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         // @}
  31
  32         /**
  33          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  34          * commonly used titles. On a batch operation this can become a memory leak
  35          * if not bounded. After hitting this many titles reset the cache.
  36          */
  37         const CACHE_MAX = 1000;
  38
  39
  40         /**
  41          * @name Private member variables
  42          * Please use the accessor functions instead.
  43          * @private
  44          */
  45         // @{
  46
  47         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  48         var $mUrlform = '';               // /< URL-encoded form of the main part
  49         var $mDbkeyform = '';             // /< Main part with underscores
  50         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  51         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  52         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  53         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  54         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  55         var $mLatestID = false;           // /< ID of most recent revision
  56         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  57         var $mOldRestrictions = false;
  58         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  59         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  60         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  61         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  62         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  63         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  64         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  65         var $mTitleProtection;            ///< Cached value of getTitleProtection
  66         # Don't change the following default, NS_MAIN is hardcoded in several
  67         # places.  See bug 696.
  68         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  69                                           # Zero except in {{transclusion}} tags
  70         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  71         var $mLength = -1;                // /< The page length, 0 for special pages
  72         var $mRedirect = null;            // /< Is the article at this title a redirect?
  73         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  74         var $mBacklinkCache = null;       // /< Cache of links to this title
  75         // @}
  76
  77
  78         /**
  79          * Constructor
  80          * @private
  81          */
  82         /* private */ function __construct() { }
  83
  84         /**
  85          * Create a new Title from a prefixed DB key
  86          *
  87          * @param $key \type{\string} The database key, which has underscores
  88          *      instead of spaces, possibly including namespace and
  89          *      interwiki prefixes
  90          * @return \type{Title} the new object, or NULL on an error
  91          */
  92         public static function newFromDBkey( $key ) {
  93                 $t = new Title();
  94                 $t->mDbkeyform = $key;
  95                 if ( $t->secureAndSplit() ) {
  96                         return $t;
  97                 } else {
  98                         return null;
  99                 }
 100         }
 101
 102         /**
 103          * Create a new Title from text, such as what one would find in a link. De-
 104          * codes any HTML entities in the text.
 105          *
 106          * @param $text string  The link text; spaces, prefixes, and an
 107          *   initial ':' indicating the main namespace are accepted.
 108          * @param $defaultNamespace int The namespace to use if none is speci-
 109          *   fied by a prefix.  If you want to force a specific namespace even if
 110          *   $text might begin with a namespace prefix, use makeTitle() or
 111          *   makeTitleSafe().
 112          * @return Title  The new object, or null on an error.
 113          */
 114         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 115                 if ( is_object( $text ) ) {
 116                         throw new MWException( 'Title::newFromText given an object' );
 117                 }
 118
 119                 /**
 120                  * Wiki pages often contain multiple links to the same page.
 121                  * Title normalization and parsing can become expensive on
 122                  * pages with many links, so we can save a little time by
 123                  * caching them.
 124                  *
 125                  * In theory these are value objects and won't get changed...
 126                  */
 127                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 128                         return Title::$titleCache[$text];
 129                 }
 130
 131                 /**
 132                  * Convert things like &eacute; &#257; or &#x3017; into normalized(bug 14952) text
 133                  */
 134                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 135
 136                 $t = new Title();
 137                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 138                 $t->mDefaultNamespace = $defaultNamespace;
 139
 140                 static $cachedcount = 0 ;
 141                 if ( $t->secureAndSplit() ) {
 142                         if ( $defaultNamespace == NS_MAIN ) {
 143                                 if ( $cachedcount >= self::CACHE_MAX ) {
 144                                         # Avoid memory leaks on mass operations...
 145                                         Title::$titleCache = array();
 146                                         $cachedcount = 0;
 147                                 }
 148                                 $cachedcount++;
 149                                 Title::$titleCache[$text] =& $t;
 150                         }
 151                         return $t;
 152                 } else {
 153                         $ret = null;
 154                         return $ret;
 155                 }
 156         }
 157
 158         /**
 159          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 160          *
 161          * Example of wrong and broken code:
 162          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 163          *
 164          * Example of right code:
 165          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 166          *
 167          * Create a new Title from URL-encoded text. Ensures that
 168          * the given title's length does not exceed the maximum.
 169          *
 170          * @param $url \type{\string} the title, as might be taken from a URL
 171          * @return \type{Title} the new object, or NULL on an error
 172          */
 173         public static function newFromURL( $url ) {
 174                 global $wgLegalTitleChars;
 175                 $t = new Title();
 176
 177                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 178                 # but some URLs used it as a space replacement and they still come
 179                 # from some external search tools.
 180                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 181                         $url = str_replace( '+', ' ', $url );
 182                 }
 183
 184                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 185                 if ( $t->secureAndSplit() ) {
 186                         return $t;
 187                 } else {
 188                         return null;
 189                 }
 190         }
 191
 192         /**
 193          * Create a new Title from an article ID
 194          *
 195          * @param $id \type{\int} the page_id corresponding to the Title to create
 196          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 197          * @return \type{Title} the new object, or NULL on an error
 198          */
 199         public static function newFromID( $id, $flags = 0 ) {
 200                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 201                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 202                 if ( $row !== false ) {
 203                         $title = Title::newFromRow( $row );
 204                 } else {
 205                         $title = null;
 206                 }
 207                 return $title;
 208         }
 209
 210         /**
 211          * Make an array of titles from an array of IDs
 212          *
 213          * @param $ids \type{\arrayof{\int}} Array of IDs
 214          * @return \type{\arrayof{Title}} Array of Titles
 215          */
 216         public static function newFromIDs( $ids ) {
 217                 if ( !count( $ids ) ) {
 218                         return array();
 219                 }
 220                 $dbr = wfGetDB( DB_SLAVE );
 221
 222                 $res = $dbr->select(
 223                         'page',
 224                         array(
 225                                 'page_namespace', 'page_title', 'page_id',
 226                                 'page_len', 'page_is_redirect', 'page_latest',
 227                         ),
 228                         array( 'page_id' => $ids ),
 229                         __METHOD__
 230                 );
 231
 232                 $titles = array();
 233                 foreach ( $res as $row ) {
 234                         $titles[] = Title::newFromRow( $row );
 235                 }
 236                 return $titles;
 237         }
 238
 239         /**
 240          * Make a Title object from a DB row
 241          *
 242          * @param $row \type{Row} (needs at least page_title,page_namespace)
 243          * @return \type{Title} corresponding Title
 244          */
 245         public static function newFromRow( $row ) {
 246                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 247
 248                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 249                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 250                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 251                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 252
 253                 return $t;
 254         }
 255
 256         /**
 257          * Create a new Title from a namespace index and a DB key.
 258          * It's assumed that $ns and $title are *valid*, for instance when
 259          * they came directly from the database or a special page name.
 260          * For convenience, spaces are converted to underscores so that
 261          * eg user_text fields can be used directly.
 262          *
 263          * @param $ns \type{\int} the namespace of the article
 264          * @param $title \type{\string} the unprefixed database key form
 265          * @param $fragment \type{\string} The link fragment (after the "#")
 266          * @param $interwiki \type{\string} The interwiki prefix
 267          * @return \type{Title} the new object
 268          */
 269         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 270                 $t = new Title();
 271                 $t->mInterwiki = $interwiki;
 272                 $t->mFragment = $fragment;
 273                 $t->mNamespace = $ns = intval( $ns );
 274                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 275                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 276                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 277                 $t->mTextform = str_replace( '_', ' ', $title );
 278                 return $t;
 279         }
 280
 281         /**
 282          * Create a new Title from a namespace index and a DB key.
 283          * The parameters will be checked for validity, which is a bit slower
 284          * than makeTitle() but safer for user-provided data.
 285          *
 286          * @param $ns \type{\int} the namespace of the article
 287          * @param $title \type{\string} the database key form
 288          * @param $fragment \type{\string} The link fragment (after the "#")
 289          * @param $interwiki \type{\string} The interwiki prefix
 290          * @return \type{Title} the new object, or NULL on an error
 291          */
 292         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 293                 $t = new Title();
 294                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 295                 if ( $t->secureAndSplit() ) {
 296                         return $t;
 297                 } else {
 298                         return null;
 299                 }
 300         }
 301
 302         /**
 303          * Create a new Title for the Main Page
 304          *
 305          * @return \type{Title} the new object
 306          */
 307         public static function newMainPage() {
 308                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 309                 // Don't give fatal errors if the message is broken
 310                 if ( !$title ) {
 311                         $title = Title::newFromText( 'Main Page' );
 312                 }
 313                 return $title;
 314         }
 315
 316         /**
 317          * Extract a redirect destination from a string and return the
 318          * Title, or null if the text doesn't contain a valid redirect
 319          * This will only return the very next target, useful for
 320          * the redirect table and other checks that don't need full recursion
 321          *
 322          * @param $text \type{\string} Text with possible redirect
 323          * @return \type{Title} The corresponding Title
 324          */
 325         public static function newFromRedirect( $text ) {
 326                 return self::newFromRedirectInternal( $text );
 327         }
 328
 329         /**
 330          * Extract a redirect destination from a string and return the
 331          * Title, or null if the text doesn't contain a valid redirect
 332          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 333          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 334          *
 335          * @param $text \type{\string} Text with possible redirect
 336          * @return \type{Title} The corresponding Title
 337          */
 338         public static function newFromRedirectRecurse( $text ) {
 339                 $titles = self::newFromRedirectArray( $text );
 340                 return $titles ? array_pop( $titles ) : null;
 341         }
 342
 343         /**
 344          * Extract a redirect destination from a string and return an
 345          * array of Titles, or null if the text doesn't contain a valid redirect
 346          * The last element in the array is the final destination after all redirects
 347          * have been resolved (up to $wgMaxRedirects times)
 348          *
 349          * @param $text \type{\string} Text with possible redirect
 350          * @return \type{\array} Array of Titles, with the destination last
 351          */
 352         public static function newFromRedirectArray( $text ) {
 353                 global $wgMaxRedirects;
 354                 // are redirects disabled?
 355                 if ( $wgMaxRedirects < 1 ) {
 356                         return null;
 357                 }
 358                 $title = self::newFromRedirectInternal( $text );
 359                 if ( is_null( $title ) ) {
 360                         return null;
 361                 }
 362                 // recursive check to follow double redirects
 363                 $recurse = $wgMaxRedirects;
 364                 $titles = array( $title );
 365                 while ( --$recurse > 0 ) {
 366                         if ( $title->isRedirect() ) {
 367                                 $article = new Article( $title, 0 );
 368                                 $newtitle = $article->getRedirectTarget();
 369                         } else {
 370                                 break;
 371                         }
 372                         // Redirects to some special pages are not permitted
 373                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 374                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 375                                 $title = $newtitle;
 376                                 $titles[] = $newtitle;
 377                         } else {
 378                                 break;
 379                         }
 380                 }
 381                 return $titles;
 382         }
 383
 384         /**
 385          * Really extract the redirect destination
 386          * Do not call this function directly, use one of the newFromRedirect* functions above
 387          *
 388          * @param $text \type{\string} Text with possible redirect
 389          * @return \type{Title} The corresponding Title
 390          */
 391         protected static function newFromRedirectInternal( $text ) {
 392                 $redir = MagicWord::get( 'redirect' );
 393                 $text = trim( $text );
 394                 if ( $redir->matchStartAndRemove( $text ) ) {
 395                         // Extract the first link and see if it's usable
 396                         // Ensure that it really does come directly after #REDIRECT
 397                         // Some older redirects included a colon, so don't freak about that!
 398                         $m = array();
 399                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 400                                 // Strip preceding colon used to "escape" categories, etc.
 401                                 // and URL-decode links
 402                                 if ( strpos( $m[1], '%' ) !== false ) {
 403                                         // Match behavior of inline link parsing here;
 404                                         // don't interpret + as " " most of the time!
 405                                         // It might be safe to just use rawurldecode instead, though.
 406                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 407                                 }
 408                                 $title = Title::newFromText( $m[1] );
 409                                 // If the title is a redirect to bad special pages or is invalid, return null
 410                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 411                                         return null;
 412                                 }
 413                                 return $title;
 414                         }
 415                 }
 416                 return null;
 417         }
 418
 419 # ----------------------------------------------------------------------------
 420 #       Static functions
 421 # ----------------------------------------------------------------------------
 422
 423         /**
 424          * Get the prefixed DB key associated with an ID
 425          *
 426          * @param $id \type{\int} the page_id of the article
 427          * @return \type{Title} an object representing the article, or NULL
 428          *  if no such article was found
 429          */
 430         public static function nameOf( $id ) {
 431                 $dbr = wfGetDB( DB_SLAVE );
 432
 433                 $s = $dbr->selectRow(
 434                         'page',
 435                         array( 'page_namespace', 'page_title' ),
 436                         array( 'page_id' => $id ),
 437                         __METHOD__
 438                 );
 439                 if ( $s === false ) {
 440                         return null;
 441                 }
 442
 443                 $n = self::makeName( $s->page_namespace, $s->page_title );
 444                 return $n;
 445         }
 446
 447         /**
 448          * Get a regex character class describing the legal characters in a link
 449          *
 450          * @return \type{\string} the list of characters, not delimited
 451          */
 452         public static function legalChars() {
 453                 global $wgLegalTitleChars;
 454                 return $wgLegalTitleChars;
 455         }
 456
 457         /**
 458          * Get a string representation of a title suitable for
 459          * including in a search index
 460          *
 461          * @param $ns \type{\int} a namespace index
 462          * @param $title \type{\string} text-form main part
 463          * @return \type{\string} a stripped-down title string ready for the
 464          *  search index
 465          */
 466         public static function indexTitle( $ns, $title ) {
 467                 global $wgContLang;
 468
 469                 $lc = SearchEngine::legalSearchChars() . '&#;';
 470                 $t = $wgContLang->normalizeForSearch( $title );
 471                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 472                 $t = $wgContLang->lc( $t );
 473
 474                 # Handle 's, s'
 475                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 476                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 477
 478                 $t = preg_replace( "/\\s+/", ' ', $t );
 479
 480                 if ( $ns == NS_FILE ) {
 481                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 482                 }
 483                 return trim( $t );
 484         }
 485
 486         /**
 487          * Make a prefixed DB key from a DB key and a namespace index
 488          *
 489          * @param $ns \type{\int} numerical representation of the namespace
 490          * @param $title \type{\string} the DB key form the title
 491          * @param $fragment \type{\string} The link fragment (after the "#")
 492          * @param $interwiki \type{\string} The interwiki prefix
 493          * @return \type{\string} the prefixed form of the title
 494          */
 495         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 496                 global $wgContLang;
 497
 498                 $namespace = $wgContLang->getNsText( $ns );
 499                 $name = $namespace == '' ? $title : "$namespace:$title";
 500                 if ( strval( $interwiki ) != '' ) {
 501                         $name = "$interwiki:$name";
 502                 }
 503                 if ( strval( $fragment ) != '' ) {
 504                         $name .= '#' . $fragment;
 505                 }
 506                 return $name;
 507         }
 508
 509         /**
 510          * Determine whether the object refers to a page within
 511          * this project.
 512          *
 513          * @return \type{\bool} TRUE if this is an in-project interwiki link
 514          *      or a wikilink, FALSE otherwise
 515          */
 516         public function isLocal() {
 517                 if ( $this->mInterwiki != '' ) {
 518                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 519                 } else {
 520                         return true;
 521                 }
 522         }
 523
 524         /**
 525          * Determine whether the object refers to a page within
 526          * this project and is transcludable.
 527          *
 528          * @return \type{\bool} TRUE if this is transcludable
 529          */
 530         public function isTrans() {
 531                 if ( $this->mInterwiki == '' ) {
 532                         return false;
 533                 }
 534
 535                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 536         }
 537
 538         /**
 539          * Returns the DB name of the distant wiki
 540          * which owns the object.
 541          *
 542          * @return \type{\string} the DB name
 543          */
 544         public function getTransWikiID() {
 545                 if ( $this->mInterwiki == '' ) {
 546                         return false;
 547                 }
 548
 549                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 550         }
 551
 552         /**
 553          * Escape a text fragment, say from a link, for a URL
 554          *
 555          * @param $fragment string containing a URL or link fragment (after the "#")
 556          * @return String: escaped string
 557          */
 558         static function escapeFragmentForURL( $fragment ) {
 559                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 560                 # fragments appear not to work in IE (at least up to 7) or in at least
 561                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 562                 # to care if they aren't encoded.
 563                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 564         }
 565
 566 # ----------------------------------------------------------------------------
 567 #       Other stuff
 568 # ----------------------------------------------------------------------------
 569
 570         /** Simple accessors */
 571         /**
 572          * Get the text form (spaces not underscores) of the main part
 573          *
 574          * @return \type{\string} Main part of the title
 575          */
 576         public function getText() { return $this->mTextform; }
 577
 578         /**
 579          * Get the URL-encoded form of the main part
 580          *
 581          * @return \type{\string} Main part of the title, URL-encoded
 582          */
 583         public function getPartialURL() { return $this->mUrlform; }
 584
 585         /**
 586          * Get the main part with underscores
 587          *
 588          * @return \type{\string} Main part of the title, with underscores
 589          */
 590         public function getDBkey() { return $this->mDbkeyform; }
 591
 592         /**
 593          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 594          *
 595          * @return \type{\int} Namespace index
 596          */
 597         public function getNamespace() { return $this->mNamespace; }
 598
 599         /**
 600          * Get the namespace text
 601          *
 602          * @return \type{\string} Namespace text
 603          */
 604         public function getNsText() {
 605                 global $wgContLang;
 606
 607                 if ( $this->mInterwiki != '' ) {
 608                         // This probably shouldn't even happen. ohh man, oh yuck.
 609                         // But for interwiki transclusion it sometimes does.
 610                         // Shit. Shit shit shit.
 611                         //
 612                         // Use the canonical namespaces if possible to try to
 613                         // resolve a foreign namespace.
 614                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 615                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 616                         }
 617                 }
 618                 return $wgContLang->getNsText( $this->mNamespace );
 619         }
 620
 621         /**
 622          * Get the DB key with the initial letter case as specified by the user
 623          *
 624          * @return \type{\string} DB key
 625          */
 626         function getUserCaseDBKey() {
 627                 return $this->mUserCaseDBKey;
 628         }
 629
 630         /**
 631          * Get the namespace text of the subject (rather than talk) page
 632          *
 633          * @return \type{\string} Namespace text
 634          */
 635         public function getSubjectNsText() {
 636                 global $wgContLang;
 637                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 638         }
 639
 640         /**
 641          * Get the namespace text of the talk page
 642          *
 643          * @return \type{\string} Namespace text
 644          */
 645         public function getTalkNsText() {
 646                 global $wgContLang;
 647                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 648         }
 649
 650         /**
 651          * Could this title have a corresponding talk page?
 652          *
 653          * @return \type{\bool} TRUE or FALSE
 654          */
 655         public function canTalk() {
 656                 return( MWNamespace::canTalk( $this->mNamespace ) );
 657         }
 658
 659         /**
 660          * Get the interwiki prefix (or null string)
 661          *
 662          * @return \type{\string} Interwiki prefix
 663          */
 664         public function getInterwiki() { return $this->mInterwiki; }
 665
 666         /**
 667          * Get the Title fragment (i.e.\ the bit after the #) in text form
 668          *
 669          * @return \type{\string} Title fragment
 670          */
 671         public function getFragment() { return $this->mFragment; }
 672
 673         /**
 674          * Get the fragment in URL form, including the "#" character if there is one
 675          * @return \type{\string} Fragment in URL form
 676          */
 677         public function getFragmentForURL() {
 678                 if ( $this->mFragment == '' ) {
 679                         return '';
 680                 } else {
 681                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 682                 }
 683         }
 684
 685         /**
 686          * Get the default namespace index, for when there is no namespace
 687          *
 688          * @return \type{\int} Default namespace index
 689          */
 690         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 691
 692         /**
 693          * Get title for search index
 694          *
 695          * @return \type{\string} a stripped-down title string ready for the
 696          *  search index
 697          */
 698         public function getIndexTitle() {
 699                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 700         }
 701
 702         /**
 703          * Get the prefixed database key form
 704          *
 705          * @return \type{\string} the prefixed title, with underscores and
 706          *  any interwiki and namespace prefixes
 707          */
 708         public function getPrefixedDBkey() {
 709                 $s = $this->prefix( $this->mDbkeyform );
 710                 $s = str_replace( ' ', '_', $s );
 711                 return $s;
 712         }
 713
 714         /**
 715          * Get the prefixed title with spaces.
 716          * This is the form usually used for display
 717          *
 718          * @return \type{\string} the prefixed title, with spaces
 719          */
 720         public function getPrefixedText() {
 721                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 722                         $s = $this->prefix( $this->mTextform );
 723                         $s = str_replace( '_', ' ', $s );
 724                         $this->mPrefixedText = $s;
 725                 }
 726                 return $this->mPrefixedText;
 727         }
 728
 729         /**
 730          * Get the prefixed title with spaces, plus any fragment
 731          * (part beginning with '#')
 732          *
 733          * @return \type{\string} the prefixed title, with spaces and
 734          *  the fragment, including '#'
 735          */
 736         public function getFullText() {
 737                 $text = $this->getPrefixedText();
 738                 if ( $this->mFragment != '' ) {
 739                         $text .= '#' . $this->mFragment;
 740                 }
 741                 return $text;
 742         }
 743
 744         /**
 745          * Get the base name, i.e. the leftmost parts before the /
 746          *
 747          * @return \type{\string} Base name
 748          */
 749         public function getBaseText() {
 750                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 751                         return $this->getText();
 752                 }
 753
 754                 $parts = explode( '/', $this->getText() );
 755                 # Don't discard the real title if there's no subpage involved
 756                 if ( count( $parts ) > 1 ) {
 757                         unset( $parts[count( $parts ) - 1] );
 758                 }
 759                 return implode( '/', $parts );
 760         }
 761
 762         /**
 763          * Get the lowest-level subpage name, i.e. the rightmost part after /
 764          *
 765          * @return \type{\string} Subpage name
 766          */
 767         public function getSubpageText() {
 768                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 769                         return( $this->mTextform );
 770                 }
 771                 $parts = explode( '/', $this->mTextform );
 772                 return( $parts[count( $parts ) - 1] );
 773         }
 774
 775         /**
 776          * Get a URL-encoded form of the subpage text
 777          *
 778          * @return \type{\string} URL-encoded subpage name
 779          */
 780         public function getSubpageUrlForm() {
 781                 $text = $this->getSubpageText();
 782                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 783                 return( $text );
 784         }
 785
 786         /**
 787          * Get a URL-encoded title (not an actual URL) including interwiki
 788          *
 789          * @return \type{\string} the URL-encoded form
 790          */
 791         public function getPrefixedURL() {
 792                 $s = $this->prefix( $this->mDbkeyform );
 793                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 794                 return $s;
 795         }
 796
 797         /**
 798          * Get a real URL referring to this title, with interwiki link and
 799          * fragment
 800          *
 801          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 802          *   links. Can be specified as an associative array as well, e.g.,
 803          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 804          * @param $variant \type{\string} language variant of url (for sr, zh..)
 805          * @return \type{\string} the URL
 806          */
 807         public function getFullURL( $query = '', $variant = false ) {
 808                 global $wgServer, $wgRequest;
 809
 810                 if ( is_array( $query ) ) {
 811                         $query = wfArrayToCGI( $query );
 812                 }
 813
 814                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 815                 if ( !$interwiki ) {
 816                         $url = $this->getLocalURL( $query, $variant );
 817
 818                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 819                         // Correct fix would be to move the prepending elsewhere.
 820                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 821                                 $url = $wgServer . $url;
 822                         }
 823                 } else {
 824                         $baseUrl = $interwiki->getURL();
 825
 826                         $namespace = wfUrlencode( $this->getNsText() );
 827                         if ( $namespace != '' ) {
 828                                 # Can this actually happen? Interwikis shouldn't be parsed.
 829                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 830                                 $namespace .= ':';
 831                         }
 832                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 833                         $url = wfAppendQuery( $url, $query );
 834                 }
 835
 836                 # Finally, add the fragment.
 837                 $url .= $this->getFragmentForURL();
 838
 839                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 840                 return $url;
 841         }
 842
 843         /**
 844          * Get a URL with no fragment or server name.  If this page is generated
 845          * with action=render, $wgServer is prepended.
 846          *
 847          * @param $query Mixed: an optional query string; if not specified,
 848          *   $wgArticlePath will be used.  Can be specified as an associative array
 849          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 850          *   URL-escaped).
 851          * @param $variant \type{\string} language variant of url (for sr, zh..)
 852          * @return \type{\string} the URL
 853          */
 854         public function getLocalURL( $query = '', $variant = false ) {
 855                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 856                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 857
 858                 if ( is_array( $query ) ) {
 859                         $query = wfArrayToCGI( $query );
 860                 }
 861
 862                 // internal links should point to same variant as current page (only anonymous users)
 863                 if ( !$variant && $wgContLang->hasVariants() && !$wgUser->isLoggedIn() ) {
 864                         $pref = $wgContLang->getPreferredVariant( false );
 865                         if ( $pref != $wgContLang->getCode() ) {
 866                                 $variant = $pref;
 867                         }
 868                 }
 869
 870                 if ( $this->isExternal() ) {
 871                         $url = $this->getFullURL();
 872                         if ( $query ) {
 873                                 // This is currently only used for edit section links in the
 874                                 // context of interwiki transclusion. In theory we should
 875                                 // append the query to the end of any existing query string,
 876                                 // but interwiki transclusion is already broken in that case.
 877                                 $url .= "?$query";
 878                         }
 879                 } else {
 880                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 881                         if ( $query == '' ) {
 882                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 883                                         if ( !$wgVariantArticlePath ) {
 884                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 885                                         } else {
 886                                                 $variantArticlePath = $wgVariantArticlePath;
 887                                         }
 888                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 889                                         $url = str_replace( '$1', $dbkey, $url  );
 890                                 } else {
 891                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 892                                 }
 893                         } else {
 894                                 global $wgActionPaths;
 895                                 $url = false;
 896                                 $matches = array();
 897                                 if ( !empty( $wgActionPaths ) &&
 898                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 899                                 {
 900                                         $action = urldecode( $matches[2] );
 901                                         if ( isset( $wgActionPaths[$action] ) ) {
 902                                                 $query = $matches[1];
 903                                                 if ( isset( $matches[4] ) ) {
 904                                                         $query .= $matches[4];
 905                                                 }
 906                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 907                                                 if ( $query != '' ) {
 908                                                         $url = wfAppendQuery( $url, $query );
 909                                                 }
 910                                         }
 911                                 }
 912                                 if ( $url === false ) {
 913                                         if ( $query == '-' ) {
 914                                                 $query = '';
 915                                         }
 916                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 917                                 }
 918                         }
 919
 920                         // FIXME: this causes breakage in various places when we
 921                         // actually expected a local URL and end up with dupe prefixes.
 922                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 923                                 $url = $wgServer . $url;
 924                         }
 925                 }
 926                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 927                 return $url;
 928         }
 929
 930         /**
 931          * Get a URL that's the simplest URL that will be valid to link, locally,
 932          * to the current Title.  It includes the fragment, but does not include
 933          * the server unless action=render is used (or the link is external).  If
 934          * there's a fragment but the prefixed text is empty, we just return a link
 935          * to the fragment.
 936          *
 937          * The result obviously should not be URL-escaped, but does need to be
 938          * HTML-escaped if it's being output in HTML.
 939          *
 940          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 941          *   query string.  Keys and values will be escaped.
 942          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 943          *   for external links.  Default is "false" (same variant as current page,
 944          *   for anonymous users).
 945          * @return \type{\string} the URL
 946          */
 947         public function getLinkUrl( $query = array(), $variant = false ) {
 948                 wfProfileIn( __METHOD__ );
 949                 if ( $this->isExternal() ) {
 950                         $ret = $this->getFullURL( $query );
 951                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 952                         $ret = $this->getFragmentForURL();
 953                 } else {
 954                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 955                 }
 956                 wfProfileOut( __METHOD__ );
 957                 return $ret;
 958         }
 959
 960         /**
 961          * Get an HTML-escaped version of the URL form, suitable for
 962          * using in a link, without a server name or fragment
 963          *
 964          * @param $query \type{\string} an optional query string
 965          * @return \type{\string} the URL
 966          */
 967         public function escapeLocalURL( $query = '' ) {
 968                 return htmlspecialchars( $this->getLocalURL( $query ) );
 969         }
 970
 971         /**
 972          * Get an HTML-escaped version of the URL form, suitable for
 973          * using in a link, including the server name and fragment
 974          *
 975          * @param $query \type{\string} an optional query string
 976          * @return \type{\string} the URL
 977          */
 978         public function escapeFullURL( $query = '' ) {
 979                 return htmlspecialchars( $this->getFullURL( $query ) );
 980         }
 981
 982         /**
 983          * Get the URL form for an internal link.
 984          * - Used in various Squid-related code, in case we have a different
 985          * internal hostname for the server from the exposed one.
 986          *
 987          * @param $query \type{\string} an optional query string
 988          * @param $variant \type{\string} language variant of url (for sr, zh..)
 989          * @return \type{\string} the URL
 990          */
 991         public function getInternalURL( $query = '', $variant = false ) {
 992                 global $wgInternalServer;
 993                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 994                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 995                 return $url;
 996         }
 997
 998         /**
 999          * Get the edit URL for this Title
1000          *
1001          * @return \type{\string} the URL, or a null string if this is an
1002          *  interwiki link
1003          */
1004         public function getEditURL() {
1005                 if ( $this->mInterwiki != '' ) {
1006                         return '';
1007                 }
1008                 $s = $this->getLocalURL( 'action=edit' );
1009
1010                 return $s;
1011         }
1012
1013         /**
1014          * Get the HTML-escaped displayable text form.
1015          * Used for the title field in <a> tags.
1016          *
1017          * @return \type{\string} the text, including any prefixes
1018          */
1019         public function getEscapedText() {
1020                 return htmlspecialchars( $this->getPrefixedText() );
1021         }
1022
1023         /**
1024          * Is this Title interwiki?
1025          *
1026          * @return \type{\bool}
1027          */
1028         public function isExternal() {
1029                 return ( $this->mInterwiki != '' );
1030         }
1031
1032         /**
1033          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1034          *
1035          * @param $action \type{\string} Action to check (default: edit)
1036          * @return \type{\bool}
1037          */
1038         public function isSemiProtected( $action = 'edit' ) {
1039                 if ( $this->exists() ) {
1040                         $restrictions = $this->getRestrictions( $action );
1041                         if ( count( $restrictions ) > 0 ) {
1042                                 foreach ( $restrictions as $restriction ) {
1043                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1044                                                 return false;
1045                                         }
1046                                 }
1047                         } else {
1048                                 # Not protected
1049                                 return false;
1050                         }
1051                         return true;
1052                 } else {
1053                         # If it doesn't exist, it can't be protected
1054                         return false;
1055                 }
1056         }
1057
1058         /**
1059          * Does the title correspond to a protected article?
1060          *
1061          * @param $action \type{\string} the action the page is protected from,
1062          * by default checks all actions.
1063          * @return \type{\bool}
1064          */
1065         public function isProtected( $action = '' ) {
1066                 global $wgRestrictionLevels;
1067
1068                 $restrictionTypes = $this->getRestrictionTypes();
1069
1070                 # Special pages have inherent protection
1071                 if( $this->getNamespace() == NS_SPECIAL ) {
1072                         return true;
1073                 }
1074
1075                 # Check regular protection levels
1076                 foreach ( $restrictionTypes as $type ) {
1077                         if ( $action == $type || $action == '' ) {
1078                                 $r = $this->getRestrictions( $type );
1079                                 foreach ( $wgRestrictionLevels as $level ) {
1080                                         if ( in_array( $level, $r ) && $level != '' ) {
1081                                                 return true;
1082                                         }
1083                                 }
1084                         }
1085                 }
1086
1087                 return false;
1088         }
1089
1090         /**
1091          * Is this a conversion table for the LanguageConverter?
1092          *
1093          * @return \type{\bool}
1094          */
1095         public function isConversionTable() {
1096                 if(
1097                         $this->getNamespace() == NS_MEDIAWIKI &&
1098                         strpos( $this->getText(), 'Conversiontable' ) !== false
1099                 )
1100                 {
1101                         return true;
1102                 }
1103
1104                 return false;
1105         }
1106
1107         /**
1108          * Is $wgUser watching this page?
1109          *
1110          * @return \type{\bool}
1111          */
1112         public function userIsWatching() {
1113                 global $wgUser;
1114
1115                 if ( is_null( $this->mWatched ) ) {
1116                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1117                                 $this->mWatched = false;
1118                         } else {
1119                                 $this->mWatched = $wgUser->isWatched( $this );
1120                         }
1121                 }
1122                 return $this->mWatched;
1123         }
1124
1125         /**
1126          * Can $wgUser perform $action on this page?
1127          * This skips potentially expensive cascading permission checks
1128          * as well as avoids expensive error formatting
1129          *
1130          * Suitable for use for nonessential UI controls in common cases, but
1131          * _not_ for functional access control.
1132          *
1133          * May provide false positives, but should never provide a false negative.
1134          *
1135          * @param $action \type{\string} action that permission needs to be checked for
1136          * @return \type{\bool}
1137          */
1138         public function quickUserCan( $action ) {
1139                 return $this->userCan( $action, false );
1140         }
1141
1142         /**
1143          * Determines if $wgUser is unable to edit this page because it has been protected
1144          * by $wgNamespaceProtection.
1145          *
1146          * @return \type{\bool}
1147          */
1148         public function isNamespaceProtected() {
1149                 global $wgNamespaceProtection, $wgUser;
1150                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1151                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1152                                 if ( $right != '' && !$wgUser->isAllowed( $right ) ) {
1153                                         return true;
1154                                 }
1155                         }
1156                 }
1157                 return false;
1158         }
1159
1160         /**
1161          * Can $wgUser perform $action on this page?
1162          *
1163          * @param $action \type{\string} action that permission needs to be checked for
1164          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1165          * @return \type{\bool}
1166          */
1167         public function userCan( $action, $doExpensiveQueries = true ) {
1168                 global $wgUser;
1169                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1170         }
1171
1172         /**
1173          * Can $user perform $action on this page?
1174          *
1175          * FIXME: This *does not* check throttles (User::pingLimiter()).
1176          *
1177          * @param $action \type{\string}action that permission needs to be checked for
1178          * @param $user \type{User} user to check
1179          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1180          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1181          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1182          */
1183         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1184                 if ( !StubObject::isRealObject( $user ) ) {
1185                         // Since StubObject is always used on globals, we can
1186                         // unstub $wgUser here and set $user = $wgUser
1187                         global $wgUser;
1188                         $wgUser->_unstub( '', 5 );
1189                         $user = $wgUser;
1190                 }
1191
1192                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1193
1194                 // Remove the errors being ignored.
1195                 foreach ( $errors as $index => $error ) {
1196                         $error_key = is_array( $error ) ? $error[0] : $error;
1197
1198                         if ( in_array( $error_key, $ignoreErrors ) ) {
1199                                 unset( $errors[$index] );
1200                         }
1201                 }
1202
1203                 return $errors;
1204         }
1205
1206         /**
1207          * Permissions checks that fail most often, and which are easiest to test.
1208          *
1209          * @param $action String the action to check
1210          * @param $user User user to check
1211          * @param $errors Array list of current errors
1212          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1213          * @param $short Boolean short circuit on first error
1214          *
1215          * @return Array list of errors
1216          */
1217         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1218                 if ( $action == 'create' ) {
1219                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1220                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1221                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1222                         }
1223                 } elseif ( $action == 'move' ) {
1224                         if ( !$user->isAllowed( 'move-rootuserpages' )
1225                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1226                                 // Show user page-specific message only if the user can move other pages
1227                                 $errors[] = array( 'cant-move-user-page' );
1228                         }
1229
1230                         // Check if user is allowed to move files if it's a file
1231                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1232                                 $errors[] = array( 'movenotallowedfile' );
1233                         }
1234
1235                         if ( !$user->isAllowed( 'move' ) ) {
1236                                 // User can't move anything
1237                                 global $wgGroupPermissions;
1238                                 $userCanMove = false;
1239                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1240                                         $userCanMove = $wgGroupPermissions['user']['move'];
1241                                 }
1242                                 $autoconfirmedCanMove = false;
1243                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1244                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1245                                 }
1246                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1247                                         // custom message if logged-in users without any special rights can move
1248                                         $errors[] = array( 'movenologintext' );
1249                                 } else {
1250                                         $errors[] = array( 'movenotallowed' );
1251                                 }
1252                         }
1253                 } elseif ( $action == 'move-target' ) {
1254                         if ( !$user->isAllowed( 'move' ) ) {
1255                                 // User can't move anything
1256                                 $errors[] = array( 'movenotallowed' );
1257                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1258                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1259                                 // Show user page-specific message only if the user can move other pages
1260                                 $errors[] = array( 'cant-move-to-user-page' );
1261                         }
1262                 } elseif ( !$user->isAllowed( $action ) ) {
1263                         $return = null;
1264
1265                         // We avoid expensive display logic for quickUserCan's and such
1266                         $groups = false;
1267                         if ( !$short ) {
1268                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1269                                         User::getGroupsWithPermission( $action ) );
1270                         }
1271
1272                         if ( $groups ) {
1273                                 global $wgLang;
1274                                 $return = array(
1275                                         'badaccess-groups',
1276                                         $wgLang->commaList( $groups ),
1277                                         count( $groups )
1278                                 );
1279                         } else {
1280                                 $return = array( 'badaccess-group0' );
1281                         }
1282                         $errors[] = $return;
1283                 }
1284
1285                 return $errors;
1286         }
1287
1288         /**
1289          * Add the resulting error code to the errors array
1290          *
1291          * @param $errors Array list of current errors
1292          * @param $result Mixed result of errors
1293          *
1294          * @return Array list of errors
1295          */
1296         private function resultToError( $errors, $result ) {
1297                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1298                         // A single array representing an error
1299                         $errors[] = $result;
1300                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1301                         // A nested array representing multiple errors
1302                         $errors = array_merge( $errors, $result );
1303                 } else if ( $result !== '' && is_string( $result ) ) {
1304                         // A string representing a message-id
1305                         $errors[] = array( $result );
1306                 } else if ( $result === false ) {
1307                         // a generic "We don't want them to do that"
1308                         $errors[] = array( 'badaccess-group0' );
1309                 }
1310                 return $errors;
1311         }
1312
1313         /**
1314          * Check various permission hooks
1315          * @see checkQuickPermissions for parameter information
1316          */
1317         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1318                 // Use getUserPermissionsErrors instead
1319                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1320                         return $result ? array() : array( array( 'badaccess-group0' ) );
1321                 }
1322                 // Check getUserPermissionsErrors hook
1323                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1324                         $errors = $this->resultToError( $errors, $result );
1325                 }
1326                 // Check getUserPermissionsErrorsExpensive hook
1327                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1328                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1329                         $errors = $this->resultToError( $errors, $result );
1330                 }
1331
1332                 return $errors;
1333         }
1334
1335         /**
1336          * Check permissions on special pages & namespaces
1337          * @see checkQuickPermissions for parameter information
1338          */
1339         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1340                 # Only 'createaccount' and 'execute' can be performed on
1341                 # special pages, which don't actually exist in the DB.
1342                 $specialOKActions = array( 'createaccount', 'execute' );
1343                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1344                         $errors[] = array( 'ns-specialprotected' );
1345                 }
1346
1347                 # Check $wgNamespaceProtection for restricted namespaces
1348                 if ( $this->isNamespaceProtected() ) {
1349                         $ns = $this->mNamespace == NS_MAIN ?
1350                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1351                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1352                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1353                 }
1354
1355                 return $errors;
1356         }
1357
1358         /**
1359          * Check CSS/JS sub-page permissions
1360          * @see checkQuickPermissions for parameter information
1361          */
1362         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1363                 # Protect css/js subpages of user pages
1364                 # XXX: this might be better using restrictions
1365                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1366                 #      and $this->userCanEditJsSubpage() from working
1367                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1368                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1369                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1370                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1371                                 $errors[] = array( 'customcssjsprotected' );
1372                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1373                                 $errors[] = array( 'customcssjsprotected' );
1374                         }
1375                 }
1376
1377                 return $errors;
1378         }
1379
1380         /**
1381          * Check against page_restrictions table requirements on this
1382          * page. The user must possess all required rights for this
1383          * action.
1384          * @see checkQuickPermissions for parameter information
1385          */
1386         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1387                 foreach ( $this->getRestrictions( $action ) as $right ) {
1388                         // Backwards compatibility, rewrite sysop -> protect
1389                         if ( $right == 'sysop' ) {
1390                                 $right = 'protect';
1391                         }
1392                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1393                                 // Users with 'editprotected' permission can edit protected pages
1394                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1395                                         // Users with 'editprotected' permission cannot edit protected pages
1396                                         // with cascading option turned on.
1397                                         if ( $this->mCascadeRestriction ) {
1398                                                 $errors[] = array( 'protectedpagetext', $right );
1399                                         }
1400                                 } else {
1401                                         $errors[] = array( 'protectedpagetext', $right );
1402                                 }
1403                         }
1404                 }
1405
1406                 return $errors;
1407         }
1408
1409         /**
1410          * Check restrictions on cascading pages.
1411          * @see checkQuickPermissions for parameter information
1412          */
1413         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1414                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1415                         # We /could/ use the protection level on the source page, but it's
1416                         # fairly ugly as we have to establish a precedence hierarchy for pages
1417                         # included by multiple cascade-protected pages. So just restrict
1418                         # it to people with 'protect' permission, as they could remove the
1419                         # protection anyway.
1420                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1421                         # Cascading protection depends on more than this page...
1422                         # Several cascading protected pages may include this page...
1423                         # Check each cascading level
1424                         # This is only for protection restrictions, not for all actions
1425                         if ( isset( $restrictions[$action] ) ) {
1426                                 foreach ( $restrictions[$action] as $right ) {
1427                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1428                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1429                                                 $pages = '';
1430                                                 foreach ( $cascadingSources as $page )
1431                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1432                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1433                                         }
1434                                 }
1435                         }
1436                 }
1437
1438                 return $errors;
1439         }
1440
1441         /**
1442          * Check action permissions not already checked in checkQuickPermissions
1443          * @see checkQuickPermissions for parameter information
1444          */
1445         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1446                 if ( $action == 'protect' ) {
1447                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1448                                 // If they can't edit, they shouldn't protect.
1449                                 $errors[] = array( 'protect-cantedit' );
1450                         }
1451                 } elseif ( $action == 'create' ) {
1452                         $title_protection = $this->getTitleProtection();
1453                         if( $title_protection ) {
1454                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1455                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1456                                 }
1457                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1458                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1459                                 }
1460                         }
1461                 } elseif ( $action == 'move' ) {
1462                         // Check for immobile pages
1463                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1464                                 // Specific message for this case
1465                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1466                         } elseif ( !$this->isMovable() ) {
1467                                 // Less specific message for rarer cases
1468                                 $errors[] = array( 'immobile-page' );
1469                         }
1470                 } elseif ( $action == 'move-target' ) {
1471                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1472                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1473                         } elseif ( !$this->isMovable() ) {
1474                                 $errors[] = array( 'immobile-target-page' );
1475                         }
1476                 }
1477                 return $errors;
1478         }
1479
1480         /**
1481          * Check that the user isn't blocked from editting.
1482          * @see checkQuickPermissions for parameter information
1483          */
1484         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1485                 if( $short ) {
1486                         return $errors;
1487                 }
1488
1489                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1490
1491                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1492                         $errors[] = array( 'confirmedittext' );
1493                 }
1494
1495                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1496                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1497                         $block = $user->mBlock;
1498
1499                         // This is from OutputPage::blockedPage
1500                         // Copied at r23888 by werdna
1501
1502                         $id = $user->blockedBy();
1503                         $reason = $user->blockedFor();
1504                         if ( $reason == '' ) {
1505                                 $reason = wfMsg( 'blockednoreason' );
1506                         }
1507                         $ip = wfGetIP();
1508
1509                         if ( is_numeric( $id ) ) {
1510                                 $name = User::whoIs( $id );
1511                         } else {
1512                                 $name = $id;
1513                         }
1514
1515                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1516                         $blockid = $block->mId;
1517                         $blockExpiry = $user->mBlock->mExpiry;
1518                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1519                         if ( $blockExpiry == 'infinity' ) {
1520                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1521                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1522
1523                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1524                                         if ( !strpos( $option, ':' ) )
1525                                                 continue;
1526
1527                                         list( $show, $value ) = explode( ':', $option );
1528
1529                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1530                                                 $blockExpiry = $show;
1531                                                 break;
1532                                         }
1533                                 }
1534                         } else {
1535                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1536                         }
1537
1538                         $intended = $user->mBlock->mAddress;
1539
1540                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1541                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1542                 }
1543
1544                 return $errors;
1545         }
1546
1547         /**
1548          * Can $user perform $action on this page? This is an internal function,
1549          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1550          * checks on wfReadOnly() and blocks)
1551          *
1552          * @param $action \type{\string} action that permission needs to be checked for
1553          * @param $user \type{User} user to check
1554          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1555          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1556          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1557          */
1558         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1559                 wfProfileIn( __METHOD__ );
1560
1561                 $errors = array();
1562                 $checks = array(
1563                         'checkQuickPermissions',
1564                         'checkPermissionHooks',
1565                         'checkSpecialsAndNSPermissions',
1566                         'checkCSSandJSPermissions',
1567                         'checkPageRestrictions',
1568                         'checkCascadingSourcesRestrictions',
1569                         'checkActionPermissions',
1570                         'checkUserBlock'
1571                 );
1572
1573                 while( count( $checks ) > 0 &&
1574                            !( $short && count( $errors ) > 0 ) ) {
1575                         $method = array_shift( $checks );
1576                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1577                 }
1578
1579                 wfProfileOut( __METHOD__ );
1580                 return $errors;
1581         }
1582
1583         /**
1584          * Is this title subject to title protection?
1585          *
1586          * @return \type{\mixed} An associative array representing any existent title
1587          *   protection, or false if there's none.
1588          */
1589         private function getTitleProtection() {
1590                 // Can't protect pages in special namespaces
1591                 if ( $this->getNamespace() < 0 ) {
1592                         return false;
1593                 }
1594
1595                 // Can't protect pages that exist.
1596                 if ( $this->exists() ) {
1597                         return false;
1598                 }
1599
1600                 if ( !isset( $this->mTitleProtection ) ) {
1601                         $dbr = wfGetDB( DB_SLAVE );
1602                         $res = $dbr->select( 'protected_titles', '*',
1603                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1604                                 __METHOD__ );
1605
1606                         // fetchRow returns false if there are no rows.
1607                         $this->mTitleProtection = $dbr->fetchRow( $res );
1608                 }
1609                 return $this->mTitleProtection;
1610         }
1611
1612         /**
1613          * Update the title protection status
1614          *
1615          * @param $create_perm \type{\string} Permission required for creation
1616          * @param $reason \type{\string} Reason for protection
1617          * @param $expiry \type{\string} Expiry timestamp
1618          * @return boolean true
1619          */
1620         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1621                 global $wgUser, $wgContLang;
1622
1623                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1624                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1625                         // No change
1626                         return true;
1627                 }
1628
1629                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1630
1631                 $dbw = wfGetDB( DB_MASTER );
1632
1633                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1634
1635                 $expiry_description = '';
1636                 if ( $encodedExpiry != 'infinity' ) {
1637                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1638                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1639                 } else {
1640                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1641                 }
1642
1643                 # Update protection table
1644                 if ( $create_perm != '' ) {
1645                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1646                                 array(
1647                                         'pt_namespace' => $namespace,
1648                                         'pt_title' => $title,
1649                                         'pt_create_perm' => $create_perm,
1650                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1651                                         'pt_expiry' => $encodedExpiry,
1652                                         'pt_user' => $wgUser->getId(),
1653                                         'pt_reason' => $reason,
1654                                 ), __METHOD__
1655                         );
1656                 } else {
1657                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1658                                 'pt_title' => $title ), __METHOD__ );
1659                 }
1660                 # Update the protection log
1661                 if ( $dbw->affectedRows() ) {
1662                         $log = new LogPage( 'protect' );
1663
1664                         if ( $create_perm ) {
1665                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1666                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1667                         } else {
1668                                 $log->addEntry( 'unprotect', $this, $reason );
1669                         }
1670                 }
1671
1672                 return true;
1673         }
1674
1675         /**
1676          * Remove any title protection due to page existing
1677          */
1678         public function deleteTitleProtection() {
1679                 $dbw = wfGetDB( DB_MASTER );
1680
1681                 $dbw->delete(
1682                         'protected_titles',
1683                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1684                         __METHOD__
1685                 );
1686         }
1687
1688         /**
1689          * Would anybody with sufficient privileges be able to move this page?
1690          * Some pages just aren't movable.
1691          *
1692          * @return \type{\bool} TRUE or FALSE
1693          */
1694         public function isMovable() {
1695                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1696         }
1697
1698         /**
1699          * Can $wgUser read this page?
1700          *
1701          * @return \type{\bool}
1702          * @todo fold these checks into userCan()
1703          */
1704         public function userCanRead() {
1705                 global $wgUser, $wgGroupPermissions;
1706
1707                 static $useShortcut = null;
1708
1709                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1710                 if ( is_null( $useShortcut ) ) {
1711                         global $wgRevokePermissions;
1712                         $useShortcut = true;
1713                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1714                                 # Not a public wiki, so no shortcut
1715                                 $useShortcut = false;
1716                         } elseif ( !empty( $wgRevokePermissions ) ) {
1717                                 /*
1718                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1719                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1720                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1721                                  * reading is allowed.
1722                                  */
1723                                 foreach ( $wgRevokePermissions as $perms ) {
1724                                         if ( !empty( $perms['read'] ) ) {
1725                                                 # We might be removing the read right from the user, so no shortcut
1726                                                 $useShortcut = false;
1727                                                 break;
1728                                         }
1729                                 }
1730                         }
1731                 }
1732
1733                 $result = null;
1734                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1735                 if ( $result !== null ) {
1736                         return $result;
1737                 }
1738
1739                 # Shortcut for public wikis, allows skipping quite a bit of code
1740                 if ( $useShortcut ) {
1741                         return true;
1742                 }
1743
1744                 if ( $wgUser->isAllowed( 'read' ) ) {
1745                         return true;
1746                 } else {
1747                         global $wgWhitelistRead;
1748
1749                         /**
1750                          * Always grant access to the login page.
1751                          * Even anons need to be able to log in.
1752                         */
1753                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1754                                 return true;
1755                         }
1756
1757                         /**
1758                          * Bail out if there isn't whitelist
1759                          */
1760                         if ( !is_array( $wgWhitelistRead ) ) {
1761                                 return false;
1762                         }
1763
1764                         /**
1765                          * Check for explicit whitelisting
1766                          */
1767                         $name = $this->getPrefixedText();
1768                         $dbName = $this->getPrefixedDBKey();
1769                         // Check with and without underscores
1770                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1771                                 return true;
1772
1773                         /**
1774                          * Old settings might have the title prefixed with
1775                          * a colon for main-namespace pages
1776                          */
1777                         if ( $this->getNamespace() == NS_MAIN ) {
1778                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1779                                         return true;
1780                                 }
1781                         }
1782
1783                         /**
1784                          * If it's a special page, ditch the subpage bit
1785                          * and check again
1786                          */
1787                         if ( $this->getNamespace() == NS_SPECIAL ) {
1788                                 $name = $this->getDBkey();
1789                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1790                                 if ( $name === false ) {
1791                                         # Invalid special page, but we show standard login required message
1792                                         return false;
1793                                 }
1794
1795                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1796                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1797                                         return true;
1798                                 }
1799                         }
1800
1801                 }
1802                 return false;
1803         }
1804
1805         /**
1806          * Is this a talk page of some sort?
1807          *
1808          * @return \type{\bool}
1809          */
1810         public function isTalkPage() {
1811                 return MWNamespace::isTalk( $this->getNamespace() );
1812         }
1813
1814         /**
1815          * Is this a subpage?
1816          *
1817          * @return \type{\bool}
1818          */
1819         public function isSubpage() {
1820                 return MWNamespace::hasSubpages( $this->mNamespace )
1821                         ? strpos( $this->getText(), '/' ) !== false
1822                         : false;
1823         }
1824
1825         /**
1826          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1827          *
1828          * @return \type{\bool}
1829          */
1830         public function hasSubpages() {
1831                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1832                         # Duh
1833                         return false;
1834                 }
1835
1836                 # We dynamically add a member variable for the purpose of this method
1837                 # alone to cache the result.  There's no point in having it hanging
1838                 # around uninitialized in every Title object; therefore we only add it
1839                 # if needed and don't declare it statically.
1840                 if ( isset( $this->mHasSubpages ) ) {
1841                         return $this->mHasSubpages;
1842                 }
1843
1844                 $subpages = $this->getSubpages( 1 );
1845                 if ( $subpages instanceof TitleArray ) {
1846                         return $this->mHasSubpages = (bool)$subpages->count();
1847                 }
1848                 return $this->mHasSubpages = false;
1849         }
1850
1851         /**
1852          * Get all subpages of this page.
1853          *
1854          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1855          * @return mixed TitleArray, or empty array if this page's namespace
1856          *  doesn't allow subpages
1857          */
1858         public function getSubpages( $limit = -1 ) {
1859                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1860                         return array();
1861                 }
1862
1863                 $dbr = wfGetDB( DB_SLAVE );
1864                 $conds['page_namespace'] = $this->getNamespace();
1865                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1866                 $options = array();
1867                 if ( $limit > -1 ) {
1868                         $options['LIMIT'] = $limit;
1869                 }
1870                 return $this->mSubpages = TitleArray::newFromResult(
1871                         $dbr->select( 'page',
1872                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1873                                 $conds,
1874                                 __METHOD__,
1875                                 $options
1876                         )
1877                 );
1878         }
1879
1880         /**
1881          * Could this page contain custom CSS or JavaScript, based
1882          * on the title?
1883          *
1884          * @return \type{\bool}
1885          */
1886         public function isCssOrJsPage() {
1887                 return $this->mNamespace == NS_MEDIAWIKI
1888                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1889         }
1890
1891         /**
1892          * Is this a .css or .js subpage of a user page?
1893          * @return \type{\bool}
1894          */
1895         public function isCssJsSubpage() {
1896                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1897         }
1898
1899         /**
1900          * Is this a *valid* .css or .js subpage of a user page?
1901          * Check that the corresponding skin exists
1902          *
1903          * @return \type{\bool}
1904          */
1905         public function isValidCssJsSubpage() {
1906                 if ( $this->isCssJsSubpage() ) {
1907                         $name = $this->getSkinFromCssJsSubpage();
1908                         if ( $name == 'common' ) {
1909                                 return true;
1910                         }
1911                         $skinNames = Skin::getSkinNames();
1912                         return array_key_exists( $name, $skinNames );
1913                 } else {
1914                         return false;
1915                 }
1916         }
1917
1918         /**
1919          * Trim down a .css or .js subpage title to get the corresponding skin name
1920          *
1921          * @return string containing skin name from .css or .js subpage title
1922          */
1923         public function getSkinFromCssJsSubpage() {
1924                 $subpage = explode( '/', $this->mTextform );
1925                 $subpage = $subpage[ count( $subpage ) - 1 ];
1926                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1927         }
1928
1929         /**
1930          * Is this a .css subpage of a user page?
1931          *
1932          * @return \type{\bool}
1933          */
1934         public function isCssSubpage() {
1935                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1936         }
1937
1938         /**
1939          * Is this a .js subpage of a user page?
1940          *
1941          * @return \type{\bool}
1942          */
1943         public function isJsSubpage() {
1944                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1945         }
1946
1947         /**
1948          * Protect css subpages of user pages: can $wgUser edit
1949          * this page?
1950          *
1951          * @return \type{\bool}
1952          * @todo XXX: this might be better using restrictions
1953          */
1954         public function userCanEditCssSubpage() {
1955                 global $wgUser;
1956                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1957                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1958         }
1959
1960         /**
1961          * Protect js subpages of user pages: can $wgUser edit
1962          * this page?
1963          *
1964          * @return \type{\bool}
1965          * @todo XXX: this might be better using restrictions
1966          */
1967         public function userCanEditJsSubpage() {
1968                 global $wgUser;
1969                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1970                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1971         }
1972
1973         /**
1974          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1975          *
1976          * @return \type{\bool} If the page is subject to cascading restrictions.
1977          */
1978         public function isCascadeProtected() {
1979                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1980                 return ( $sources > 0 );
1981         }
1982
1983         /**
1984          * Cascading protection: Get the source of any cascading restrictions on this page.
1985          *
1986          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1987          *        that the restrictions have come from.
1988          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1989          *         objects of the pages from which cascading restrictions have come,
1990          *         false for none, or true if such restrictions exist, but $getPages was not set.
1991          *         The restriction array is an array of each type, each of which contains a
1992          *         array of unique groups.
1993          */
1994         public function getCascadeProtectionSources( $getPages = true ) {
1995                 $pagerestrictions = array();
1996
1997                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1998                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1999                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2000                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2001                 }
2002
2003                 wfProfileIn( __METHOD__ );
2004
2005                 $dbr = wfGetDB( DB_SLAVE );
2006
2007                 if ( $this->getNamespace() == NS_FILE ) {
2008                         $tables = array( 'imagelinks', 'page_restrictions' );
2009                         $where_clauses = array(
2010                                 'il_to' => $this->getDBkey(),
2011                                 'il_from=pr_page',
2012                                 'pr_cascade' => 1
2013                         );
2014                 } else {
2015                         $tables = array( 'templatelinks', 'page_restrictions' );
2016                         $where_clauses = array(
2017                                 'tl_namespace' => $this->getNamespace(),
2018                                 'tl_title' => $this->getDBkey(),
2019                                 'tl_from=pr_page',
2020                                 'pr_cascade' => 1
2021                         );
2022                 }
2023
2024                 if ( $getPages ) {
2025                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2026                                                    'pr_expiry', 'pr_type', 'pr_level' );
2027                         $where_clauses[] = 'page_id=pr_page';
2028                         $tables[] = 'page';
2029                 } else {
2030                         $cols = array( 'pr_expiry' );
2031                 }
2032
2033                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2034
2035                 $sources = $getPages ? array() : false;
2036                 $now = wfTimestampNow();
2037                 $purgeExpired = false;
2038
2039                 foreach ( $res as $row ) {
2040                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2041                         if ( $expiry > $now ) {
2042                                 if ( $getPages ) {
2043                                         $page_id = $row->pr_page;
2044                                         $page_ns = $row->page_namespace;
2045                                         $page_title = $row->page_title;
2046                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2047                                         # Add groups needed for each restriction type if its not already there
2048                                         # Make sure this restriction type still exists
2049
2050                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2051                                                 $pagerestrictions[$row->pr_type] = array();
2052                                         }
2053
2054                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2055                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2056                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2057                                         }
2058                                 } else {
2059                                         $sources = true;
2060                                 }
2061                         } else {
2062                                 // Trigger lazy purge of expired restrictions from the db
2063                                 $purgeExpired = true;
2064                         }
2065                 }
2066                 if ( $purgeExpired ) {
2067                         Title::purgeExpiredRestrictions();
2068                 }
2069
2070                 wfProfileOut( __METHOD__ );
2071
2072                 if ( $getPages ) {
2073                         $this->mCascadeSources = $sources;
2074                         $this->mCascadingRestrictions = $pagerestrictions;
2075                 } else {
2076                         $this->mHasCascadingRestrictions = $sources;
2077                 }
2078
2079                 return array( $sources, $pagerestrictions );
2080         }
2081
2082         /**
2083          * Returns cascading restrictions for the current article
2084          *
2085          * @return Boolean
2086          */
2087         function areRestrictionsCascading() {
2088                 if ( !$this->mRestrictionsLoaded ) {
2089                         $this->loadRestrictions();
2090                 }
2091
2092                 return $this->mCascadeRestriction;
2093         }
2094
2095         /**
2096          * Loads a string into mRestrictions array
2097          *
2098          * @param $res \type{Resource} restrictions as an SQL result.
2099          * @param $oldFashionedRestrictions string comma-separated list of page
2100          *        restrictions from page table (pre 1.10)
2101          */
2102         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2103                 $rows = array();
2104                 $dbr = wfGetDB( DB_SLAVE );
2105
2106                 while ( $row = $dbr->fetchObject( $res ) ) {
2107                         $rows[] = $row;
2108                 }
2109
2110                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2111         }
2112
2113         /**
2114          * Compiles list of active page restrictions from both page table (pre 1.10)
2115          * and page_restrictions table
2116          *
2117          * @param $rows array of db result objects
2118          * @param $oldFashionedRestrictions string comma-separated list of page
2119          *        restrictions from page table (pre 1.10)
2120          */
2121         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2122                 $dbr = wfGetDB( DB_SLAVE );
2123
2124                 $restrictionTypes = $this->getRestrictionTypes();
2125
2126                 foreach ( $restrictionTypes as $type ) {
2127                         $this->mRestrictions[$type] = array();
2128                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2129                 }
2130
2131                 $this->mCascadeRestriction = false;
2132
2133                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2134
2135                 if ( $oldFashionedRestrictions === null ) {
2136                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2137                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2138                 }
2139
2140                 if ( $oldFashionedRestrictions != '' ) {
2141
2142                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2143                                 $temp = explode( '=', trim( $restrict ) );
2144                                 if ( count( $temp ) == 1 ) {
2145                                         // old old format should be treated as edit/move restriction
2146                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2147                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2148                                 } else {
2149                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2150                                 }
2151                         }
2152
2153                         $this->mOldRestrictions = true;
2154
2155                 }
2156
2157                 if ( count( $rows ) ) {
2158                         # Current system - load second to make them override.
2159                         $now = wfTimestampNow();
2160                         $purgeExpired = false;
2161
2162                         foreach ( $rows as $row ) {
2163                                 # Cycle through all the restrictions.
2164
2165                                 // Don't take care of restrictions types that aren't allowed
2166
2167                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2168                                         continue;
2169
2170                                 // This code should be refactored, now that it's being used more generally,
2171                                 // But I don't really see any harm in leaving it in Block for now -werdna
2172                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2173
2174                                 // Only apply the restrictions if they haven't expired!
2175                                 if ( !$expiry || $expiry > $now ) {
2176                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2177                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2178
2179                                         $this->mCascadeRestriction |= $row->pr_cascade;
2180                                 } else {
2181                                         // Trigger a lazy purge of expired restrictions
2182                                         $purgeExpired = true;
2183                                 }
2184                         }
2185
2186                         if ( $purgeExpired ) {
2187                                 Title::purgeExpiredRestrictions();
2188                         }
2189                 }
2190
2191                 $this->mRestrictionsLoaded = true;
2192         }
2193
2194         /**
2195          * Load restrictions from the page_restrictions table
2196          *
2197          * @param $oldFashionedRestrictions string comma-separated list of page
2198          *        restrictions from page table (pre 1.10)
2199          */
2200         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2201                 if ( !$this->mRestrictionsLoaded ) {
2202                         if ( $this->exists() ) {
2203                                 $dbr = wfGetDB( DB_SLAVE );
2204
2205                                 $res = $dbr->select( 'page_restrictions', '*',
2206                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2207
2208                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2209                         } else {
2210                                 $title_protection = $this->getTitleProtection();
2211
2212                                 if ( $title_protection ) {
2213                                         $now = wfTimestampNow();
2214                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2215
2216                                         if ( !$expiry || $expiry > $now ) {
2217                                                 // Apply the restrictions
2218                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2219                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2220                                         } else { // Get rid of the old restrictions
2221                                                 Title::purgeExpiredRestrictions();
2222                                         }
2223                                 } else {
2224                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2225                                 }
2226                                 $this->mRestrictionsLoaded = true;
2227                         }
2228                 }
2229         }
2230
2231         /**
2232          * Purge expired restrictions from the page_restrictions table
2233          */
2234         static function purgeExpiredRestrictions() {
2235                 $dbw = wfGetDB( DB_MASTER );
2236                 $dbw->delete(
2237                         'page_restrictions',
2238                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2239                         __METHOD__
2240                 );
2241
2242                 $dbw->delete(
2243                         'protected_titles',
2244                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2245                         __METHOD__
2246                 );
2247         }
2248
2249         /**
2250          * Accessor/initialisation for mRestrictions
2251          *
2252          * @param $action \type{\string} action that permission needs to be checked for
2253          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2254          */
2255         public function getRestrictions( $action ) {
2256                 if ( !$this->mRestrictionsLoaded ) {
2257                         $this->loadRestrictions();
2258                 }
2259                 return isset( $this->mRestrictions[$action] )
2260                                 ? $this->mRestrictions[$action]
2261                                 : array();
2262         }
2263
2264         /**
2265          * Get the expiry time for the restriction against a given action
2266          *
2267          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2268          *      or not protected at all, or false if the action is not recognised.
2269          */
2270         public function getRestrictionExpiry( $action ) {
2271                 if ( !$this->mRestrictionsLoaded ) {
2272                         $this->loadRestrictions();
2273                 }
2274                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2275         }
2276
2277         /**
2278          * Is there a version of this page in the deletion archive?
2279          *
2280          * @return \type{\int} the number of archived revisions
2281          */
2282         public function isDeleted() {
2283                 if ( $this->getNamespace() < 0 ) {
2284                         $n = 0;
2285                 } else {
2286                         $dbr = wfGetDB( DB_SLAVE );
2287                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2288                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2289                                 __METHOD__
2290                         );
2291                         if ( $this->getNamespace() == NS_FILE ) {
2292                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2293                                         array( 'fa_name' => $this->getDBkey() ),
2294                                         __METHOD__
2295                                 );
2296                         }
2297                 }
2298                 return (int)$n;
2299         }
2300
2301         /**
2302          * Is there a version of this page in the deletion archive?
2303          *
2304          * @return Boolean
2305          */
2306         public function isDeletedQuick() {
2307                 if ( $this->getNamespace() < 0 ) {
2308                         return false;
2309                 }
2310                 $dbr = wfGetDB( DB_SLAVE );
2311                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2312                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2313                         __METHOD__
2314                 );
2315                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2316                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2317                                 array( 'fa_name' => $this->getDBkey() ),
2318                                 __METHOD__
2319                         );
2320                 }
2321                 return $deleted;
2322         }
2323
2324         /**
2325          * Get the article ID for this Title from the link cache,
2326          * adding it if necessary
2327          *
2328          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2329          *  for update
2330          * @return \type{\int} the ID
2331          */
2332         public function getArticleID( $flags = 0 ) {
2333                 if ( $this->getNamespace() < 0 ) {
2334                         return $this->mArticleID = 0;
2335                 }
2336                 $linkCache = LinkCache::singleton();
2337                 if ( $flags & GAID_FOR_UPDATE ) {
2338                         $oldUpdate = $linkCache->forUpdate( true );
2339                         $linkCache->clearLink( $this );
2340                         $this->mArticleID = $linkCache->addLinkObj( $this );
2341                         $linkCache->forUpdate( $oldUpdate );
2342                 } else {
2343                         if ( -1 == $this->mArticleID ) {
2344                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2345                         }
2346                 }
2347                 return $this->mArticleID;
2348         }
2349
2350         /**
2351          * Is this an article that is a redirect page?
2352          * Uses link cache, adding it if necessary
2353          *
2354          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2355          * @return \type{\bool}
2356          */
2357         public function isRedirect( $flags = 0 ) {
2358                 if ( !is_null( $this->mRedirect ) ) {
2359                         return $this->mRedirect;
2360                 }
2361                 # Calling getArticleID() loads the field from cache as needed
2362                 if ( !$this->getArticleID( $flags ) ) {
2363                         return $this->mRedirect = false;
2364                 }
2365                 $linkCache = LinkCache::singleton();
2366                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2367
2368                 return $this->mRedirect;
2369         }
2370
2371         /**
2372          * What is the length of this page?
2373          * Uses link cache, adding it if necessary
2374          *
2375          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2376          * @return \type{\bool}
2377          */
2378         public function getLength( $flags = 0 ) {
2379                 if ( $this->mLength != -1 ) {
2380                         return $this->mLength;
2381                 }
2382                 # Calling getArticleID() loads the field from cache as needed
2383                 if ( !$this->getArticleID( $flags ) ) {
2384                         return $this->mLength = 0;
2385                 }
2386                 $linkCache = LinkCache::singleton();
2387                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2388
2389                 return $this->mLength;
2390         }
2391
2392         /**
2393          * What is the page_latest field for this page?
2394          *
2395          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2396          * @return \type{\int} or 0 if the page doesn't exist
2397          */
2398         public function getLatestRevID( $flags = 0 ) {
2399                 if ( $this->mLatestID !== false ) {
2400                         return intval( $this->mLatestID );
2401                 }
2402                 # Calling getArticleID() loads the field from cache as needed
2403                 if ( !$this->getArticleID( $flags ) ) {
2404                         return $this->mLatestID = 0;
2405                 }
2406                 $linkCache = LinkCache::singleton();
2407                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2408
2409                 return $this->mLatestID;
2410         }
2411
2412         /**
2413          * This clears some fields in this object, and clears any associated
2414          * keys in the "bad links" section of the link cache.
2415          *
2416          * @param $newid \type{\int} the new Article ID
2417          */
2418         public function resetArticleID( $newid ) {
2419                 $linkCache = LinkCache::singleton();
2420                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2421
2422                 if ( $newid === false ) {
2423                         $this->mArticleID = -1;
2424                 } else {
2425                         $this->mArticleID = intval( $newid );
2426                 }
2427                 $this->mRestrictionsLoaded = false;
2428                 $this->mRestrictions = array();
2429                 $this->mRedirect = null;
2430                 $this->mLength = -1;
2431                 $this->mLatestID = false;
2432         }
2433
2434         /**
2435          * Updates page_touched for this page; called from LinksUpdate.php
2436          *
2437          * @return \type{\bool} true if the update succeded
2438          */
2439         public function invalidateCache() {
2440                 if ( wfReadOnly() ) {
2441                         return;
2442                 }
2443                 $dbw = wfGetDB( DB_MASTER );
2444                 $success = $dbw->update(
2445                         'page',
2446                         array( 'page_touched' => $dbw->timestamp() ),
2447                         $this->pageCond(),
2448                         __METHOD__
2449                 );
2450                 HTMLFileCache::clearFileCache( $this );
2451                 return $success;
2452         }
2453
2454         /**
2455          * Prefix some arbitrary text with the namespace or interwiki prefix
2456          * of this object
2457          *
2458          * @param $name \type{\string} the text
2459          * @return \type{\string} the prefixed text
2460          * @private
2461          */
2462         /* private */ function prefix( $name ) {
2463                 $p = '';
2464                 if ( $this->mInterwiki != '' ) {
2465                         $p = $this->mInterwiki . ':';
2466                 }
2467                 if ( 0 != $this->mNamespace ) {
2468                         $p .= $this->getNsText() . ':';
2469                 }
2470                 return $p . $name;
2471         }
2472
2473         /**
2474          * Returns a simple regex that will match on characters and sequences invalid in titles.
2475          * Note that this doesn't pick up many things that could be wrong with titles, but that
2476          * replacing this regex with something valid will make many titles valid.
2477          *
2478          * @return string regex string
2479          */
2480         static function getTitleInvalidRegex() {
2481                 static $rxTc = false;
2482                 if ( !$rxTc ) {
2483                         # Matching titles will be held as illegal.
2484                         $rxTc = '/' .
2485                                 # Any character not allowed is forbidden...
2486                                 '[^' . Title::legalChars() . ']' .
2487                                 # URL percent encoding sequences interfere with the ability
2488                                 # to round-trip titles -- you can't link to them consistently.
2489                                 '|%[0-9A-Fa-f]{2}' .
2490                                 # XML/HTML character references produce similar issues.
2491                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2492                                 '|&#[0-9]+;' .
2493                                 '|&#x[0-9A-Fa-f]+;' .
2494                                 '/S';
2495                 }
2496
2497                 return $rxTc;
2498         }
2499
2500         /**
2501          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2502          *
2503          * @param $text string containing title to capitalize
2504          * @param $ns int namespace index, defaults to NS_MAIN
2505          * @return String containing capitalized title
2506          */
2507         public static function capitalize( $text, $ns = NS_MAIN ) {
2508                 global $wgContLang;
2509
2510                 if ( MWNamespace::isCapitalized( $ns ) ) {
2511                         return $wgContLang->ucfirst( $text );
2512                 } else {
2513                         return $text;
2514                 }
2515         }
2516
2517         /**
2518          * Secure and split - main initialisation function for this object
2519          *
2520          * Assumes that mDbkeyform has been set, and is urldecoded
2521          * and uses underscores, but not otherwise munged.  This function
2522          * removes illegal characters, splits off the interwiki and
2523          * namespace prefixes, sets the other forms, and canonicalizes
2524          * everything.
2525          *
2526          * @return \type{\bool} true on success
2527          */
2528         private function secureAndSplit() {
2529                 global $wgContLang, $wgLocalInterwiki;
2530
2531                 # Initialisation
2532                 $rxTc = self::getTitleInvalidRegex();
2533
2534                 $this->mInterwiki = $this->mFragment = '';
2535                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2536
2537                 $dbkey = $this->mDbkeyform;
2538
2539                 # Strip Unicode bidi override characters.
2540                 # Sometimes they slip into cut-n-pasted page titles, where the
2541                 # override chars get included in list displays.
2542                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2543
2544                 # Clean up whitespace
2545                 # Note: use of the /u option on preg_replace here will cause
2546                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2547                 # conveniently disabling them.
2548                 #
2549                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2550                 $dbkey = trim( $dbkey, '_' );
2551
2552                 if ( $dbkey == '' ) {
2553                         return false;
2554                 }
2555
2556                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2557                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2558                         return false;
2559                 }
2560
2561                 $this->mDbkeyform = $dbkey;
2562
2563                 # Initial colon indicates main namespace rather than specified default
2564                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2565                 if ( ':' == $dbkey { 0 } ) {
2566                         $this->mNamespace = NS_MAIN;
2567                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2568                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2569                 }
2570
2571                 # Namespace or interwiki prefix
2572                 $firstPass = true;
2573                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2574                 do {
2575                         $m = array();
2576                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2577                                 $p = $m[1];
2578                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2579                                         # Ordinary namespace
2580                                         $dbkey = $m[2];
2581                                         $this->mNamespace = $ns;
2582                                         # For Talk:X pages, check if X has a "namespace" prefix
2583                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2584                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2585                                                         return false; # Disallow Talk:File:x type titles...
2586                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2587                                                         return false; # Disallow Talk:Interwiki:x type titles...
2588                                                 }
2589                                         }
2590                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2591                                         if ( !$firstPass ) {
2592                                                 # Can't make a local interwiki link to an interwiki link.
2593                                                 # That's just crazy!
2594                                                 return false;
2595                                         }
2596
2597                                         # Interwiki link
2598                                         $dbkey = $m[2];
2599                                         $this->mInterwiki = $wgContLang->lc( $p );
2600
2601                                         # Redundant interwiki prefix to the local wiki
2602                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2603                                                 if ( $dbkey == '' ) {
2604                                                         # Can't have an empty self-link
2605                                                         return false;
2606                                                 }
2607                                                 $this->mInterwiki = '';
2608                                                 $firstPass = false;
2609                                                 # Do another namespace split...
2610                                                 continue;
2611                                         }
2612
2613                                         # If there's an initial colon after the interwiki, that also
2614                                         # resets the default namespace
2615                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2616                                                 $this->mNamespace = NS_MAIN;
2617                                                 $dbkey = substr( $dbkey, 1 );
2618                                         }
2619                                 }
2620                                 # If there's no recognized interwiki or namespace,
2621                                 # then let the colon expression be part of the title.
2622                         }
2623                         break;
2624                 } while ( true );
2625
2626                 # We already know that some pages won't be in the database!
2627                 #
2628                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2629                         $this->mArticleID = 0;
2630                 }
2631                 $fragment = strstr( $dbkey, '#' );
2632                 if ( false !== $fragment ) {
2633                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2634                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2635                         # remove whitespace again: prevents "Foo_bar_#"
2636                         # becoming "Foo_bar_"
2637                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2638                 }
2639
2640                 # Reject illegal characters.
2641                 #
2642                 if ( preg_match( $rxTc, $dbkey ) ) {
2643                         return false;
2644                 }
2645
2646                 /**
2647                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2648                  * reachable due to the way web browsers deal with 'relative' URLs.
2649                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2650                  */
2651                 if ( strpos( $dbkey, '.' ) !== false &&
2652                      ( $dbkey === '.' || $dbkey === '..' ||
2653                        strpos( $dbkey, './' ) === 0  ||
2654                        strpos( $dbkey, '../' ) === 0 ||
2655                        strpos( $dbkey, '/./' ) !== false ||
2656                        strpos( $dbkey, '/../' ) !== false  ||
2657                        substr( $dbkey, -2 ) == '/.' ||
2658                        substr( $dbkey, -3 ) == '/..' ) )
2659                 {
2660                         return false;
2661                 }
2662
2663                 /**
2664                  * Magic tilde sequences? Nu-uh!
2665                  */
2666                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2667                         return false;
2668                 }
2669
2670                 /**
2671                  * Limit the size of titles to 255 bytes.
2672                  * This is typically the size of the underlying database field.
2673                  * We make an exception for special pages, which don't need to be stored
2674                  * in the database, and may edge over 255 bytes due to subpage syntax
2675                  * for long titles, e.g. [[Special:Block/Long name]]
2676                  */
2677                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2678                   strlen( $dbkey ) > 512 )
2679                 {
2680                         return false;
2681                 }
2682
2683                 /**
2684                  * Normally, all wiki links are forced to have
2685                  * an initial capital letter so [[foo]] and [[Foo]]
2686                  * point to the same place.
2687                  *
2688                  * Don't force it for interwikis, since the other
2689                  * site might be case-sensitive.
2690                  */
2691                 $this->mUserCaseDBKey = $dbkey;
2692                 if ( $this->mInterwiki == '' ) {
2693                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2694                 }
2695
2696                 /**
2697                  * Can't make a link to a namespace alone...
2698                  * "empty" local links can only be self-links
2699                  * with a fragment identifier.
2700                  */
2701                 if ( $dbkey == '' &&
2702                         $this->mInterwiki == '' &&
2703                         $this->mNamespace != NS_MAIN ) {
2704                         return false;
2705                 }
2706                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2707                 // IP names are not allowed for accounts, and can only be referring to
2708                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2709                 // there are numerous ways to present the same IP. Having sp:contribs scan
2710                 // them all is silly and having some show the edits and others not is
2711                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2712                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2713                         IP::sanitizeIP( $dbkey ) : $dbkey;
2714                 // Any remaining initial :s are illegal.
2715                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2716                         return false;
2717                 }
2718
2719                 # Fill fields
2720                 $this->mDbkeyform = $dbkey;
2721                 $this->mUrlform = wfUrlencode( $dbkey );
2722
2723                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2724
2725                 return true;
2726         }
2727
2728         /**
2729          * Set the fragment for this title. Removes the first character from the
2730          * specified fragment before setting, so it assumes you're passing it with
2731          * an initial "#".
2732          *
2733          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2734          * Still in active use privately.
2735          *
2736          * @param $fragment \type{\string} text
2737          */
2738         public function setFragment( $fragment ) {
2739                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2740         }
2741
2742         /**
2743          * Get a Title object associated with the talk page of this article
2744          *
2745          * @return \type{Title} the object for the talk page
2746          */
2747         public function getTalkPage() {
2748                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2749         }
2750
2751         /**
2752          * Get a title object associated with the subject page of this
2753          * talk page
2754          *
2755          * @return \type{Title} the object for the subject page
2756          */
2757         public function getSubjectPage() {
2758                 // Is this the same title?
2759                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2760                 if ( $this->getNamespace() == $subjectNS ) {
2761                         return $this;
2762                 }
2763                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2764         }
2765
2766         /**
2767          * Get an array of Title objects linking to this Title
2768          * Also stores the IDs in the link cache.
2769          *
2770          * WARNING: do not use this function on arbitrary user-supplied titles!
2771          * On heavily-used templates it will max out the memory.
2772          *
2773          * @param $options Array: may be FOR UPDATE
2774          * @param $table String: table name
2775          * @param $prefix String: fields prefix
2776          * @return \type{\arrayof{Title}} the Title objects linking here
2777          */
2778         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2779                 $linkCache = LinkCache::singleton();
2780
2781                 if ( count( $options ) > 0 ) {
2782                         $db = wfGetDB( DB_MASTER );
2783                 } else {
2784                         $db = wfGetDB( DB_SLAVE );
2785                 }
2786
2787                 $res = $db->select(
2788                         array( 'page', $table ),
2789                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2790                         array(
2791                                 "{$prefix}_from=page_id",
2792                                 "{$prefix}_namespace" => $this->getNamespace(),
2793                                 "{$prefix}_title"     => $this->getDBkey() ),
2794                         __METHOD__,
2795                         $options
2796                 );
2797
2798                 $retVal = array();
2799                 if ( $db->numRows( $res ) ) {
2800                         foreach ( $res as $row ) {
2801                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2802                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2803                                         $retVal[] = $titleObj;
2804                                 }
2805                         }
2806                 }
2807                 return $retVal;
2808         }
2809
2810         /**
2811          * Get an array of Title objects using this Title as a template
2812          * Also stores the IDs in the link cache.
2813          *
2814          * WARNING: do not use this function on arbitrary user-supplied titles!
2815          * On heavily-used templates it will max out the memory.
2816          *
2817          * @param $options Array: may be FOR UPDATE
2818          * @return \type{\arrayof{Title}} the Title objects linking here
2819          */
2820         public function getTemplateLinksTo( $options = array() ) {
2821                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2822         }
2823
2824         /**
2825          * Get an array of Title objects referring to non-existent articles linked from this page
2826          *
2827          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2828          * @return \type{\arrayof{Title}} the Title objects
2829          */
2830         public function getBrokenLinksFrom() {
2831                 if ( $this->getArticleId() == 0 ) {
2832                         # All links from article ID 0 are false positives
2833                         return array();
2834                 }
2835
2836                 $dbr = wfGetDB( DB_SLAVE );
2837                 $res = $dbr->select(
2838                         array( 'page', 'pagelinks' ),
2839                         array( 'pl_namespace', 'pl_title' ),
2840                         array(
2841                                 'pl_from' => $this->getArticleId(),
2842                                 'page_namespace IS NULL'
2843                         ),
2844                         __METHOD__, array(),
2845                         array(
2846                                 'page' => array(
2847                                         'LEFT JOIN',
2848                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2849                                 )
2850                         )
2851                 );
2852
2853                 $retVal = array();
2854                 foreach ( $res as $row ) {
2855                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2856                 }
2857                 return $retVal;
2858         }
2859
2860
2861         /**
2862          * Get a list of URLs to purge from the Squid cache when this
2863          * page changes
2864          *
2865          * @return \type{\arrayof{\string}} the URLs
2866          */
2867         public function getSquidURLs() {
2868                 global $wgContLang;
2869
2870                 $urls = array(
2871                         $this->getInternalURL(),
2872                         $this->getInternalURL( 'action=history' )
2873                 );
2874
2875                 // purge variant urls as well
2876                 if ( $wgContLang->hasVariants() ) {
2877                         $variants = $wgContLang->getVariants();
2878                         foreach ( $variants as $vCode ) {
2879                                 $urls[] = $this->getInternalURL( '', $vCode );
2880                         }
2881                 }
2882
2883                 return $urls;
2884         }
2885
2886         /**
2887          * Purge all applicable Squid URLs
2888          */
2889         public function purgeSquid() {
2890                 global $wgUseSquid;
2891                 if ( $wgUseSquid ) {
2892                         $urls = $this->getSquidURLs();
2893                         $u = new SquidUpdate( $urls );
2894                         $u->doUpdate();
2895                 }
2896         }
2897
2898         /**
2899          * Move this page without authentication
2900          *
2901          * @param $nt \type{Title} the new page Title
2902          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2903          */
2904         public function moveNoAuth( &$nt ) {
2905                 return $this->moveTo( $nt, false );
2906         }
2907
2908         /**
2909          * Check whether a given move operation would be valid.
2910          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2911          *
2912          * @param $nt \type{Title} the new title
2913          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2914          *  should be checked
2915          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2916          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2917          */
2918         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2919                 global $wgUser;
2920
2921                 $errors = array();
2922                 if ( !$nt ) {
2923                         // Normally we'd add this to $errors, but we'll get
2924                         // lots of syntax errors if $nt is not an object
2925                         return array( array( 'badtitletext' ) );
2926                 }
2927                 if ( $this->equals( $nt ) ) {
2928                         $errors[] = array( 'selfmove' );
2929                 }
2930                 if ( !$this->isMovable() ) {
2931                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2932                 }
2933                 if ( $nt->getInterwiki() != '' ) {
2934                         $errors[] = array( 'immobile-target-namespace-iw' );
2935                 }
2936                 if ( !$nt->isMovable() ) {
2937                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2938                 }
2939
2940                 $oldid = $this->getArticleID();
2941                 $newid = $nt->getArticleID();
2942
2943                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2944                         $errors[] = array( 'articleexists' );
2945                 }
2946                 if ( ( $this->getDBkey() == '' ) ||
2947                          ( !$oldid ) ||
2948                      ( $nt->getDBkey() == '' ) ) {
2949                         $errors[] = array( 'badarticleerror' );
2950                 }
2951
2952                 // Image-specific checks
2953                 if ( $this->getNamespace() == NS_FILE ) {
2954                         if ( $nt->getNamespace() != NS_FILE ) {
2955                                 $errors[] = array( 'imagenocrossnamespace' );
2956                         }
2957                         $file = wfLocalFile( $this );
2958                         if ( $file->exists() ) {
2959                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2960                                         $errors[] = array( 'imageinvalidfilename' );
2961                                 }
2962                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2963                                         $errors[] = array( 'imagetypemismatch' );
2964                                 }
2965                         }
2966                         $destfile = wfLocalFile( $nt );
2967                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2968                                 $errors[] = array( 'file-exists-sharedrepo' );
2969                         }
2970                 }
2971
2972                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2973                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2974                 }
2975
2976                 if ( $auth ) {
2977                         $errors = wfMergeErrorArrays( $errors,
2978                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2979                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2980                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2981                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2982                 }
2983
2984                 $match = EditPage::matchSummarySpamRegex( $reason );
2985                 if ( $match !== false ) {
2986                         // This is kind of lame, won't display nice
2987                         $errors[] = array( 'spamprotectiontext' );
2988                 }
2989
2990                 $err = null;
2991                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2992                         $errors[] = array( 'hookaborted', $err );
2993                 }
2994
2995                 # The move is allowed only if (1) the target doesn't exist, or
2996                 # (2) the target is a redirect to the source, and has no history
2997                 # (so we can undo bad moves right after they're done).
2998
2999                 if ( 0 != $newid ) { # Target exists; check for validity
3000                         if ( !$this->isValidMoveTarget( $nt ) ) {
3001                                 $errors[] = array( 'articleexists' );
3002                         }
3003                 } else {
3004                         $tp = $nt->getTitleProtection();
3005                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3006                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3007                                 $errors[] = array( 'cantmove-titleprotected' );
3008                         }
3009                 }
3010                 if ( empty( $errors ) ) {
3011                         return true;
3012                 }
3013                 return $errors;
3014         }
3015
3016         /**
3017          * Move a title to a new location
3018          *
3019          * @param $nt \type{Title} the new title
3020          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3021          *  should be checked
3022          * @param $reason \type{\string} The reason for the move
3023          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3024          *  Ignored if the user doesn't have the suppressredirect right.
3025          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3026          */
3027         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3028                 global $wgContLang;
3029
3030                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3031                 if ( is_array( $err ) ) {
3032                         return $err;
3033                 }
3034
3035                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3036                 $dbw = wfGetDB( DB_MASTER );
3037                 if ( $this->getNamespace() == NS_FILE ) {
3038                         $file = wfLocalFile( $this );
3039                         if ( $file->exists() ) {
3040                                 $status = $file->move( $nt );
3041                                 if ( !$status->isOk() ) {
3042                                         return $status->getErrorsArray();
3043                                 }
3044                         }
3045                 }
3046
3047                 $pageid = $this->getArticleID();
3048                 $protected = $this->isProtected();
3049                 if ( $nt->exists() ) {
3050                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3051                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3052                 } else { # Target didn't exist, do normal move.
3053                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3054                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3055                 }
3056
3057                 if ( is_array( $err ) ) {
3058                         return $err;
3059                 }
3060                 $redirid = $this->getArticleID();
3061
3062                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3063                 // cl_timestamp, which may disturb time-based lists on some sites.
3064                 $prefix = $dbw->selectField(
3065                         'categorylinks',
3066                         'cl_sortkey_prefix',
3067                         array( 'cl_from' => $pageid ),
3068                         __METHOD__
3069                 );
3070                 $dbw->update( 'categorylinks',
3071                         array(
3072                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3073                                 'cl_timestamp=cl_timestamp' ),
3074                         array( 'cl_from' => $pageid ),
3075                         __METHOD__ );
3076
3077                 if ( $protected ) {
3078                         # Protect the redirect title as the title used to be...
3079                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3080                                 array(
3081                                         'pr_page'    => $redirid,
3082                                         'pr_type'    => 'pr_type',
3083                                         'pr_level'   => 'pr_level',
3084                                         'pr_cascade' => 'pr_cascade',
3085                                         'pr_user'    => 'pr_user',
3086                                         'pr_expiry'  => 'pr_expiry'
3087                                 ),
3088                                 array( 'pr_page' => $pageid ),
3089                                 __METHOD__,
3090                                 array( 'IGNORE' )
3091                         );
3092                         # Update the protection log
3093                         $log = new LogPage( 'protect' );
3094                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3095                         if ( $reason ) {
3096                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3097                         }
3098                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3099                 }
3100
3101                 # Update watchlists
3102                 $oldnamespace = $this->getNamespace() & ~1;
3103                 $newnamespace = $nt->getNamespace() & ~1;
3104                 $oldtitle = $this->getDBkey();
3105                 $newtitle = $nt->getDBkey();
3106
3107                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3108                         WatchedItem::duplicateEntries( $this, $nt );
3109                 }
3110
3111                 # Update search engine
3112                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3113                 $u->doUpdate();
3114                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3115                 $u->doUpdate();
3116
3117                 # Update site_stats
3118                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3119                         # No longer a content page
3120                         # Not viewed, edited, removing
3121                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3122                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3123                         # Now a content page
3124                         # Not viewed, edited, adding
3125                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3126                 } elseif ( $pageCountChange ) {
3127                         # Redirect added
3128                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3129                 } else {
3130                         # Nothing special
3131                         $u = false;
3132                 }
3133                 if ( $u ) {
3134                         $u->doUpdate();
3135                 }
3136                 # Update message cache for interface messages
3137                 global $wgMessageCache;
3138                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3139                         # @bug 17860: old article can be deleted, if this the case,
3140                         # delete it from message cache
3141                         if ( $this->getArticleID() === 0 ) {
3142                                 $wgMessageCache->replace( $this->getDBkey(), false );
3143                         } else {
3144                                 $oldarticle = new Article( $this );
3145                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3146                         }
3147                 }
3148                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3149                         $newarticle = new Article( $nt );
3150                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3151                 }
3152
3153                 global $wgUser;
3154                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3155                 return true;
3156         }
3157
3158         /**
3159          * Move page to a title which is at present a redirect to the
3160          * source page
3161          *
3162          * @param $nt \type{Title} the page to move to, which should currently
3163          *  be a redirect
3164          * @param $reason \type{\string} The reason for the move
3165          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3166          *  Ignored if the user doesn't have the suppressredirect right
3167          */
3168         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3169                 global $wgUseSquid, $wgUser, $wgContLang;
3170
3171                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3172
3173                 if ( $reason ) {
3174                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3175                 }
3176                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3177                 $comment = $wgContLang->truncate( $comment, 250 );
3178
3179                 $now = wfTimestampNow();
3180                 $newid = $nt->getArticleID();
3181                 $oldid = $this->getArticleID();
3182                 $latest = $this->getLatestRevID();
3183
3184                 $dbw = wfGetDB( DB_MASTER );
3185
3186                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3187                 $newns = $nt->getNamespace();
3188                 $newdbk = $nt->getDBkey();
3189
3190                 # Delete the old redirect. We don't save it to history since
3191                 # by definition if we've got here it's rather uninteresting.
3192                 # We have to remove it so that the next step doesn't trigger
3193                 # a conflict on the unique namespace+title index...
3194                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3195                 if ( !$dbw->cascadingDeletes() ) {
3196                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3197                         global $wgUseTrackbacks;
3198                         if ( $wgUseTrackbacks ) {
3199                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3200                         }
3201                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3202                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3203                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3204                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3205                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3206                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3207                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3208                 }
3209                 // If the redirect was recently created, it may have an entry in recentchanges still
3210                 $dbw->delete( 'recentchanges',
3211                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3212                         __METHOD__
3213                 );
3214
3215                 # Save a null revision in the page's history notifying of the move
3216                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3217                 $nullRevId = $nullRevision->insertOn( $dbw );
3218
3219                 $article = new Article( $this );
3220                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3221
3222                 # Change the name of the target page:
3223                 $dbw->update( 'page',
3224                         /* SET */ array(
3225                                 'page_touched'   => $dbw->timestamp( $now ),
3226                                 'page_namespace' => $nt->getNamespace(),
3227                                 'page_title'     => $nt->getDBkey(),
3228                                 'page_latest'    => $nullRevId,
3229                         ),
3230                         /* WHERE */ array( 'page_id' => $oldid ),
3231                         __METHOD__
3232                 );
3233                 $nt->resetArticleID( $oldid );
3234
3235                 # Recreate the redirect, this time in the other direction.
3236                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3237                         $mwRedir = MagicWord::get( 'redirect' );
3238                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3239                         $redirectArticle = new Article( $this );
3240                         $newid = $redirectArticle->insertOn( $dbw );
3241                         $redirectRevision = new Revision( array(
3242                                 'page'    => $newid,
3243                                 'comment' => $comment,
3244                                 'text'    => $redirectText ) );
3245                         $redirectRevision->insertOn( $dbw );
3246                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3247
3248                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3249
3250                         # Now, we record the link from the redirect to the new title.
3251                         # It should have no other outgoing links...
3252                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3253                         $dbw->insert( 'pagelinks',
3254                                 array(
3255                                         'pl_from'      => $newid,
3256                                         'pl_namespace' => $nt->getNamespace(),
3257                                         'pl_title'     => $nt->getDBkey() ),
3258                                 __METHOD__ );
3259                         $redirectSuppressed = false;
3260                 } else {
3261                         $this->resetArticleID( 0 );
3262                         $redirectSuppressed = true;
3263                 }
3264
3265                 # Log the move
3266                 $log = new LogPage( 'move' );
3267                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3268
3269                 # Purge squid
3270                 if ( $wgUseSquid ) {
3271                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3272                         $u = new SquidUpdate( $urls );
3273                         $u->doUpdate();
3274                 }
3275
3276         }
3277
3278         /**
3279          * Move page to non-existing title.
3280          *
3281          * @param $nt \type{Title} the new Title
3282          * @param $reason \type{\string} The reason for the move
3283          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3284          *  Ignored if the user doesn't have the suppressredirect right
3285          */
3286         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3287                 global $wgUser, $wgContLang;
3288
3289                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3290                 if ( $reason ) {
3291                         $comment .= wfMsgExt( 'colon-separator',
3292                                 array( 'escapenoentities', 'content' ) );
3293                         $comment .= $reason;
3294                 }
3295                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3296                 $comment = $wgContLang->truncate( $comment, 250 );
3297
3298                 $newid = $nt->getArticleID();
3299                 $oldid = $this->getArticleID();
3300                 $latest = $this->getLatestRevId();
3301
3302                 $dbw = wfGetDB( DB_MASTER );
3303                 $now = $dbw->timestamp();
3304
3305                 # Save a null revision in the page's history notifying of the move
3306                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3307                 if ( !is_object( $nullRevision ) ) {
3308                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3309                 }
3310                 $nullRevId = $nullRevision->insertOn( $dbw );
3311
3312                 $article = new Article( $this );
3313                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3314
3315                 # Rename page entry
3316                 $dbw->update( 'page',
3317                         /* SET */ array(
3318                                 'page_touched'   => $now,
3319                                 'page_namespace' => $nt->getNamespace(),
3320                                 'page_title'     => $nt->getDBkey(),
3321                                 'page_latest'    => $nullRevId,
3322                         ),
3323                         /* WHERE */ array( 'page_id' => $oldid ),
3324                         __METHOD__
3325                 );
3326                 $nt->resetArticleID( $oldid );
3327
3328                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3329                         # Insert redirect
3330                         $mwRedir = MagicWord::get( 'redirect' );
3331                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3332                         $redirectArticle = new Article( $this );
3333                         $newid = $redirectArticle->insertOn( $dbw );
3334                         $redirectRevision = new Revision( array(
3335                                 'page'    => $newid,
3336                                 'comment' => $comment,
3337                                 'text'    => $redirectText ) );
3338                         $redirectRevision->insertOn( $dbw );
3339                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3340
3341                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3342
3343                         # Record the just-created redirect's linking to the page
3344                         $dbw->insert( 'pagelinks',
3345                                 array(
3346                                         'pl_from'      => $newid,
3347                                         'pl_namespace' => $nt->getNamespace(),
3348                                         'pl_title'     => $nt->getDBkey() ),
3349                                 __METHOD__ );
3350                         $redirectSuppressed = false;
3351                 } else {
3352                         $this->resetArticleID( 0 );
3353                         $redirectSuppressed = true;
3354                 }
3355
3356                 # Log the move
3357                 $log = new LogPage( 'move' );
3358                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3359
3360                 # Purge caches as per article creation
3361                 Article::onArticleCreate( $nt );
3362
3363                 # Purge old title from squid
3364                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3365                 $this->purgeSquid();
3366         }
3367
3368         /**
3369          * Move this page's subpages to be subpages of $nt
3370          *
3371          * @param $nt Title Move target
3372          * @param $auth bool Whether $wgUser's permissions should be checked
3373          * @param $reason string The reason for the move
3374          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3375          *  Ignored if the user doesn't have the 'suppressredirect' right
3376          * @return mixed array with old page titles as keys, and strings (new page titles) or
3377          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3378          */
3379         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3380                 global $wgMaximumMovedPages;
3381                 // Check permissions
3382                 if ( !$this->userCan( 'move-subpages' ) ) {
3383                         return array( 'cant-move-subpages' );
3384                 }
3385                 // Do the source and target namespaces support subpages?
3386                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3387                         return array( 'namespace-nosubpages',
3388                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3389                 }
3390                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3391                         return array( 'namespace-nosubpages',
3392                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3393                 }
3394
3395                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3396                 $retval = array();
3397                 $count = 0;
3398                 foreach ( $subpages as $oldSubpage ) {
3399                         $count++;
3400                         if ( $count > $wgMaximumMovedPages ) {
3401                                 $retval[$oldSubpage->getPrefixedTitle()] =
3402                                                 array( 'movepage-max-pages',
3403                                                         $wgMaximumMovedPages );
3404                                 break;
3405                         }
3406
3407                         // We don't know whether this function was called before
3408                         // or after moving the root page, so check both
3409                         // $this and $nt
3410                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3411                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3412                         {
3413                                 // When moving a page to a subpage of itself,
3414                                 // don't move it twice
3415                                 continue;
3416                         }
3417                         $newPageName = preg_replace(
3418                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3419                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3420                                         $oldSubpage->getDBkey() );
3421                         if ( $oldSubpage->isTalkPage() ) {
3422                                 $newNs = $nt->getTalkPage()->getNamespace();
3423                         } else {
3424                                 $newNs = $nt->getSubjectPage()->getNamespace();
3425                         }
3426                         # Bug 14385: we need makeTitleSafe because the new page names may
3427                         # be longer than 255 characters.
3428                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3429
3430                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3431                         if ( $success === true ) {
3432                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3433                         } else {
3434                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3435                         }
3436                 }
3437                 return $retval;
3438         }
3439
3440         /**
3441          * Checks if this page is just a one-rev redirect.
3442          * Adds lock, so don't use just for light purposes.
3443          *
3444          * @return \type{\bool}
3445          */
3446         public function isSingleRevRedirect() {
3447                 $dbw = wfGetDB( DB_MASTER );
3448                 # Is it a redirect?
3449                 $row = $dbw->selectRow( 'page',
3450                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3451                         $this->pageCond(),
3452                         __METHOD__,
3453                         array( 'FOR UPDATE' )
3454                 );
3455                 # Cache some fields we may want
3456                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3457                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3458                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3459                 if ( !$this->mRedirect ) {
3460                         return false;
3461                 }
3462                 # Does the article have a history?
3463                 $row = $dbw->selectField( array( 'page', 'revision' ),
3464                         'rev_id',
3465                         array( 'page_namespace' => $this->getNamespace(),
3466                                 'page_title' => $this->getDBkey(),
3467                                 'page_id=rev_page',
3468                                 'page_latest != rev_id'
3469                         ),
3470                         __METHOD__,
3471                         array( 'FOR UPDATE' )
3472                 );
3473                 # Return true if there was no history
3474                 return ( $row === false );
3475         }
3476
3477         /**
3478          * Checks if $this can be moved to a given Title
3479          * - Selects for update, so don't call it unless you mean business
3480          *
3481          * @param $nt \type{Title} the new title to check
3482          * @return \type{\bool} TRUE or FALSE
3483          */
3484         public function isValidMoveTarget( $nt ) {
3485                 # Is it an existing file?
3486                 if ( $nt->getNamespace() == NS_FILE ) {
3487                         $file = wfLocalFile( $nt );
3488                         if ( $file->exists() ) {
3489                                 wfDebug( __METHOD__ . ": file exists\n" );
3490                                 return false;
3491                         }
3492                 }
3493                 # Is it a redirect with no history?
3494                 if ( !$nt->isSingleRevRedirect() ) {
3495                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3496                         return false;
3497                 }
3498                 # Get the article text
3499                 $rev = Revision::newFromTitle( $nt );
3500                 $text = $rev->getText();
3501                 # Does the redirect point to the source?
3502                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3503                 $m = array();
3504                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3505                         $redirTitle = Title::newFromText( $m[1] );
3506                         if ( !is_object( $redirTitle ) ||
3507                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3508                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3509                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3510                                 return false;
3511                         }
3512                 } else {
3513                         # Fail safe
3514                         wfDebug( __METHOD__ . ": failsafe\n" );
3515                         return false;
3516                 }
3517                 return true;
3518         }
3519
3520         /**
3521          * Can this title be added to a user's watchlist?
3522          *
3523          * @return \type{\bool} TRUE or FALSE
3524          */
3525         public function isWatchable() {
3526                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3527         }
3528
3529         /**
3530          * Get categories to which this Title belongs and return an array of
3531          * categories' names.
3532          *
3533          * @return \type{\array} array an array of parents in the form:
3534          *      $parent => $currentarticle
3535          */
3536         public function getParentCategories() {
3537                 global $wgContLang;
3538
3539                 $titlekey = $this->getArticleId();
3540                 $dbr = wfGetDB( DB_SLAVE );
3541                 $categorylinks = $dbr->tableName( 'categorylinks' );
3542
3543                 # NEW SQL
3544                 $sql = "SELECT * FROM $categorylinks"
3545                      . " WHERE cl_from='$titlekey'"
3546                          . " AND cl_from <> '0'"
3547                          . " ORDER BY cl_sortkey";
3548
3549                 $res = $dbr->query( $sql );
3550
3551                 if ( $dbr->numRows( $res ) > 0 ) {
3552                         foreach ( $res as $row )
3553                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3554                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3555                 } else {
3556                         $data = array();
3557                 }
3558                 return $data;
3559         }
3560
3561         /**
3562          * Get a tree of parent categories
3563          *
3564          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3565          * @return \type{\array} Tree of parent categories
3566          */
3567         public function getParentCategoryTree( $children = array() ) {
3568                 $stack = array();
3569                 $parents = $this->getParentCategories();
3570
3571                 if ( $parents ) {
3572                         foreach ( $parents as $parent => $current ) {
3573                                 if ( array_key_exists( $parent, $children ) ) {
3574                                         # Circular reference
3575                                         $stack[$parent] = array();
3576                                 } else {
3577                                         $nt = Title::newFromText( $parent );
3578                                         if ( $nt ) {
3579                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3580                                         }
3581                                 }
3582                         }
3583                         return $stack;
3584                 } else {
3585                         return array();
3586                 }
3587         }
3588
3589
3590         /**
3591          * Get an associative array for selecting this title from
3592          * the "page" table
3593          *
3594          * @return \type{\array} Selection array
3595          */
3596         public function pageCond() {
3597                 if ( $this->mArticleID > 0 ) {
3598                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3599                         return array( 'page_id' => $this->mArticleID );
3600                 } else {
3601                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3602                 }
3603         }
3604
3605         /**
3606          * Get the revision ID of the previous revision
3607          *
3608          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3609          * @param $flags \type{\int} GAID_FOR_UPDATE
3610          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3611          */
3612         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3613                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3614                 return $db->selectField( 'revision', 'rev_id',
3615                         array(
3616                                 'rev_page' => $this->getArticleId( $flags ),
3617                                 'rev_id < ' . intval( $revId )
3618                         ),
3619                         __METHOD__,
3620                         array( 'ORDER BY' => 'rev_id DESC' )
3621                 );
3622         }
3623
3624         /**
3625          * Get the revision ID of the next revision
3626          *
3627          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3628          * @param $flags \type{\int} GAID_FOR_UPDATE
3629          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3630          */
3631         public function getNextRevisionID( $revId, $flags = 0 ) {
3632                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3633                 return $db->selectField( 'revision', 'rev_id',
3634                         array(
3635                                 'rev_page' => $this->getArticleId( $flags ),
3636                                 'rev_id > ' . intval( $revId )
3637                         ),
3638                         __METHOD__,
3639                         array( 'ORDER BY' => 'rev_id' )
3640                 );
3641         }
3642
3643         /**
3644          * Get the first revision of the page
3645          *
3646          * @param $flags \type{\int} GAID_FOR_UPDATE
3647          * @return Revision (or NULL if page doesn't exist)
3648          */
3649         public function getFirstRevision( $flags = 0 ) {
3650                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3651                 $pageId = $this->getArticleId( $flags );
3652                 if ( !$pageId ) {
3653                         return null;
3654                 }
3655                 $row = $db->selectRow( 'revision', '*',
3656                         array( 'rev_page' => $pageId ),
3657                         __METHOD__,
3658                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3659                 );
3660                 if ( !$row ) {
3661                         return null;
3662                 } else {
3663                         return new Revision( $row );
3664                 }
3665         }
3666
3667         /**
3668          * Check if this is a new page
3669          *
3670          * @return bool
3671          */
3672         public function isNewPage() {
3673                 $dbr = wfGetDB( DB_SLAVE );
3674                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3675         }
3676
3677         /**
3678          * Get the oldest revision timestamp of this page
3679          *
3680          * @return String: MW timestamp
3681          */
3682         public function getEarliestRevTime() {
3683                 $dbr = wfGetDB( DB_SLAVE );
3684                 if ( $this->exists() ) {
3685                         $min = $dbr->selectField( 'revision',
3686                                 'MIN(rev_timestamp)',
3687                                 array( 'rev_page' => $this->getArticleId() ),
3688                                 __METHOD__ );
3689                         return wfTimestampOrNull( TS_MW, $min );
3690                 }
3691                 return null;
3692         }
3693
3694         /**
3695          * Get the number of revisions between the given revision IDs.
3696          * Used for diffs and other things that really need it.
3697          *
3698          * @param $old \type{\int} Revision ID.
3699          * @param $new \type{\int} Revision ID.
3700          * @return \type{\int} Number of revisions between these IDs.
3701          */
3702         public function countRevisionsBetween( $old, $new ) {
3703                 $dbr = wfGetDB( DB_SLAVE );
3704                 return (int)$dbr->selectField( 'revision', 'count(*)',
3705                         'rev_page = ' . intval( $this->getArticleId() ) .
3706                         ' AND rev_id > ' . intval( $old ) .
3707                         ' AND rev_id < ' . intval( $new ),
3708                         __METHOD__
3709                 );
3710         }
3711
3712         /**
3713          * Compare with another title.
3714          *
3715          * @param $title \type{Title}
3716          * @return \type{\bool} TRUE or FALSE
3717          */
3718         public function equals( Title $title ) {
3719                 // Note: === is necessary for proper matching of number-like titles.
3720                 return $this->getInterwiki() === $title->getInterwiki()
3721                         && $this->getNamespace() == $title->getNamespace()
3722                         && $this->getDBkey() === $title->getDBkey();
3723         }
3724
3725         /**
3726          * Callback for usort() to do title sorts by (namespace, title)
3727          *
3728          * @return Integer: result of string comparison, or namespace comparison
3729          */
3730         public static function compare( $a, $b ) {
3731                 if ( $a->getNamespace() == $b->getNamespace() ) {
3732                         return strcmp( $a->getText(), $b->getText() );
3733                 } else {
3734                         return $a->getNamespace() - $b->getNamespace();
3735                 }
3736         }
3737
3738         /**
3739          * Return a string representation of this title
3740          *
3741          * @return \type{\string} String representation of this title
3742          */
3743         public function __toString() {
3744                 return $this->getPrefixedText();
3745         }
3746
3747         /**
3748          * Check if page exists.  For historical reasons, this function simply
3749          * checks for the existence of the title in the page table, and will
3750          * thus return false for interwiki links, special pages and the like.
3751          * If you want to know if a title can be meaningfully viewed, you should
3752          * probably call the isKnown() method instead.
3753          *
3754          * @return \type{\bool}
3755          */
3756         public function exists() {
3757                 return $this->getArticleId() != 0;
3758         }
3759
3760         /**
3761          * Should links to this title be shown as potentially viewable (i.e. as
3762          * "bluelinks"), even if there's no record by this title in the page
3763          * table?
3764          *
3765          * This function is semi-deprecated for public use, as well as somewhat
3766          * misleadingly named.  You probably just want to call isKnown(), which
3767          * calls this function internally.
3768          *
3769          * (ISSUE: Most of these checks are cheap, but the file existence check
3770          * can potentially be quite expensive.  Including it here fixes a lot of
3771          * existing code, but we might want to add an optional parameter to skip
3772          * it and any other expensive checks.)
3773          *
3774          * @return \type{\bool}
3775          */
3776         public function isAlwaysKnown() {
3777                 if ( $this->mInterwiki != '' ) {
3778                         return true;  // any interwiki link might be viewable, for all we know
3779                 }
3780                 switch( $this->mNamespace ) {
3781                 case NS_MEDIA:
3782                 case NS_FILE:
3783                         return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3784                 case NS_SPECIAL:
3785                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3786                 case NS_MAIN:
3787                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3788                 case NS_MEDIAWIKI:
3789                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3790                         // the full l10n of that language to be loaded. That takes much memory and
3791                         // isn't needed. So we strip the language part away.
3792                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3793                         return (bool)wfMsgWeirdKey( $basename );  // known system message
3794                 default:
3795                         return false;
3796                 }
3797         }
3798
3799         /**
3800          * Does this title refer to a page that can (or might) be meaningfully
3801          * viewed?  In particular, this function may be used to determine if
3802          * links to the title should be rendered as "bluelinks" (as opposed to
3803          * "redlinks" to non-existent pages).
3804          *
3805          * @return \type{\bool}
3806          */
3807         public function isKnown() {
3808                 return $this->exists() || $this->isAlwaysKnown();
3809         }
3810
3811         /**
3812          * Does this page have source text?
3813          *
3814          * @return Boolean
3815          */
3816         public function hasSourceText() {
3817                 if ( $this->exists() ) {
3818                         return true;
3819                 }
3820
3821                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3822                         // If the page doesn't exist but is a known system message, default
3823                         // message content will be displayed, same for language subpages
3824                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3825                         // causes the full l10n of that language to be loaded. That takes much
3826                         // memory and isn't needed. So we strip the language part away.
3827                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3828                         return (bool)wfMsgWeirdKey( $basename );
3829                 }
3830
3831                 return false;
3832         }
3833
3834         /**
3835          * Is this in a namespace that allows actual pages?
3836          *
3837          * @return \type{\bool}
3838          * @internal note -- uses hardcoded namespace index instead of constants
3839          */
3840         public function canExist() {
3841                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3842         }
3843
3844         /**
3845          * Update page_touched timestamps and send squid purge messages for
3846          * pages linking to this title. May be sent to the job queue depending
3847          * on the number of links. Typically called on create and delete.
3848          */
3849         public function touchLinks() {
3850                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3851                 $u->doUpdate();
3852
3853                 if ( $this->getNamespace() == NS_CATEGORY ) {
3854                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3855                         $u->doUpdate();
3856                 }
3857         }
3858
3859         /**
3860          * Get the last touched timestamp
3861          *
3862          * @param $db DatabaseBase: optional db
3863          * @return \type{\string} Last touched timestamp
3864          */
3865         public function getTouched( $db = null ) {
3866                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3867                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3868                 return $touched;
3869         }
3870
3871         /**
3872          * Get the timestamp when this page was updated since the user last saw it.
3873          *
3874          * @param $user User
3875          * @return Mixed: string/null
3876          */
3877         public function getNotificationTimestamp( $user = null ) {
3878                 global $wgUser, $wgShowUpdatedMarker;
3879                 // Assume current user if none given
3880                 if ( !$user ) {
3881                         $user = $wgUser;
3882                 }
3883                 // Check cache first
3884                 $uid = $user->getId();
3885                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3886                         return $this->mNotificationTimestamp[$uid];
3887                 }
3888                 if ( !$uid || !$wgShowUpdatedMarker ) {
3889                         return $this->mNotificationTimestamp[$uid] = false;
3890                 }
3891                 // Don't cache too much!
3892                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3893                         $this->mNotificationTimestamp = array();
3894                 }
3895                 $dbr = wfGetDB( DB_SLAVE );
3896                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3897                         'wl_notificationtimestamp',
3898                         array( 'wl_namespace' => $this->getNamespace(),
3899                                 'wl_title' => $this->getDBkey(),
3900                                 'wl_user' => $user->getId()
3901                         ),
3902                         __METHOD__
3903                 );
3904                 return $this->mNotificationTimestamp[$uid];
3905         }
3906
3907         /**
3908          * Get the trackback URL for this page
3909          *
3910          * @return \type{\string} Trackback URL
3911          */
3912         public function trackbackURL() {
3913                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3914
3915                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3916                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3917         }
3918
3919         /**
3920          * Get the trackback RDF for this page
3921          *
3922          * @return \type{\string} Trackback RDF
3923          */
3924         public function trackbackRDF() {
3925                 $url = htmlspecialchars( $this->getFullURL() );
3926                 $title = htmlspecialchars( $this->getText() );
3927                 $tburl = $this->trackbackURL();
3928
3929                 // Autodiscovery RDF is placed in comments so HTML validator
3930                 // won't barf. This is a rather icky workaround, but seems
3931                 // frequently used by this kind of RDF thingy.
3932                 //
3933                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3934                 return "<!--
3935 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3936          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3937          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3938 <rdf:Description
3939    rdf:about=\"$url\"
3940    dc:identifier=\"$url\"
3941    dc:title=\"$title\"
3942    trackback:ping=\"$tburl\" />
3943 </rdf:RDF>
3944 -->";
3945         }
3946
3947         /**
3948          * Generate strings used for xml 'id' names in monobook tabs
3949          *
3950          * @param $prepend string defaults to 'nstab-'
3951          * @return \type{\string} XML 'id' name
3952          */
3953         public function getNamespaceKey( $prepend = 'nstab-' ) {
3954                 global $wgContLang;
3955                 // Gets the subject namespace if this title
3956                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3957                 // Checks if cononical namespace name exists for namespace
3958                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3959                         // Uses canonical namespace name
3960                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3961                 } else {
3962                         // Uses text of namespace
3963                         $namespaceKey = $this->getSubjectNsText();
3964                 }
3965                 // Makes namespace key lowercase
3966                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3967                 // Uses main
3968                 if ( $namespaceKey == '' ) {
3969                         $namespaceKey = 'main';
3970                 }
3971                 // Changes file to image for backwards compatibility
3972                 if ( $namespaceKey == 'file' ) {
3973                         $namespaceKey = 'image';
3974                 }
3975                 return $prepend . $namespaceKey;
3976         }
3977
3978         /**
3979          * Returns true if this is a special page.
3980          *
3981          * @return boolean
3982          */
3983         public function isSpecialPage() {
3984                 return $this->getNamespace() == NS_SPECIAL;
3985         }
3986
3987         /**
3988          * Returns true if this title resolves to the named special page
3989          *
3990          * @param $name \type{\string} The special page name
3991          * @return boolean
3992          */
3993         public function isSpecial( $name ) {
3994                 if ( $this->getNamespace() == NS_SPECIAL ) {
3995                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3996                         if ( $name == $thisName ) {
3997                                 return true;
3998                         }
3999                 }
4000                 return false;
4001         }
4002
4003         /**
4004          * If the Title refers to a special page alias which is not the local default,
4005          *
4006          * @return \type{Title} A new Title which points to the local default.
4007          *         Otherwise, returns $this.
4008          */
4009         public function fixSpecialName() {
4010                 if ( $this->getNamespace() == NS_SPECIAL ) {
4011                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4012                         if ( $canonicalName ) {
4013                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4014                                 if ( $localName != $this->mDbkeyform ) {
4015                                         return Title::makeTitle( NS_SPECIAL, $localName );
4016                                 }
4017                         }
4018                 }
4019                 return $this;
4020         }
4021
4022         /**
4023          * Is this Title in a namespace which contains content?
4024          * In other words, is this a content page, for the purposes of calculating
4025          * statistics, etc?
4026          *
4027          * @return \type{\bool}
4028          */
4029         public function isContentPage() {
4030                 return MWNamespace::isContent( $this->getNamespace() );
4031         }
4032
4033         /**
4034          * Get all extant redirects to this Title
4035          *
4036          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4037          *            NULL to consider all namespaces
4038          * @return \type{\arrayof{Title}} Redirects to this title
4039          */
4040         public function getRedirectsHere( $ns = null ) {
4041                 $redirs = array();
4042
4043                 $dbr = wfGetDB( DB_SLAVE );
4044                 $where = array(
4045                         'rd_namespace' => $this->getNamespace(),
4046                         'rd_title' => $this->getDBkey(),
4047                         'rd_from = page_id'
4048                 );
4049                 if ( !is_null( $ns ) ) {
4050                         $where['page_namespace'] = $ns;
4051                 }
4052
4053                 $res = $dbr->select(
4054                         array( 'redirect', 'page' ),
4055                         array( 'page_namespace', 'page_title' ),
4056                         $where,
4057                         __METHOD__
4058                 );
4059
4060
4061                 foreach ( $res as $row ) {
4062                         $redirs[] = self::newFromRow( $row );
4063                 }
4064                 return $redirs;
4065         }
4066
4067         /**
4068          * Check if this Title is a valid redirect target
4069          *
4070          * @return \type{\bool}
4071          */
4072         public function isValidRedirectTarget() {
4073                 global $wgInvalidRedirectTargets;
4074
4075                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4076                 if ( $this->isSpecial( 'Userlogout' ) ) {
4077                         return false;
4078                 }
4079
4080                 foreach ( $wgInvalidRedirectTargets as $target ) {
4081                         if ( $this->isSpecial( $target ) ) {
4082                                 return false;
4083                         }
4084                 }
4085
4086                 return true;
4087         }
4088
4089         /**
4090          * Get a backlink cache object
4091          *
4092          * @return object BacklinkCache
4093          */
4094         function getBacklinkCache() {
4095                 if ( is_null( $this->mBacklinkCache ) ) {
4096                         $this->mBacklinkCache = new BacklinkCache( $this );
4097                 }
4098                 return $this->mBacklinkCache;
4099         }
4100
4101         /**
4102          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4103          * this page.
4104          *
4105          * @return Boolean
4106          */
4107         public function canUseNoindex() {
4108                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4109
4110                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4111                         ? $wgContentNamespaces
4112                         : $wgExemptFromUserRobotsControl;
4113
4114                 return !in_array( $this->mNamespace, $bannedNamespaces );
4115
4116         }
4117
4118         /**
4119          * Returns restriction types for the current Title
4120          *
4121          * @return array applicable restriction types
4122          */
4123         public function getRestrictionTypes() {
4124                 global $wgRestrictionTypes;
4125                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4126
4127                 if ( $this->getNamespace() == NS_FILE ) {
4128                         $types[] = 'upload';
4129                 }
4130
4131                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4132
4133                 return $types;
4134         }
4135
4136         /**
4137          * Returns the raw sort key to be used for categories, with the specified
4138          * prefix.  This will be fed to Language::convertToSortkey() to get a
4139          * binary sortkey that can be used for actual sorting.
4140          *
4141          * @param $prefix string The prefix to be used, specified using
4142          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4143          *   prefix.
4144          * @return string
4145          */
4146         public function getCategorySortkey( $prefix = '' ) {
4147                 $unprefixed = $this->getText();
4148                 if ( $prefix !== '' ) {
4149                         # Separate with a null byte, so the unprefixed part is only used as
4150                         # a tiebreaker when two pages have the exact same prefix -- null
4151                         # sorts before everything else (hopefully).
4152                         return "$prefix\0$unprefixed";
4153                 }
4154                 return $unprefixed;
4155         }
4156 }