( __METHOD__ );
 882                 return $ret;
 883         }
 884
 885         /**
 886          * Get an HTML-escaped version of the URL form, suitable for
 887          * using in a link, without a server name or fragment
 888          * @param $query \type{\string} an optional query string
 889          * @return \type{\string} the URL
 890          */
 891         public function escapeLocalURL( $query = '' ) {
 892                 return htmlspecialchars( $this->getLocalURL( $query ) );
 893         }
 894
 895         /**
 896          * Get an HTML-escaped version of the URL form, suitable for
 897          * using in a link, including the server name and fragment
 898          *
 899          * @param $query \type{\string} an optional query string
 900          * @return \type{\string} the URL
 901          */
 902         public function escapeFullURL( $query = '' ) {
 903                 return htmlspecialchars( $this->getFullURL( $query ) );
 904         }
 905
 906         /**
 907          * Get the URL form for an internal link.
 908          * - Used in various Squid-related code, in case we have a different
 909          * internal hostname for the server from the exposed one.
 910          *
 911          * @param $query \type{\string} an optional query string
 912          * @param $variant \type{\string} language variant of url (for sr, zh..)
 913          * @return \type{\string} the URL
 914          */
 915         public function getInternalURL( $query = '', $variant = false ) {
 916                 global $wgInternalServer;
 917                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 918                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 919                 return $url;
 920         }
 921
 922         /**
 923          * Get the edit URL for this Title
 924          * @return \type{\string} the URL, or a null string if this is an
 925          *      interwiki link
 926          */
 927         public function getEditURL() {
 928                 if ( '' != $this->mInterwiki ) { return ''; }
 929                 $s = $this->getLocalURL( 'action=edit' );
 930
 931                 return $s;
 932         }
 933
 934         /**
 935          * Get the HTML-escaped displayable text form.
 936          * Used for the title field in <a> tags.
 937          * @return \type{\string} the text, including any prefixes
 938          */
 939         public function getEscapedText() {
 940                 return htmlspecialchars( $this->getPrefixedText() );
 941         }
 942
 943         /**
 944          * Is this Title interwiki?
 945          * @return \type{\bool}
 946          */
 947         public function isExternal() { return ( '' != $this->mInterwiki ); }
 948
 949         /**
 950          * Is this page "semi-protected" - the *only* protection is autoconfirm?
 951          *
 952          * @param @action \type{\string} Action to check (default: edit)
 953          * @return \type{\bool}
 954          */
 955         public function isSemiProtected( $action = 'edit' ) {
 956                 if( $this->exists() ) {
 957                         $restrictions = $this->getRestrictions( $action );
 958                         if( count( $restrictions ) > 0 ) {
 959                                 foreach( $restrictions as $restriction ) {
 960                                         if( strtolower( $restriction ) != 'autoconfirmed' )
 961                                                 return false;
 962                                 }
 963                         } else {
 964                                 # Not protected
 965                                 return false;
 966                         }
 967                         return true;
 968                 } else {
 969                         # If it doesn't exist, it can't be protected
 970                         return false;
 971                 }
 972         }
 973
 974         /**
 975          * Does the title correspond to a protected article?
 976          * @param $what \type{\string} the action the page is protected from,
 977          * by default checks move and edit
 978          * @return \type{\bool}
 979          */
 980         public function isProtected( $action = '' ) {
 981                 global $wgRestrictionLevels, $wgRestrictionTypes;
 982
 983                 # Special pages have inherent protection
 984                 if( $this->getNamespace() == NS_SPECIAL )
 985                         return true;
 986
 987                 # Check regular protection levels
 988                 foreach( $wgRestrictionTypes as $type ){
 989                         if( $action == $type || $action == '' ) {
 990                                 $r = $this->getRestrictions( $type );
 991                                 foreach( $wgRestrictionLevels as $level ) {
 992                                         if( in_array( $level, $r ) && $level != '' ) {
 993                                                 return true;
 994                                         }
 995                                 }
 996                         }
 997                 }
 998
 999                 return false;
1000         }
1001
1002         /**
1003          * Is $wgUser watching this page?
1004          * @return \type{\bool}
1005          */
1006         public function userIsWatching() {
1007                 global $wgUser;
1008
1009                 if ( is_null( $this->mWatched ) ) {
1010                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
1011                                 $this->mWatched = false;
1012                         } else {
1013                                 $this->mWatched = $wgUser->isWatched( $this );
1014                         }
1015                 }
1016                 return $this->mWatched;
1017         }
1018
1019         /**
1020          * Can $wgUser perform $action on this page?
1021          * This skips potentially expensive cascading permission checks
1022          * as well as avoids expensive error formatting
1023          *
1024          * Suitable for use for nonessential UI controls in common cases, but
1025          * _not_ for functional access control.
1026          *
1027          * May provide false positives, but should never provide a false negative.
1028          *
1029          * @param $action \type{\string} action that permission needs to be checked for
1030          * @return \type{\bool}
1031          */
1032         public function quickUserCan( $action ) {
1033                 return $this->userCan( $action, false );
1034         }
1035
1036         /**
1037          * Determines if $wgUser is unable to edit this page because it has been protected
1038          * by $wgNamespaceProtection.
1039          *
1040          * @return \type{\bool}
1041          */
1042         public function isNamespaceProtected() {
1043                 global $wgNamespaceProtection, $wgUser;
1044                 if( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1045                         foreach( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1046                                 if( $right != '' && !$wgUser->isAllowed( $right ) )
1047                                         return true;
1048                         }
1049                 }
1050                 return false;
1051         }
1052
1053         /**
1054          * Can $wgUser perform $action on this page?
1055          * @param $action \type{\string} action that permission needs to be checked for
1056          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1057          * @return \type{\bool}
1058          */
1059         public function userCan( $action, $doExpensiveQueries = true ) {
1060                 global $wgUser;
1061                 return ($this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array());
1062         }
1063
1064         /**
1065          * Can $user perform $action on this page?
1066          *
1067          * FIXME: This *does not* check throttles (User::pingLimiter()).
1068          *
1069          * @param $action \type{\string}action that permission needs to be checked for
1070          * @param $user \type{User} user to check
1071          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1072          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1073          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1074          */
1075         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1076                 if( !StubObject::isRealObject( $user ) ) {
1077                         //Since StubObject is always used on globals, we can unstub $wgUser here and set $user = $wgUser
1078                         global $wgUser;
1079                         $wgUser->_unstub( '', 5 );
1080                         $user = $wgUser;
1081                 }
1082                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1083
1084                 global $wgContLang;
1085                 global $wgLang;
1086                 global $wgEmailConfirmToEdit;
1087
1088                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1089                         $errors[] = array( 'confirmedittext' );
1090                 }
1091
1092                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1093                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1094                         $block = $user->mBlock;
1095
1096                         // This is from OutputPage::blockedPage
1097                         // Copied at r23888 by werdna
1098
1099                         $id = $user->blockedBy();
1100                         $reason = $user->blockedFor();
1101                         if( $reason == '' ) {
1102                                 $reason = wfMsg( 'blockednoreason' );
1103                         }
1104                         $ip = wfGetIP();
1105
1106                         if ( is_numeric( $id ) ) {
1107                                 $name = User::whoIs( $id );
1108                         } else {
1109                                 $name = $id;
1110                         }
1111
1112                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1113                         $blockid = $block->mId;
1114                         $blockExpiry = $user->mBlock->mExpiry;
1115                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1116
1117                         if ( $blockExpiry == 'infinity' ) {
1118                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1119                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1120
1121                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1122                                         if ( strpos( $option, ':' ) == false )
1123                                                 continue;
1124
1125                                         list ($show, $value) = explode( ":", $option );
1126
1127                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1128                                                 $blockExpiry = $show;
1129                                                 break;
1130                                         }
1131                                 }
1132                         } else {
1133                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1134                         }
1135
1136                         $intended = $user->mBlock->mAddress;
1137
1138                         $errors[] = array( ($block->mAuto ? 'autoblockedtext' : 'blockedtext'), $link, $reason, $ip, $name,
1139                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1140                 }
1141
1142                 // Remove the errors being ignored.
1143
1144                 foreach( $errors as $index => $error ) {
1145                         $error_key = is_array($error) ? $error[0] : $error;
1146
1147                         if (in_array( $error_key, $ignoreErrors )) {
1148                                 unset($errors[$index]);
1149                         }
1150                 }
1151
1152                 return $errors;
1153         }
1154
1155         /**
1156          * Can $user perform $action on this page? This is an internal function,
1157          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1158          * checks on wfReadOnly() and blocks)
1159          *
1160          * @param $action \type{\string} action that permission needs to be checked for
1161          * @param $user \type{User} user to check
1162          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1163          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1164          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1165          */
1166         private function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries=true, $short=false ) {
1167                 wfProfileIn( __METHOD__ );
1168
1169                 $errors = array();
1170
1171                 // First stop is permissions checks, which fail most often, and which are easiest to test.
1172                 if ( $action == 'move' ) {
1173                         if( !$user->isAllowed( 'move-rootuserpages' )
1174                                         && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1175                         {
1176                                 // Show user page-specific message only if the user can move other pages
1177                                 $errors[] = array( 'cant-move-user-page' );
1178                         }
1179
1180                         // Check if user is allowed to move files if it's a file
1181                         if( $this->getNamespace() == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1182                                 $errors[] = array( 'movenotallowedfile' );
1183                         }
1184
1185                         if( !$user->isAllowed( 'move' ) ) {
1186                                 // User can't move anything
1187                                 $errors[] = $user->isAnon() ? array ( 'movenologintext' ) : array ('movenotallowed');
1188                         }
1189                 } elseif ( $action == 'create' ) {
1190                         if( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1191                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) )
1192                         {
1193                                 $errors[] = $user->isAnon() ? array ('nocreatetext') : array ('nocreate-loggedin');
1194                         }
1195                 } elseif( $action == 'move-target' ) {
1196                         if( !$user->isAllowed( 'move' ) ) {
1197                                 // User can't move anything
1198                                 $errors[] = $user->isAnon() ? array ( 'movenologintext' ) : array ('movenotallowed');
1199                         } elseif( !$user->isAllowed( 'move-rootuserpages' )
1200                                 && $this->getNamespace() == NS_USER && !$this->isSubpage() )
1201                         {
1202                                 // Show user page-specific message only if the user can move other pages
1203                                 $errors[] = array( 'cant-move-to-user-page' );
1204                         }
1205                 } elseif( !$user->isAllowed( $action ) ) {
1206                         $return = null;
1207
1208                         // We avoid expensive display logic for quickUserCan's and such
1209                         $groups = false;
1210                         if (!$short) {
1211                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1212                                         User::getGroupsWithPermission( $action ) );
1213                         }
1214
1215                         if( $groups ) {
1216                                 $return = array( 'badaccess-groups',
1217                                         array( implode( ', ', $groups ), count( $groups ) ) );
1218                         } else {
1219                                 $return = array( "badaccess-group0" );
1220                         }
1221                         $errors[] = $return;
1222                 }
1223
1224                 # Short-circuit point
1225                 if( $short && count($errors) > 0 ) {
1226                         wfProfileOut( __METHOD__ );
1227                         return $errors;
1228                 }
1229
1230                 // Use getUserPermissionsErrors instead
1231                 if( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1232                         wfProfileOut( __METHOD__ );
1233                         return $result ? array() : array( array( 'badaccess-group0' ) );
1234                 }
1235                 // Check getUserPermissionsErrors hook
1236                 if( !wfRunHooks( 'getUserPermissionsErrors', array(&$this,&$user,$action,&$result) ) ) {
1237                         if( is_array($result) && count($result) && !is_array($result[0]) )
1238                                 $errors[] = $result; # A single array representing an error
1239                         else if( is_array($result) && is_array($result[0]) )
1240                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1241                         else if( $result !== '' && is_string($result) )
1242                                 $errors[] = array($result); # A string representing a message-id
1243                         else if( $result === false )
1244                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1245                 }
1246                 # Short-circuit point
1247                 if( $short && count($errors) > 0 ) {
1248                         wfProfileOut( __METHOD__ );
1249                         return $errors;
1250                 }
1251                 // Check getUserPermissionsErrorsExpensive hook
1252                 if( $doExpensiveQueries && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array(&$this,&$user,$action,&$result) ) ) {
1253                         if( is_array($result) && count($result) && !is_array($result[0]) )
1254                                 $errors[] = $result; # A single array representing an error
1255                         else if( is_array($result) && is_array($result[0]) )
1256                                 $errors = array_merge( $errors, $result ); # A nested array representing multiple errors
1257                         else if( $result !== '' && is_string($result) )
1258                                 $errors[] = array($result); # A string representing a message-id
1259                         else if( $result === false )
1260                                 $errors[] = array('badaccess-group0'); # a generic "We don't want them to do that"
1261                 }
1262                 # Short-circuit point
1263                 if( $short && count($errors) > 0 ) {
1264                         wfProfileOut( __METHOD__ );
1265                         return $errors;
1266                 }
1267
1268                 # Only 'createaccount' and 'execute' can be performed on
1269                 # special pages, which don't actually exist in the DB.
1270                 $specialOKActions = array( 'createaccount', 'execute' );
1271                 if( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions) ) {
1272                         $errors[] = array('ns-specialprotected');
1273                 }
1274
1275                 # Check $wgNamespaceProtection for restricted namespaces
1276                 if( $this->isNamespaceProtected() ) {
1277                         $ns = $this->getNamespace() == NS_MAIN ?
1278                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1279                         $errors[] = NS_MEDIAWIKI == $this->mNamespace ?
1280                                 array('protectedinterface') : array( 'namespaceprotected',  $ns );
1281                 }
1282
1283                 # Protect css/js subpages of user pages
1284                 # XXX: this might be better using restrictions
1285                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
1286                 if( $this->isCssJsSubpage() && !$user->isAllowed('editusercssjs')
1287                         && !preg_match('/^'.preg_quote($user->getName(), '/').'\//', $this->mTextform) )
1288                 {
1289                         $errors[] = array('customcssjsprotected');
1290                 }
1291
1292                 # Check against page_restrictions table requirements on this
1293                 # page. The user must possess all required rights for this action.
1294                 foreach( $this->getRestrictions($action) as $right ) {
1295                         // Backwards compatibility, rewrite sysop -> protect
1296                         if( $right == 'sysop' ) {
1297                                 $right = 'protect';
1298                         }
1299                         if( '' != $right && !$user->isAllowed( $right ) ) {
1300                                 // Users with 'editprotected' permission can edit protected pages
1301                                 if( $action=='edit' && $user->isAllowed( 'editprotected' ) ) {
1302                                         // Users with 'editprotected' permission cannot edit protected pages
1303                                         // with cascading option turned on.
1304                                         if( $this->mCascadeRestriction ) {
1305                                                 $errors[] = array( 'protectedpagetext', $right );
1306                                         }
1307                                 } else {
1308                                         $errors[] = array( 'protectedpagetext', $right );
1309                                 }
1310                         }
1311                 }
1312                 # Short-circuit point
1313                 if( $short && count($errors) > 0 ) {
1314                         wfProfileOut( __METHOD__ );
1315                         return $errors;
1316                 }
1317
1318                 if( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1319                         # We /could/ use the protection level on the source page, but it's fairly ugly
1320                         #  as we have to establish a precedence hierarchy for pages included by multiple
1321                         #  cascade-protected pages. So just restrict it to people with 'protect' permission,
1322                         #  as they could remove the protection anyway.
1323                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1324                         # Cascading protection depends on more than this page...
1325                         # Several cascading protected pages may include this page...
1326                         # Check each cascading level
1327                         # This is only for protection restrictions, not for all actions
1328                         if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
1329                                 foreach( $restrictions[$action] as $right ) {
1330                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1331                                         if( '' != $right && !$user->isAllowed( $right ) ) {
1332                                                 $pages = '';
1333                                                 foreach( $cascadingSources as $page )
1334                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1335                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1336                                         }
1337                                 }
1338                         }
1339                 }
1340                 # Short-circuit point
1341                 if( $short && count($errors) > 0 ) {
1342                         wfProfileOut( __METHOD__ );
1343                         return $errors;
1344                 }
1345
1346                 if( $action == 'protect' ) {
1347                         if( $this->getUserPermissionsErrors('edit', $user) != array() ) {
1348                                 $errors[] = array( 'protect-cantedit' ); // If they can't edit, they shouldn't protect.
1349                         }
1350                 }
1351
1352                 if( $action == 'create' ) {
1353                         $title_protection = $this->getTitleProtection();
1354                         if( is_array($title_protection) ) {
1355                                 extract($title_protection); // is this extract() really needed?
1356
1357                                 if( $pt_create_perm == 'sysop' ) {
1358                                         $pt_create_perm = 'protect'; // B/C
1359                                 }
1360                                 if( $pt_create_perm == '' || !$user->isAllowed($pt_create_perm) ) {
1361                                         $errors[] = array( 'titleprotected', User::whoIs($pt_user), $pt_reason );
1362                                 }
1363                         }
1364                 } elseif( $action == 'move' ) {
1365                         // Check for immobile pages
1366                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1367                                 // Specific message for this case
1368                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1369                         } elseif( !$this->isMovable() ) {
1370                                 // Less specific message for rarer cases
1371                                 $errors[] = array( 'immobile-page' );
1372                         }
1373                 } elseif( $action == 'move-target' ) {
1374                         if( !MWNamespace::isMovable( $this->getNamespace() ) ) {
1375                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1376                         } elseif( !$this->isMovable() ) {
1377                                 $errors[] = array( 'immobile-target-page' );
1378                         }
1379                 }
1380
1381                 wfProfileOut( __METHOD__ );
1382                 return $errors;
1383         }
1384
1385         /**
1386          * Is this title subject to title protection?
1387          * @return \type{\mixed} An associative array representing any existent title
1388          *   protection, or false if there's none.
1389          */
1390         private function getTitleProtection() {
1391                 // Can't protect pages in special namespaces
1392                 if ( $this->getNamespace() < 0 ) {
1393                         return false;
1394                 }
1395
1396                 $dbr = wfGetDB( DB_SLAVE );
1397                 $res = $dbr->select( 'protected_titles', '*',
1398                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1399                         __METHOD__ );
1400
1401                 if ($row = $dbr->fetchRow( $res )) {
1402                         return $row;
1403                 } else {
1404                         return false;
1405                 }
1406         }
1407
1408         /**
1409          * Update the title protection status
1410          * @param $create_perm \type{\string} Permission required for creation
1411          * @param $reason \type{\string} Reason for protection
1412          * @param $expiry \type{\string} Expiry timestamp
1413          */
1414         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1415                 global $wgUser,$wgContLang;
1416
1417                 if ($create_perm == implode(',',$this->getRestrictions('create'))
1418                         && $expiry == $this->mRestrictionsExpiry['create']) {
1419                         // No change
1420                         return true;
1421                 }
1422
1423                 list ($namespace, $title) = array( $this->getNamespace(), $this->getDBkey() );
1424
1425                 $dbw = wfGetDB( DB_MASTER );
1426
1427                 $encodedExpiry = Block::encodeExpiry($expiry, $dbw );
1428
1429                 $expiry_description = '';
1430                 if ( $encodedExpiry != 'infinity' ) {
1431                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ) , $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ).')';
1432                 }
1433                 else {
1434                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ).')';
1435                 }
1436
1437                 # Update protection table
1438                 if ($create_perm != '' ) {
1439                         $dbw->replace( 'protected_titles', array(array('pt_namespace', 'pt_title')),
1440                                 array( 'pt_namespace' => $namespace, 'pt_title' => $title
1441                                         , 'pt_create_perm' => $create_perm
1442                                         , 'pt_timestamp' => Block::encodeExpiry(wfTimestampNow(), $dbw)
1443                                         , 'pt_expiry' => $encodedExpiry
1444                                         , 'pt_user' => $wgUser->getId(), 'pt_reason' => $reason ), __METHOD__  );
1445                 } else {
1446                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1447                                 'pt_title' => $title ), __METHOD__ );
1448                 }
1449                 # Update the protection log
1450                 $log = new LogPage( 'protect' );
1451
1452                 if( $create_perm ) {
1453                         $params = array("[create=$create_perm] $expiry_description",'');
1454                         $log->addEntry( $this->mRestrictions['create'] ? 'modify' : 'protect', $this, trim( $reason ), $params );
1455                 } else {
1456                         $log->addEntry( 'unprotect', $this, $reason );
1457                 }
1458
1459                 return true;
1460         }
1461
1462         /**
1463          * Remove any title protection due to page existing
1464          */
1465         public function deleteTitleProtection() {
1466                 $dbw = wfGetDB( DB_MASTER );
1467
1468                 $dbw->delete( 'protected_titles',
1469                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1470                         __METHOD__ );
1471         }
1472
1473         /**
1474          * Can $wgUser edit this page?
1475          * @return \type{\bool} TRUE or FALSE
1476          * @deprecated use userCan('edit')
1477          */
1478         public function userCanEdit( $doExpensiveQueries = true ) {
1479                 return $this->userCan( 'edit', $doExpensiveQueries );
1480         }
1481
1482         /**
1483          * Can $wgUser create this page?
1484          * @return \type{\bool} TRUE or FALSE
1485          * @deprecated use userCan('create')
1486          */
1487         public function userCanCreate( $doExpensiveQueries = true ) {
1488                 return $this->userCan( 'create', $doExpensiveQueries );
1489         }
1490
1491         /**
1492          * Can $wgUser move this page?
1493          * @return \type{\bool} TRUE or FALSE
1494          * @deprecated use userCan('move')
1495          */
1496         public function userCanMove( $doExpensiveQueries = true ) {
1497                 return $this->userCan( 'move', $doExpensiveQueries );
1498         }
1499
1500         /**
1501          * Would anybody with sufficient privileges be able to move this page?
1502          * Some pages just aren't movable.
1503          *
1504          * @return \type{\bool} TRUE or FALSE
1505          */
1506         public function isMovable() {
1507                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1508         }
1509
1510         /**
1511          * Can $wgUser read this page?
1512          * @return \type{\bool} TRUE or FALSE
1513          * @todo fold these checks into userCan()
1514          */
1515         public function userCanRead() {
1516                 global $wgUser, $wgGroupPermissions;
1517
1518                 $result = null;
1519                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1520                 if ( $result !== null ) {
1521                         return $result;
1522                 }
1523
1524                 # Shortcut for public wikis, allows skipping quite a bit of code
1525                 if ( !empty( $wgGroupPermissions['*']['read'] ) )
1526                         return true;
1527
1528                 if( $wgUser->isAllowed( 'read' ) ) {
1529                         return true;
1530                 } else {
1531                         global $wgWhitelistRead;
1532
1533                         /**
1534                          * Always grant access to the login page.
1535                          * Even anons need to be able to log in.
1536                         */
1537                         if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1538                                 return true;
1539                         }
1540
1541                         /**
1542                          * Bail out if there isn't whitelist
1543                          */
1544                         if( !is_array($wgWhitelistRead) ) {
1545                                 return false;
1546                         }
1547
1548                         /**
1549                          * Check for explicit whitelisting
1550                          */
1551                         $name = $this->getPrefixedText();
1552                         $dbName = $this->getPrefixedDBKey();
1553                         // Check with and without underscores
1554                         if( in_array($name,$wgWhitelistRead,true) || in_array($dbName,$wgWhitelistRead,true) )
1555                                 return true;
1556
1557                         /**
1558                          * Old settings might have the title prefixed with
1559                          * a colon for main-namespace pages
1560                          */
1561                         if( $this->getNamespace() == NS_MAIN ) {
1562                                 if( in_array( ':' . $name, $wgWhitelistRead ) )
1563                                         return true;
1564                         }
1565
1566                         /**
1567                          * If it's a special page, ditch the subpage bit
1568                          * and check again
1569                          */
1570                         if( $this->getNamespace() == NS_SPECIAL ) {
1571                                 $name = $this->getDBkey();
1572                                 list( $name, /* $subpage */) = SpecialPage::resolveAliasWithSubpage( $name );
1573                                 if ( $name === false ) {
1574                                         # Invalid special page, but we show standard login required message
1575                                         return false;
1576                                 }
1577
1578                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1579                                 if( in_array( $pure, $wgWhitelistRead, true ) )
1580                                         return true;
1581                         }
1582
1583                 }
1584                 return false;
1585         }
1586
1587         /**
1588          * Is this a talk page of some sort?
1589          * @return \type{\bool} TRUE or FALSE
1590          */
1591         public function isTalkPage() {
1592                 return MWNamespace::isTalk( $this->getNamespace() );
1593         }
1594
1595         /**
1596          * Is this a subpage?
1597          * @return \type{\bool} TRUE or FALSE
1598          */
1599         public function isSubpage() {
1600                 return MWNamespace::hasSubpages( $this->mNamespace )
1601                         ? strpos( $this->getText(), '/' ) !== false
1602                         : false;
1603         }
1604
1605         /**
1606          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1607          * @return \type{\bool} TRUE or FALSE
1608          */
1609         public function hasSubpages() {
1610                 if( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1611                         # Duh
1612                         return false;
1613                 }
1614
1615                 # We dynamically add a member variable for the purpose of this method
1616                 # alone to cache the result.  There's no point in having it hanging
1617                 # around uninitialized in every Title object; therefore we only add it
1618                 # if needed and don't declare it statically.
1619                 if( isset( $this->mHasSubpages ) ) {
1620                         return $this->mHasSubpages;
1621                 }
1622
1623                 $subpages = $this->getSubpages( 1 );
1624                 if( $subpages instanceof TitleArray )
1625                         return $this->mHasSubpages = (bool)$subpages->count();
1626                 return $this->mHasSubpages = false;
1627         }
1628
1629         /**
1630          * Get all subpages of this page.
1631          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1632          * @return mixed TitleArray, or empty array if this page's namespace
1633          *  doesn't allow subpages
1634          */
1635         public function getSubpages( $limit = -1 ) {
1636                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1637                         return array();
1638
1639                 $dbr = wfGetDB( DB_SLAVE );
1640                 $conds['page_namespace'] = $this->getNamespace();
1641                 $conds[] = 'page_title LIKE ' . $dbr->addQuotes(
1642                                 $dbr->escapeLike( $this->getDBkey() ) . '/%' );
1643                 $options = array();
1644                 if( $limit > -1 )
1645                         $options['LIMIT'] = $limit;
1646                 return $this->mSubpages = TitleArray::newFromResult(
1647                         $dbr->select( 'page',
1648                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1649                                 $conds,
1650                                 __METHOD__,
1651                                 $options
1652                         )
1653                 );
1654         }
1655
1656         /**
1657          * Could this page contain custom CSS or JavaScript, based
1658          * on the title?
1659          *
1660          * @return \type{\bool} TRUE or FALSE
1661          */
1662         public function isCssOrJsPage() {
1663                 return $this->mNamespace == NS_MEDIAWIKI
1664                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1665         }
1666
1667         /**
1668          * Is this a .css or .js subpage of a user page?
1669          * @return \type{\bool} TRUE or FALSE
1670          */
1671         public function isCssJsSubpage() {
1672                 return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1673         }
1674         /**
1675          * Is this a *valid* .css or .js subpage of a user page?
1676          * Check that the corresponding skin exists
1677          * @return \type{\bool} TRUE or FALSE
1678          */
1679         public function isValidCssJsSubpage() {
1680                 if ( $this->isCssJsSubpage() ) {
1681                         $skinNames = Skin::getSkinNames();
1682                         return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
1683                 } else {
1684                         return false;
1685                 }
1686         }
1687         /**
1688          * Trim down a .css or .js subpage title to get the corresponding skin name
1689          */
1690         public function getSkinFromCssJsSubpage() {
1691                 $subpage = explode( '/', $this->mTextform );
1692                 $subpage = $subpage[ count( $subpage ) - 1 ];
1693                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1694         }
1695         /**
1696          * Is this a .css subpage of a user page?
1697          * @return \type{\bool} TRUE or FALSE
1698          */
1699         public function isCssSubpage() {
1700                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.css$/", $this->mTextform ) );
1701         }
1702         /**
1703          * Is this a .js subpage of a user page?
1704          * @return \type{\bool} TRUE or FALSE
1705          */
1706         public function isJsSubpage() {
1707                 return ( NS_USER == $this->mNamespace && preg_match("/\\/.*\\.js$/", $this->mTextform ) );
1708         }
1709         /**
1710          * Protect css/js subpages of user pages: can $wgUser edit
1711          * this page?
1712          *
1713          * @return \type{\bool} TRUE or FALSE
1714          * @todo XXX: this might be better using restrictions
1715          */
1716         public function userCanEditCssJsSubpage() {
1717                 global $wgUser;
1718                 return ( $wgUser->isAllowed('editusercssjs') || preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
1719         }
1720
1721         /**
1722          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1723          *
1724          * @return \type{\bool} If the page is subject to cascading restrictions.
1725          */
1726         public function isCascadeProtected() {
1727                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1728                 return ( $sources > 0 );
1729         }
1730
1731         /**
1732          * Cascading protection: Get the source of any cascading restrictions on this page.
1733          *
1734          * @param $get_pages \type{\bool} Whether or not to retrieve the actual pages that the restrictions have come from.
1735          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title objects of the pages from
1736          *         which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
1737          *         The restriction array is an array of each type, each of which contains an array of unique groups.
1738          */
1739         public function getCascadeProtectionSources( $get_pages = true ) {
1740                 global $wgRestrictionTypes;
1741
1742                 # Define our dimension of restrictions types
1743                 $pagerestrictions = array();
1744                 foreach( $wgRestrictionTypes as $action )
1745                         $pagerestrictions[$action] = array();
1746
1747                 if ( isset( $this->mCascadeSources ) && $get_pages ) {
1748                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1749                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
1750                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1751                 }
1752
1753                 wfProfileIn( __METHOD__ );
1754
1755                 $dbr = wfGetDB( DB_SLAVE );
1756
1757                 if ( $this->getNamespace() == NS_FILE ) {
1758                         $tables = array ('imagelinks', 'page_restrictions');
1759                         $where_clauses = array(
1760                                 'il_to' => $this->getDBkey(),
1761                                 'il_from=pr_page',
1762                                 'pr_cascade' => 1 );
1763                 } else {
1764                         $tables = array ('templatelinks', 'page_restrictions');
1765                         $where_clauses = array(
1766                                 'tl_namespace' => $this->getNamespace(),
1767                                 'tl_title' => $this->getDBkey(),
1768                                 'tl_from=pr_page',
1769                                 'pr_cascade' => 1 );
1770                 }
1771
1772                 if ( $get_pages ) {
1773                         $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
1774                         $where_clauses[] = 'page_id=pr_page';
1775                         $tables[] = 'page';
1776                 } else {
1777                         $cols = array( 'pr_expiry' );
1778                 }
1779
1780                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1781
1782                 $sources = $get_pages ? array() : false;
1783                 $now = wfTimestampNow();
1784                 $purgeExpired = false;
1785
1786                 foreach( $res as $row ) {
1787                         $expiry = Block::decodeExpiry( $row->pr_expiry );
1788                         if( $expiry > $now ) {
1789                                 if ($get_pages) {
1790                                         $page_id = $row->pr_page;
1791                                         $page_ns = $row->page_namespace;
1792                                         $page_title = $row->page_title;
1793                                         $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
1794                                         # Add groups needed for each restriction type if its not already there
1795                                         # Make sure this restriction type still exists
1796                                         if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
1797                                                 $pagerestrictions[$row->pr_type][]=$row->pr_level;
1798                                         }
1799                                 } else {
1800                                         $sources = true;
1801                                 }
1802                         } else {
1803                                 // Trigger lazy purge of expired restrictions from the db
1804                                 $purgeExpired = true;
1805                         }
1806                 }
1807                 if( $purgeExpired ) {
1808                         Title::purgeExpiredRestrictions();
1809                 }
1810
1811                 wfProfileOut( __METHOD__ );
1812
1813                 if ( $get_pages ) {
1814                         $this->mCascadeSources = $sources;
1815                         $this->mCascadingRestrictions = $pagerestrictions;
1816                 } else {
1817                         $this->mHasCascadingRestrictions = $sources;
1818                 }
1819                 return array( $sources, $pagerestrictions );
1820         }
1821
1822         function areRestrictionsCascading() {
1823                 if (!$this->mRestrictionsLoaded) {
1824                         $this->loadRestrictions();
1825                 }
1826
1827                 return $this->mCascadeRestriction;
1828         }
1829
1830         /**
1831          * Loads a string into mRestrictions array
1832          * @param $res \type{Resource} restrictions as an SQL result.
1833          */
1834         private function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
1835                 global $wgRestrictionTypes;
1836                 $dbr = wfGetDB( DB_SLAVE );
1837
1838                 foreach( $wgRestrictionTypes as $type ){
1839                         $this->mRestrictions[$type] = array();
1840                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry('');
1841                 }
1842
1843                 $this->mCascadeRestriction = false;
1844
1845                 # Backwards-compatibility: also load the restrictions from the page record (old format).
1846
1847                 if ( $oldFashionedRestrictions === NULL ) {
1848                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
1849                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
1850                 }
1851
1852                 if ($oldFashionedRestrictions != '') {
1853
1854                         foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
1855                                 $temp = explode( '=', trim( $restrict ) );
1856                                 if(count($temp) == 1) {
1857                                         // old old format should be treated as edit/move restriction
1858                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
1859                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
1860                                 } else {
1861                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
1862                                 }
1863                         }
1864
1865                         $this->mOldRestrictions = true;
1866
1867                 }
1868
1869                 if( $dbr->numRows( $res ) ) {
1870                         # Current system - load second to make them override.
1871                         $now = wfTimestampNow();
1872                         $purgeExpired = false;
1873
1874                         foreach( $res as $row ) {
1875                                 # Cycle through all the restrictions.
1876
1877                                 // Don't take care of restrictions types that aren't in $wgRestrictionTypes
1878                                 if( !in_array( $row->pr_type, $wgRestrictionTypes ) )
1879                                         continue;
1880
1881                                 // This code should be refactored, now that it's being used more generally,
1882                                 // But I don't really see any harm in leaving it in Block for now -werdna
1883                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
1884
1885                                 // Only apply the restrictions if they haven't expired!
1886                                 if ( !$expiry || $expiry > $now ) {
1887                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
1888                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
1889
1890                                         $this->mCascadeRestriction |= $row->pr_cascade;
1891                                 } else {
1892                                         // Trigger a lazy purge of expired restrictions
1893                                         $purgeExpired = true;
1894                                 }
1895                         }
1896
1897                         if( $purgeExpired ) {
1898                                 Title::purgeExpiredRestrictions();
1899                         }
1900                 }
1901
1902                 $this->mRestrictionsLoaded = true;
1903         }
1904
1905         /**
1906          * Load restrictions from the page_restrictions table
1907          */
1908         public function loadRestrictions( $oldFashionedRestrictions = NULL ) {
1909                 if( !$this->mRestrictionsLoaded ) {
1910                         if ($this->exists()) {
1911                                 $dbr = wfGetDB( DB_SLAVE );
1912
1913                                 $res = $dbr->select( 'page_restrictions', '*',
1914                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
1915
1916                                 $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
1917                         } else {
1918                                 $title_protection = $this->getTitleProtection();
1919
1920                                 if (is_array($title_protection)) {
1921                                         extract($title_protection);
1922
1923                                         $now = wfTimestampNow();
1924                                         $expiry = Block::decodeExpiry($pt_expiry);
1925
1926                                         if (!$expiry || $expiry > $now) {
1927                                                 // Apply the restrictions
1928                                                 $this->mRestrictionsExpiry['create'] = $expiry;
1929                                                 $this->mRestrictions['create'] = explode(',', trim($pt_create_perm) );
1930                                         } else { // Get rid of the old restrictions
1931                                                 Title::purgeExpiredRestrictions();
1932                                         }
1933                                 } else {
1934                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry('');
1935                                 }
1936                                 $this->mRestrictionsLoaded = true;
1937                         }
1938                 }
1939         }
1940
1941         /**
1942          * Purge expired restrictions from the page_restrictions table
1943          */
1944         static function purgeExpiredRestrictions() {
1945                 $dbw = wfGetDB( DB_MASTER );
1946                 $dbw->delete( 'page_restrictions',
1947                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1948                         __METHOD__ );
1949
1950                 $dbw->delete( 'protected_titles',
1951                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
1952                         __METHOD__ );
1953         }
1954
1955         /**
1956          * Accessor/initialisation for mRestrictions
1957          *
1958          * @param $action \type{\string} action that permission needs to be checked for
1959          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
1960          */
1961         public function getRestrictions( $action ) {
1962                 if( !$this->mRestrictionsLoaded ) {
1963                         $this->loadRestrictions();
1964                 }
1965                 return isset( $this->mRestrictions[$action] )
1966                                 ? $this->mRestrictions[$action]
1967                                 : array();
1968         }
1969
1970         /**
1971          * Get the expiry time for the restriction against a given action
1972          * @return 14-char timestamp, or 'infinity' if the page is protected forever
1973          * or not protected at all, or false if the action is not recognised.
1974          */
1975         public function getRestrictionExpiry( $action ) {
1976                 if( !$this->mRestrictionsLoaded ) {
1977                         $this->loadRestrictions();
1978                 }
1979                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
1980         }
1981
1982         /**
1983          * Is there a version of this page in the deletion archive?
1984          * @return \type{\int} the number of archived revisions
1985          */
1986         public function isDeleted() {
1987                 if( $this->getNamespace() < 0 ) {
1988                         $n = 0;
1989                 } else {
1990                         $dbr = wfGetDB( DB_SLAVE );
1991                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
1992                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
1993                                 __METHOD__
1994                         );
1995                         if( $this->getNamespace() == NS_FILE ) {
1996                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
1997                                         array( 'fa_name' => $this->getDBkey() ),
1998                                         __METHOD__
1999                                 );
2000                         }
2001                 }
2002                 return (int)$n;
2003         }
2004
2005         /**
2006          * Is there a version of this page in the deletion archive?
2007          * @return bool
2008          */
2009         public function isDeletedQuick() {
2010                 if( $this->getNamespace() < 0 ) {
2011                         return false;
2012                 }
2013                 $dbr = wfGetDB( DB_SLAVE );
2014                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2015                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2016                         __METHOD__
2017                 );
2018                 if( !$deleted && $this->getNamespace() == NS_FILE ) {
2019                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2020                                 array( 'fa_name' => $this->getDBkey() ),
2021                                 __METHOD__
2022                         );
2023                 }
2024                 return $deleted;
2025         }
2026
2027         /**
2028          * Get the article ID for this Title from the link cache,
2029          * adding it if necessary
2030          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2031          *      for update
2032          * @return \type{\int} the ID
2033          */
2034         public function getArticleID( $flags = 0 ) {
2035                 if( $this->getNamespace() < 0 ) {
2036                         return $this->mArticleID = 0;
2037                 }
2038                 $linkCache = LinkCache::singleton();
2039                 if( $flags & GAID_FOR_UPDATE ) {
2040                         $oldUpdate = $linkCache->forUpdate( true );
2041                         $linkCache->clearLink( $this );
2042                         $this->mArticleID = $linkCache->addLinkObj( $this );
2043                         $linkCache->forUpdate( $oldUpdate );
2044                 } else {
2045                         if( -1 == $this->mArticleID ) {
2046                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2047                         }
2048                 }
2049                 return $this->mArticleID;
2050         }
2051
2052         /**
2053          * Is this an article that is a redirect page?
2054          * Uses link cache, adding it if necessary
2055          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2056          * @return \type{\bool}
2057          */
2058         public function isRedirect( $flags = 0 ) {
2059                 if( !is_null($this->mRedirect) )
2060                         return $this->mRedirect;
2061                 # Calling getArticleID() loads the field from cache as needed
2062                 if( !$this->getArticleID($flags) ) {
2063                         return $this->mRedirect = false;
2064                 }
2065                 $linkCache = LinkCache::singleton();
2066                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2067
2068                 return $this->mRedirect;
2069         }
2070
2071         /**
2072          * What is the length of this page?
2073          * Uses link cache, adding it if necessary
2074          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2075          * @return \type{\bool}
2076          */
2077         public function getLength( $flags = 0 ) {
2078                 if( $this->mLength != -1 )
2079                         return $this->mLength;
2080                 # Calling getArticleID() loads the field from cache as needed
2081                 if( !$this->getArticleID($flags) ) {
2082                         return $this->mLength = 0;
2083                 }
2084                 $linkCache = LinkCache::singleton();
2085                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2086
2087                 return $this->mLength;
2088         }
2089
2090         /**
2091          * What is the page_latest field for this page?
2092          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2093          * @return \type{\int}
2094          */
2095         public function getLatestRevID( $flags = 0 ) {
2096                 if( $this->mLatestID !== false )
2097                         return $this->mLatestID;
2098
2099                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB(DB_MASTER) : wfGetDB(DB_SLAVE);
2100                 $this->mLatestID = $db->selectField( 'page', 'page_latest', $this->pageCond(), __METHOD__ );
2101                 return $this->mLatestID;
2102         }
2103
2104         /**
2105          * This clears some fields in this object, and clears any associated
2106          * keys in the "bad links" section of the link cache.
2107          *
2108          * - This is called from Article::insertNewArticle() to allow
2109          * loading of the new page_id. It's also called from
2110          * Article::doDeleteArticle()
2111          *
2112          * @param $newid \type{\int} the new Article ID
2113          */
2114         public function resetArticleID( $newid ) {
2115                 $linkCache = LinkCache::singleton();
2116                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2117
2118                 if ( $newid === false ) { $this->mArticleID = -1; }
2119                 else { $this->mArticleID = $newid; }
2120                 $this->mRestrictionsLoaded = false;
2121                 $this->mRestrictions = array();
2122         }
2123
2124         /**
2125          * Updates page_touched for this page; called from LinksUpdate.php
2126          * @return \type{\bool} true if the update succeded
2127          */
2128         public function invalidateCache() {
2129                 if( wfReadOnly() ) {
2130                         return;
2131                 }
2132                 $dbw = wfGetDB( DB_MASTER );
2133                 $success = $dbw->update( 'page',
2134                         array( 'page_touched' => $dbw->timestamp() ),
2135                         $this->pageCond(),
2136                         __METHOD__
2137                 );
2138                 HTMLFileCache::clearFileCache( $this );
2139                 return $success;
2140         }
2141
2142         /**
2143          * Prefix some arbitrary text with the namespace or interwiki prefix
2144          * of this object
2145          *
2146          * @param $name \type{\string} the text
2147          * @return \type{\string} the prefixed text
2148          * @private
2149          */
2150         /* private */ function prefix( $name ) {
2151                 $p = '';
2152                 if ( '' != $this->mInterwiki ) {
2153                         $p = $this->mInterwiki . ':';
2154                 }
2155                 if ( 0 != $this->mNamespace ) {
2156                         $p .= $this->getNsText() . ':';
2157                 }
2158                 return $p . $name;
2159         }
2160
2161         /**
2162          * Secure and split - main initialisation function for this object
2163          *
2164          * Assumes that mDbkeyform has been set, and is urldecoded
2165          * and uses underscores, but not otherwise munged.  This function
2166          * removes illegal characters, splits off the interwiki and
2167          * namespace prefixes, sets the other forms, and canonicalizes
2168          * everything.
2169          * @return \type{\bool} true on success
2170          */
2171         private function secureAndSplit() {
2172                 global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;
2173
2174                 # Initialisation
2175                 static $rxTc = false;
2176                 if( !$rxTc ) {
2177                         # Matching titles will be held as illegal.
2178                         $rxTc = '/' .
2179                                 # Any character not allowed is forbidden...
2180                                 '[^' . Title::legalChars() . ']' .
2181                                 # URL percent encoding sequences interfere with the ability
2182                                 # to round-trip titles -- you can't link to them consistently.
2183                                 '|%[0-9A-Fa-f]{2}' .
2184                                 # XML/HTML character references produce similar issues.
2185                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2186                                 '|&#[0-9]+;' .
2187                                 '|&#x[0-9A-Fa-f]+;' .
2188                                 '/S';
2189                 }
2190
2191                 $this->mInterwiki = $this->mFragment = '';
2192                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2193
2194                 $dbkey = $this->mDbkeyform;
2195
2196                 # Strip Unicode bidi override characters.
2197                 # Sometimes they slip into cut-n-pasted page titles, where the
2198                 # override chars get included in list displays.
2199                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2200
2201                 # Clean up whitespace
2202                 #
2203                 $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
2204                 $dbkey = trim( $dbkey, '_' );
2205
2206                 if ( '' == $dbkey ) {
2207                         return false;
2208                 }
2209
2210                 if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2211                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2212                         return false;
2213                 }
2214
2215                 $this->mDbkeyform = $dbkey;
2216
2217                 # Initial colon indicates main namespace rather than specified default
2218                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2219                 if ( ':' == $dbkey{0} ) {
2220                         $this->mNamespace = NS_MAIN;
2221                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2222                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2223                 }
2224
2225                 # Namespace or interwiki prefix
2226                 $firstPass = true;
2227                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2228                 do {
2229                         $m = array();
2230                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2231                                 $p = $m[1];
2232                                 if ( $ns = $wgContLang->getNsIndex( $p ) ) {
2233                                         # Ordinary namespace
2234                                         $dbkey = $m[2];
2235                                         $this->mNamespace = $ns;
2236                                         # For Talk:X pages, check if X has a "namespace" prefix
2237                                         if( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2238                                                 if( $wgContLang->getNsIndex( $x[1] ) )
2239                                                         return false; # Disallow Talk:File:x type titles...
2240                                                 else if( Interwiki::isValidInterwiki( $x[1] ) )
2241                                                         return false; # Disallow Talk:Interwiki:x type titles...
2242                                         }
2243                                 } elseif( Interwiki::isValidInterwiki( $p ) ) {
2244                                         if( !$firstPass ) {
2245                                                 # Can't make a local interwiki link to an interwiki link.
2246                                                 # That's just crazy!
2247                                                 return false;
2248                                         }
2249
2250                                         # Interwiki link
2251                                         $dbkey = $m[2];
2252                                         $this->mInterwiki = $wgContLang->lc( $p );
2253
2254                                         # Redundant interwiki prefix to the local wiki
2255                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2256                                                 if( $dbkey == '' ) {
2257                                                         # Can't have an empty self-link
2258                                                         return false;
2259                                                 }
2260                                                 $this->mInterwiki = '';
2261                                                 $firstPass = false;
2262                                                 # Do another namespace split...
2263                                                 continue;
2264                                         }
2265
2266                                         # If there's an initial colon after the interwiki, that also
2267                                         # resets the default namespace
2268                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2269                                                 $this->mNamespace = NS_MAIN;
2270                                                 $dbkey = substr( $dbkey, 1 );
2271                                         }
2272                                 }
2273                                 # If there's no recognized interwiki or namespace,
2274                                 # then let the colon expression be part of the title.
2275                         }
2276                         break;
2277                 } while( true );
2278
2279                 # We already know that some pages won't be in the database!
2280                 #
2281                 if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
2282                         $this->mArticleID = 0;
2283                 }
2284                 $fragment = strstr( $dbkey, '#' );
2285                 if ( false !== $fragment ) {
2286                         $this->setFragment( $fragment );
2287                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2288                         # remove whitespace again: prevents "Foo_bar_#"
2289                         # becoming "Foo_bar_"
2290                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2291                 }
2292
2293                 # Reject illegal characters.
2294                 #
2295                 if( preg_match( $rxTc, $dbkey ) ) {
2296                         return false;
2297                 }
2298
2299                 /**
2300                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2301                  * reachable due to the way web browsers deal with 'relative' URLs.
2302                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2303                  */
2304                 if ( strpos( $dbkey, '.' ) !== false &&
2305                      ( $dbkey === '.' || $dbkey === '..' ||
2306                        strpos( $dbkey, './' ) === 0  ||
2307                        strpos( $dbkey, '../' ) === 0 ||
2308                        strpos( $dbkey, '/./' ) !== false ||
2309                        strpos( $dbkey, '/../' ) !== false  ||
2310                        substr( $dbkey, -2 ) == '/.' ||
2311                        substr( $dbkey, -3 ) == '/..' ) )
2312                 {
2313                         return false;
2314                 }
2315
2316                 /**
2317                  * Magic tilde sequences? Nu-uh!
2318                  */
2319                 if( strpos( $dbkey, '~~~' ) !== false ) {
2320                         return false;
2321                 }
2322
2323                 /**
2324                  * Limit the size of titles to 255 bytes.
2325                  * This is typically the size of the underlying database field.
2326                  * We make an exception for special pages, which don't need to be stored
2327                  * in the database, and may edge over 255 bytes due to subpage syntax
2328                  * for long titles, e.g. [[Special:Block/Long name]]
2329                  */
2330                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2331                   strlen( $dbkey ) > 512 )
2332                 {
2333                         return false;
2334                 }
2335
2336                 /**
2337                  * Normally, all wiki links are forced to have
2338                  * an initial capital letter so [[foo]] and [[Foo]]
2339                  * point to the same place.
2340                  *
2341                  * Don't force it for interwikis, since the other
2342                  * site might be case-sensitive.
2343                  */
2344                 $this->mUserCaseDBKey = $dbkey;
2345                 if( $wgCapitalLinks && $this->mInterwiki == '') {
2346                         $dbkey = $wgContLang->ucfirst( $dbkey );
2347                 }
2348
2349                 /**
2350                  * Can't make a link to a namespace alone...
2351                  * "empty" local links can only be self-links
2352                  * with a fragment identifier.
2353                  */
2354                 if( $dbkey == '' &&
2355                         $this->mInterwiki == '' &&
2356                         $this->mNamespace != NS_MAIN ) {
2357                         return false;
2358                 }
2359                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2360                 // IP names are not allowed for accounts, and can only be referring to
2361                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2362                 // there are numerous ways to present the same IP. Having sp:contribs scan
2363                 // them all is silly and having some show the edits and others not is
2364                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2365                 $dbkey = ($this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK) ?
2366                         IP::sanitizeIP( $dbkey ) : $dbkey;
2367                 // Any remaining initial :s are illegal.
2368                 if ( $dbkey !== '' && ':' == $dbkey{0} ) {
2369                         return false;
2370                 }
2371
2372                 # Fill fields
2373                 $this->mDbkeyform = $dbkey;
2374                 $this->mUrlform = wfUrlencode( $dbkey );
2375
2376                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2377
2378                 return true;
2379         }
2380
2381         /**
2382          * Set the fragment for this title. Removes the first character from the
2383          * specified fragment before setting, so it assumes you're passing it with
2384          * an initial "#".
2385          *
2386          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2387          * Still in active use privately.
2388          *
2389          * @param $fragment \type{\string} text
2390          */
2391         public function setFragment( $fragment ) {
2392                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2393         }
2394
2395         /**
2396          * Get a Title object associated with the talk page of this article
2397          * @return \type{Title} the object for the talk page
2398          */
2399         public function getTalkPage() {
2400                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2401         }
2402
2403         /**
2404          * Get a title object associated with the subject page of this
2405          * talk page
2406          *
2407          * @return \type{Title} the object for the subject page
2408          */
2409         public function getSubjectPage() {
2410                 // Is this the same title?
2411                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2412                 if( $this->getNamespace() == $subjectNS ) {
2413                         return $this;
2414                 }
2415                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2416         }
2417
2418         /**
2419          * Get an array of Title objects linking to this Title
2420          * Also stores the IDs in the link cache.
2421          *
2422          * WARNING: do not use this function on arbitrary user-supplied titles!
2423          * On heavily-used templates it will max out the memory.
2424          *
2425          * @param array $options may be FOR UPDATE
2426          * @return \type{\arrayof{Title}} the Title objects linking here
2427          */
2428         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2429                 $linkCache = LinkCache::singleton();
2430
2431                 if ( count( $options ) > 0 ) {
2432                         $db = wfGetDB( DB_MASTER );
2433                 } else {
2434                         $db = wfGetDB( DB_SLAVE );
2435                 }
2436
2437                 $res = $db->select( array( 'page', $table ),
2438                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect' ),
2439                         array(
2440                                 "{$prefix}_from=page_id",
2441                                 "{$prefix}_namespace" => $this->getNamespace(),
2442                                 "{$prefix}_title"     => $this->getDBkey() ),
2443                         __METHOD__,
2444                         $options );
2445
2446                 $retVal = array();
2447                 if ( $db->numRows( $res ) ) {
2448                         foreach( $res as $row ) {
2449                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2450                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect );
2451                                         $retVal[] = $titleObj;
2452                                 }
2453                         }
2454                 }
2455                 $db->freeResult( $res );
2456                 return $retVal;
2457         }
2458
2459         /**
2460          * Get an array of Title objects using this Title as a template
2461          * Also stores the IDs in the link cache.
2462          *
2463          * WARNING: do not use this function on arbitrary user-supplied titles!
2464          * On heavily-used templates it will max out the memory.
2465          *
2466          * @param array $options may be FOR UPDATE
2467          * @return \type{\arrayof{Title}} the Title objects linking here
2468          */
2469         public function getTemplateLinksTo( $options = array() ) {
2470                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2471         }
2472
2473         /**
2474          * Get an array of Title objects referring to non-existent articles linked from this page
2475          *
2476          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2477          * @return \type{\arrayof{Title}} the Title objects
2478          */
2479         public function getBrokenLinksFrom() {
2480                 if ( $this->getArticleId() == 0 ) {
2481                         # All links from article ID 0 are false positives
2482                         return array();
2483                 }
2484
2485                 $dbr = wfGetDB( DB_SLAVE );
2486                 $res = $dbr->select(
2487                         array( 'page', 'pagelinks' ),
2488                         array( 'pl_namespace', 'pl_title' ),
2489                         array(
2490                                 'pl_from' => $this->getArticleId(),
2491                                 'page_namespace IS NULL'
2492                         ),
2493                         __METHOD__, array(),
2494                         array(
2495                                 'page' => array(
2496                                         'LEFT JOIN',
2497                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2498                                 )
2499                         )
2500                 );
2501
2502                 $retVal = array();
2503                 foreach( $res as $row ) {
2504                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2505                 }
2506                 return $retVal;
2507         }
2508
2509
2510         /**
2511          * Get a list of URLs to purge from the Squid cache when this
2512          * page changes
2513          *
2514          * @return \type{\arrayof{\string}} the URLs
2515          */
2516         public function getSquidURLs() {
2517                 global $wgContLang;
2518
2519                 $urls = array(
2520                         $this->getInternalURL(),
2521                         $this->getInternalURL( 'action=history' )
2522                 );
2523
2524                 // purge variant urls as well
2525                 if($wgContLang->hasVariants()){
2526                         $variants = $wgContLang->getVariants();
2527                         foreach($variants as $vCode){
2528                                 if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
2529                                 $urls[] = $this->getInternalURL('',$vCode);
2530                         }
2531                 }
2532
2533                 return $urls;
2534         }
2535
2536         /**
2537          * Purge all applicable Squid URLs
2538          */
2539         public function purgeSquid() {
2540                 global $wgUseSquid;
2541                 if ( $wgUseSquid ) {
2542                         $urls = $this->getSquidURLs();
2543                         $u = new SquidUpdate( $urls );
2544                         $u->doUpdate();
2545                 }
2546         }
2547
2548         /**
2549          * Move this page without authentication
2550          * @param &$nt \type{Title} the new page Title
2551          */
2552         public function moveNoAuth( &$nt ) {
2553                 return $this->moveTo( $nt, false );
2554         }
2555
2556         /**
2557          * Check whether a given move operation would be valid.
2558          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2559          * @param &$nt \type{Title} the new title
2560          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2561          *      should be checked
2562          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2563          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2564          */
2565         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2566                 global $wgUser;
2567
2568                 $errors = array();
2569                 if( !$nt ) {
2570                         // Normally we'd add this to $errors, but we'll get
2571                         // lots of syntax errors if $nt is not an object
2572                         return array(array('badtitletext'));
2573                 }
2574                 if( $this->equals( $nt ) ) {
2575                         $errors[] = array('selfmove');
2576                 }
2577                 if( !$this->isMovable() ) {
2578                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2579                 }
2580                 if ( $nt->getInterwiki() != '' ) {
2581                         $errors[] = array( 'immobile-target-namespace-iw' );
2582                 }
2583                 if ( !$nt->isMovable() ) {
2584                         $errors[] = array('immobile-target-namespace', $nt->getNsText() );
2585                 }
2586
2587                 $oldid = $this->getArticleID();
2588                 $newid = $nt->getArticleID();
2589
2590                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2591                         $errors[] = array('articleexists');
2592                 }
2593                 if ( ( '' == $this->getDBkey() ) ||
2594                          ( !$oldid ) ||
2595                      ( '' == $nt->getDBkey() ) ) {
2596                         $errors[] = array('badarticleerror');
2597                 }
2598
2599                 // Image-specific checks
2600                 if( $this->getNamespace() == NS_FILE ) {
2601                         $file = wfLocalFile( $this );
2602                         if( $file->exists() ) {
2603                                 if( $nt->getNamespace() != NS_FILE ) {
2604                                         $errors[] = array('imagenocrossnamespace');
2605                                 }
2606                                 if( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2607                                         $errors[] = array('imageinvalidfilename');
2608                                 }
2609                                 if( !File::checkExtensionCompatibility( $file, $nt->getDBKey() ) ) {
2610                                         $errors[] = array('imagetypemismatch');
2611                                 }
2612                         }
2613                 }
2614
2615                 if ( $auth ) {
2616                         $errors = wfMergeErrorArrays( $errors,
2617                                 $this->getUserPermissionsErrors('move', $wgUser),
2618                                 $this->getUserPermissionsErrors('edit', $wgUser),
2619                                 $nt->getUserPermissionsErrors('move-target', $wgUser),
2620                                 $nt->getUserPermissionsErrors('edit', $wgUser) );
2621                 }
2622
2623                 $match = EditPage::matchSummarySpamRegex( $reason );
2624                 if( $match !== false ) {
2625                         // This is kind of lame, won't display nice
2626                         $errors[] = array('spamprotectiontext');
2627                 }
2628
2629                 $err = null;
2630                 if( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2631                         $errors[] = array('hookaborted', $err);
2632                 }
2633
2634                 # The move is allowed only if (1) the target doesn't exist, or
2635                 # (2) the target is a redirect to the source, and has no history
2636                 # (so we can undo bad moves right after they're done).
2637
2638                 if ( 0 != $newid ) { # Target exists; check for validity
2639                         if ( ! $this->isValidMoveTarget( $nt ) ) {
2640                                 $errors[] = array('articleexists');
2641                         }
2642                 } else {
2643                         $tp = $nt->getTitleProtection();
2644                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2645                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2646                                 $errors[] = array('cantmove-titleprotected');
2647                         }
2648                 }
2649                 if(empty($errors))
2650                         return true;
2651                 return $errors;
2652         }
2653
2654         /**
2655          * Move a title to a new location
2656          * @param &$nt \type{Title} the new title
2657          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2658          *      should be checked
2659          * @param $reason \type{\string} The reason for the move
2660          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2661          *  Ignored if the user doesn't have the suppressredirect right.
2662          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2663          */
2664         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2665                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2666                 if( is_array( $err ) ) {
2667                         return $err;
2668                 }
2669
2670                 // If it is a file, more it first. It is done before all other moving stuff is done because it's hard to revert
2671                 $dbw = wfGetDB( DB_MASTER );
2672                 if( $this->getNamespace() == NS_FILE ) {
2673                         $file = wfLocalFile( $this );
2674                         if( $file->exists() ) {
2675                                 $status = $file->move( $nt );
2676                                 if( !$status->isOk() ) {
2677                                         return $status->getErrorsArray();
2678                                 }
2679                         }
2680                 }
2681
2682                 $pageid = $this->getArticleID();
2683                 $protected = $this->isProtected();
2684                 if( $nt->exists() ) {
2685                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2686                         $pageCountChange = ($createRedirect ? 0 : -1);
2687                 } else { # Target didn't exist, do normal move.
2688                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2689                         $pageCountChange = ($createRedirect ? 1 : 0);
2690                 }
2691
2692                 if( is_array( $err ) ) {
2693                         return $err;
2694                 }
2695                 $redirid = $this->getArticleID();
2696
2697                 // Category memberships include a sort key which may be customized.
2698                 // If it's left as the default (the page title), we need to update
2699                 // the sort key to match the new title.
2700                 //
2701                 // Be careful to avoid resetting cl_timestamp, which may disturb
2702                 // time-based lists on some sites.
2703                 //
2704                 // Warning -- if the sort key is *explicitly* set to the old title,
2705                 // we can't actually distinguish it from a default here, and it'll
2706                 // be set to the new title even though it really shouldn't.
2707                 // It'll get corrected on the next edit, but resetting cl_timestamp.
2708                 $dbw->update( 'categorylinks',
2709                         array(
2710                                 'cl_sortkey' => $nt->getPrefixedText(),
2711                                 'cl_timestamp=cl_timestamp' ),
2712                         array(
2713                                 'cl_from' => $pageid,
2714                                 'cl_sortkey' => $this->getPrefixedText() ),
2715                         __METHOD__ );
2716
2717                 if( $protected ) {
2718                         # Protect the redirect title as the title used to be...
2719                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
2720                                 array(
2721                                         'pr_page'    => $redirid,
2722                                         'pr_type'    => 'pr_type',
2723                                         'pr_level'   => 'pr_level',
2724                                         'pr_cascade' => 'pr_cascade',
2725                                         'pr_user'    => 'pr_user',
2726                                         'pr_expiry'  => 'pr_expiry'
2727                                 ),
2728                                 array( 'pr_page' => $pageid ),
2729                                 __METHOD__,
2730                                 array( 'IGNORE' )
2731                         );
2732                         # Update the protection log
2733                         $log = new LogPage( 'protect' );
2734                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2735                         if( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
2736                         $log->addEntry( 'move_prot', $nt, $comment, array($this->getPrefixedText()) ); // FIXME: $params?
2737                 }
2738
2739                 # Update watchlists
2740                 $oldnamespace = $this->getNamespace() & ~1;
2741                 $newnamespace = $nt->getNamespace() & ~1;
2742                 $oldtitle = $this->getDBkey();
2743                 $newtitle = $nt->getDBkey();
2744
2745                 if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
2746                         WatchedItem::duplicateEntries( $this, $nt );
2747                 }
2748
2749                 # Update search engine
2750                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
2751                 $u->doUpdate();
2752                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
2753                 $u->doUpdate();
2754
2755                 # Update site_stats
2756                 if( $this->isContentPage() && !$nt->isContentPage() ) {
2757                         # No longer a content page
2758                         # Not viewed, edited, removing
2759                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
2760                 } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
2761                         # Now a content page
2762                         # Not viewed, edited, adding
2763                         $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
2764                 } elseif( $pageCountChange ) {
2765                         # Redirect added
2766                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
2767                 } else {
2768                         # Nothing special
2769                         $u = false;
2770                 }
2771                 if( $u )
2772                         $u->doUpdate();
2773                 # Update message cache for interface messages
2774                 if( $nt->getNamespace() == NS_MEDIAWIKI ) {
2775                         global $wgMessageCache;
2776
2777                         # @bug 17860: old article can be deleted, if this the case,
2778                         # delete it from message cache
2779                         if ( $this->getArticleID() === 0 ) {
2780                                 $wgMessageCache->replace( $this->getDBkey(), false );
2781                         } else {
2782                                 $oldarticle = new Article( $this );
2783                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
2784                         }
2785
2786                         $newarticle = new Article( $nt );
2787                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
2788                 }
2789
2790                 global $wgUser;
2791                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
2792                 return true;
2793         }
2794
2795         /**
2796          * Move page to a title which is at present a redirect to the
2797          * source page
2798          *
2799          * @param &$nt \type{Title} the page to move to, which should currently
2800          *      be a redirect
2801          * @param $reason \type{\string} The reason for the move
2802          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
2803          *  Ignored if the user doesn't have the suppressredirect right
2804          */
2805         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
2806                 global $wgUseSquid, $wgUser;
2807                 $fname = 'Title::moveOverExistingRedirect';
2808                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
2809
2810                 if ( $reason ) {
2811                         $comment .= ": $reason";
2812                 }
2813
2814                 $now = wfTimestampNow();
2815                 $newid = $nt->getArticleID();
2816                 $oldid = $this->getArticleID();
2817                 $latest = $this->getLatestRevID();
2818
2819                 $dbw = wfGetDB( DB_MASTER );
2820
2821                 # Delete the old redirect. We don't save it to history since
2822                 # by definition if we've got here it's rather uninteresting.
2823                 # We have to remove it so that the next step doesn't trigger
2824                 # a conflict on the unique namespace+title index...
2825                 $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );
2826                 if ( !$dbw->cascadingDeletes() ) {
2827                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
2828                         global $wgUseTrackbacks;
2829                         if ($wgUseTrackbacks)
2830                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
2831                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
2832                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
2833                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
2834                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
2835                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
2836                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
2837                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
2838                 }
2839
2840                 # Save a null revision in the page's history notifying of the move
2841                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2842                 $nullRevId = $nullRevision->insertOn( $dbw );
2843
2844                 $article = new Article( $this );
2845                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2846
2847                 # Change the name of the target page:
2848                 $dbw->update( 'page',
2849                         /* SET */ array(
2850                                 'page_touched'   => $dbw->timestamp($now),
2851                                 'page_namespace' => $nt->getNamespace(),
2852                                 'page_title'     => $nt->getDBkey(),
2853                                 'page_latest'    => $nullRevId,
2854                         ),
2855                         /* WHERE */ array( 'page_id' => $oldid ),
2856                         $fname
2857                 );
2858                 $nt->resetArticleID( $oldid );
2859
2860                 # Recreate the redirect, this time in the other direction.
2861                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2862                         $mwRedir = MagicWord::get( 'redirect' );
2863                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2864                         $redirectArticle = new Article( $this );
2865                         $newid = $redirectArticle->insertOn( $dbw );
2866                         $redirectRevision = new Revision( array(
2867                                 'page'    => $newid,
2868                                 'comment' => $comment,
2869                                 'text'    => $redirectText ) );
2870                         $redirectRevision->insertOn( $dbw );
2871                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2872
2873                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2874
2875                         # Now, we record the link from the redirect to the new title.
2876                         # It should have no other outgoing links...
2877                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
2878                         $dbw->insert( 'pagelinks',
2879                                 array(
2880                                         'pl_from'      => $newid,
2881                                         'pl_namespace' => $nt->getNamespace(),
2882                                         'pl_title'     => $nt->getDBkey() ),
2883                                 $fname );
2884                         $redirectSuppressed = false;
2885                 } else {
2886                         $this->resetArticleID( 0 );
2887                         $redirectSuppressed = true;
2888                 }
2889
2890                 # Log the move
2891                 $log = new LogPage( 'move' );
2892                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2893
2894                 # Purge squid
2895                 if ( $wgUseSquid ) {
2896                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
2897                         $u = new SquidUpdate( $urls );
2898                         $u->doUpdate();
2899                 }
2900
2901         }
2902
2903         /**
2904          * Move page to non-existing title.
2905          * @param &$nt \type{Title} the new Title
2906          * @param $reason \type{\string} The reason for the move
2907          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
2908          *  Ignored if the user doesn't have the suppressredirect right
2909          */
2910         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
2911                 global $wgUseSquid, $wgUser;
2912                 $fname = 'MovePageForm::moveToNewTitle';
2913                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
2914                 if ( $reason ) {
2915                         $comment .= wfMsgExt( 'colon-separator',
2916                                 array( 'escapenoentities', 'content' ) );
2917                         $comment .= $reason;
2918                 }
2919
2920                 $newid = $nt->getArticleID();
2921                 $oldid = $this->getArticleID();
2922                 $latest = $this->getLatestRevId();
2923
2924                 $dbw = wfGetDB( DB_MASTER );
2925                 $now = $dbw->timestamp();
2926
2927                 # Save a null revision in the page's history notifying of the move
2928                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
2929                 $nullRevId = $nullRevision->insertOn( $dbw );
2930
2931                 $article = new Article( $this );
2932                 wfRunHooks( 'NewRevisionFromEditComplete', array($article, $nullRevision, $latest, $wgUser) );
2933
2934                 # Rename page entry
2935                 $dbw->update( 'page',
2936                         /* SET */ array(
2937                                 'page_touched'   => $now,
2938                                 'page_namespace' => $nt->getNamespace(),
2939                                 'page_title'     => $nt->getDBkey(),
2940                                 'page_latest'    => $nullRevId,
2941                         ),
2942                         /* WHERE */ array( 'page_id' => $oldid ),
2943                         $fname
2944                 );
2945                 $nt->resetArticleID( $oldid );
2946
2947                 if( $createRedirect || !$wgUser->isAllowed('suppressredirect') ) {
2948                         # Insert redirect
2949                         $mwRedir = MagicWord::get( 'redirect' );
2950                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
2951                         $redirectArticle = new Article( $this );
2952                         $newid = $redirectArticle->insertOn( $dbw );
2953                         $redirectRevision = new Revision( array(
2954                                 'page'    => $newid,
2955                                 'comment' => $comment,
2956                                 'text'    => $redirectText ) );
2957                         $redirectRevision->insertOn( $dbw );
2958                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
2959
2960                         wfRunHooks( 'NewRevisionFromEditComplete', array($redirectArticle, $redirectRevision, false, $wgUser) );
2961
2962                         # Record the just-created redirect's linking to the page
2963                         $dbw->insert( 'pagelinks',
2964                                 array(
2965                                         'pl_from'      => $newid,
2966                                         'pl_namespace' => $nt->getNamespace(),
2967                                         'pl_title'     => $nt->getDBkey() ),
2968                                 $fname );
2969                         $redirectSuppressed = false;
2970                 } else {
2971                         $this->resetArticleID( 0 );
2972                         $redirectSuppressed = true;
2973                 }
2974
2975                 # Log the move
2976                 $log = new LogPage( 'move' );
2977                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
2978
2979                 # Purge caches as per article creation
2980                 Article::onArticleCreate( $nt );
2981
2982                 # Purge old title from squid
2983                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
2984                 $this->purgeSquid();
2985
2986         }
2987
2988         /**
2989          * Move this page's subpages to be subpages of $nt
2990          * @param $nt Title Move target
2991          * @param $auth bool Whether $wgUser's permissions should be checked
2992          * @param $reason string The reason for the move
2993          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
2994          *  Ignored if the user doesn't have the 'suppressredirect' right
2995          * @return mixed array with old page titles as keys, and strings (new page titles) or
2996          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
2997          */
2998         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
2999                 global $wgMaximumMovedPages;
3000                 // Check permissions
3001                 if( !$this->userCan( 'move-subpages' ) )
3002                         return array( 'cant-move-subpages' );
3003                 // Do the source and target namespaces support subpages?
3004                 if( !MWNamespace::hasSubpages( $this->getNamespace() ) )
3005                         return array( 'namespace-nosubpages',
3006                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3007                 if( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
3008                         return array( 'namespace-nosubpages',
3009                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3010
3011                 $subpages = $this->getSubpages($wgMaximumMovedPages + 1);
3012                 $retval = array();
3013                 $count = 0;
3014                 foreach( $subpages as $oldSubpage ) {
3015                         $count++;
3016                         if( $count > $wgMaximumMovedPages ) {
3017                                 $retval[$oldSubpage->getPrefixedTitle()] =
3018                                                 array( 'movepage-max-pages',
3019                                                         $wgMaximumMovedPages );
3020                                 break;
3021                         }
3022
3023                         if( $oldSubpage->getArticleId() == $this->getArticleId() )
3024                                 // When moving a page to a subpage of itself,
3025                                 // don't move it twice
3026                                 continue;
3027                         $newPageName = preg_replace(
3028                                         '#^'.preg_quote( $this->getDBKey(), '#' ).'#',
3029                                         $nt->getDBKey(), $oldSubpage->getDBKey() );
3030                         if( $oldSubpage->isTalkPage() ) {
3031                                 $newNs = $nt->getTalkPage()->getNamespace();
3032                         } else {
3033                                 $newNs = $nt->getSubjectPage()->getNamespace();
3034                         }
3035                         # Bug 14385: we need makeTitleSafe because the new page names may
3036                         # be longer than 255 characters.
3037                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3038
3039                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3040                         if( $success === true ) {
3041                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3042                         } else {
3043                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3044                         }
3045                 }
3046                 return $retval;
3047         }
3048
3049         /**
3050          * Checks if this page is just a one-rev redirect.
3051          * Adds lock, so don't use just for light purposes.
3052          *
3053          * @return \type{\bool} TRUE or FALSE
3054          */
3055         public function isSingleRevRedirect() {
3056                 $dbw = wfGetDB( DB_MASTER );
3057                 # Is it a redirect?
3058                 $row = $dbw->selectRow( 'page',
3059                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3060                         $this->pageCond(),
3061                         __METHOD__,
3062                         array( 'FOR UPDATE' )
3063                 );
3064                 # Cache some fields we may want
3065                 $this->mArticleID = $row ? intval($row->page_id) : 0;
3066                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3067                 $this->mLatestID = $row ? intval($row->page_latest) : false;
3068                 if( !$this->mRedirect ) {
3069                         return false;
3070                 }
3071                 # Does the article have a history?
3072                 $row = $dbw->selectField( array( 'page', 'revision'),
3073                         'rev_id',
3074                         array( 'page_namespace' => $this->getNamespace(),
3075                                 'page_title' => $this->getDBkey(),
3076                                 'page_id=rev_page',
3077                                 'page_latest != rev_id'
3078                         ),
3079                         __METHOD__,
3080                         array( 'FOR UPDATE' )
3081                 );
3082                 # Return true if there was no history
3083                 return ($row === false);
3084         }
3085
3086         /**
3087          * Checks if $this can be moved to a given Title
3088          * - Selects for update, so don't call it unless you mean business
3089          *
3090          * @param &$nt \type{Title} the new title to check
3091          * @return \type{\bool} TRUE or FALSE
3092          */
3093         public function isValidMoveTarget( $nt ) {
3094                 $dbw = wfGetDB( DB_MASTER );
3095                 # Is it an existsing file?
3096                 if( $nt->getNamespace() == NS_FILE ) {
3097                         $file = wfLocalFile( $nt );
3098                         if( $file->exists() ) {
3099                                 wfDebug( __METHOD__ . ": file exists\n" );
3100                                 return false;
3101                         }
3102                 }
3103                 # Is it a redirect with no history?
3104                 if( !$nt->isSingleRevRedirect() ) {
3105                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3106                         return false;
3107                 }
3108                 # Get the article text
3109                 $rev = Revision::newFromTitle( $nt );
3110                 $text = $rev->getText();
3111                 # Does the redirect point to the source?
3112                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3113                 $m = array();
3114                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3115                         $redirTitle = Title::newFromText( $m[1] );
3116                         if( !is_object( $redirTitle ) ||
3117                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3118                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3119                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3120                                 return false;
3121                         }
3122                 } else {
3123                         # Fail safe
3124                         wfDebug( __METHOD__ . ": failsafe\n" );
3125                         return false;
3126                 }
3127                 return true;
3128         }
3129
3130         /**
3131          * Can this title be added to a user's watchlist?
3132          *
3133          * @return \type{\bool} TRUE or FALSE
3134          */
3135         public function isWatchable() {
3136                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3137         }
3138
3139         /**
3140          * Get categories to which this Title belongs and return an array of
3141          * categories' names.
3142          *
3143          * @return \type{\array} array an array of parents in the form:
3144          *      $parent => $currentarticle
3145          */
3146         public function getParentCategories() {
3147                 global $wgContLang;
3148
3149                 $titlekey = $this->getArticleId();
3150                 $dbr = wfGetDB( DB_SLAVE );
3151                 $categorylinks = $dbr->tableName( 'categorylinks' );
3152
3153                 # NEW SQL
3154                 $sql = "SELECT * FROM $categorylinks"
3155                      ." WHERE cl_from='$titlekey'"
3156                          ." AND cl_from <> '0'"
3157                          ." ORDER BY cl_sortkey";
3158
3159                 $res = $dbr->query( $sql );
3160
3161                 if( $dbr->numRows( $res ) > 0 ) {
3162                         foreach( $res as $row )
3163                                 //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3164                                 $data[$wgContLang->getNSText( NS_CATEGORY ).':'.$row->cl_to] = $this->getFullText();
3165                         $dbr->freeResult( $res );
3166                 } else {
3167                         $data = array();
3168                 }
3169                 return $data;
3170         }
3171
3172         /**
3173          * Get a tree of parent categories
3174          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3175          * @return \type{\array} Tree of parent categories
3176          */
3177         public function getParentCategoryTree( $children = array() ) {
3178                 $stack = array();
3179                 $parents = $this->getParentCategories();
3180
3181                 if( $parents ) {
3182                         foreach( $parents as $parent => $current ) {
3183                                 if ( array_key_exists( $parent, $children ) ) {
3184                                         # Circular reference
3185                                         $stack[$parent] = array();
3186                                 } else {
3187                                         $nt = Title::newFromText($parent);
3188                                         if ( $nt ) {
3189                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
3190                                         }
3191                                 }
3192                         }
3193                         return $stack;
3194                 } else {
3195                         return array();
3196                 }
3197         }
3198
3199
3200         /**
3201          * Get an associative array for selecting this title from
3202          * the "page" table
3203          *
3204          * @return \type{\array} Selection array
3205          */
3206         public function pageCond() {
3207                 if( $this->mArticleID > 0 ) {
3208                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3209                         return array( 'page_id' => $this->mArticleID );
3210                 } else {
3211                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3212                 }
3213         }
3214
3215         /**
3216          * Get the revision ID of the previous revision
3217          *
3218          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3219          * @param $flags \type{\int} GAID_FOR_UPDATE
3220          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3221          */
3222         public function getPreviousRevisionID( $revId, $flags=0 ) {
3223                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3224                 return $db->selectField( 'revision', 'rev_id',
3225                         array(
3226                                 'rev_page' => $this->getArticleId($flags),
3227                                 'rev_id < ' . intval( $revId )
3228                         ),
3229                         __METHOD__,
3230                         array( 'ORDER BY' => 'rev_id DESC' )
3231                 );
3232         }
3233
3234         /**
3235          * Get the revision ID of the next revision
3236          *
3237          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3238          * @param $flags \type{\int} GAID_FOR_UPDATE
3239          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3240          */
3241         public function getNextRevisionID( $revId, $flags=0 ) {
3242                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3243                 return $db->selectField( 'revision', 'rev_id',
3244                         array(
3245                                 'rev_page' => $this->getArticleId($flags),
3246                                 'rev_id > ' . intval( $revId )
3247                         ),
3248                         __METHOD__,
3249                         array( 'ORDER BY' => 'rev_id' )
3250                 );
3251         }
3252
3253         /**
3254          * Get the first revision of the page
3255          *
3256          * @param $flags \type{\int} GAID_FOR_UPDATE
3257          * @return Revision (or NULL if page doesn't exist)
3258          */
3259         public function getFirstRevision( $flags=0 ) {
3260                 $db = ($flags & GAID_FOR_UPDATE) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3261                 $pageId = $this->getArticleId($flags);
3262                 if( !$pageId ) return NULL;
3263                 $row = $db->selectRow( 'revision', '*',
3264                         array( 'rev_page' => $pageId ),
3265                         __METHOD__,
3266                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3267                 );
3268                 if( !$row ) {
3269                         return NULL;
3270                 } else {
3271                         return new Revision( $row );
3272                 }
3273         }
3274
3275         /**
3276          * Check if this is a new page
3277          *
3278          * @return bool
3279          */
3280         public function isNewPage() {
3281                 $dbr = wfGetDB( DB_SLAVE );
3282                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3283         }
3284
3285         /**
3286          * Get the oldest revision timestamp of this page
3287          *
3288          * @return string, MW timestamp
3289          */
3290         public function getEarliestRevTime() {
3291                 $dbr = wfGetDB( DB_SLAVE );
3292                 if( $this->exists() ) {
3293                         $min = $dbr->selectField( 'revision',
3294                                 'MIN(rev_timestamp)',
3295                                 array( 'rev_page' => $this->getArticleId() ),
3296                                 __METHOD__ );
3297                         return wfTimestampOrNull( TS_MW, $min );
3298                 }
3299                 return null;
3300         }
3301
3302         /**
3303          * Get the number of revisions between the given revision IDs.
3304          * Used for diffs and other things that really need it.
3305          *
3306          * @param $old \type{\int} Revision ID.
3307          * @param $new \type{\int} Revision ID.
3308          * @return \type{\int} Number of revisions between these IDs.
3309          */
3310         public function countRevisionsBetween( $old, $new ) {
3311                 $dbr = wfGetDB( DB_SLAVE );
3312                 return $dbr->selectField( 'revision', 'count(*)',
3313                         'rev_page = ' . intval( $this->getArticleId() ) .
3314                         ' AND rev_id > ' . intval( $old ) .
3315                         ' AND rev_id < ' . intval( $new ),
3316                         __METHOD__
3317                 );
3318         }
3319
3320         /**
3321          * Compare with another title.
3322          *
3323          * @param \type{Title} $title
3324          * @return \type{\bool} TRUE or FALSE
3325          */
3326         public function equals( Title $title ) {
3327                 // Note: === is necessary for proper matching of number-like titles.
3328                 return $this->getInterwiki() === $title->getInterwiki()
3329                         && $this->getNamespace() == $title->getNamespace()
3330                         && $this->getDBkey() === $title->getDBkey();
3331         }
3332
3333         /**
3334          * Callback for usort() to do title sorts by (namespace, title)
3335          */
3336         public static function compare( $a, $b ) {
3337                 if( $a->getNamespace() == $b->getNamespace() ) {
3338                         return strcmp( $a->getText(), $b->getText() );
3339                 } else {
3340                         return $a->getNamespace() - $b->getNamespace();
3341                 }
3342         }
3343
3344         /**
3345          * Return a string representation of this title
3346          *
3347          * @return \type{\string} String representation of this title
3348          */
3349         public function __toString() {
3350                 return $this->getPrefixedText();
3351         }
3352
3353         /**
3354          * Check if page exists.  For historical reasons, this function simply
3355          * checks for the existence of the title in the page table, and will
3356          * thus return false for interwiki links, special pages and the like.
3357          * If you want to know if a title can be meaningfully viewed, you should
3358          * probably call the isKnown() method instead.
3359          *
3360          * @return \type{\bool} TRUE or FALSE
3361          */
3362         public function exists() {
3363                 return $this->getArticleId() != 0;
3364         }
3365
3366         /**
3367          * Should links to this title be shown as potentially viewable (i.e. as
3368          * "bluelinks"), even if there's no record by this title in the page
3369          * table?
3370          *
3371          * This function is semi-deprecated for public use, as well as somewhat
3372          * misleadingly named.  You probably just want to call isKnown(), which
3373          * calls this function internally.
3374          *
3375          * (ISSUE: Most of these checks are cheap, but the file existence check
3376          * can potentially be quite expensive.  Including it here fixes a lot of
3377          * existing code, but we might want to add an optional parameter to skip
3378          * it and any other expensive checks.)
3379          *
3380          * @return \type{\bool} TRUE or FALSE
3381          */
3382         public function isAlwaysKnown() {
3383                 if( $this->mInterwiki != '' ) {
3384                         return true;  // any interwiki link might be viewable, for all we know
3385                 }
3386                 switch( $this->mNamespace ) {
3387                 case NS_MEDIA:
3388                 case NS_FILE:
3389                         return wfFindFile( $this );  // file exists, possibly in a foreign repo
3390                 case NS_SPECIAL:
3391                         return SpecialPage::exists( $this->getDBKey() );  // valid special page
3392                 case NS_MAIN:
3393                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3394                 case NS_MEDIAWIKI:
3395                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3396                         // the full l10n of that language to be loaded. That takes much memory and
3397                         // isn't needed. So we strip the language part away.
3398                         // Also, extension messages which are not loaded, are shown as red, because
3399                         // we don't call MessageCache::loadAllMessages.
3400                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3401                         return wfMsgWeirdKey( $basename );  // known system message
3402                 default:
3403                         return false;
3404                 }
3405         }
3406
3407         /**
3408          * Does this title refer to a page that can (or might) be meaningfully
3409          * viewed?  In particular, this function may be used to determine if
3410          * links to the title should be rendered as "bluelinks" (as opposed to
3411          * "redlinks" to non-existent pages).
3412          *
3413          * @return \type{\bool} TRUE or FALSE
3414          */
3415         public function isKnown() {
3416                 return $this->exists() || $this->isAlwaysKnown();
3417         }
3418
3419         /**
3420         * Is this in a namespace that allows actual pages?
3421         *
3422         * @return \type{\bool} TRUE or FALSE
3423         */
3424         public function canExist() {
3425                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3426         }
3427
3428         /**
3429          * Update page_touched timestamps and send squid purge messages for
3430          * pages linking to this title. May be sent to the job queue depending
3431          * on the number of links. Typically called on create and delete.
3432          */
3433         public function touchLinks() {
3434                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3435                 $u->doUpdate();
3436
3437                 if ( $this->getNamespace() == NS_CATEGORY ) {
3438                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3439                         $u->doUpdate();
3440                 }
3441         }
3442
3443         /**
3444          * Get the last touched timestamp
3445          * @param Database $db, optional db
3446          * @return \type{\string} Last touched timestamp
3447          */
3448         public function getTouched( $db = NULL ) {
3449                 $db = isset($db) ? $db : wfGetDB( DB_SLAVE );
3450                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3451                 return $touched;
3452         }
3453
3454         /**
3455          * Get the timestamp when this page was updated since the user last saw it.
3456          * @param User $user
3457          * @return mixed string/NULL
3458          */
3459         public function getNotificationTimestamp( $user = NULL ) {
3460                 global $wgUser, $wgShowUpdatedMarker;
3461                 // Assume current user if none given
3462                 if( !$user ) $user = $wgUser;
3463                 // Check cache first
3464                 $uid = $user->getId();
3465                 if( isset($this->mNotificationTimestamp[$uid]) ) {
3466                         return $this->mNotificationTimestamp[$uid];
3467                 }
3468                 if( !$uid || !$wgShowUpdatedMarker ) {
3469                         return $this->mNotificationTimestamp[$uid] = false;
3470                 }
3471                 // Don't cache too much!
3472                 if( count($this->mNotificationTimestamp) >= self::CACHE_MAX ) {
3473                         $this->mNotificationTimestamp = array();
3474                 }
3475                 $dbr = wfGetDB( DB_SLAVE );
3476                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3477                         'wl_notificationtimestamp',
3478                         array( 'wl_namespace' => $this->getNamespace(),
3479                                 'wl_title' => $this->getDBkey(),
3480                                 'wl_user' => $user->getId()
3481                         ),
3482                         __METHOD__
3483                 );
3484                 return $this->mNotificationTimestamp[$uid];
3485         }
3486
3487         /**
3488          * Get the trackback URL for this page
3489          * @return \type{\string} Trackback URL
3490          */
3491         public function trackbackURL() {
3492                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3493
3494                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3495                         . htmlspecialchars(urlencode($this->getPrefixedDBkey()));
3496         }
3497
3498         /**
3499          * Get the trackback RDF for this page
3500          * @return \type{\string} Trackback RDF
3501          */
3502         public function trackbackRDF() {
3503                 $url = htmlspecialchars($this->getFullURL());
3504                 $title = htmlspecialchars($this->getText());
3505                 $tburl = $this->trackbackURL();
3506
3507                 // Autodiscovery RDF is placed in comments so HTML validator
3508                 // won't barf. This is a rather icky workaround, but seems
3509                 // frequently used by this kind of RDF thingy.
3510                 //
3511                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3512                 return "<!--
3513 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3514          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3515          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3516 <rdf:Description
3517    rdf:about=\"$url\"
3518    dc:identifier=\"$url\"
3519    dc:title=\"$title\"
3520    trackback:ping=\"$tburl\" />
3521 </rdf:RDF>
3522 -->";
3523         }
3524
3525         /**
3526          * Generate strings used for xml 'id' names in monobook tabs
3527          * @return \type{\string} XML 'id' name
3528          */
3529         public function getNamespaceKey() {
3530                 global $wgContLang;
3531                 switch ($this->getNamespace()) {
3532                         case NS_MAIN:
3533                         case NS_TALK:
3534                                 return 'nstab-main';
3535                         case NS_USER:
3536                         case NS_USER_TALK:
3537                                 return 'nstab-user';
3538                         case NS_MEDIA:
3539                                 return 'nstab-media';
3540                         case NS_SPECIAL:
3541                                 return 'nstab-special';
3542                         case NS_PROJECT:
3543                         case NS_PROJECT_TALK:
3544                                 return 'nstab-project';
3545                         case NS_FILE:
3546                         case NS_FILE_TALK:
3547                                 return 'nstab-image';
3548                         case NS_MEDIAWIKI:
3549                         case NS_MEDIAWIKI_TALK:
3550                                 return 'nstab-mediawiki';
3551                         case NS_TEMPLATE:
3552                         case NS_TEMPLATE_TALK:
3553                                 return 'nstab-template';
3554                         case NS_HELP:
3555                         case NS_HELP_TALK:
3556                                 return 'nstab-help';
3557                         case NS_CATEGORY:
3558                         case NS_CATEGORY_TALK:
3559                                 return 'nstab-category';
3560                         default:
3561                                 return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
3562                 }
3563         }
3564
3565         /**
3566          * Returns true if this title resolves to the named special page
3567          * @param $name \type{\string} The special page name
3568          */
3569         public function isSpecial( $name ) {
3570                 if ( $this->getNamespace() == NS_SPECIAL ) {
3571                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3572                         if ( $name == $thisName ) {
3573                                 return true;
3574                         }
3575                 }
3576                 return false;
3577         }
3578
3579         /**
3580          * If the Title refers to a special page alias which is not the local default,
3581          * @return \type{Title} A new Title which points to the local default. Otherwise, returns $this.
3582          */
3583         public function fixSpecialName() {
3584                 if ( $this->getNamespace() == NS_SPECIAL ) {
3585                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3586                         if ( $canonicalName ) {
3587                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3588                                 if ( $localName != $this->mDbkeyform ) {
3589                                         return Title::makeTitle( NS_SPECIAL, $localName );
3590                                 }
3591                         }
3592                 }
3593                 return $this;
3594         }
3595
3596         /**
3597          * Is this Title in a namespace which contains content?
3598          * In other words, is this a content page, for the purposes of calculating
3599          * statistics, etc?
3600          *
3601          * @return \type{\bool} TRUE or FALSE
3602          */
3603         public function isContentPage() {
3604                 return MWNamespace::isContent( $this->getNamespace() );
3605         }
3606
3607         /**
3608          * Get all extant redirects to this Title
3609          *
3610          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3611          *            NULL to consider all namespaces
3612          * @return \type{\arrayof{Title}} Redirects to this title
3613          */
3614         public function getRedirectsHere( $ns = null ) {
3615                 $redirs = array();
3616
3617                 $dbr = wfGetDB( DB_SLAVE );
3618                 $where = array(
3619                         'rd_namespace' => $this->getNamespace(),
3620                         'rd_title' => $this->getDBkey(),
3621                         'rd_from = page_id'
3622                 );
3623                 if ( !is_null($ns) ) $where['page_namespace'] = $ns;
3624
3625                 $res = $dbr->select(
3626                         array( 'redirect', 'page' ),
3627                         array( 'page_namespace', 'page_title' ),
3628                         $where,
3629                         __METHOD__
3630                 );
3631
3632
3633                 foreach( $res as $row ) {
3634                         $redirs[] = self::newFromRow( $row );
3635                 }
3636                 return $redirs;
3637         }
3638
3639         /**
3640          * Check if this Title is a valid redirect target
3641          *
3642          * @return \type{\bool} TRUE or FALSE
3643          */
3644         public function isValidRedirectTarget() {
3645                 global $wgInvalidRedirectTargets;
3646
3647                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
3648                 if( $this->isSpecial( 'Userlogout' ) ) {
3649                         return false;
3650                 }
3651
3652                 foreach( $wgInvalidRedirectTargets as $target ) {
3653                         if( $this->isSpecial( $target ) ) {
3654                                 return false;
3655                         }
3656                 }
3657
3658                 return true;
3659         }
3660
3661         /**
3662          * Get a backlink cache object
3663          */
3664         function getBacklinkCache() {
3665                 if ( is_null( $this->mBacklinkCache ) ) {
3666                         $this->mBacklinkCache = new BacklinkCache( $this );
3667                 }
3668                 return $this->mBacklinkCache;
3669         }
3670 }