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