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