includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * @todo:  determine if it is really necessary to load this.  Appears to be left over from pre-autoloader versions, and
   9  *   is only really needed to provide access to constant UTF8_REPLACEMENT, which actually resides in UtfNormalDefines.php
  10  *   and is loaded by UtfNormalUtil.php, which is loaded by UtfNormal.php.
  11  */
  12 if ( !class_exists( 'UtfNormal' ) ) {
  13         require_once( dirname( __FILE__ ) . '/normal/UtfNormal.php' );
  14 }
  15
  16 define ( 'GAID_FOR_UPDATE', 1 );
  17
  18 /**
  19  * Represents a title within MediaWiki.
  20  * Optionally may contain an interwiki designation or namespace.
  21  * @note This class can fetch various kinds of data from the database;
  22  *       however, it does so inefficiently.
  23  *
  24  * @internal documentation reviewed 15 Mar 2010
  25  */
  26 class Title {
  27         /** @name Static cache variables */
  28         // @{
  29         static private $titleCache = array();
  30         static private $interwikiCache = array();
  31         // @}
  32
  33         /**
  34          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  35          * commonly used titles. On a batch operation this can become a memory leak
  36          * if not bounded. After hitting this many titles reset the cache.
  37          */
  38         const CACHE_MAX = 1000;
  39
  40
  41         /**
  42          * @name Private member variables
  43          * Please use the accessor functions instead.
  44          * @private
  45          */
  46         // @{
  47
  48         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  49         var $mUrlform = '';               // /< URL-encoded form of the main part
  50         var $mDbkeyform = '';             // /< Main part with underscores
  51         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  52         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  53         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  54         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  55         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  56         var $mLatestID = false;           // /< ID of most recent revision
  57         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  58         var $mOldRestrictions = false;
  59         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  60         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  61         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  62         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  63         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  64         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  65         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  66         var $mTitleProtection;            ///< Cached value of getTitleProtection
  67         # Don't change the following default, NS_MAIN is hardcoded in several
  68         # places.  See bug 696.
  69         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  70                                           # Zero except in {{transclusion}} tags
  71         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  72         var $mLength = -1;                // /< The page length, 0 for special pages
  73         var $mRedirect = null;            // /< Is the article at this title a redirect?
  74         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  75         var $mBacklinkCache = null;       // /< Cache of links to this title
  76         // @}
  77
  78
  79         /**
  80          * Constructor
  81          * @private
  82          */
  83         /* private */ function __construct() { }
  84
  85         /**
  86          * Create a new Title from a prefixed DB key
  87          *
  88          * @param $key \type{\string} The database key, which has underscores
  89          *      instead of spaces, possibly including namespace and
  90          *      interwiki prefixes
  91          * @return \type{Title} the new object, or NULL on an error
  92          */
  93         public static function newFromDBkey( $key ) {
  94                 $t = new Title();
  95                 $t->mDbkeyform = $key;
  96                 if ( $t->secureAndSplit() )
  97                         return $t;
  98                 else
  99                         return null;
 100         }
 101
 102         /**
 103          * Create a new Title from text, such as what one would find in a link. De-
 104          * codes any HTML entities in the text.
 105          *
 106          * @param $text string  The link text; spaces, prefixes, and an
 107          *   initial ':' indicating the main namespace are accepted.
 108          * @param $defaultNamespace int The namespace to use if none is speci-
 109          *   fied by a prefix.  If you want to force a specific namespace even if
 110          *   $text might begin with a namespace prefix, use makeTitle() or
 111          *   makeTitleSafe().
 112          * @return Title  The new object, or null on an error.
 113          */
 114         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 115                 if ( is_object( $text ) ) {
 116                         throw new MWException( 'Title::newFromText given an object' );
 117                 }
 118
 119                 /**
 120                  * Wiki pages often contain multiple links to the same page.
 121                  * Title normalization and parsing can become expensive on
 122                  * pages with many links, so we can save a little time by
 123                  * caching them.
 124                  *
 125                  * In theory these are value objects and won't get changed...
 126                  */
 127                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 128                         return Title::$titleCache[$text];
 129                 }
 130
 131                 /**
 132                  * Convert things like &eacute; &#257; or &#x3017; into normalized(bug 14952) text
 133                  */
 134                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 135
 136                 $t = new Title();
 137                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 138                 $t->mDefaultNamespace = $defaultNamespace;
 139
 140                 static $cachedcount = 0 ;
 141                 if ( $t->secureAndSplit() ) {
 142                         if ( $defaultNamespace == NS_MAIN ) {
 143                                 if ( $cachedcount >= self::CACHE_MAX ) {
 144                                         # Avoid memory leaks on mass operations...
 145                                         Title::$titleCache = array();
 146                                         $cachedcount = 0;
 147                                 }
 148                                 $cachedcount++;
 149                                 Title::$titleCache[$text] =& $t;
 150                         }
 151                         return $t;
 152                 } else {
 153                         $ret = null;
 154                         return $ret;
 155                 }
 156         }
 157
 158         /**
 159          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 160          *
 161          * Example of wrong and broken code:
 162          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 163          *
 164          * Example of right code:
 165          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 166          *
 167          * Create a new Title from URL-encoded text. Ensures that
 168          * the given title's length does not exceed the maximum.
 169          *
 170          * @param $url \type{\string} the title, as might be taken from a URL
 171          * @return \type{Title} the new object, or NULL on an error
 172          */
 173         public static function newFromURL( $url ) {
 174                 global $wgLegalTitleChars;
 175                 $t = new Title();
 176
 177                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 178                 # but some URLs used it as a space replacement and they still come
 179                 # from some external search tools.
 180                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 181                         $url = str_replace( '+', ' ', $url );
 182                 }
 183
 184                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 185                 if ( $t->secureAndSplit() ) {
 186                         return $t;
 187                 } else {
 188                         return null;
 189                 }
 190         }
 191
 192         /**
 193          * Create a new Title from an article ID
 194          *
 195          * @param $id \type{\int} the page_id corresponding to the Title to create
 196          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 197          * @return \type{Title} the new object, or NULL on an error
 198          */
 199         public static function newFromID( $id, $flags = 0 ) {
 200                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 201                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 202                 if ( $row !== false ) {
 203                         $title = Title::newFromRow( $row );
 204                 } else {
 205                         $title = null;
 206                 }
 207                 return $title;
 208         }
 209
 210         /**
 211          * Make an array of titles from an array of IDs
 212          *
 213          * @param $ids \type{\arrayof{\int}} Array of IDs
 214          * @return \type{\arrayof{Title}} Array of Titles
 215          */
 216         public static function newFromIDs( $ids ) {
 217                 if ( !count( $ids ) ) {
 218                         return array();
 219                 }
 220                 $dbr = wfGetDB( DB_SLAVE );
 221
 222                 $res = $dbr->select( 'page', array( '*' ),
 223                         array( 'page_id' => $ids ), __METHOD__ );
 224
 225                 $titles = array();
 226                 foreach ( $res as $row ) {
 227                         $titles[] = Title::newFromRow( $row );
 228                 }
 229                 return $titles;
 230         }
 231
 232         /**
 233          * Make a Title object from a DB row
 234          *
 235          * @param $row \type{Row} (needs at least page_title,page_namespace)
 236          * @return \type{Title} corresponding Title
 237          */
 238         public static function newFromRow( $row ) {
 239                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 240
 241                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 242                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 243                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 244                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 245
 246                 return $t;
 247         }
 248
 249         /**
 250          * Create a new Title from a namespace index and a DB key.
 251          * It's assumed that $ns and $title are *valid*, for instance when
 252          * they came directly from the database or a special page name.
 253          * For convenience, spaces are converted to underscores so that
 254          * eg user_text fields can be used directly.
 255          *
 256          * @param $ns \type{\int} the namespace of the article
 257          * @param $title \type{\string} the unprefixed database key form
 258          * @param $fragment \type{\string} The link fragment (after the "#")
 259          * @param $interwiki \type{\string} The interwiki prefix
 260          * @return \type{Title} the new object
 261          */
 262         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 263                 $t = new Title();
 264                 $t->mInterwiki = $interwiki;
 265                 $t->mFragment = $fragment;
 266                 $t->mNamespace = $ns = intval( $ns );
 267                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 268                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 269                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 270                 $t->mTextform = str_replace( '_', ' ', $title );
 271                 return $t;
 272         }
 273
 274         /**
 275          * Create a new Title from a namespace index and a DB key.
 276          * The parameters will be checked for validity, which is a bit slower
 277          * than makeTitle() but safer for user-provided data.
 278          *
 279          * @param $ns \type{\int} the namespace of the article
 280          * @param $title \type{\string} the database key form
 281          * @param $fragment \type{\string} The link fragment (after the "#")
 282          * @param $interwiki \type{\string} The interwiki prefix
 283          * @return \type{Title} the new object, or NULL on an error
 284          */
 285         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 286                 $t = new Title();
 287                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 288                 if ( $t->secureAndSplit() ) {
 289                         return $t;
 290                 } else {
 291                         return null;
 292                 }
 293         }
 294
 295         /**
 296          * Create a new Title for the Main Page
 297          *
 298          * @return \type{Title} the new object
 299          */
 300         public static function newMainPage() {
 301                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 302                 // Don't give fatal errors if the message is broken
 303                 if ( !$title ) {
 304                         $title = Title::newFromText( 'Main Page' );
 305                 }
 306                 return $title;
 307         }
 308
 309         /**
 310          * Extract a redirect destination from a string and return the
 311          * Title, or null if the text doesn't contain a valid redirect
 312          * This will only return the very next target, useful for
 313          * the redirect table and other checks that don't need full recursion
 314          *
 315          * @param $text \type{\string} Text with possible redirect
 316          * @return \type{Title} The corresponding Title
 317          */
 318         public static function newFromRedirect( $text ) {
 319                 return self::newFromRedirectInternal( $text );
 320         }
 321
 322         /**
 323          * Extract a redirect destination from a string and return the
 324          * Title, or null if the text doesn't contain a valid redirect
 325          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 326          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 327          *
 328          * @param $text \type{\string} Text with possible redirect
 329          * @return \type{Title} The corresponding Title
 330          */
 331         public static function newFromRedirectRecurse( $text ) {
 332                 $titles = self::newFromRedirectArray( $text );
 333                 return $titles ? array_pop( $titles ) : null;
 334         }
 335
 336         /**
 337          * Extract a redirect destination from a string and return an
 338          * array of Titles, or null if the text doesn't contain a valid redirect
 339          * The last element in the array is the final destination after all redirects
 340          * have been resolved (up to $wgMaxRedirects times)
 341          *
 342          * @param $text \type{\string} Text with possible redirect
 343          * @return \type{\array} Array of Titles, with the destination last
 344          */
 345         public static function newFromRedirectArray( $text ) {
 346                 global $wgMaxRedirects;
 347                 // are redirects disabled?
 348                 if ( $wgMaxRedirects < 1 )
 349                         return null;
 350                 $title = self::newFromRedirectInternal( $text );
 351                 if ( is_null( $title ) )
 352                         return null;
 353                 // recursive check to follow double redirects
 354                 $recurse = $wgMaxRedirects;
 355                 $titles = array( $title );
 356                 while ( --$recurse > 0 ) {
 357                         if ( $title->isRedirect() ) {
 358                                 $article = new Article( $title, 0 );
 359                                 $newtitle = $article->getRedirectTarget();
 360                         } else {
 361                                 break;
 362                         }
 363                         // Redirects to some special pages are not permitted
 364                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 365                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 366                                 $title = $newtitle;
 367                                 $titles[] = $newtitle;
 368                         } else {
 369                                 break;
 370                         }
 371                 }
 372                 return $titles;
 373         }
 374
 375         /**
 376          * Really extract the redirect destination
 377          * Do not call this function directly, use one of the newFromRedirect* functions above
 378          *
 379          * @param $text \type{\string} Text with possible redirect
 380          * @return \type{Title} The corresponding Title
 381          */
 382         protected static function newFromRedirectInternal( $text ) {
 383                 $redir = MagicWord::get( 'redirect' );
 384                 $text = trim( $text );
 385                 if ( $redir->matchStartAndRemove( $text ) ) {
 386                         // Extract the first link and see if it's usable
 387                         // Ensure that it really does come directly after #REDIRECT
 388                         // Some older redirects included a colon, so don't freak about that!
 389                         $m = array();
 390                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 391                                 // Strip preceding colon used to "escape" categories, etc.
 392                                 // and URL-decode links
 393                                 if ( strpos( $m[1], '%' ) !== false ) {
 394                                         // Match behavior of inline link parsing here;
 395                                         // don't interpret + as " " most of the time!
 396                                         // It might be safe to just use rawurldecode instead, though.
 397                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 398                                 }
 399                                 $title = Title::newFromText( $m[1] );
 400                                 // If the title is a redirect to bad special pages or is invalid, return null
 401                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 402                                         return null;
 403                                 }
 404                                 return $title;
 405                         }
 406                 }
 407                 return null;
 408         }
 409
 410 # ----------------------------------------------------------------------------
 411 #       Static functions
 412 # ----------------------------------------------------------------------------
 413
 414         /**
 415          * Get the prefixed DB key associated with an ID
 416          *
 417          * @param $id \type{\int} the page_id of the article
 418          * @return \type{Title} an object representing the article, or NULL
 419          *  if no such article was found
 420          */
 421         public static function nameOf( $id ) {
 422                 $dbr = wfGetDB( DB_SLAVE );
 423
 424                 $s = $dbr->selectRow( 'page',
 425                         array( 'page_namespace', 'page_title' ),
 426                         array( 'page_id' => $id ),
 427                         __METHOD__ );
 428                 if ( $s === false ) { return null; }
 429
 430                 $n = self::makeName( $s->page_namespace, $s->page_title );
 431                 return $n;
 432         }
 433
 434         /**
 435          * Get a regex character class describing the legal characters in a link
 436          *
 437          * @return \type{\string} the list of characters, not delimited
 438          */
 439         public static function legalChars() {
 440                 global $wgLegalTitleChars;
 441                 return $wgLegalTitleChars;
 442         }
 443
 444         /**
 445          * Get a string representation of a title suitable for
 446          * including in a search index
 447          *
 448          * @param $ns \type{\int} a namespace index
 449          * @param $title \type{\string} text-form main part
 450          * @return \type{\string} a stripped-down title string ready for the
 451          *  search index
 452          */
 453         public static function indexTitle( $ns, $title ) {
 454                 global $wgContLang;
 455
 456                 $lc = SearchEngine::legalSearchChars() . '&#;';
 457                 $t = $wgContLang->normalizeForSearch( $title );
 458                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 459                 $t = $wgContLang->lc( $t );
 460
 461                 # Handle 's, s'
 462                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 463                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 464
 465                 $t = preg_replace( "/\\s+/", ' ', $t );
 466
 467                 if ( $ns == NS_FILE ) {
 468                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 469                 }
 470                 return trim( $t );
 471         }
 472
 473         /**
 474          * Make a prefixed DB key from a DB key and a namespace index
 475          *
 476          * @param $ns \type{\int} numerical representation of the namespace
 477          * @param $title \type{\string} the DB key form the title
 478          * @param $fragment \type{\string} The link fragment (after the "#")
 479          * @param $interwiki \type{\string} The interwiki prefix
 480          * @return \type{\string} the prefixed form of the title
 481          */
 482         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 483                 global $wgContLang;
 484
 485                 $namespace = $wgContLang->getNsText( $ns );
 486                 $name = $namespace == '' ? $title : "$namespace:$title";
 487                 if ( strval( $interwiki ) != '' ) {
 488                         $name = "$interwiki:$name";
 489                 }
 490                 if ( strval( $fragment ) != '' ) {
 491                         $name .= '#' . $fragment;
 492                 }
 493                 return $name;
 494         }
 495
 496         /**
 497          * Determine whether the object refers to a page within
 498          * this project.
 499          *
 500          * @return \type{\bool} TRUE if this is an in-project interwiki link
 501          *      or a wikilink, FALSE otherwise
 502          */
 503         public function isLocal() {
 504                 if ( $this->mInterwiki != '' ) {
 505                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 506                 } else {
 507                         return true;
 508                 }
 509         }
 510
 511         /**
 512          * Determine whether the object refers to a page within
 513          * this project and is transcludable.
 514          *
 515          * @return \type{\bool} TRUE if this is transcludable
 516          */
 517         public function isTrans() {
 518                 if ( $this->mInterwiki == '' )
 519                         return false;
 520
 521                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 522         }
 523
 524         /**
 525          * Returns the DB name of the distant wiki
 526          * which owns the object.
 527          *
 528          * @return \type{\string} the DB name
 529          */
 530         public function getTransWikiID() {
 531                 if ( $this->mInterwiki == '' )
 532                         return false;
 533
 534                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 535         }
 536
 537         /**
 538          * Escape a text fragment, say from a link, for a URL
 539          *
 540          * @param $fragment string containing a URL or link fragment (after the "#")
 541          * @return String: escaped string
 542          */
 543         static function escapeFragmentForURL( $fragment ) {
 544                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 545                 # fragments appear not to work in IE (at least up to 7) or in at least
 546                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 547                 # to care if they aren't encoded.
 548                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 549         }
 550
 551 # ----------------------------------------------------------------------------
 552 #       Other stuff
 553 # ----------------------------------------------------------------------------
 554
 555         /** Simple accessors */
 556         /**
 557          * Get the text form (spaces not underscores) of the main part
 558          *
 559          * @return \type{\string} Main part of the title
 560          */
 561         public function getText() { return $this->mTextform; }
 562
 563         /**
 564          * Get the URL-encoded form of the main part
 565          *
 566          * @return \type{\string} Main part of the title, URL-encoded
 567          */
 568         public function getPartialURL() { return $this->mUrlform; }
 569
 570         /**
 571          * Get the main part with underscores
 572          *
 573          * @return \type{\string} Main part of the title, with underscores
 574          */
 575         public function getDBkey() { return $this->mDbkeyform; }
 576
 577         /**
 578          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 579          *
 580          * @return \type{\int} Namespace index
 581          */
 582         public function getNamespace() { return $this->mNamespace; }
 583
 584         /**
 585          * Get the namespace text
 586          *
 587          * @return \type{\string} Namespace text
 588          */
 589         public function getNsText() {
 590                 global $wgContLang;
 591
 592                 if ( $this->mInterwiki != '' ) {
 593                         // This probably shouldn't even happen. ohh man, oh yuck.
 594                         // But for interwiki transclusion it sometimes does.
 595                         // Shit. Shit shit shit.
 596                         //
 597                         // Use the canonical namespaces if possible to try to
 598                         // resolve a foreign namespace.
 599                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 600                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 601                         }
 602                 }
 603                 return $wgContLang->getNsText( $this->mNamespace );
 604         }
 605
 606         /**
 607          * Get the DB key with the initial letter case as specified by the user
 608          *
 609          * @return \type{\string} DB key
 610          */
 611         function getUserCaseDBKey() {
 612                 return $this->mUserCaseDBKey;
 613         }
 614
 615         /**
 616          * Get the namespace text of the subject (rather than talk) page
 617          *
 618          * @return \type{\string} Namespace text
 619          */
 620         public function getSubjectNsText() {
 621                 global $wgContLang;
 622                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 623         }
 624
 625         /**
 626          * Get the namespace text of the talk page
 627          *
 628          * @return \type{\string} Namespace text
 629          */
 630         public function getTalkNsText() {
 631                 global $wgContLang;
 632                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 633         }
 634
 635         /**
 636          * Could this title have a corresponding talk page?
 637          *
 638          * @return \type{\bool} TRUE or FALSE
 639          */
 640         public function canTalk() {
 641                 return( MWNamespace::canTalk( $this->mNamespace ) );
 642         }
 643
 644         /**
 645          * Get the interwiki prefix (or null string)
 646          *
 647          * @return \type{\string} Interwiki prefix
 648          */
 649         public function getInterwiki() { return $this->mInterwiki; }
 650
 651         /**
 652          * Get the Title fragment (i.e.\ the bit after the #) in text form
 653          *
 654          * @return \type{\string} Title fragment
 655          */
 656         public function getFragment() { return $this->mFragment; }
 657
 658         /**
 659          * Get the fragment in URL form, including the "#" character if there is one
 660          * @return \type{\string} Fragment in URL form
 661          */
 662         public function getFragmentForURL() {
 663                 if ( $this->mFragment == '' ) {
 664                         return '';
 665                 } else {
 666                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 667                 }
 668         }
 669
 670         /**
 671          * Get the default namespace index, for when there is no namespace
 672          *
 673          * @return \type{\int} Default namespace index
 674          */
 675         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 676
 677         /**
 678          * Get title for search index
 679          *
 680          * @return \type{\string} a stripped-down title string ready for the
 681          *  search index
 682          */
 683         public function getIndexTitle() {
 684                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 685         }
 686
 687         /**
 688          * Get the prefixed database key form
 689          *
 690          * @return \type{\string} the prefixed title, with underscores and
 691          *  any interwiki and namespace prefixes
 692          */
 693         public function getPrefixedDBkey() {
 694                 $s = $this->prefix( $this->mDbkeyform );
 695                 $s = str_replace( ' ', '_', $s );
 696                 return $s;
 697         }
 698
 699         /**
 700          * Get the prefixed title with spaces.
 701          * This is the form usually used for display
 702          *
 703          * @return \type{\string} the prefixed title, with spaces
 704          */
 705         public function getPrefixedText() {
 706                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 707                         $s = $this->prefix( $this->mTextform );
 708                         $s = str_replace( '_', ' ', $s );
 709                         $this->mPrefixedText = $s;
 710                 }
 711                 return $this->mPrefixedText;
 712         }
 713
 714         /**
 715          * Get the prefixed title with spaces, plus any fragment
 716          * (part beginning with '#')
 717          *
 718          * @return \type{\string} the prefixed title, with spaces and
 719          *  the fragment, including '#'
 720          */
 721         public function getFullText() {
 722                 $text = $this->getPrefixedText();
 723                 if ( $this->mFragment != '' ) {
 724                         $text .= '#' . $this->mFragment;
 725                 }
 726                 return $text;
 727         }
 728
 729         /**
 730          * Get the base name, i.e. the leftmost parts before the /
 731          *
 732          * @return \type{\string} Base name
 733          */
 734         public function getBaseText() {
 735                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 736                         return $this->getText();
 737                 }
 738
 739                 $parts = explode( '/', $this->getText() );
 740                 # Don't discard the real title if there's no subpage involved
 741                 if ( count( $parts ) > 1 )
 742                         unset( $parts[ count( $parts ) - 1 ] );
 743                 return implode( '/', $parts );
 744         }
 745
 746         /**
 747          * Get the lowest-level subpage name, i.e. the rightmost part after /
 748          *
 749          * @return \type{\string} Subpage name
 750          */
 751         public function getSubpageText() {
 752                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 753                         return( $this->mTextform );
 754                 }
 755                 $parts = explode( '/', $this->mTextform );
 756                 return( $parts[ count( $parts ) - 1 ] );
 757         }
 758
 759         /**
 760          * Get a URL-encoded form of the subpage text
 761          *
 762          * @return \type{\string} URL-encoded subpage name
 763          */
 764         public function getSubpageUrlForm() {
 765                 $text = $this->getSubpageText();
 766                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 767                 return( $text );
 768         }
 769
 770         /**
 771          * Get a URL-encoded title (not an actual URL) including interwiki
 772          *
 773          * @return \type{\string} the URL-encoded form
 774          */
 775         public function getPrefixedURL() {
 776                 $s = $this->prefix( $this->mDbkeyform );
 777                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 778                 return $s;
 779         }
 780
 781         /**
 782          * Get a real URL referring to this title, with interwiki link and
 783          * fragment
 784          *
 785          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 786          *   links. Can be specified as an associative array as well, e.g.,
 787          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 788          * @param $variant \type{\string} language variant of url (for sr, zh..)
 789          * @return \type{\string} the URL
 790          */
 791         public function getFullURL( $query = '', $variant = false ) {
 792                 global $wgContLang, $wgServer, $wgRequest;
 793
 794                 if ( is_array( $query ) ) {
 795                         $query = wfArrayToCGI( $query );
 796                 }
 797
 798                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 799                 if ( !$interwiki ) {
 800                         $url = $this->getLocalURL( $query, $variant );
 801
 802                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 803                         // Correct fix would be to move the prepending elsewhere.
 804                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 805                                 $url = $wgServer . $url;
 806                         }
 807                 } else {
 808                         $baseUrl = $interwiki->getURL( );
 809
 810                         $namespace = wfUrlencode( $this->getNsText() );
 811                         if ( $namespace != '' ) {
 812                                 # Can this actually happen? Interwikis shouldn't be parsed.
 813                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 814                                 $namespace .= ':';
 815                         }
 816                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 817                         $url = wfAppendQuery( $url, $query );
 818                 }
 819
 820                 # Finally, add the fragment.
 821                 $url .= $this->getFragmentForURL();
 822
 823                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 824                 return $url;
 825         }
 826
 827         /**
 828          * Get a URL with no fragment or server name.  If this page is generated
 829          * with action=render, $wgServer is prepended.
 830          *
 831          * @param $query Mixed: an optional query string; if not specified,
 832          *   $wgArticlePath will be used.  Can be specified as an associative array
 833          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 834          *   URL-escaped).
 835          * @param $variant \type{\string} language variant of url (for sr, zh..)
 836          * @return \type{\string} the URL
 837          */
 838         public function getLocalURL( $query = '', $variant = false ) {
 839                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 840                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 841
 842                 if ( is_array( $query ) ) {
 843                         $query = wfArrayToCGI( $query );
 844                 }
 845
 846                 // internal links should point to same variant as current page (only anonymous users)
 847                 if ( !$variant && $wgContLang->hasVariants() && !$wgUser->isLoggedIn() ) {
 848                         $pref = $wgContLang->getPreferredVariant( false );
 849                         if ( $pref != $wgContLang->getCode() )
 850                                 $variant = $pref;
 851                 }
 852
 853                 if ( $this->isExternal() ) {
 854                         $url = $this->getFullURL();
 855                         if ( $query ) {
 856                                 // This is currently only used for edit section links in the
 857                                 // context of interwiki transclusion. In theory we should
 858                                 // append the query to the end of any existing query string,
 859                                 // but interwiki transclusion is already broken in that case.
 860                                 $url .= "?$query";
 861                         }
 862                 } else {
 863                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 864                         if ( $query == '' ) {
 865                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 866                                         if ( !$wgVariantArticlePath ) {
 867                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 868                                         } else {
 869                                                 $variantArticlePath = $wgVariantArticlePath;
 870                                         }
 871                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 872                                         $url = str_replace( '$1', $dbkey, $url  );
 873                                 } else {
 874                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 875                                 }
 876                         } else {
 877                                 global $wgActionPaths;
 878                                 $url = false;
 879                                 $matches = array();
 880                                 if ( !empty( $wgActionPaths ) &&
 881                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 882                                 {
 883                                         $action = urldecode( $matches[2] );
 884                                         if ( isset( $wgActionPaths[$action] ) ) {
 885                                                 $query = $matches[1];
 886                                                 if ( isset( $matches[4] ) ) $query .= $matches[4];
 887                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 888                                                 if ( $query != '' ) {
 889                                                         $url = wfAppendQuery( $url, $query );
 890                                                 }
 891                                         }
 892                                 }
 893                                 if ( $url === false ) {
 894                                         if ( $query == '-' ) {
 895                                                 $query = '';
 896                                         }
 897                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 898                                 }
 899                         }
 900
 901                         // FIXME: this causes breakage in various places when we
 902                         // actually expected a local URL and end up with dupe prefixes.
 903                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 904                                 $url = $wgServer . $url;
 905                         }
 906                 }
 907                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 908                 return $url;
 909         }
 910
 911         /**
 912          * Get a URL that's the simplest URL that will be valid to link, locally,
 913          * to the current Title.  It includes the fragment, but does not include
 914          * the server unless action=render is used (or the link is external).  If
 915          * there's a fragment but the prefixed text is empty, we just return a link
 916          * to the fragment.
 917          *
 918          * The result obviously should not be URL-escaped, but does need to be
 919          * HTML-escaped if it's being output in HTML.
 920          *
 921          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 922          *   query string.  Keys and values will be escaped.
 923          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 924          *   for external links.  Default is "false" (same variant as current page,
 925          *   for anonymous users).
 926          * @return \type{\string} the URL
 927          */
 928         public function getLinkUrl( $query = array(), $variant = false ) {
 929                 wfProfileIn( __METHOD__ );
 930                 if ( $this->isExternal() ) {
 931                         $ret = $this->getFullURL( $query );
 932                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 933                         $ret = $this->getFragmentForURL();
 934                 } else {
 935                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 936                 }
 937                 wfProfileOut( __METHOD__ );
 938                 return $ret;
 939         }
 940
 941         /**
 942          * Get an HTML-escaped version of the URL form, suitable for
 943          * using in a link, without a server name or fragment
 944          *
 945          * @param $query \type{\string} an optional query string
 946          * @return \type{\string} the URL
 947          */
 948         public function escapeLocalURL( $query = '' ) {
 949                 return htmlspecialchars( $this->getLocalURL( $query ) );
 950         }
 951
 952         /**
 953          * Get an HTML-escaped version of the URL form, suitable for
 954          * using in a link, including the server name and fragment
 955          *
 956          * @param $query \type{\string} an optional query string
 957          * @return \type{\string} the URL
 958          */
 959         public function escapeFullURL( $query = '' ) {
 960                 return htmlspecialchars( $this->getFullURL( $query ) );
 961         }
 962
 963         /**
 964          * Get the URL form for an internal link.
 965          * - Used in various Squid-related code, in case we have a different
 966          * internal hostname for the server from the exposed one.
 967          *
 968          * @param $query \type{\string} an optional query string
 969          * @param $variant \type{\string} language variant of url (for sr, zh..)
 970          * @return \type{\string} the URL
 971          */
 972         public function getInternalURL( $query = '', $variant = false ) {
 973                 global $wgInternalServer;
 974                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 975                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 976                 return $url;
 977         }
 978
 979         /**
 980          * Get the edit URL for this Title
 981          *
 982          * @return \type{\string} the URL, or a null string if this is an
 983          *  interwiki link
 984          */
 985         public function getEditURL() {
 986                 if ( $this->mInterwiki != '' ) { return ''; }
 987                 $s = $this->getLocalURL( 'action=edit' );
 988
 989                 return $s;
 990         }
 991
 992         /**
 993          * Get the HTML-escaped displayable text form.
 994          * Used for the title field in <a> tags.
 995          *
 996          * @return \type{\string} the text, including any prefixes
 997          */
 998         public function getEscapedText() {
 999                 return htmlspecialchars( $this->getPrefixedText() );
1000         }
1001
1002         /**
1003          * Is this Title interwiki?
1004          *
1005          * @return \type{\bool}
1006          */
1007         public function isExternal() { return ( $this->mInterwiki != '' ); }
1008
1009         /**
1010          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1011          *
1012          * @param $action \type{\string} Action to check (default: edit)
1013          * @return \type{\bool}
1014          */
1015         public function isSemiProtected( $action = 'edit' ) {
1016                 if ( $this->exists() ) {
1017                         $restrictions = $this->getRestrictions( $action );
1018                         if ( count( $restrictions ) > 0 ) {
1019                                 foreach ( $restrictions as $restriction ) {
1020                                         if ( strtolower( $restriction ) != 'autoconfirmed' )
1021                                                 return false;
1022                                 }
1023                         } else {
1024                                 # Not protected
1025                                 return false;
1026                         }
1027                         return true;
1028                 } else {
1029                         # If it doesn't exist, it can't be protected
1030                         return false;
1031                 }
1032         }
1033
1034         /**
1035          * Does the title correspond to a protected article?
1036          *
1037          * @param $action \type{\string} the action the page is protected from,
1038          * by default checks all actions.
1039          * @return \type{\bool}
1040          */
1041         public function isProtected( $action = '' ) {
1042                 global $wgRestrictionLevels;
1043
1044                 $restrictionTypes = $this->getRestrictionTypes();
1045
1046                 # Special pages have inherent protection
1047                 if( $this->getNamespace() == NS_SPECIAL )
1048                         return true;
1049
1050                 # Check regular protection levels
1051                 foreach ( $restrictionTypes as $type ) {
1052                         if ( $action == $type || $action == '' ) {
1053                                 $r = $this->getRestrictions( $type );
1054                                 foreach ( $wgRestrictionLevels as $level ) {
1055                                         if ( in_array( $level, $r ) && $level != '' ) {
1056                                                 return true;
1057                                         }
1058                                 }
1059                         }
1060                 }
1061
1062                 return false;
1063         }
1064
1065         /**
1066          * Is this a conversion table for the LanguageConverter?
1067          *
1068          * @return \type{\bool}
1069          */
1070         public function isConversionTable() {
1071                 if($this->getNamespace() == NS_MEDIAWIKI
1072                    && strpos( $this->getText(), 'Conversiontable' ) !== false ) {
1073                         return true;
1074                 }
1075
1076                 return false;
1077         }
1078
1079         /**
1080          * Is $wgUser watching this page?
1081          *
1082          * @return \type{\bool}
1083          */
1084         public function userIsWatching() {
1085                 global $wgUser;
1086
1087                 if ( is_null( $this->mWatched ) ) {
1088                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1089                                 $this->mWatched = false;
1090                         } else {
1091                                 $this->mWatched = $wgUser->isWatched( $this );
1092                         }
1093                 }
1094                 return $this->mWatched;
1095         }
1096
1097         /**
1098          * Can $wgUser perform $action on this page?
1099          * This skips potentially expensive cascading permission checks
1100          * as well as avoids expensive error formatting
1101          *
1102          * Suitable for use for nonessential UI controls in common cases, but
1103          * _not_ for functional access control.
1104          *
1105          * May provide false positives, but should never provide a false negative.
1106          *
1107          * @param $action \type{\string} action that permission needs to be checked for
1108          * @return \type{\bool}
1109          */
1110         public function quickUserCan( $action ) {
1111                 return $this->userCan( $action, false );
1112         }
1113
1114         /**
1115          * Determines if $wgUser is unable to edit this page because it has been protected
1116          * by $wgNamespaceProtection.
1117          *
1118          * @return \type{\bool}
1119          */
1120         public function isNamespaceProtected() {
1121                 global $wgNamespaceProtection, $wgUser;
1122                 if ( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1123                         foreach ( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1124                                 if ( $right != '' && !$wgUser->isAllowed( $right ) )
1125                                         return true;
1126                         }
1127                 }
1128                 return false;
1129         }
1130
1131         /**
1132          * Can $wgUser perform $action on this page?
1133          *
1134          * @param $action \type{\string} action that permission needs to be checked for
1135          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1136          * @return \type{\bool}
1137          */
1138         public function userCan( $action, $doExpensiveQueries = true ) {
1139                 global $wgUser;
1140                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1141         }
1142
1143         /**
1144          * Can $user perform $action on this page?
1145          *
1146          * FIXME: This *does not* check throttles (User::pingLimiter()).
1147          *
1148          * @param $action \type{\string}action that permission needs to be checked for
1149          * @param $user \type{User} user to check
1150          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1151          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1152          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1153          */
1154         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1155                 if ( !StubObject::isRealObject( $user ) ) {
1156                         // Since StubObject is always used on globals, we can
1157                         // unstub $wgUser here and set $user = $wgUser
1158                         global $wgUser;
1159                         $wgUser->_unstub( '', 5 );
1160                         $user = $wgUser;
1161                 }
1162
1163                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1164
1165                 // Remove the errors being ignored.
1166                 foreach ( $errors as $index => $error ) {
1167                         $error_key = is_array( $error ) ? $error[0] : $error;
1168
1169                         if ( in_array( $error_key, $ignoreErrors ) ) {
1170                                 unset( $errors[$index] );
1171                         }
1172                 }
1173
1174                 return $errors;
1175         }
1176
1177         /**
1178          * Permissions checks that fail most often, and which are easiest to test.
1179          *
1180          * @param $action String the action to check
1181          * @param $user User user to check
1182          * @param $errors Array list of current errors
1183          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1184          * @param $short Boolean short circuit on first error
1185          *
1186          * @return Array list of errors
1187          */
1188         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1189                 if ( $action == 'create' ) {
1190                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1191                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1192                                 $errors[] = $user->isAnon() ? array ( 'nocreatetext' ) : array ( 'nocreate-loggedin' );
1193                         }
1194                 } elseif ( $action == 'move' ) {
1195                         if ( !$user->isAllowed( 'move-rootuserpages' )
1196                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1197                                 // Show user page-specific message only if the user can move other pages
1198                                 $errors[] = array( 'cant-move-user-page' );
1199                         }
1200
1201                         // Check if user is allowed to move files if it's a file
1202                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1203                                 $errors[] = array( 'movenotallowedfile' );
1204                         }
1205
1206                         if ( !$user->isAllowed( 'move' ) ) {
1207                                 // User can't move anything
1208                                 global $wgGroupPermissions;
1209                                 $userCanMove = false;
1210                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1211                                         $userCanMove = $wgGroupPermissions['user']['move'];
1212                                 }
1213                                 $autoconfirmedCanMove = false;
1214                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1215                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1216                                 }
1217                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1218                                         // custom message if logged-in users without any special rights can move
1219                                         $errors[] = array ( 'movenologintext' );
1220                                 } else {
1221                                         $errors[] = array ( 'movenotallowed' );
1222                                 }
1223                         }
1224                 } elseif ( $action == 'move-target' ) {
1225                         if ( !$user->isAllowed( 'move' ) ) {
1226                                 // User can't move anything
1227                                 $errors[] = array ( 'movenotallowed' );
1228                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1229                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1230                                 // Show user page-specific message only if the user can move other pages
1231                                 $errors[] = array( 'cant-move-to-user-page' );
1232                         }
1233                 } elseif ( !$user->isAllowed( $action ) ) {
1234                         $return = null;
1235
1236                         // We avoid expensive display logic for quickUserCan's and such
1237                         $groups = false;
1238                         if ( !$short ) {
1239                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1240                                         User::getGroupsWithPermission( $action ) );
1241                         }
1242
1243                         if ( $groups ) {
1244                                 global $wgLang;
1245                                 $return = array(
1246                                         'badaccess-groups',
1247                                         $wgLang->commaList( $groups ),
1248                                         count( $groups )
1249                                 );
1250                         } else {
1251                                 $return = array( "badaccess-group0" );
1252                         }
1253                         $errors[] = $return;
1254                 }
1255
1256                 return $errors;
1257         }
1258
1259         /**
1260          * Add the resulting error code to the errors array
1261          *
1262          * @param $errors Array list of current errors
1263          * @param $result Mixed result of errors
1264          *
1265          * @return Array list of errors
1266          */
1267         private function resultToError( $errors, $result ) {
1268                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1269                         // A single array representing an error
1270                         $errors[] = $result;
1271                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1272                         // A nested array representing multiple errors
1273                         $errors = array_merge( $errors, $result );
1274                 } else if ( $result !== '' && is_string( $result ) ) {
1275                         // A string representing a message-id
1276                         $errors[] = array( $result );
1277                 } else if ( $result === false ) {
1278                         // a generic "We don't want them to do that"
1279                         $errors[] = array( 'badaccess-group0' );
1280                 }
1281                 return $errors;
1282         }
1283
1284         /**
1285          * Check various permission hooks
1286          * @see checkQuickPermissions for parameter information
1287          */
1288         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1289                 // Use getUserPermissionsErrors instead
1290                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1291                         return $result ? array() : array( array( 'badaccess-group0' ) );
1292                 }
1293                 // Check getUserPermissionsErrors hook
1294                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1295                         $errors = $this->resultToError( $errors, $result );
1296                 }
1297                 // Check getUserPermissionsErrorsExpensive hook
1298                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1299                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1300                         $errors = $this->resultToError( $errors, $result );
1301                 }
1302
1303                 return $errors;
1304         }
1305
1306         /**
1307          * Check permissions on special pages & namespaces
1308          * @see checkQuickPermissions for parameter information
1309          */
1310         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1311                 # Only 'createaccount' and 'execute' can be performed on
1312                 # special pages, which don't actually exist in the DB.
1313                 $specialOKActions = array( 'createaccount', 'execute' );
1314                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1315                         $errors[] = array( 'ns-specialprotected' );
1316                 }
1317
1318                 # Check $wgNamespaceProtection for restricted namespaces
1319                 if ( $this->isNamespaceProtected() ) {
1320                         $ns = $this->mNamespace == NS_MAIN ?
1321                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1322                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1323                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1324                 }
1325
1326                 return $errors;
1327         }
1328
1329         /**
1330          * Check CSS/JS sub-page permissions
1331          * @see checkQuickPermissions for parameter information
1332          */
1333         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1334                 # Protect css/js subpages of user pages
1335                 # XXX: this might be better using restrictions
1336                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1337                 #      and $this->userCanEditJsSubpage() from working
1338                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1339                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1340                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1341                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1342                                 $errors[] = array( 'customcssjsprotected' );
1343                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1344                                 $errors[] = array( 'customcssjsprotected' );
1345                         }
1346                 }
1347
1348                 return $errors;
1349         }
1350
1351         /**
1352          * Check against page_restrictions table requirements on this
1353          * page. The user must possess all required rights for this
1354          * action.
1355          * @see checkQuickPermissions for parameter information
1356          */
1357         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1358                 foreach ( $this->getRestrictions( $action ) as $right ) {
1359                         // Backwards compatibility, rewrite sysop -> protect
1360                         if ( $right == 'sysop' ) {
1361                                 $right = 'protect';
1362                         }
1363                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1364                                 // Users with 'editprotected' permission can edit protected pages
1365                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1366                                         // Users with 'editprotected' permission cannot edit protected pages
1367                                         // with cascading option turned on.
1368                                         if ( $this->mCascadeRestriction ) {
1369                                                 $errors[] = array( 'protectedpagetext', $right );
1370                                         }
1371                                 } else {
1372                                         $errors[] = array( 'protectedpagetext', $right );
1373                                 }
1374                         }
1375                 }
1376
1377                 return $errors;
1378         }
1379
1380         /**
1381          * Check restrictions on cascading pages.
1382          * @see checkQuickPermissions for parameter information
1383          */
1384         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1385                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1386                         # We /could/ use the protection level on the source page, but it's
1387                         # fairly ugly as we have to establish a precedence hierarchy for pages
1388                         # included by multiple cascade-protected pages. So just restrict
1389                         # it to people with 'protect' permission, as they could remove the
1390                         # protection anyway.
1391                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1392                         # Cascading protection depends on more than this page...
1393                         # Several cascading protected pages may include this page...
1394                         # Check each cascading level
1395                         # This is only for protection restrictions, not for all actions
1396                         if ( isset( $restrictions[$action] ) ) {
1397                                 foreach ( $restrictions[$action] as $right ) {
1398                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1399                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1400                                                 $pages = '';
1401                                                 foreach ( $cascadingSources as $page )
1402                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1403                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1404                                         }
1405                                 }
1406                         }
1407                 }
1408
1409                 return $errors;
1410         }
1411
1412         /**
1413          * Check action permissions not already checked in checkQuickPermissions
1414          * @see checkQuickPermissions for parameter information
1415          */
1416         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1417                 if ( $action == 'protect' ) {
1418                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1419                                 // If they can't edit, they shouldn't protect.
1420                                 $errors[] = array( 'protect-cantedit' );
1421                         }
1422                 } elseif ( $action == 'create' ) {
1423                         $title_protection = $this->getTitleProtection();
1424                         if( $title_protection ) {
1425                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1426                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1427                                 }
1428                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1429                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1430                                 }
1431                         }
1432                 } elseif ( $action == 'move' ) {
1433                         // Check for immobile pages
1434                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1435                                 // Specific message for this case
1436                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1437                         } elseif ( !$this->isMovable() ) {
1438                                 // Less specific message for rarer cases
1439                                 $errors[] = array( 'immobile-page' );
1440                         }
1441                 } elseif ( $action == 'move-target' ) {
1442                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1443                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1444                         } elseif ( !$this->isMovable() ) {
1445                                 $errors[] = array( 'immobile-target-page' );
1446                         }
1447                 }
1448                 return $errors;
1449         }
1450
1451         /**
1452          * Check that the user isn't blocked from editting.
1453          * @see checkQuickPermissions for parameter information
1454          */
1455         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1456                 if( $short ) {
1457                         return $errors;
1458                 }
1459
1460                 global $wgContLang;
1461                 global $wgLang;
1462                 global $wgEmailConfirmToEdit;
1463
1464                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1465                         $errors[] = array( 'confirmedittext' );
1466                 }
1467
1468                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1469                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1470                         $block = $user->mBlock;
1471
1472                         // This is from OutputPage::blockedPage
1473                         // Copied at r23888 by werdna
1474
1475                         $id = $user->blockedBy();
1476                         $reason = $user->blockedFor();
1477                         if ( $reason == '' ) {
1478                                 $reason = wfMsg( 'blockednoreason' );
1479                         }
1480                         $ip = wfGetIP();
1481
1482                         if ( is_numeric( $id ) ) {
1483                                 $name = User::whoIs( $id );
1484                         } else {
1485                                 $name = $id;
1486                         }
1487
1488                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1489                         $blockid = $block->mId;
1490                         $blockExpiry = $user->mBlock->mExpiry;
1491                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1492                         if ( $blockExpiry == 'infinity' ) {
1493                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1494                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1495
1496                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1497                                         if ( !strpos( $option, ':' ) )
1498                                                 continue;
1499
1500                                         list ( $show, $value ) = explode( ":", $option );
1501
1502                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1503                                                 $blockExpiry = $show;
1504                                                 break;
1505                                         }
1506                                 }
1507                         } else {
1508                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1509                         }
1510
1511                         $intended = $user->mBlock->mAddress;
1512
1513                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1514                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1515                 }
1516
1517                 return $errors;
1518         }
1519
1520         /**
1521          * Can $user perform $action on this page? This is an internal function,
1522          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1523          * checks on wfReadOnly() and blocks)
1524          *
1525          * @param $action \type{\string} action that permission needs to be checked for
1526          * @param $user \type{User} user to check
1527          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1528          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1529          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1530          */
1531         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1532                 wfProfileIn( __METHOD__ );
1533
1534                 $errors = array();
1535                 $checks = array( 'checkQuickPermissions',
1536                         'checkPermissionHooks',
1537                         'checkSpecialsAndNSPermissions',
1538                         'checkCSSandJSPermissions',
1539                         'checkPageRestrictions',
1540                         'checkCascadingSourcesRestrictions',
1541                         'checkActionPermissions',
1542                         'checkUserBlock' );
1543
1544                 while( count( $checks ) > 0 &&
1545                            !( $short && count( $errors ) > 0 ) ) {
1546                         $method = array_shift( $checks );
1547                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1548                 }
1549
1550                 wfProfileOut( __METHOD__ );
1551                 return $errors;
1552         }
1553
1554         /**
1555          * Is this title subject to title protection?
1556          *
1557          * @return \type{\mixed} An associative array representing any existent title
1558          *   protection, or false if there's none.
1559          */
1560         private function getTitleProtection() {
1561                 // Can't protect pages in special namespaces
1562                 if ( $this->getNamespace() < 0 ) {
1563                         return false;
1564                 }
1565
1566                 // Can't protect pages that exist.
1567                 if ( $this->exists() ) {
1568                         return false;
1569                 }
1570
1571                 if ( !isset( $this->mTitleProtection ) ) {
1572                         $dbr = wfGetDB( DB_SLAVE );
1573                         $res = $dbr->select( 'protected_titles', '*',
1574                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1575                                 __METHOD__ );
1576
1577                         // fetchRow returns false if there are no rows.
1578                         $this->mTitleProtection = $dbr->fetchRow( $res );
1579                 }
1580                 return $this->mTitleProtection;
1581         }
1582
1583         /**
1584          * Update the title protection status
1585          *
1586          * @param $create_perm \type{\string} Permission required for creation
1587          * @param $reason \type{\string} Reason for protection
1588          * @param $expiry \type{\string} Expiry timestamp
1589          * @return boolean true
1590          */
1591         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1592                 global $wgUser, $wgContLang;
1593
1594                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1595                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1596                         // No change
1597                         return true;
1598                 }
1599
1600                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1601
1602                 $dbw = wfGetDB( DB_MASTER );
1603
1604                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1605
1606                 $expiry_description = '';
1607                 if ( $encodedExpiry != 'infinity' ) {
1608                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1609                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1610                 }
1611                 else {
1612                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1613                 }
1614
1615                 # Update protection table
1616                 if ( $create_perm != '' ) {
1617                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1618                                 array(
1619                                         'pt_namespace' => $namespace,
1620                                         'pt_title' => $title,
1621                                         'pt_create_perm' => $create_perm,
1622                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1623                                         'pt_expiry' => $encodedExpiry,
1624                                         'pt_user' => $wgUser->getId(),
1625                                         'pt_reason' => $reason,
1626                                 ), __METHOD__
1627                         );
1628                 } else {
1629                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1630                                 'pt_title' => $title ), __METHOD__ );
1631                 }
1632                 # Update the protection log
1633                 if ( $dbw->affectedRows() ) {
1634                         $log = new LogPage( 'protect' );
1635
1636                         if ( $create_perm ) {
1637                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1638                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1639                         } else {
1640                                 $log->addEntry( 'unprotect', $this, $reason );
1641                         }
1642                 }
1643
1644                 return true;
1645         }
1646
1647         /**
1648          * Remove any title protection due to page existing
1649          */
1650         public function deleteTitleProtection() {
1651                 $dbw = wfGetDB( DB_MASTER );
1652
1653                 $dbw->delete( 'protected_titles',
1654                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1655                         __METHOD__ );
1656         }
1657
1658         /**
1659          * Would anybody with sufficient privileges be able to move this page?
1660          * Some pages just aren't movable.
1661          *
1662          * @return \type{\bool} TRUE or FALSE
1663          */
1664         public function isMovable() {
1665                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1666         }
1667
1668         /**
1669          * Can $wgUser read this page?
1670          *
1671          * @return \type{\bool}
1672          * @todo fold these checks into userCan()
1673          */
1674         public function userCanRead() {
1675                 global $wgUser, $wgGroupPermissions;
1676
1677                 static $useShortcut = null;
1678
1679                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1680                 if ( is_null( $useShortcut ) ) {
1681                         global $wgRevokePermissions;
1682                         $useShortcut = true;
1683                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1684                                 # Not a public wiki, so no shortcut
1685                                 $useShortcut = false;
1686                         } elseif ( !empty( $wgRevokePermissions ) ) {
1687                                 /*
1688                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1689                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1690                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1691                                  * reading is allowed.
1692                                  */
1693                                 foreach ( $wgRevokePermissions as $perms ) {
1694                                         if ( !empty( $perms['read'] ) ) {
1695                                                 # We might be removing the read right from the user, so no shortcut
1696                                                 $useShortcut = false;
1697                                                 break;
1698                                         }
1699                                 }
1700                         }
1701                 }
1702
1703                 $result = null;
1704                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1705                 if ( $result !== null ) {
1706                         return $result;
1707                 }
1708
1709                 # Shortcut for public wikis, allows skipping quite a bit of code
1710                 if ( $useShortcut )
1711                         return true;
1712
1713                 if ( $wgUser->isAllowed( 'read' ) ) {
1714                         return true;
1715                 } else {
1716                         global $wgWhitelistRead;
1717
1718                         /**
1719                          * Always grant access to the login page.
1720                          * Even anons need to be able to log in.
1721                         */
1722                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1723                                 return true;
1724                         }
1725
1726                         /**
1727                          * Bail out if there isn't whitelist
1728                          */
1729                         if ( !is_array( $wgWhitelistRead ) ) {
1730                                 return false;
1731                         }
1732
1733                         /**
1734                          * Check for explicit whitelisting
1735                          */
1736                         $name = $this->getPrefixedText();
1737                         $dbName = $this->getPrefixedDBKey();
1738                         // Check with and without underscores
1739                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1740                                 return true;
1741
1742                         /**
1743                          * Old settings might have the title prefixed with
1744                          * a colon for main-namespace pages
1745                          */
1746                         if ( $this->getNamespace() == NS_MAIN ) {
1747                                 if ( in_array( ':' . $name, $wgWhitelistRead ) )
1748                                         return true;
1749                         }
1750
1751                         /**
1752                          * If it's a special page, ditch the subpage bit
1753                          * and check again
1754                          */
1755                         if ( $this->getNamespace() == NS_SPECIAL ) {
1756                                 $name = $this->getDBkey();
1757                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1758                                 if ( $name === false ) {
1759                                         # Invalid special page, but we show standard login required message
1760                                         return false;
1761                                 }
1762
1763                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1764                                 if ( in_array( $pure, $wgWhitelistRead, true ) )
1765                                         return true;
1766                         }
1767
1768                 }
1769                 return false;
1770         }
1771
1772         /**
1773          * Is this a talk page of some sort?
1774          *
1775          * @return \type{\bool}
1776          */
1777         public function isTalkPage() {
1778                 return MWNamespace::isTalk( $this->getNamespace() );
1779         }
1780
1781         /**
1782          * Is this a subpage?
1783          *
1784          * @return \type{\bool}
1785          */
1786         public function isSubpage() {
1787                 return MWNamespace::hasSubpages( $this->mNamespace )
1788                         ? strpos( $this->getText(), '/' ) !== false
1789                         : false;
1790         }
1791
1792         /**
1793          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1794          *
1795          * @return \type{\bool}
1796          */
1797         public function hasSubpages() {
1798                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1799                         # Duh
1800                         return false;
1801                 }
1802
1803                 # We dynamically add a member variable for the purpose of this method
1804                 # alone to cache the result.  There's no point in having it hanging
1805                 # around uninitialized in every Title object; therefore we only add it
1806                 # if needed and don't declare it statically.
1807                 if ( isset( $this->mHasSubpages ) ) {
1808                         return $this->mHasSubpages;
1809                 }
1810
1811                 $subpages = $this->getSubpages( 1 );
1812                 if ( $subpages instanceof TitleArray )
1813                         return $this->mHasSubpages = (bool)$subpages->count();
1814                 return $this->mHasSubpages = false;
1815         }
1816
1817         /**
1818          * Get all subpages of this page.
1819          *
1820          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1821          * @return mixed TitleArray, or empty array if this page's namespace
1822          *  doesn't allow subpages
1823          */
1824         public function getSubpages( $limit = -1 ) {
1825                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1826                         return array();
1827
1828                 $dbr = wfGetDB( DB_SLAVE );
1829                 $conds['page_namespace'] = $this->getNamespace();
1830                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1831                 $options = array();
1832                 if ( $limit > -1 )
1833                         $options['LIMIT'] = $limit;
1834                 return $this->mSubpages = TitleArray::newFromResult(
1835                         $dbr->select( 'page',
1836                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1837                                 $conds,
1838                                 __METHOD__,
1839                                 $options
1840                         )
1841                 );
1842         }
1843
1844         /**
1845          * Could this page contain custom CSS or JavaScript, based
1846          * on the title?
1847          *
1848          * @return \type{\bool}
1849          */
1850         public function isCssOrJsPage() {
1851                 return $this->mNamespace == NS_MEDIAWIKI
1852                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1853         }
1854
1855         /**
1856          * Is this a .css or .js subpage of a user page?
1857          * @return \type{\bool}
1858          */
1859         public function isCssJsSubpage() {
1860                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1861         }
1862
1863         /**
1864          * Is this a *valid* .css or .js subpage of a user page?
1865          * Check that the corresponding skin exists
1866          *
1867          * @return \type{\bool}
1868          */
1869         public function isValidCssJsSubpage() {
1870                 if ( $this->isCssJsSubpage() ) {
1871                         $name = $this->getSkinFromCssJsSubpage();
1872                         if ( $name == 'common' ) return true;
1873                         $skinNames = Skin::getSkinNames();
1874                         return array_key_exists( $name, $skinNames );
1875                 } else {
1876                         return false;
1877                 }
1878         }
1879
1880         /**
1881          * Trim down a .css or .js subpage title to get the corresponding skin name
1882          *
1883          * @return string containing skin name from .css or .js subpage title
1884          */
1885         public function getSkinFromCssJsSubpage() {
1886                 $subpage = explode( '/', $this->mTextform );
1887                 $subpage = $subpage[ count( $subpage ) - 1 ];
1888                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1889         }
1890
1891         /**
1892          * Is this a .css subpage of a user page?
1893          *
1894          * @return \type{\bool}
1895          */
1896         public function isCssSubpage() {
1897                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1898         }
1899
1900         /**
1901          * Is this a .js subpage of a user page?
1902          *
1903          * @return \type{\bool}
1904          */
1905         public function isJsSubpage() {
1906                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1907         }
1908
1909         /**
1910          * Protect css subpages of user pages: can $wgUser edit
1911          * this page?
1912          *
1913          * @return \type{\bool}
1914          * @todo XXX: this might be better using restrictions
1915          */
1916         public function userCanEditCssSubpage() {
1917                 global $wgUser;
1918                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1919                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1920         }
1921         /**
1922          * Protect js subpages of user pages: can $wgUser edit
1923          * this page?
1924          *
1925          * @return \type{\bool}
1926          * @todo XXX: this might be better using restrictions
1927          */
1928         public function userCanEditJsSubpage() {
1929                 global $wgUser;
1930                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1931                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1932         }
1933
1934         /**
1935          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1936          *
1937          * @return \type{\bool} If the page is subject to cascading restrictions.
1938          */
1939         public function isCascadeProtected() {
1940                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1941                 return ( $sources > 0 );
1942         }
1943
1944         /**
1945          * Cascading protection: Get the source of any cascading restrictions on this page.
1946          *
1947          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1948          *        that the restrictions have come from.
1949          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1950          *         objects of the pages from which cascading restrictions have come,
1951          *         false for none, or true if such restrictions exist, but $getPages was not set.
1952          *         The restriction array is an array of each type, each of which contains a
1953          *         array of unique groups.
1954          */
1955         public function getCascadeProtectionSources( $getPages = true ) {
1956                 $pagerestrictions = array();
1957
1958                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1959                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1960                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
1961                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1962                 }
1963
1964                 wfProfileIn( __METHOD__ );
1965
1966                 $dbr = wfGetDB( DB_SLAVE );
1967
1968                 if ( $this->getNamespace() == NS_FILE ) {
1969                         $tables = array ( 'imagelinks', 'page_restrictions' );
1970                         $where_clauses = array(
1971                                 'il_to' => $this->getDBkey(),
1972                                 'il_from=pr_page',
1973                                 'pr_cascade' => 1 );
1974                 } else {
1975                         $tables = array ( 'templatelinks', 'page_restrictions' );
1976                         $where_clauses = array(
1977                                 'tl_namespace' => $this->getNamespace(),
1978                                 'tl_title' => $this->getDBkey(),
1979                                 'tl_from=pr_page',
1980                                 'pr_cascade' => 1 );
1981                 }
1982
1983                 if ( $getPages ) {
1984                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
1985                                                    'pr_expiry', 'pr_type', 'pr_level' );
1986                         $where_clauses[] = 'page_id=pr_page';
1987                         $tables[] = 'page';
1988                 } else {
1989                         $cols = array( 'pr_expiry' );
1990                 }
1991
1992                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
1993
1994                 $sources = $getPages ? array() : false;
1995                 $now = wfTimestampNow();
1996                 $purgeExpired = false;
1997
1998                 foreach ( $res as $row ) {
1999                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2000                         if ( $expiry > $now ) {
2001                                 if ( $getPages ) {
2002                                         $page_id = $row->pr_page;
2003                                         $page_ns = $row->page_namespace;
2004                                         $page_title = $row->page_title;
2005                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2006                                         # Add groups needed for each restriction type if its not already there
2007                                         # Make sure this restriction type still exists
2008
2009                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2010                                                 $pagerestrictions[$row->pr_type] = array();
2011                                         }
2012
2013                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2014                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2015                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2016                                         }
2017                                 } else {
2018                                         $sources = true;
2019                                 }
2020                         } else {
2021                                 // Trigger lazy purge of expired restrictions from the db
2022                                 $purgeExpired = true;
2023                         }
2024                 }
2025                 if ( $purgeExpired ) {
2026                         Title::purgeExpiredRestrictions();
2027                 }
2028
2029                 wfProfileOut( __METHOD__ );
2030
2031                 if ( $getPages ) {
2032                         $this->mCascadeSources = $sources;
2033                         $this->mCascadingRestrictions = $pagerestrictions;
2034                 } else {
2035                         $this->mHasCascadingRestrictions = $sources;
2036                 }
2037
2038                 return array( $sources, $pagerestrictions );
2039         }
2040
2041         /**
2042          * Returns cascading restrictions for the current article
2043          *
2044          * @return Boolean
2045          */
2046         function areRestrictionsCascading() {
2047                 if ( !$this->mRestrictionsLoaded ) {
2048                         $this->loadRestrictions();
2049                 }
2050
2051                 return $this->mCascadeRestriction;
2052         }
2053
2054         /**
2055          * Loads a string into mRestrictions array
2056          *
2057          * @param $res \type{Resource} restrictions as an SQL result.
2058          * @param $oldFashionedRestrictions string comma-separated list of page
2059          *        restrictions from page table (pre 1.10)
2060          */
2061         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2062                 $rows = array();
2063                 $dbr = wfGetDB( DB_SLAVE );
2064
2065                 while ( $row = $dbr->fetchObject( $res ) ) {
2066                         $rows[] = $row;
2067                 }
2068
2069                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2070         }
2071
2072         /**
2073          * Compiles list of active page restrictions from both page table (pre 1.10)
2074          * and page_restrictions table
2075          *
2076          * @param $rows array of db result objects
2077          * @param $oldFashionedRestrictions string comma-separated list of page
2078          *        restrictions from page table (pre 1.10)
2079          */
2080         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2081                 $dbr = wfGetDB( DB_SLAVE );
2082
2083                 $restrictionTypes = $this->getRestrictionTypes();
2084
2085                 foreach ( $restrictionTypes as $type ) {
2086                         $this->mRestrictions[$type] = array();
2087                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2088                 }
2089
2090                 $this->mCascadeRestriction = false;
2091
2092                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2093
2094                 if ( $oldFashionedRestrictions === null ) {
2095                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2096                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2097                 }
2098
2099                 if ( $oldFashionedRestrictions != '' ) {
2100
2101                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2102                                 $temp = explode( '=', trim( $restrict ) );
2103                                 if ( count( $temp ) == 1 ) {
2104                                         // old old format should be treated as edit/move restriction
2105                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2106                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2107                                 } else {
2108                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2109                                 }
2110                         }
2111
2112                         $this->mOldRestrictions = true;
2113
2114                 }
2115
2116                 if ( count( $rows ) ) {
2117                         # Current system - load second to make them override.
2118                         $now = wfTimestampNow();
2119                         $purgeExpired = false;
2120
2121                         foreach ( $rows as $row ) {
2122                                 # Cycle through all the restrictions.
2123
2124                                 // Don't take care of restrictions types that aren't allowed
2125
2126                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2127                                         continue;
2128
2129                                 // This code should be refactored, now that it's being used more generally,
2130                                 // But I don't really see any harm in leaving it in Block for now -werdna
2131                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2132
2133                                 // Only apply the restrictions if they haven't expired!
2134                                 if ( !$expiry || $expiry > $now ) {
2135                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2136                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2137
2138                                         $this->mCascadeRestriction |= $row->pr_cascade;
2139                                 } else {
2140                                         // Trigger a lazy purge of expired restrictions
2141                                         $purgeExpired = true;
2142                                 }
2143                         }
2144
2145                         if ( $purgeExpired ) {
2146                                 Title::purgeExpiredRestrictions();
2147                         }
2148                 }
2149
2150                 $this->mRestrictionsLoaded = true;
2151         }
2152
2153         /**
2154          * Load restrictions from the page_restrictions table
2155          *
2156          * @param $oldFashionedRestrictions string comma-separated list of page
2157          *        restrictions from page table (pre 1.10)
2158          */
2159         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2160                 if ( !$this->mRestrictionsLoaded ) {
2161                         if ( $this->exists() ) {
2162                                 $dbr = wfGetDB( DB_SLAVE );
2163
2164                                 $res = $dbr->select( 'page_restrictions', '*',
2165                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2166
2167                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2168                         } else {
2169                                 $title_protection = $this->getTitleProtection();
2170
2171                                 if ( $title_protection ) {
2172                                         $now = wfTimestampNow();
2173                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2174
2175                                         if ( !$expiry || $expiry > $now ) {
2176                                                 // Apply the restrictions
2177                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2178                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2179                                         } else { // Get rid of the old restrictions
2180                                                 Title::purgeExpiredRestrictions();
2181                                         }
2182                                 } else {
2183                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2184                                 }
2185                                 $this->mRestrictionsLoaded = true;
2186                         }
2187                 }
2188         }
2189
2190         /**
2191          * Purge expired restrictions from the page_restrictions table
2192          */
2193         static function purgeExpiredRestrictions() {
2194                 $dbw = wfGetDB( DB_MASTER );
2195                 $dbw->delete( 'page_restrictions',
2196                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2197                         __METHOD__ );
2198
2199                 $dbw->delete( 'protected_titles',
2200                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2201                         __METHOD__ );
2202         }
2203
2204         /**
2205          * Accessor/initialisation for mRestrictions
2206          *
2207          * @param $action \type{\string} action that permission needs to be checked for
2208          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2209          */
2210         public function getRestrictions( $action ) {
2211                 if ( !$this->mRestrictionsLoaded ) {
2212                         $this->loadRestrictions();
2213                 }
2214                 return isset( $this->mRestrictions[$action] )
2215                                 ? $this->mRestrictions[$action]
2216                                 : array();
2217         }
2218
2219         /**
2220          * Get the expiry time for the restriction against a given action
2221          *
2222          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2223          *      or not protected at all, or false if the action is not recognised.
2224          */
2225         public function getRestrictionExpiry( $action ) {
2226                 if ( !$this->mRestrictionsLoaded ) {
2227                         $this->loadRestrictions();
2228                 }
2229                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2230         }
2231
2232         /**
2233          * Is there a version of this page in the deletion archive?
2234          *
2235          * @return \type{\int} the number of archived revisions
2236          */
2237         public function isDeleted() {
2238                 if ( $this->getNamespace() < 0 ) {
2239                         $n = 0;
2240                 } else {
2241                         $dbr = wfGetDB( DB_SLAVE );
2242                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2243                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2244                                 __METHOD__
2245                         );
2246                         if ( $this->getNamespace() == NS_FILE ) {
2247                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2248                                         array( 'fa_name' => $this->getDBkey() ),
2249                                         __METHOD__
2250                                 );
2251                         }
2252                 }
2253                 return (int)$n;
2254         }
2255
2256         /**
2257          * Is there a version of this page in the deletion archive?
2258          *
2259          * @return Boolean
2260          */
2261         public function isDeletedQuick() {
2262                 if ( $this->getNamespace() < 0 ) {
2263                         return false;
2264                 }
2265                 $dbr = wfGetDB( DB_SLAVE );
2266                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2267                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2268                         __METHOD__
2269                 );
2270                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2271                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2272                                 array( 'fa_name' => $this->getDBkey() ),
2273                                 __METHOD__
2274                         );
2275                 }
2276                 return $deleted;
2277         }
2278
2279         /**
2280          * Get the article ID for this Title from the link cache,
2281          * adding it if necessary
2282          *
2283          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2284          *  for update
2285          * @return \type{\int} the ID
2286          */
2287         public function getArticleID( $flags = 0 ) {
2288                 if ( $this->getNamespace() < 0 ) {
2289                         return $this->mArticleID = 0;
2290                 }
2291                 $linkCache = LinkCache::singleton();
2292                 if ( $flags & GAID_FOR_UPDATE ) {
2293                         $oldUpdate = $linkCache->forUpdate( true );
2294                         $linkCache->clearLink( $this );
2295                         $this->mArticleID = $linkCache->addLinkObj( $this );
2296                         $linkCache->forUpdate( $oldUpdate );
2297                 } else {
2298                         if ( -1 == $this->mArticleID ) {
2299                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2300                         }
2301                 }
2302                 return $this->mArticleID;
2303         }
2304
2305         /**
2306          * Is this an article that is a redirect page?
2307          * Uses link cache, adding it if necessary
2308          *
2309          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2310          * @return \type{\bool}
2311          */
2312         public function isRedirect( $flags = 0 ) {
2313                 if ( !is_null( $this->mRedirect ) )
2314                         return $this->mRedirect;
2315                 # Calling getArticleID() loads the field from cache as needed
2316                 if ( !$this->getArticleID( $flags ) ) {
2317                         return $this->mRedirect = false;
2318                 }
2319                 $linkCache = LinkCache::singleton();
2320                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2321
2322                 return $this->mRedirect;
2323         }
2324
2325         /**
2326          * What is the length of this page?
2327          * Uses link cache, adding it if necessary
2328          *
2329          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2330          * @return \type{\bool}
2331          */
2332         public function getLength( $flags = 0 ) {
2333                 if ( $this->mLength != -1 )
2334                         return $this->mLength;
2335                 # Calling getArticleID() loads the field from cache as needed
2336                 if ( !$this->getArticleID( $flags ) ) {
2337                         return $this->mLength = 0;
2338                 }
2339                 $linkCache = LinkCache::singleton();
2340                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2341
2342                 return $this->mLength;
2343         }
2344
2345         /**
2346          * What is the page_latest field for this page?
2347          *
2348          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2349          * @return \type{\int} or 0 if the page doesn't exist
2350          */
2351         public function getLatestRevID( $flags = 0 ) {
2352                 if ( $this->mLatestID !== false )
2353                         return intval( $this->mLatestID );
2354                 # Calling getArticleID() loads the field from cache as needed
2355                 if ( !$this->getArticleID( $flags ) ) {
2356                         return $this->mLatestID = 0;
2357                 }
2358                 $linkCache = LinkCache::singleton();
2359                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2360
2361                 return $this->mLatestID;
2362         }
2363
2364         /**
2365          * This clears some fields in this object, and clears any associated
2366          * keys in the "bad links" section of the link cache.
2367          *
2368          * @param $newid \type{\int} the new Article ID
2369          */
2370         public function resetArticleID( $newid ) {
2371                 $linkCache = LinkCache::singleton();
2372                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2373
2374                 if ( $newid === false ) {
2375                         $this->mArticleID = -1;
2376                 } else {
2377                         $this->mArticleID = intval( $newid );
2378                 }
2379                 $this->mRestrictionsLoaded = false;
2380                 $this->mRestrictions = array();
2381                 $this->mRedirect = null;
2382                 $this->mLength = -1;
2383                 $this->mLatestID = false;
2384         }
2385
2386         /**
2387          * Updates page_touched for this page; called from LinksUpdate.php
2388          *
2389          * @return \type{\bool} true if the update succeded
2390          */
2391         public function invalidateCache() {
2392                 if ( wfReadOnly() ) {
2393                         return;
2394                 }
2395                 $dbw = wfGetDB( DB_MASTER );
2396                 $success = $dbw->update( 'page',
2397                         array( 'page_touched' => $dbw->timestamp() ),
2398                         $this->pageCond(),
2399                         __METHOD__
2400                 );
2401                 HTMLFileCache::clearFileCache( $this );
2402                 return $success;
2403         }
2404
2405         /**
2406          * Prefix some arbitrary text with the namespace or interwiki prefix
2407          * of this object
2408          *
2409          * @param $name \type{\string} the text
2410          * @return \type{\string} the prefixed text
2411          * @private
2412          */
2413         /* private */ function prefix( $name ) {
2414                 $p = '';
2415                 if ( $this->mInterwiki != '' ) {
2416                         $p = $this->mInterwiki . ':';
2417                 }
2418                 if ( 0 != $this->mNamespace ) {
2419                         $p .= $this->getNsText() . ':';
2420                 }
2421                 return $p . $name;
2422         }
2423
2424         /**
2425          * Returns a simple regex that will match on characters and sequences invalid in titles.
2426          * Note that this doesn't pick up many things that could be wrong with titles, but that
2427          * replacing this regex with something valid will make many titles valid.
2428          *
2429          * @return string regex string
2430          */
2431         static function getTitleInvalidRegex() {
2432                 static $rxTc = false;
2433                 if ( !$rxTc ) {
2434                         # Matching titles will be held as illegal.
2435                         $rxTc = '/' .
2436                                 # Any character not allowed is forbidden...
2437                                 '[^' . Title::legalChars() . ']' .
2438                                 # URL percent encoding sequences interfere with the ability
2439                                 # to round-trip titles -- you can't link to them consistently.
2440                                 '|%[0-9A-Fa-f]{2}' .
2441                                 # XML/HTML character references produce similar issues.
2442                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2443                                 '|&#[0-9]+;' .
2444                                 '|&#x[0-9A-Fa-f]+;' .
2445                                 '/S';
2446                 }
2447
2448                 return $rxTc;
2449         }
2450
2451         /**
2452          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2453          *
2454          * @param $text string containing title to capitalize
2455          * @param $ns int namespace index, defaults to NS_MAIN
2456          * @return String containing capitalized title
2457          */
2458         public static function capitalize( $text, $ns = NS_MAIN ) {
2459                 global $wgContLang;
2460
2461                 if ( MWNamespace::isCapitalized( $ns ) )
2462                         return $wgContLang->ucfirst( $text );
2463                 else
2464                         return $text;
2465         }
2466
2467         /**
2468          * Secure and split - main initialisation function for this object
2469          *
2470          * Assumes that mDbkeyform has been set, and is urldecoded
2471          * and uses underscores, but not otherwise munged.  This function
2472          * removes illegal characters, splits off the interwiki and
2473          * namespace prefixes, sets the other forms, and canonicalizes
2474          * everything.
2475          *
2476          * @return \type{\bool} true on success
2477          */
2478         private function secureAndSplit() {
2479                 global $wgContLang, $wgLocalInterwiki;
2480
2481                 # Initialisation
2482                 $rxTc = self::getTitleInvalidRegex();
2483
2484                 $this->mInterwiki = $this->mFragment = '';
2485                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2486
2487                 $dbkey = $this->mDbkeyform;
2488
2489                 # Strip Unicode bidi override characters.
2490                 # Sometimes they slip into cut-n-pasted page titles, where the
2491                 # override chars get included in list displays.
2492                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2493
2494                 # Clean up whitespace
2495                 # Note: use of the /u option on preg_replace here will cause
2496                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2497                 # conveniently disabling them.
2498                 #
2499                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2500                 $dbkey = trim( $dbkey, '_' );
2501
2502                 if ( $dbkey == '' ) {
2503                         return false;
2504                 }
2505
2506                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2507                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2508                         return false;
2509                 }
2510
2511                 $this->mDbkeyform = $dbkey;
2512
2513                 # Initial colon indicates main namespace rather than specified default
2514                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2515                 if ( ':' == $dbkey { 0 } ) {
2516                         $this->mNamespace = NS_MAIN;
2517                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2518                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2519                 }
2520
2521                 # Namespace or interwiki prefix
2522                 $firstPass = true;
2523                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2524                 do {
2525                         $m = array();
2526                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2527                                 $p = $m[1];
2528                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2529                                         # Ordinary namespace
2530                                         $dbkey = $m[2];
2531                                         $this->mNamespace = $ns;
2532                                         # For Talk:X pages, check if X has a "namespace" prefix
2533                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2534                                                 if ( $wgContLang->getNsIndex( $x[1] ) )
2535                                                         return false; # Disallow Talk:File:x type titles...
2536                                                 else if ( Interwiki::isValidInterwiki( $x[1] ) )
2537                                                         return false; # Disallow Talk:Interwiki:x type titles...
2538                                         }
2539                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2540                                         if ( !$firstPass ) {
2541                                                 # Can't make a local interwiki link to an interwiki link.
2542                                                 # That's just crazy!
2543                                                 return false;
2544                                         }
2545
2546                                         # Interwiki link
2547                                         $dbkey = $m[2];
2548                                         $this->mInterwiki = $wgContLang->lc( $p );
2549
2550                                         # Redundant interwiki prefix to the local wiki
2551                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2552                                                 if ( $dbkey == '' ) {
2553                                                         # Can't have an empty self-link
2554                                                         return false;
2555                                                 }
2556                                                 $this->mInterwiki = '';
2557                                                 $firstPass = false;
2558                                                 # Do another namespace split...
2559                                                 continue;
2560                                         }
2561
2562                                         # If there's an initial colon after the interwiki, that also
2563                                         # resets the default namespace
2564                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2565                                                 $this->mNamespace = NS_MAIN;
2566                                                 $dbkey = substr( $dbkey, 1 );
2567                                         }
2568                                 }
2569                                 # If there's no recognized interwiki or namespace,
2570                                 # then let the colon expression be part of the title.
2571                         }
2572                         break;
2573                 } while ( true );
2574
2575                 # We already know that some pages won't be in the database!
2576                 #
2577                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2578                         $this->mArticleID = 0;
2579                 }
2580                 $fragment = strstr( $dbkey, '#' );
2581                 if ( false !== $fragment ) {
2582                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2583                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2584                         # remove whitespace again: prevents "Foo_bar_#"
2585                         # becoming "Foo_bar_"
2586                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2587                 }
2588
2589                 # Reject illegal characters.
2590                 #
2591                 if ( preg_match( $rxTc, $dbkey ) ) {
2592                         return false;
2593                 }
2594
2595                 /**
2596                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2597                  * reachable due to the way web browsers deal with 'relative' URLs.
2598                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2599                  */
2600                 if ( strpos( $dbkey, '.' ) !== false &&
2601                      ( $dbkey === '.' || $dbkey === '..' ||
2602                        strpos( $dbkey, './' ) === 0  ||
2603                        strpos( $dbkey, '../' ) === 0 ||
2604                        strpos( $dbkey, '/./' ) !== false ||
2605                        strpos( $dbkey, '/../' ) !== false  ||
2606                        substr( $dbkey, -2 ) == '/.' ||
2607                        substr( $dbkey, -3 ) == '/..' ) )
2608                 {
2609                         return false;
2610                 }
2611
2612                 /**
2613                  * Magic tilde sequences? Nu-uh!
2614                  */
2615                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2616                         return false;
2617                 }
2618
2619                 /**
2620                  * Limit the size of titles to 255 bytes.
2621                  * This is typically the size of the underlying database field.
2622                  * We make an exception for special pages, which don't need to be stored
2623                  * in the database, and may edge over 255 bytes due to subpage syntax
2624                  * for long titles, e.g. [[Special:Block/Long name]]
2625                  */
2626                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2627                   strlen( $dbkey ) > 512 )
2628                 {
2629                         return false;
2630                 }
2631
2632                 /**
2633                  * Normally, all wiki links are forced to have
2634                  * an initial capital letter so [[foo]] and [[Foo]]
2635                  * point to the same place.
2636                  *
2637                  * Don't force it for interwikis, since the other
2638                  * site might be case-sensitive.
2639                  */
2640                 $this->mUserCaseDBKey = $dbkey;
2641                 if (  $this->mInterwiki == '' ) {
2642                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2643                 }
2644
2645                 /**
2646                  * Can't make a link to a namespace alone...
2647                  * "empty" local links can only be self-links
2648                  * with a fragment identifier.
2649                  */
2650                 if ( $dbkey == '' &&
2651                         $this->mInterwiki == '' &&
2652                         $this->mNamespace != NS_MAIN ) {
2653                         return false;
2654                 }
2655                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2656                 // IP names are not allowed for accounts, and can only be referring to
2657                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2658                 // there are numerous ways to present the same IP. Having sp:contribs scan
2659                 // them all is silly and having some show the edits and others not is
2660                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2661                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2662                         IP::sanitizeIP( $dbkey ) : $dbkey;
2663                 // Any remaining initial :s are illegal.
2664                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2665                         return false;
2666                 }
2667
2668                 # Fill fields
2669                 $this->mDbkeyform = $dbkey;
2670                 $this->mUrlform = wfUrlencode( $dbkey );
2671
2672                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2673
2674                 return true;
2675         }
2676
2677         /**
2678          * Set the fragment for this title. Removes the first character from the
2679          * specified fragment before setting, so it assumes you're passing it with
2680          * an initial "#".
2681          *
2682          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2683          * Still in active use privately.
2684          *
2685          * @param $fragment \type{\string} text
2686          */
2687         public function setFragment( $fragment ) {
2688                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2689         }
2690
2691         /**
2692          * Get a Title object associated with the talk page of this article
2693          *
2694          * @return \type{Title} the object for the talk page
2695          */
2696         public function getTalkPage() {
2697                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2698         }
2699
2700         /**
2701          * Get a title object associated with the subject page of this
2702          * talk page
2703          *
2704          * @return \type{Title} the object for the subject page
2705          */
2706         public function getSubjectPage() {
2707                 // Is this the same title?
2708                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2709                 if ( $this->getNamespace() == $subjectNS ) {
2710                         return $this;
2711                 }
2712                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2713         }
2714
2715         /**
2716          * Get an array of Title objects linking to this Title
2717          * Also stores the IDs in the link cache.
2718          *
2719          * WARNING: do not use this function on arbitrary user-supplied titles!
2720          * On heavily-used templates it will max out the memory.
2721          *
2722          * @param $options Array: may be FOR UPDATE
2723          * @param $table String: table name
2724          * @param $prefix String: fields prefix
2725          * @return \type{\arrayof{Title}} the Title objects linking here
2726          */
2727         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2728                 $linkCache = LinkCache::singleton();
2729
2730                 if ( count( $options ) > 0 ) {
2731                         $db = wfGetDB( DB_MASTER );
2732                 } else {
2733                         $db = wfGetDB( DB_SLAVE );
2734                 }
2735
2736                 $res = $db->select( array( 'page', $table ),
2737                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2738                         array(
2739                                 "{$prefix}_from=page_id",
2740                                 "{$prefix}_namespace" => $this->getNamespace(),
2741                                 "{$prefix}_title"     => $this->getDBkey() ),
2742                         __METHOD__,
2743                         $options );
2744
2745                 $retVal = array();
2746                 if ( $db->numRows( $res ) ) {
2747                         foreach ( $res as $row ) {
2748                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2749                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2750                                         $retVal[] = $titleObj;
2751                                 }
2752                         }
2753                 }
2754                 $db->freeResult( $res );
2755                 return $retVal;
2756         }
2757
2758         /**
2759          * Get an array of Title objects using this Title as a template
2760          * Also stores the IDs in the link cache.
2761          *
2762          * WARNING: do not use this function on arbitrary user-supplied titles!
2763          * On heavily-used templates it will max out the memory.
2764          *
2765          * @param $options Array: may be FOR UPDATE
2766          * @return \type{\arrayof{Title}} the Title objects linking here
2767          */
2768         public function getTemplateLinksTo( $options = array() ) {
2769                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2770         }
2771
2772         /**
2773          * Get an array of Title objects referring to non-existent articles linked from this page
2774          *
2775          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2776          * @return \type{\arrayof{Title}} the Title objects
2777          */
2778         public function getBrokenLinksFrom() {
2779                 if ( $this->getArticleId() == 0 ) {
2780                         # All links from article ID 0 are false positives
2781                         return array();
2782                 }
2783
2784                 $dbr = wfGetDB( DB_SLAVE );
2785                 $res = $dbr->select(
2786                         array( 'page', 'pagelinks' ),
2787                         array( 'pl_namespace', 'pl_title' ),
2788                         array(
2789                                 'pl_from' => $this->getArticleId(),
2790                                 'page_namespace IS NULL'
2791                         ),
2792                         __METHOD__, array(),
2793                         array(
2794                                 'page' => array(
2795                                         'LEFT JOIN',
2796                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2797                                 )
2798                         )
2799                 );
2800
2801                 $retVal = array();
2802                 foreach ( $res as $row ) {
2803                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2804                 }
2805                 return $retVal;
2806         }
2807
2808
2809         /**
2810          * Get a list of URLs to purge from the Squid cache when this
2811          * page changes
2812          *
2813          * @return \type{\arrayof{\string}} the URLs
2814          */
2815         public function getSquidURLs() {
2816                 global $wgContLang;
2817
2818                 $urls = array(
2819                         $this->getInternalURL(),
2820                         $this->getInternalURL( 'action=history' )
2821                 );
2822
2823                 // purge variant urls as well
2824                 if ( $wgContLang->hasVariants() ) {
2825                         $variants = $wgContLang->getVariants();
2826                         foreach ( $variants as $vCode ) {
2827                                 $urls[] = $this->getInternalURL( '', $vCode );
2828                         }
2829                 }
2830
2831                 return $urls;
2832         }
2833
2834         /**
2835          * Purge all applicable Squid URLs
2836          */
2837         public function purgeSquid() {
2838                 global $wgUseSquid;
2839                 if ( $wgUseSquid ) {
2840                         $urls = $this->getSquidURLs();
2841                         $u = new SquidUpdate( $urls );
2842                         $u->doUpdate();
2843                 }
2844         }
2845
2846         /**
2847          * Move this page without authentication
2848          *
2849          * @param $nt \type{Title} the new page Title
2850          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2851          */
2852         public function moveNoAuth( &$nt ) {
2853                 return $this->moveTo( $nt, false );
2854         }
2855
2856         /**
2857          * Check whether a given move operation would be valid.
2858          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2859          *
2860          * @param $nt \type{Title} the new title
2861          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2862          *  should be checked
2863          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2864          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2865          */
2866         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2867                 global $wgUser;
2868
2869                 $errors = array();
2870                 if ( !$nt ) {
2871                         // Normally we'd add this to $errors, but we'll get
2872                         // lots of syntax errors if $nt is not an object
2873                         return array( array( 'badtitletext' ) );
2874                 }
2875                 if ( $this->equals( $nt ) ) {
2876                         $errors[] = array( 'selfmove' );
2877                 }
2878                 if ( !$this->isMovable() ) {
2879                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2880                 }
2881                 if ( $nt->getInterwiki() != '' ) {
2882                         $errors[] = array( 'immobile-target-namespace-iw' );
2883                 }
2884                 if ( !$nt->isMovable() ) {
2885                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2886                 }
2887
2888                 $oldid = $this->getArticleID();
2889                 $newid = $nt->getArticleID();
2890
2891                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2892                         $errors[] = array( 'articleexists' );
2893                 }
2894                 if ( ( $this->getDBkey() == '' ) ||
2895                          ( !$oldid ) ||
2896                      ( $nt->getDBkey() == '' ) ) {
2897                         $errors[] = array( 'badarticleerror' );
2898                 }
2899
2900                 // Image-specific checks
2901                 if ( $this->getNamespace() == NS_FILE ) {
2902                         $file = wfLocalFile( $this );
2903                         if ( $file->exists() ) {
2904                                 if ( $nt->getNamespace() != NS_FILE ) {
2905                                         $errors[] = array( 'imagenocrossnamespace' );
2906                                 }
2907                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2908                                         $errors[] = array( 'imageinvalidfilename' );
2909                                 }
2910                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2911                                         $errors[] = array( 'imagetypemismatch' );
2912                                 }
2913                         }
2914                         $destfile = wfLocalFile( $nt );
2915                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2916                                 $errors[] = array( 'file-exists-sharedrepo' );
2917                         }
2918
2919                 }
2920
2921                 if ( $auth ) {
2922                         $errors = wfMergeErrorArrays( $errors,
2923                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2924                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2925                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2926                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2927                 }
2928
2929                 $match = EditPage::matchSummarySpamRegex( $reason );
2930                 if ( $match !== false ) {
2931                         // This is kind of lame, won't display nice
2932                         $errors[] = array( 'spamprotectiontext' );
2933                 }
2934
2935                 $err = null;
2936                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2937                         $errors[] = array( 'hookaborted', $err );
2938                 }
2939
2940                 # The move is allowed only if (1) the target doesn't exist, or
2941                 # (2) the target is a redirect to the source, and has no history
2942                 # (so we can undo bad moves right after they're done).
2943
2944                 if ( 0 != $newid ) { # Target exists; check for validity
2945                         if ( !$this->isValidMoveTarget( $nt ) ) {
2946                                 $errors[] = array( 'articleexists' );
2947                         }
2948                 } else {
2949                         $tp = $nt->getTitleProtection();
2950                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2951                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2952                                 $errors[] = array( 'cantmove-titleprotected' );
2953                         }
2954                 }
2955                 if ( empty( $errors ) )
2956                         return true;
2957                 return $errors;
2958         }
2959
2960         /**
2961          * Move a title to a new location
2962          *
2963          * @param $nt \type{Title} the new title
2964          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2965          *  should be checked
2966          * @param $reason \type{\string} The reason for the move
2967          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2968          *  Ignored if the user doesn't have the suppressredirect right.
2969          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2970          */
2971         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2972                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2973                 if ( is_array( $err ) ) {
2974                         return $err;
2975                 }
2976
2977                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
2978                 $dbw = wfGetDB( DB_MASTER );
2979                 if ( $this->getNamespace() == NS_FILE ) {
2980                         $file = wfLocalFile( $this );
2981                         if ( $file->exists() ) {
2982                                 $status = $file->move( $nt );
2983                                 if ( !$status->isOk() ) {
2984                                         return $status->getErrorsArray();
2985                                 }
2986                         }
2987                 }
2988
2989                 $pageid = $this->getArticleID();
2990                 $protected = $this->isProtected();
2991                 if ( $nt->exists() ) {
2992                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
2993                         $pageCountChange = ( $createRedirect ? 0 : -1 );
2994                 } else { # Target didn't exist, do normal move.
2995                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
2996                         $pageCountChange = ( $createRedirect ? 1 : 0 );
2997                 }
2998
2999                 if ( is_array( $err ) ) {
3000                         return $err;
3001                 }
3002                 $redirid = $this->getArticleID();
3003
3004                 // Category memberships include a sort key which may be customized.
3005                 // If it's left as the default (the page title), we need to update
3006                 // the sort key to match the new title.
3007                 //
3008                 // Be careful to avoid resetting cl_timestamp, which may disturb
3009                 // time-based lists on some sites.
3010                 //
3011                 // Warning -- if the sort key is *explicitly* set to the old title,
3012                 // we can't actually distinguish it from a default here, and it'll
3013                 // be set to the new title even though it really shouldn't.
3014                 // It'll get corrected on the next edit, but resetting cl_timestamp.
3015                 $dbw->update( 'categorylinks',
3016                         array(
3017                                 'cl_sortkey' => $nt->getPrefixedText(),
3018                                 'cl_timestamp=cl_timestamp' ),
3019                         array(
3020                                 'cl_from' => $pageid,
3021                                 'cl_sortkey' => $this->getPrefixedText() ),
3022                         __METHOD__ );
3023
3024                 if ( $protected ) {
3025                         # Protect the redirect title as the title used to be...
3026                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3027                                 array(
3028                                         'pr_page'    => $redirid,
3029                                         'pr_type'    => 'pr_type',
3030                                         'pr_level'   => 'pr_level',
3031                                         'pr_cascade' => 'pr_cascade',
3032                                         'pr_user'    => 'pr_user',
3033                                         'pr_expiry'  => 'pr_expiry'
3034                                 ),
3035                                 array( 'pr_page' => $pageid ),
3036                                 __METHOD__,
3037                                 array( 'IGNORE' )
3038                         );
3039                         # Update the protection log
3040                         $log = new LogPage( 'protect' );
3041                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3042                         if ( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3043                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3044                 }
3045
3046                 # Update watchlists
3047                 $oldnamespace = $this->getNamespace() & ~1;
3048                 $newnamespace = $nt->getNamespace() & ~1;
3049                 $oldtitle = $this->getDBkey();
3050                 $newtitle = $nt->getDBkey();
3051
3052                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3053                         WatchedItem::duplicateEntries( $this, $nt );
3054                 }
3055
3056                 # Update search engine
3057                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3058                 $u->doUpdate();
3059                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3060                 $u->doUpdate();
3061
3062                 # Update site_stats
3063                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3064                         # No longer a content page
3065                         # Not viewed, edited, removing
3066                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3067                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3068                         # Now a content page
3069                         # Not viewed, edited, adding
3070                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3071                 } elseif ( $pageCountChange ) {
3072                         # Redirect added
3073                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3074                 } else {
3075                         # Nothing special
3076                         $u = false;
3077                 }
3078                 if ( $u )
3079                         $u->doUpdate();
3080                 # Update message cache for interface messages
3081                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3082                         global $wgMessageCache;
3083
3084                         # @bug 17860: old article can be deleted, if this the case,
3085                         # delete it from message cache
3086                         if ( $this->getArticleID() === 0 ) {
3087                                 $wgMessageCache->replace( $this->getDBkey(), false );
3088                         } else {
3089                                 $oldarticle = new Article( $this );
3090                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3091                         }
3092
3093                         $newarticle = new Article( $nt );
3094                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3095                 }
3096
3097                 global $wgUser;
3098                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3099                 return true;
3100         }
3101
3102         /**
3103          * Move page to a title which is at present a redirect to the
3104          * source page
3105          *
3106          * @param $nt \type{Title} the page to move to, which should currently
3107          *  be a redirect
3108          * @param $reason \type{\string} The reason for the move
3109          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3110          *  Ignored if the user doesn't have the suppressredirect right
3111          */
3112         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3113                 global $wgUseSquid, $wgUser, $wgContLang;
3114
3115                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3116
3117                 if ( $reason ) {
3118                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3119                 }
3120                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3121                 $comment = $wgContLang->truncate( $comment, 250 );
3122
3123                 $now = wfTimestampNow();
3124                 $newid = $nt->getArticleID();
3125                 $oldid = $this->getArticleID();
3126                 $latest = $this->getLatestRevID();
3127
3128                 $dbw = wfGetDB( DB_MASTER );
3129
3130                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3131                 $newns = $nt->getNamespace();
3132                 $newdbk = $nt->getDBkey();
3133
3134                 # Delete the old redirect. We don't save it to history since
3135                 # by definition if we've got here it's rather uninteresting.
3136                 # We have to remove it so that the next step doesn't trigger
3137                 # a conflict on the unique namespace+title index...
3138                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3139                 if ( !$dbw->cascadingDeletes() ) {
3140                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3141                         global $wgUseTrackbacks;
3142                         if ( $wgUseTrackbacks )
3143                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3144                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3145                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3146                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3147                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3148                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3149                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3150                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3151                 }
3152                 // If the redirect was recently created, it may have an entry in recentchanges still
3153                 $dbw->delete( 'recentchanges',
3154                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3155                         __METHOD__
3156                 );
3157
3158                 # Save a null revision in the page's history notifying of the move
3159                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3160                 $nullRevId = $nullRevision->insertOn( $dbw );
3161
3162                 $article = new Article( $this );
3163                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3164
3165                 # Change the name of the target page:
3166                 $dbw->update( 'page',
3167                         /* SET */ array(
3168                                 'page_touched'   => $dbw->timestamp( $now ),
3169                                 'page_namespace' => $nt->getNamespace(),
3170                                 'page_title'     => $nt->getDBkey(),
3171                                 'page_latest'    => $nullRevId,
3172                         ),
3173                         /* WHERE */ array( 'page_id' => $oldid ),
3174                         __METHOD__
3175                 );
3176                 $nt->resetArticleID( $oldid );
3177
3178                 # Recreate the redirect, this time in the other direction.
3179                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3180                         $mwRedir = MagicWord::get( 'redirect' );
3181                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3182                         $redirectArticle = new Article( $this );
3183                         $newid = $redirectArticle->insertOn( $dbw );
3184                         $redirectRevision = new Revision( array(
3185                                 'page'    => $newid,
3186                                 'comment' => $comment,
3187                                 'text'    => $redirectText ) );
3188                         $redirectRevision->insertOn( $dbw );
3189                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3190
3191                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3192
3193                         # Now, we record the link from the redirect to the new title.
3194                         # It should have no other outgoing links...
3195                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3196                         $dbw->insert( 'pagelinks',
3197                                 array(
3198                                         'pl_from'      => $newid,
3199                                         'pl_namespace' => $nt->getNamespace(),
3200                                         'pl_title'     => $nt->getDBkey() ),
3201                                 __METHOD__ );
3202                         $redirectSuppressed = false;
3203                 } else {
3204                         $this->resetArticleID( 0 );
3205                         $redirectSuppressed = true;
3206                 }
3207
3208                 # Log the move
3209                 $log = new LogPage( 'move' );
3210                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3211
3212                 # Purge squid
3213                 if ( $wgUseSquid ) {
3214                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3215                         $u = new SquidUpdate( $urls );
3216                         $u->doUpdate();
3217                 }
3218
3219         }
3220
3221         /**
3222          * Move page to non-existing title.
3223          *
3224          * @param $nt \type{Title} the new Title
3225          * @param $reason \type{\string} The reason for the move
3226          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3227          *  Ignored if the user doesn't have the suppressredirect right
3228          */
3229         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3230                 global $wgUseSquid, $wgUser, $wgContLang;
3231
3232                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3233                 if ( $reason ) {
3234                         $comment .= wfMsgExt( 'colon-separator',
3235                                 array( 'escapenoentities', 'content' ) );
3236                         $comment .= $reason;
3237                 }
3238                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3239                 $comment = $wgContLang->truncate( $comment, 250 );
3240
3241                 $newid = $nt->getArticleID();
3242                 $oldid = $this->getArticleID();
3243                 $latest = $this->getLatestRevId();
3244
3245                 $dbw = wfGetDB( DB_MASTER );
3246                 $now = $dbw->timestamp();
3247
3248                 # Save a null revision in the page's history notifying of the move
3249                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3250                 if ( !is_object( $nullRevision ) ) {
3251                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3252                 }
3253                 $nullRevId = $nullRevision->insertOn( $dbw );
3254
3255                 $article = new Article( $this );
3256                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3257
3258                 # Rename page entry
3259                 $dbw->update( 'page',
3260                         /* SET */ array(
3261                                 'page_touched'   => $now,
3262                                 'page_namespace' => $nt->getNamespace(),
3263                                 'page_title'     => $nt->getDBkey(),
3264                                 'page_latest'    => $nullRevId,
3265                         ),
3266                         /* WHERE */ array( 'page_id' => $oldid ),
3267                         __METHOD__
3268                 );
3269                 $nt->resetArticleID( $oldid );
3270
3271                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3272                         # Insert redirect
3273                         $mwRedir = MagicWord::get( 'redirect' );
3274                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3275                         $redirectArticle = new Article( $this );
3276                         $newid = $redirectArticle->insertOn( $dbw );
3277                         $redirectRevision = new Revision( array(
3278                                 'page'    => $newid,
3279                                 'comment' => $comment,
3280                                 'text'    => $redirectText ) );
3281                         $redirectRevision->insertOn( $dbw );
3282                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3283
3284                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3285
3286                         # Record the just-created redirect's linking to the page
3287                         $dbw->insert( 'pagelinks',
3288                                 array(
3289                                         'pl_from'      => $newid,
3290                                         'pl_namespace' => $nt->getNamespace(),
3291                                         'pl_title'     => $nt->getDBkey() ),
3292                                 __METHOD__ );
3293                         $redirectSuppressed = false;
3294                 } else {
3295                         $this->resetArticleID( 0 );
3296                         $redirectSuppressed = true;
3297                 }
3298
3299                 # Log the move
3300                 $log = new LogPage( 'move' );
3301                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3302
3303                 # Purge caches as per article creation
3304                 Article::onArticleCreate( $nt );
3305
3306                 # Purge old title from squid
3307                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3308                 $this->purgeSquid();
3309
3310         }
3311
3312         /**
3313          * Move this page's subpages to be subpages of $nt
3314          *
3315          * @param $nt Title Move target
3316          * @param $auth bool Whether $wgUser's permissions should be checked
3317          * @param $reason string The reason for the move
3318          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3319          *  Ignored if the user doesn't have the 'suppressredirect' right
3320          * @return mixed array with old page titles as keys, and strings (new page titles) or
3321          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3322          */
3323         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3324                 global $wgMaximumMovedPages;
3325                 // Check permissions
3326                 if ( !$this->userCan( 'move-subpages' ) )
3327                         return array( 'cant-move-subpages' );
3328                 // Do the source and target namespaces support subpages?
3329                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) )
3330                         return array( 'namespace-nosubpages',
3331                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3332                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
3333                         return array( 'namespace-nosubpages',
3334                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3335
3336                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3337                 $retval = array();
3338                 $count = 0;
3339                 foreach ( $subpages as $oldSubpage ) {
3340                         $count++;
3341                         if ( $count > $wgMaximumMovedPages ) {
3342                                 $retval[$oldSubpage->getPrefixedTitle()] =
3343                                                 array( 'movepage-max-pages',
3344                                                         $wgMaximumMovedPages );
3345                                 break;
3346                         }
3347
3348                         // We don't know whether this function was called before
3349                         // or after moving the root page, so check both
3350                         // $this and $nt
3351                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3352                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3353                                 // When moving a page to a subpage of itself,
3354                                 // don't move it twice
3355                                 continue;
3356                         $newPageName = preg_replace(
3357                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3358                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3359                                         $oldSubpage->getDBkey() );
3360                         if ( $oldSubpage->isTalkPage() ) {
3361                                 $newNs = $nt->getTalkPage()->getNamespace();
3362                         } else {
3363                                 $newNs = $nt->getSubjectPage()->getNamespace();
3364                         }
3365                         # Bug 14385: we need makeTitleSafe because the new page names may
3366                         # be longer than 255 characters.
3367                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3368
3369                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3370                         if ( $success === true ) {
3371                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3372                         } else {
3373                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3374                         }
3375                 }
3376                 return $retval;
3377         }
3378
3379         /**
3380          * Checks if this page is just a one-rev redirect.
3381          * Adds lock, so don't use just for light purposes.
3382          *
3383          * @return \type{\bool}
3384          */
3385         public function isSingleRevRedirect() {
3386                 $dbw = wfGetDB( DB_MASTER );
3387                 # Is it a redirect?
3388                 $row = $dbw->selectRow( 'page',
3389                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3390                         $this->pageCond(),
3391                         __METHOD__,
3392                         array( 'FOR UPDATE' )
3393                 );
3394                 # Cache some fields we may want
3395                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3396                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3397                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3398                 if ( !$this->mRedirect ) {
3399                         return false;
3400                 }
3401                 # Does the article have a history?
3402                 $row = $dbw->selectField( array( 'page', 'revision' ),
3403                         'rev_id',
3404                         array( 'page_namespace' => $this->getNamespace(),
3405                                 'page_title' => $this->getDBkey(),
3406                                 'page_id=rev_page',
3407                                 'page_latest != rev_id'
3408                         ),
3409                         __METHOD__,
3410                         array( 'FOR UPDATE' )
3411                 );
3412                 # Return true if there was no history
3413                 return ( $row === false );
3414         }
3415
3416         /**
3417          * Checks if $this can be moved to a given Title
3418          * - Selects for update, so don't call it unless you mean business
3419          *
3420          * @param $nt \type{Title} the new title to check
3421          * @return \type{\bool} TRUE or FALSE
3422          */
3423         public function isValidMoveTarget( $nt ) {
3424                 $dbw = wfGetDB( DB_MASTER );
3425                 # Is it an existing file?
3426                 if ( $nt->getNamespace() == NS_FILE ) {
3427                         $file = wfLocalFile( $nt );
3428                         if ( $file->exists() ) {
3429                                 wfDebug( __METHOD__ . ": file exists\n" );
3430                                 return false;
3431                         }
3432                 }
3433                 # Is it a redirect with no history?
3434                 if ( !$nt->isSingleRevRedirect() ) {
3435                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3436                         return false;
3437                 }
3438                 # Get the article text
3439                 $rev = Revision::newFromTitle( $nt );
3440                 $text = $rev->getText();
3441                 # Does the redirect point to the source?
3442                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3443                 $m = array();
3444                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3445                         $redirTitle = Title::newFromText( $m[1] );
3446                         if ( !is_object( $redirTitle ) ||
3447                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3448                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3449                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3450                                 return false;
3451                         }
3452                 } else {
3453                         # Fail safe
3454                         wfDebug( __METHOD__ . ": failsafe\n" );
3455                         return false;
3456                 }
3457                 return true;
3458         }
3459
3460         /**
3461          * Can this title be added to a user's watchlist?
3462          *
3463          * @return \type{\bool} TRUE or FALSE
3464          */
3465         public function isWatchable() {
3466                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3467         }
3468
3469         /**
3470          * Get categories to which this Title belongs and return an array of
3471          * categories' names.
3472          *
3473          * @return \type{\array} array an array of parents in the form:
3474          *      $parent => $currentarticle
3475          */
3476         public function getParentCategories() {
3477                 global $wgContLang;
3478
3479                 $titlekey = $this->getArticleId();
3480                 $dbr = wfGetDB( DB_SLAVE );
3481                 $categorylinks = $dbr->tableName( 'categorylinks' );
3482
3483                 # NEW SQL
3484                 $sql = "SELECT * FROM $categorylinks"
3485                      . " WHERE cl_from='$titlekey'"
3486                          . " AND cl_from <> '0'"
3487                          . " ORDER BY cl_sortkey";
3488
3489                 $res = $dbr->query( $sql );
3490
3491                 if ( $dbr->numRows( $res ) > 0 ) {
3492                         foreach ( $res as $row )
3493                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3494                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3495                         $dbr->freeResult( $res );
3496                 } else {
3497                         $data = array();
3498                 }
3499                 return $data;
3500         }
3501
3502         /**
3503          * Get a tree of parent categories
3504          *
3505          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3506          * @return \type{\array} Tree of parent categories
3507          */
3508         public function getParentCategoryTree( $children = array() ) {
3509                 $stack = array();
3510                 $parents = $this->getParentCategories();
3511
3512                 if ( $parents ) {
3513                         foreach ( $parents as $parent => $current ) {
3514                                 if ( array_key_exists( $parent, $children ) ) {
3515                                         # Circular reference
3516                                         $stack[$parent] = array();
3517                                 } else {
3518                                         $nt = Title::newFromText( $parent );
3519                                         if ( $nt ) {
3520                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3521                                         }
3522                                 }
3523                         }
3524                         return $stack;
3525                 } else {
3526                         return array();
3527                 }
3528         }
3529
3530
3531         /**
3532          * Get an associative array for selecting this title from
3533          * the "page" table
3534          *
3535          * @return \type{\array} Selection array
3536          */
3537         public function pageCond() {
3538                 if ( $this->mArticleID > 0 ) {
3539                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3540                         return array( 'page_id' => $this->mArticleID );
3541                 } else {
3542                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3543                 }
3544         }
3545
3546         /**
3547          * Get the revision ID of the previous revision
3548          *
3549          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3550          * @param $flags \type{\int} GAID_FOR_UPDATE
3551          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3552          */
3553         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3554                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3555                 return $db->selectField( 'revision', 'rev_id',
3556                         array(
3557                                 'rev_page' => $this->getArticleId( $flags ),
3558                                 'rev_id < ' . intval( $revId )
3559                         ),
3560                         __METHOD__,
3561                         array( 'ORDER BY' => 'rev_id DESC' )
3562                 );
3563         }
3564
3565         /**
3566          * Get the revision ID of the next revision
3567          *
3568          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3569          * @param $flags \type{\int} GAID_FOR_UPDATE
3570          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3571          */
3572         public function getNextRevisionID( $revId, $flags = 0 ) {
3573                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3574                 return $db->selectField( 'revision', 'rev_id',
3575                         array(
3576                                 'rev_page' => $this->getArticleId( $flags ),
3577                                 'rev_id > ' . intval( $revId )
3578                         ),
3579                         __METHOD__,
3580                         array( 'ORDER BY' => 'rev_id' )
3581                 );
3582         }
3583
3584         /**
3585          * Get the first revision of the page
3586          *
3587          * @param $flags \type{\int} GAID_FOR_UPDATE
3588          * @return Revision (or NULL if page doesn't exist)
3589          */
3590         public function getFirstRevision( $flags = 0 ) {
3591                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3592                 $pageId = $this->getArticleId( $flags );
3593                 if ( !$pageId ) return null;
3594                 $row = $db->selectRow( 'revision', '*',
3595                         array( 'rev_page' => $pageId ),
3596                         __METHOD__,
3597                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3598                 );
3599                 if ( !$row ) {
3600                         return null;
3601                 } else {
3602                         return new Revision( $row );
3603                 }
3604         }
3605
3606         /**
3607          * Check if this is a new page
3608          *
3609          * @return bool
3610          */
3611         public function isNewPage() {
3612                 $dbr = wfGetDB( DB_SLAVE );
3613                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3614         }
3615
3616         /**
3617          * Get the oldest revision timestamp of this page
3618          *
3619          * @return String: MW timestamp
3620          */
3621         public function getEarliestRevTime() {
3622                 $dbr = wfGetDB( DB_SLAVE );
3623                 if ( $this->exists() ) {
3624                         $min = $dbr->selectField( 'revision',
3625                                 'MIN(rev_timestamp)',
3626                                 array( 'rev_page' => $this->getArticleId() ),
3627                                 __METHOD__ );
3628                         return wfTimestampOrNull( TS_MW, $min );
3629                 }
3630                 return null;
3631         }
3632
3633         /**
3634          * Get the number of revisions between the given revision IDs.
3635          * Used for diffs and other things that really need it.
3636          *
3637          * @param $old \type{\int} Revision ID.
3638          * @param $new \type{\int} Revision ID.
3639          * @return \type{\int} Number of revisions between these IDs.
3640          */
3641         public function countRevisionsBetween( $old, $new ) {
3642                 $dbr = wfGetDB( DB_SLAVE );
3643                 return (int)$dbr->selectField( 'revision', 'count(*)',
3644                         'rev_page = ' . intval( $this->getArticleId() ) .
3645                         ' AND rev_id > ' . intval( $old ) .
3646                         ' AND rev_id < ' . intval( $new ),
3647                         __METHOD__
3648                 );
3649         }
3650
3651         /**
3652          * Compare with another title.
3653          *
3654          * @param $title \type{Title}
3655          * @return \type{\bool} TRUE or FALSE
3656          */
3657         public function equals( Title $title ) {
3658                 // Note: === is necessary for proper matching of number-like titles.
3659                 return $this->getInterwiki() === $title->getInterwiki()
3660                         && $this->getNamespace() == $title->getNamespace()
3661                         && $this->getDBkey() === $title->getDBkey();
3662         }
3663
3664         /**
3665          * Callback for usort() to do title sorts by (namespace, title)
3666          *
3667          * @return Integer: result of string comparison, or namespace comparison
3668          */
3669         public static function compare( $a, $b ) {
3670                 if ( $a->getNamespace() == $b->getNamespace() ) {
3671                         return strcmp( $a->getText(), $b->getText() );
3672                 } else {
3673                         return $a->getNamespace() - $b->getNamespace();
3674                 }
3675         }
3676
3677         /**
3678          * Return a string representation of this title
3679          *
3680          * @return \type{\string} String representation of this title
3681          */
3682         public function __toString() {
3683                 return $this->getPrefixedText();
3684         }
3685
3686         /**
3687          * Check if page exists.  For historical reasons, this function simply
3688          * checks for the existence of the title in the page table, and will
3689          * thus return false for interwiki links, special pages and the like.
3690          * If you want to know if a title can be meaningfully viewed, you should
3691          * probably call the isKnown() method instead.
3692          *
3693          * @return \type{\bool}
3694          */
3695         public function exists() {
3696                 return $this->getArticleId() != 0;
3697         }
3698
3699         /**
3700          * Should links to this title be shown as potentially viewable (i.e. as
3701          * "bluelinks"), even if there's no record by this title in the page
3702          * table?
3703          *
3704          * This function is semi-deprecated for public use, as well as somewhat
3705          * misleadingly named.  You probably just want to call isKnown(), which
3706          * calls this function internally.
3707          *
3708          * (ISSUE: Most of these checks are cheap, but the file existence check
3709          * can potentially be quite expensive.  Including it here fixes a lot of
3710          * existing code, but we might want to add an optional parameter to skip
3711          * it and any other expensive checks.)
3712          *
3713          * @return \type{\bool}
3714          */
3715         public function isAlwaysKnown() {
3716                 if ( $this->mInterwiki != '' ) {
3717                         return true;  // any interwiki link might be viewable, for all we know
3718                 }
3719                 switch( $this->mNamespace ) {
3720                 case NS_MEDIA:
3721                 case NS_FILE:
3722                         return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3723                 case NS_SPECIAL:
3724                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3725                 case NS_MAIN:
3726                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3727                 case NS_MEDIAWIKI:
3728                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3729                         // the full l10n of that language to be loaded. That takes much memory and
3730                         // isn't needed. So we strip the language part away.
3731                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3732                         return (bool)wfMsgWeirdKey( $basename );  // known system message
3733                 default:
3734                         return false;
3735                 }
3736         }
3737
3738         /**
3739          * Does this title refer to a page that can (or might) be meaningfully
3740          * viewed?  In particular, this function may be used to determine if
3741          * links to the title should be rendered as "bluelinks" (as opposed to
3742          * "redlinks" to non-existent pages).
3743          *
3744          * @return \type{\bool}
3745          */
3746         public function isKnown() {
3747                 return $this->exists() || $this->isAlwaysKnown();
3748         }
3749
3750         /**
3751          * Does this page have source text?
3752          *
3753          * @return Boolean
3754          */
3755         public function hasSourceText() {
3756                 if ( $this->exists() )
3757                         return true;
3758
3759                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3760                         // If the page doesn't exist but is a known system message, default
3761                         // message content will be displayed, same for language subpages
3762                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3763                         // causes the full l10n of that language to be loaded. That takes much
3764                         // memory and isn't needed. So we strip the language part away.
3765                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3766                         return (bool)wfMsgWeirdKey( $basename );
3767                 }
3768
3769                 return false;
3770         }
3771
3772         /**
3773         * Is this in a namespace that allows actual pages?
3774         *
3775         * @return \type{\bool}
3776         * @internal note -- uses hardcoded namespace index instead of constants
3777         */
3778         public function canExist() {
3779                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3780         }
3781
3782         /**
3783          * Update page_touched timestamps and send squid purge messages for
3784          * pages linking to this title. May be sent to the job queue depending
3785          * on the number of links. Typically called on create and delete.
3786          */
3787         public function touchLinks() {
3788                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3789                 $u->doUpdate();
3790
3791                 if ( $this->getNamespace() == NS_CATEGORY ) {
3792                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3793                         $u->doUpdate();
3794                 }
3795         }
3796
3797         /**
3798          * Get the last touched timestamp
3799          *
3800          * @param $db DatabaseBase: optional db
3801          * @return \type{\string} Last touched timestamp
3802          */
3803         public function getTouched( $db = null ) {
3804                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3805                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3806                 return $touched;
3807         }
3808
3809         /**
3810          * Get the timestamp when this page was updated since the user last saw it.
3811          *
3812          * @param $user User
3813          * @return Mixed: string/null
3814          */
3815         public function getNotificationTimestamp( $user = null ) {
3816                 global $wgUser, $wgShowUpdatedMarker;
3817                 // Assume current user if none given
3818                 if ( !$user ) $user = $wgUser;
3819                 // Check cache first
3820                 $uid = $user->getId();
3821                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3822                         return $this->mNotificationTimestamp[$uid];
3823                 }
3824                 if ( !$uid || !$wgShowUpdatedMarker ) {
3825                         return $this->mNotificationTimestamp[$uid] = false;
3826                 }
3827                 // Don't cache too much!
3828                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3829                         $this->mNotificationTimestamp = array();
3830                 }
3831                 $dbr = wfGetDB( DB_SLAVE );
3832                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3833                         'wl_notificationtimestamp',
3834                         array( 'wl_namespace' => $this->getNamespace(),
3835                                 'wl_title' => $this->getDBkey(),
3836                                 'wl_user' => $user->getId()
3837                         ),
3838                         __METHOD__
3839                 );
3840                 return $this->mNotificationTimestamp[$uid];
3841         }
3842
3843         /**
3844          * Get the trackback URL for this page
3845          *
3846          * @return \type{\string} Trackback URL
3847          */
3848         public function trackbackURL() {
3849                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3850
3851                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3852                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3853         }
3854
3855         /**
3856          * Get the trackback RDF for this page
3857          *
3858          * @return \type{\string} Trackback RDF
3859          */
3860         public function trackbackRDF() {
3861                 $url = htmlspecialchars( $this->getFullURL() );
3862                 $title = htmlspecialchars( $this->getText() );
3863                 $tburl = $this->trackbackURL();
3864
3865                 // Autodiscovery RDF is placed in comments so HTML validator
3866                 // won't barf. This is a rather icky workaround, but seems
3867                 // frequently used by this kind of RDF thingy.
3868                 //
3869                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3870                 return "<!--
3871 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3872          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3873          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3874 <rdf:Description
3875    rdf:about=\"$url\"
3876    dc:identifier=\"$url\"
3877    dc:title=\"$title\"
3878    trackback:ping=\"$tburl\" />
3879 </rdf:RDF>
3880 -->";
3881         }
3882
3883         /**
3884          * Generate strings used for xml 'id' names in monobook tabs
3885          *
3886          * @param $prepend string defaults to 'nstab-'
3887          * @return \type{\string} XML 'id' name
3888          */
3889         public function getNamespaceKey( $prepend = 'nstab-' ) {
3890                 global $wgContLang;
3891                 // Gets the subject namespace if this title
3892                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3893                 // Checks if cononical namespace name exists for namespace
3894                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3895                         // Uses canonical namespace name
3896                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3897                 } else {
3898                         // Uses text of namespace
3899                         $namespaceKey = $this->getSubjectNsText();
3900                 }
3901                 // Makes namespace key lowercase
3902                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3903                 // Uses main
3904                 if ( $namespaceKey == '' ) {
3905                         $namespaceKey = 'main';
3906                 }
3907                 // Changes file to image for backwards compatibility
3908                 if ( $namespaceKey == 'file' ) {
3909                         $namespaceKey = 'image';
3910                 }
3911                 return $prepend . $namespaceKey;
3912         }
3913
3914         /**
3915          * Returns true if this is a special page.
3916          *
3917          * @return boolean
3918          */
3919         public function isSpecialPage( ) {
3920                 return $this->getNamespace() == NS_SPECIAL;
3921         }
3922
3923         /**
3924          * Returns true if this title resolves to the named special page
3925          *
3926          * @param $name \type{\string} The special page name
3927          * @return boolean
3928          */
3929         public function isSpecial( $name ) {
3930                 if ( $this->getNamespace() == NS_SPECIAL ) {
3931                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3932                         if ( $name == $thisName ) {
3933                                 return true;
3934                         }
3935                 }
3936                 return false;
3937         }
3938
3939         /**
3940          * If the Title refers to a special page alias which is not the local default,
3941          *
3942          * @return \type{Title} A new Title which points to the local default.
3943          *         Otherwise, returns $this.
3944          */
3945         public function fixSpecialName() {
3946                 if ( $this->getNamespace() == NS_SPECIAL ) {
3947                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3948                         if ( $canonicalName ) {
3949                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3950                                 if ( $localName != $this->mDbkeyform ) {
3951                                         return Title::makeTitle( NS_SPECIAL, $localName );
3952                                 }
3953                         }
3954                 }
3955                 return $this;
3956         }
3957
3958         /**
3959          * Is this Title in a namespace which contains content?
3960          * In other words, is this a content page, for the purposes of calculating
3961          * statistics, etc?
3962          *
3963          * @return \type{\bool}
3964          */
3965         public function isContentPage() {
3966                 return MWNamespace::isContent( $this->getNamespace() );
3967         }
3968
3969         /**
3970          * Get all extant redirects to this Title
3971          *
3972          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3973          *            NULL to consider all namespaces
3974          * @return \type{\arrayof{Title}} Redirects to this title
3975          */
3976         public function getRedirectsHere( $ns = null ) {
3977                 $redirs = array();
3978
3979                 $dbr = wfGetDB( DB_SLAVE );
3980                 $where = array(
3981                         'rd_namespace' => $this->getNamespace(),
3982                         'rd_title' => $this->getDBkey(),
3983                         'rd_from = page_id'
3984                 );
3985                 if ( !is_null( $ns ) ) $where['page_namespace'] = $ns;
3986
3987                 $res = $dbr->select(
3988                         array( 'redirect', 'page' ),
3989                         array( 'page_namespace', 'page_title' ),
3990                         $where,
3991                         __METHOD__
3992                 );
3993
3994
3995                 foreach ( $res as $row ) {
3996                         $redirs[] = self::newFromRow( $row );
3997                 }
3998                 return $redirs;
3999         }
4000
4001         /**
4002          * Check if this Title is a valid redirect target
4003          *
4004          * @return \type{\bool}
4005          */
4006         public function isValidRedirectTarget() {
4007                 global $wgInvalidRedirectTargets;
4008
4009                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4010                 if ( $this->isSpecial( 'Userlogout' ) ) {
4011                         return false;
4012                 }
4013
4014                 foreach ( $wgInvalidRedirectTargets as $target ) {
4015                         if ( $this->isSpecial( $target ) ) {
4016                                 return false;
4017                         }
4018                 }
4019
4020                 return true;
4021         }
4022
4023         /**
4024          * Get a backlink cache object
4025          *
4026          * @return object BacklinkCache
4027          */
4028         function getBacklinkCache() {
4029                 if ( is_null( $this->mBacklinkCache ) ) {
4030                         $this->mBacklinkCache = new BacklinkCache( $this );
4031                 }
4032                 return $this->mBacklinkCache;
4033         }
4034
4035         /**
4036          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4037          * this page.
4038          *
4039          * @return Boolean
4040          */
4041         public function canUseNoindex() {
4042                 global $wgArticleRobotPolicies, $wgContentNamespaces,
4043                        $wgExemptFromUserRobotsControl;
4044
4045                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4046                         ? $wgContentNamespaces
4047                         : $wgExemptFromUserRobotsControl;
4048
4049                 return !in_array( $this->mNamespace, $bannedNamespaces );
4050
4051         }
4052
4053         /**
4054          * Returns restriction types for the current Title
4055          *
4056          * @return array applicable restriction types
4057          */
4058         public function getRestrictionTypes() {
4059                 global $wgRestrictionTypes;
4060                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4061
4062                 if ( $this->getNamespace() == NS_FILE ) {
4063                         $types[] = 'upload';
4064                 }
4065
4066                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4067
4068                 return $types;
4069         }
4070 }