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 /**
  17  * @deprecated This used to be a define, but was moved to
  18  * Title::GAID_FOR_UPDATE in 1.17. This will probably be removed in 1.18
  19  */
  20 define( 'GAID_FOR_UPDATE', Title::GAID_FOR_UPDATE );
  21
  22 /**
  23  * Represents a title within MediaWiki.
  24  * Optionally may contain an interwiki designation or namespace.
  25  * @note This class can fetch various kinds of data from the database;
  26  *       however, it does so inefficiently.
  27  *
  28  * @internal documentation reviewed 15 Mar 2010
  29  */
  30 class Title {
  31         /** @name Static cache variables */
  32         // @{
  33         static private $titleCache = array();
  34         // @}
  35
  36         /**
  37          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  38          * commonly used titles. On a batch operation this can become a memory leak
  39          * if not bounded. After hitting this many titles reset the cache.
  40          */
  41         const CACHE_MAX = 1000;
  42
  43         /**
  44          * Used to be GAID_FOR_UPDATE define. Used with getArticleId() and friends
  45          * to use the master DB
  46          */
  47         const GAID_FOR_UPDATE = 1;
  48
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  67         var $mOldRestrictions = false;
  68         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  69         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  70         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  71         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  72         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  73         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  74         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  75         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  76         # Don't change the following default, NS_MAIN is hardcoded in several
  77         # places.  See bug 696.
  78         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  79                                           # Zero except in {{transclusion}} tags
  80         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  81         var $mLength = -1;                // /< The page length, 0 for special pages
  82         var $mRedirect = null;            // /< Is the article at this title a redirect?
  83         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  84         var $mBacklinkCache = null;       // /< Cache of links to this title
  85         // @}
  86
  87
  88         /**
  89          * Constructor
  90          * @private
  91          */
  92         /* private */ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String The database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title the new object, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String  The link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace int The namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title  The new object, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 /**
 142                  * Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 143                  */
 144                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 145
 146                 $t = new Title();
 147                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 148                 $t->mDefaultNamespace = $defaultNamespace;
 149
 150                 static $cachedcount = 0 ;
 151                 if ( $t->secureAndSplit() ) {
 152                         if ( $defaultNamespace == NS_MAIN ) {
 153                                 if ( $cachedcount >= self::CACHE_MAX ) {
 154                                         # Avoid memory leaks on mass operations...
 155                                         Title::$titleCache = array();
 156                                         $cachedcount = 0;
 157                                 }
 158                                 $cachedcount++;
 159                                 Title::$titleCache[$text] =& $t;
 160                         }
 161                         return $t;
 162                 } else {
 163                         $ret = null;
 164                         return $ret;
 165                 }
 166         }
 167
 168         /**
 169          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 170          *
 171          * Example of wrong and broken code:
 172          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 173          *
 174          * Example of right code:
 175          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 176          *
 177          * Create a new Title from URL-encoded text. Ensures that
 178          * the given title's length does not exceed the maximum.
 179          *
 180          * @param $url String the title, as might be taken from a URL
 181          * @return Title the new object, or NULL on an error
 182          */
 183         public static function newFromURL( $url ) {
 184                 global $wgLegalTitleChars;
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Create a new Title from an article ID
 204          *
 205          * @param $id Int the page_id corresponding to the Title to create
 206          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 207          * @return Title the new object, or NULL on an error
 208          */
 209         public static function newFromID( $id, $flags = 0 ) {
 210                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 211                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 212                 if ( $row !== false ) {
 213                         $title = Title::newFromRow( $row );
 214                 } else {
 215                         $title = null;
 216                 }
 217                 return $title;
 218         }
 219
 220         /**
 221          * Make an array of titles from an array of IDs
 222          *
 223          * @param $ids Array of Int Array of IDs
 224          * @return Array of Titles
 225          */
 226         public static function newFromIDs( $ids ) {
 227                 if ( !count( $ids ) ) {
 228                         return array();
 229                 }
 230                 $dbr = wfGetDB( DB_SLAVE );
 231
 232                 $res = $dbr->select(
 233                         'page',
 234                         array(
 235                                 'page_namespace', 'page_title', 'page_id',
 236                                 'page_len', 'page_is_redirect', 'page_latest',
 237                         ),
 238                         array( 'page_id' => $ids ),
 239                         __METHOD__
 240                 );
 241
 242                 $titles = array();
 243                 foreach ( $res as $row ) {
 244                         $titles[] = Title::newFromRow( $row );
 245                 }
 246                 return $titles;
 247         }
 248
 249         /**
 250          * Make a Title object from a DB row
 251          *
 252          * @param $row Object database row (needs at least page_title,page_namespace)
 253          * @return Title corresponding Title
 254          */
 255         public static function newFromRow( $row ) {
 256                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 257
 258                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 259                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 260                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 261                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 262
 263                 return $t;
 264         }
 265
 266         /**
 267          * Create a new Title from a namespace index and a DB key.
 268          * It's assumed that $ns and $title are *valid*, for instance when
 269          * they came directly from the database or a special page name.
 270          * For convenience, spaces are converted to underscores so that
 271          * eg user_text fields can be used directly.
 272          *
 273          * @param $ns Int the namespace of the article
 274          * @param $title String the unprefixed database key form
 275          * @param $fragment String The link fragment (after the "#")
 276          * @param $interwiki String The interwiki prefix
 277          * @return Title the new object
 278          */
 279         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 280                 $t = new Title();
 281                 $t->mInterwiki = $interwiki;
 282                 $t->mFragment = $fragment;
 283                 $t->mNamespace = $ns = intval( $ns );
 284                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 285                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 286                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 287                 $t->mTextform = str_replace( '_', ' ', $title );
 288                 return $t;
 289         }
 290
 291         /**
 292          * Create a new Title from a namespace index and a DB key.
 293          * The parameters will be checked for validity, which is a bit slower
 294          * than makeTitle() but safer for user-provided data.
 295          *
 296          * @param $ns Int the namespace of the article
 297          * @param $title String the database key form
 298          * @param $fragment String The link fragment (after the "#")
 299          * @param $interwiki String The interwiki prefix
 300          * @return Title the new object, or NULL on an error
 301          */
 302         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 303                 $t = new Title();
 304                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 305                 if ( $t->secureAndSplit() ) {
 306                         return $t;
 307                 } else {
 308                         return null;
 309                 }
 310         }
 311
 312         /**
 313          * Create a new Title for the Main Page
 314          *
 315          * @return Title the new object
 316          */
 317         public static function newMainPage() {
 318                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 319                 // Don't give fatal errors if the message is broken
 320                 if ( !$title ) {
 321                         $title = Title::newFromText( 'Main Page' );
 322                 }
 323                 return $title;
 324         }
 325
 326         /**
 327          * Extract a redirect destination from a string and return the
 328          * Title, or null if the text doesn't contain a valid redirect
 329          * This will only return the very next target, useful for
 330          * the redirect table and other checks that don't need full recursion
 331          *
 332          * @param $text String: Text with possible redirect
 333          * @return Title: The corresponding Title
 334          */
 335         public static function newFromRedirect( $text ) {
 336                 return self::newFromRedirectInternal( $text );
 337         }
 338
 339         /**
 340          * Extract a redirect destination from a string and return the
 341          * Title, or null if the text doesn't contain a valid redirect
 342          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 343          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 344          *
 345          * @param $text String Text with possible redirect
 346          * @return Title The corresponding Title
 347          */
 348         public static function newFromRedirectRecurse( $text ) {
 349                 $titles = self::newFromRedirectArray( $text );
 350                 return $titles ? array_pop( $titles ) : null;
 351         }
 352
 353         /**
 354          * Extract a redirect destination from a string and return an
 355          * array of Titles, or null if the text doesn't contain a valid redirect
 356          * The last element in the array is the final destination after all redirects
 357          * have been resolved (up to $wgMaxRedirects times)
 358          *
 359          * @param $text String Text with possible redirect
 360          * @return Array of Titles, with the destination last
 361          */
 362         public static function newFromRedirectArray( $text ) {
 363                 global $wgMaxRedirects;
 364                 // are redirects disabled?
 365                 if ( $wgMaxRedirects < 1 ) {
 366                         return null;
 367                 }
 368                 $title = self::newFromRedirectInternal( $text );
 369                 if ( is_null( $title ) ) {
 370                         return null;
 371                 }
 372                 // recursive check to follow double redirects
 373                 $recurse = $wgMaxRedirects;
 374                 $titles = array( $title );
 375                 while ( --$recurse > 0 ) {
 376                         if ( $title->isRedirect() ) {
 377                                 $article = new Article( $title, 0 );
 378                                 $newtitle = $article->getRedirectTarget();
 379                         } else {
 380                                 break;
 381                         }
 382                         // Redirects to some special pages are not permitted
 383                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 384                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 385                                 $title = $newtitle;
 386                                 $titles[] = $newtitle;
 387                         } else {
 388                                 break;
 389                         }
 390                 }
 391                 return $titles;
 392         }
 393
 394         /**
 395          * Really extract the redirect destination
 396          * Do not call this function directly, use one of the newFromRedirect* functions above
 397          *
 398          * @param $text String Text with possible redirect
 399          * @return Title The corresponding Title
 400          */
 401         protected static function newFromRedirectInternal( $text ) {
 402                 $redir = MagicWord::get( 'redirect' );
 403                 $text = trim( $text );
 404                 if ( $redir->matchStartAndRemove( $text ) ) {
 405                         // Extract the first link and see if it's usable
 406                         // Ensure that it really does come directly after #REDIRECT
 407                         // Some older redirects included a colon, so don't freak about that!
 408                         $m = array();
 409                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 410                                 // Strip preceding colon used to "escape" categories, etc.
 411                                 // and URL-decode links
 412                                 if ( strpos( $m[1], '%' ) !== false ) {
 413                                         // Match behavior of inline link parsing here;
 414                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 415                                 }
 416                                 $title = Title::newFromText( $m[1] );
 417                                 // If the title is a redirect to bad special pages or is invalid, return null
 418                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 419                                         return null;
 420                                 }
 421                                 return $title;
 422                         }
 423                 }
 424                 return null;
 425         }
 426
 427 # ----------------------------------------------------------------------------
 428 #       Static functions
 429 # ----------------------------------------------------------------------------
 430
 431         /**
 432          * Get the prefixed DB key associated with an ID
 433          *
 434          * @param $id Int the page_id of the article
 435          * @return Title an object representing the article, or NULL
 436          *  if no such article was found
 437          */
 438         public static function nameOf( $id ) {
 439                 $dbr = wfGetDB( DB_SLAVE );
 440
 441                 $s = $dbr->selectRow(
 442                         'page',
 443                         array( 'page_namespace', 'page_title' ),
 444                         array( 'page_id' => $id ),
 445                         __METHOD__
 446                 );
 447                 if ( $s === false ) {
 448                         return null;
 449                 }
 450
 451                 $n = self::makeName( $s->page_namespace, $s->page_title );
 452                 return $n;
 453         }
 454
 455         /**
 456          * Get a regex character class describing the legal characters in a link
 457          *
 458          * @return String the list of characters, not delimited
 459          */
 460         public static function legalChars() {
 461                 global $wgLegalTitleChars;
 462                 return $wgLegalTitleChars;
 463         }
 464
 465         /**
 466          * Get a string representation of a title suitable for
 467          * including in a search index
 468          *
 469          * @param $ns Int a namespace index
 470          * @param $title String text-form main part
 471          * @return String a stripped-down title string ready for the
 472          *  search index
 473          */
 474         public static function indexTitle( $ns, $title ) {
 475                 global $wgContLang;
 476
 477                 $lc = SearchEngine::legalSearchChars() . '&#;';
 478                 $t = $wgContLang->normalizeForSearch( $title );
 479                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 480                 $t = $wgContLang->lc( $t );
 481
 482                 # Handle 's, s'
 483                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 484                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 485
 486                 $t = preg_replace( "/\\s+/", ' ', $t );
 487
 488                 if ( $ns == NS_FILE ) {
 489                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 490                 }
 491                 return trim( $t );
 492         }
 493
 494         /**
 495          * Make a prefixed DB key from a DB key and a namespace index
 496          *
 497          * @param $ns Int numerical representation of the namespace
 498          * @param $title String the DB key form the title
 499          * @param $fragment String The link fragment (after the "#")
 500          * @param $interwiki String The interwiki prefix
 501          * @return String the prefixed form of the title
 502          */
 503         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 504                 global $wgContLang;
 505
 506                 $namespace = $wgContLang->getNsText( $ns );
 507                 $name = $namespace == '' ? $title : "$namespace:$title";
 508                 if ( strval( $interwiki ) != '' ) {
 509                         $name = "$interwiki:$name";
 510                 }
 511                 if ( strval( $fragment ) != '' ) {
 512                         $name .= '#' . $fragment;
 513                 }
 514                 return $name;
 515         }
 516
 517         /**
 518          * Determine whether the object refers to a page within
 519          * this project.
 520          *
 521          * @return Bool TRUE if this is an in-project interwiki link
 522          *      or a wikilink, FALSE otherwise
 523          */
 524         public function isLocal() {
 525                 if ( $this->mInterwiki != '' ) {
 526                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 527                 } else {
 528                         return true;
 529                 }
 530         }
 531
 532         /**
 533          * Determine whether the object refers to a page within
 534          * this project and is transcludable.
 535          *
 536          * @return Bool TRUE if this is transcludable
 537          */
 538         public function isTrans() {
 539                 if ( $this->mInterwiki == '' ) {
 540                         return false;
 541                 }
 542
 543                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 544         }
 545
 546         /**
 547          * Returns the DB name of the distant wiki
 548          * which owns the object.
 549          *
 550          * @return String the DB name
 551          */
 552         public function getTransWikiID() {
 553                 if ( $this->mInterwiki == '' ) {
 554                         return false;
 555                 }
 556
 557                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 558         }
 559
 560         /**
 561          * Escape a text fragment, say from a link, for a URL
 562          *
 563          * @param $fragment string containing a URL or link fragment (after the "#")
 564          * @return String: escaped string
 565          */
 566         static function escapeFragmentForURL( $fragment ) {
 567                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 568                 # fragments appear not to work in IE (at least up to 7) or in at least
 569                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 570                 # to care if they aren't encoded.
 571                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 572         }
 573
 574 # ----------------------------------------------------------------------------
 575 #       Other stuff
 576 # ----------------------------------------------------------------------------
 577
 578         /** Simple accessors */
 579         /**
 580          * Get the text form (spaces not underscores) of the main part
 581          *
 582          * @return String Main part of the title
 583          */
 584         public function getText() { return $this->mTextform; }
 585
 586         /**
 587          * Get the URL-encoded form of the main part
 588          *
 589          * @return String Main part of the title, URL-encoded
 590          */
 591         public function getPartialURL() { return $this->mUrlform; }
 592
 593         /**
 594          * Get the main part with underscores
 595          *
 596          * @return String: Main part of the title, with underscores
 597          */
 598         public function getDBkey() { return $this->mDbkeyform; }
 599
 600         /**
 601          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 602          *
 603          * @return Integer: Namespace index
 604          */
 605         public function getNamespace() { return $this->mNamespace; }
 606
 607         /**
 608          * Get the namespace text
 609          *
 610          * @return String: Namespace text
 611          */
 612         public function getNsText() {
 613                 global $wgContLang;
 614
 615                 if ( $this->mInterwiki != '' ) {
 616                         // This probably shouldn't even happen. ohh man, oh yuck.
 617                         // But for interwiki transclusion it sometimes does.
 618                         // Shit. Shit shit shit.
 619                         //
 620                         // Use the canonical namespaces if possible to try to
 621                         // resolve a foreign namespace.
 622                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 623                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 624                         }
 625                 }
 626                 return $wgContLang->getNsText( $this->mNamespace );
 627         }
 628
 629         /**
 630          * Get the DB key with the initial letter case as specified by the user
 631          *
 632          * @return String DB key
 633          */
 634         function getUserCaseDBKey() {
 635                 return $this->mUserCaseDBKey;
 636         }
 637
 638         /**
 639          * Get the namespace text of the subject (rather than talk) page
 640          *
 641          * @return String Namespace text
 642          */
 643         public function getSubjectNsText() {
 644                 global $wgContLang;
 645                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 646         }
 647
 648         /**
 649          * Get the namespace text of the talk page
 650          *
 651          * @return String Namespace text
 652          */
 653         public function getTalkNsText() {
 654                 global $wgContLang;
 655                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 656         }
 657
 658         /**
 659          * Could this title have a corresponding talk page?
 660          *
 661          * @return Bool TRUE or FALSE
 662          */
 663         public function canTalk() {
 664                 return( MWNamespace::canTalk( $this->mNamespace ) );
 665         }
 666
 667         /**
 668          * Get the interwiki prefix (or null string)
 669          *
 670          * @return String Interwiki prefix
 671          */
 672         public function getInterwiki() { return $this->mInterwiki; }
 673
 674         /**
 675          * Get the Title fragment (i.e.\ the bit after the #) in text form
 676          *
 677          * @return String Title fragment
 678          */
 679         public function getFragment() { return $this->mFragment; }
 680
 681         /**
 682          * Get the fragment in URL form, including the "#" character if there is one
 683          * @return String Fragment in URL form
 684          */
 685         public function getFragmentForURL() {
 686                 if ( $this->mFragment == '' ) {
 687                         return '';
 688                 } else {
 689                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 690                 }
 691         }
 692
 693         /**
 694          * Get the default namespace index, for when there is no namespace
 695          *
 696          * @return Int Default namespace index
 697          */
 698         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 699
 700         /**
 701          * Get title for search index
 702          *
 703          * @return String a stripped-down title string ready for the
 704          *  search index
 705          */
 706         public function getIndexTitle() {
 707                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 708         }
 709
 710         /**
 711          * Get the prefixed database key form
 712          *
 713          * @return String the prefixed title, with underscores and
 714          *  any interwiki and namespace prefixes
 715          */
 716         public function getPrefixedDBkey() {
 717                 $s = $this->prefix( $this->mDbkeyform );
 718                 $s = str_replace( ' ', '_', $s );
 719                 return $s;
 720         }
 721
 722         /**
 723          * Get the prefixed title with spaces.
 724          * This is the form usually used for display
 725          *
 726          * @return String the prefixed title, with spaces
 727          */
 728         public function getPrefixedText() {
 729                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 730                         $s = $this->prefix( $this->mTextform );
 731                         $s = str_replace( '_', ' ', $s );
 732                         $this->mPrefixedText = $s;
 733                 }
 734                 return $this->mPrefixedText;
 735         }
 736
 737         /**
 738          * Get the prefixed title with spaces, plus any fragment
 739          * (part beginning with '#')
 740          *
 741          * @return String the prefixed title, with spaces and
 742          *  the fragment, including '#'
 743          */
 744         public function getFullText() {
 745                 $text = $this->getPrefixedText();
 746                 if ( $this->mFragment != '' ) {
 747                         $text .= '#' . $this->mFragment;
 748                 }
 749                 return $text;
 750         }
 751
 752         /**
 753          * Get the base name, i.e. the leftmost parts before the /
 754          *
 755          * @return String Base name
 756          */
 757         public function getBaseText() {
 758                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 759                         return $this->getText();
 760                 }
 761
 762                 $parts = explode( '/', $this->getText() );
 763                 # Don't discard the real title if there's no subpage involved
 764                 if ( count( $parts ) > 1 ) {
 765                         unset( $parts[count( $parts ) - 1] );
 766                 }
 767                 return implode( '/', $parts );
 768         }
 769
 770         /**
 771          * Get the lowest-level subpage name, i.e. the rightmost part after /
 772          *
 773          * @return String Subpage name
 774          */
 775         public function getSubpageText() {
 776                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 777                         return( $this->mTextform );
 778                 }
 779                 $parts = explode( '/', $this->mTextform );
 780                 return( $parts[count( $parts ) - 1] );
 781         }
 782
 783         /**
 784          * Get a URL-encoded form of the subpage text
 785          *
 786          * @return String URL-encoded subpage name
 787          */
 788         public function getSubpageUrlForm() {
 789                 $text = $this->getSubpageText();
 790                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 791                 return( $text );
 792         }
 793
 794         /**
 795          * Get a URL-encoded title (not an actual URL) including interwiki
 796          *
 797          * @return String the URL-encoded form
 798          */
 799         public function getPrefixedURL() {
 800                 $s = $this->prefix( $this->mDbkeyform );
 801                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 802                 return $s;
 803         }
 804
 805         /**
 806          * Get a real URL referring to this title, with interwiki link and
 807          * fragment
 808          *
 809          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 810          *   links. Can be specified as an associative array as well, e.g.,
 811          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 812          * @param $variant String language variant of url (for sr, zh..)
 813          * @return String the URL
 814          */
 815         public function getFullURL( $query = '', $variant = false ) {
 816                 global $wgServer, $wgRequest;
 817
 818                 if ( is_array( $query ) ) {
 819                         $query = wfArrayToCGI( $query );
 820                 }
 821
 822                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 823                 if ( !$interwiki ) {
 824                         $url = $this->getLocalURL( $query, $variant );
 825
 826                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 827                         // Correct fix would be to move the prepending elsewhere.
 828                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 829                                 $url = $wgServer . $url;
 830                         }
 831                 } else {
 832                         $baseUrl = $interwiki->getURL();
 833
 834                         $namespace = wfUrlencode( $this->getNsText() );
 835                         if ( $namespace != '' ) {
 836                                 # Can this actually happen? Interwikis shouldn't be parsed.
 837                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 838                                 $namespace .= ':';
 839                         }
 840                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 841                         $url = wfAppendQuery( $url, $query );
 842                 }
 843
 844                 # Finally, add the fragment.
 845                 $url .= $this->getFragmentForURL();
 846
 847                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 848                 return $url;
 849         }
 850
 851         /**
 852          * Get a URL with no fragment or server name.  If this page is generated
 853          * with action=render, $wgServer is prepended.
 854          *
 855          * @param $query Mixed: an optional query string; if not specified,
 856          *   $wgArticlePath will be used.  Can be specified as an associative array
 857          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 858          *   URL-escaped).
 859          * @param $variant String language variant of url (for sr, zh..)
 860          * @return String the URL
 861          */
 862         public function getLocalURL( $query = '', $variant = false ) {
 863                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 864                 global $wgVariantArticlePath, $wgContLang;
 865
 866                 if ( is_array( $query ) ) {
 867                         $query = wfArrayToCGI( $query );
 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 Array of Strings An associative array of key => value pairs for the
 941          *   query string.  Keys and values will be escaped.
 942          * @param $variant 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 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 String an optional query string
 965          * @return 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 String an optional query string
 976          * @return 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 String an optional query string
 988          * @param $variant String language variant of url (for sr, zh..)
 989          * @return 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 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 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 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 String Action to check (default: edit)
1036          * @return 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 String the action the page is protected from,
1062          * by default checks all actions.
1063          * @return 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 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 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 String action that permission needs to be checked for
1136          * @return Bool
1137          */
1138         public function quickUserCan( $action ) {
1139                 return $this->userCan( $action, false );
1140         }
1141
1142         /**
1143          * Determines if $user is unable to edit this page because it has been protected
1144          * by $wgNamespaceProtection.
1145          *
1146          * @param $user User object, $wgUser will be used if not passed
1147          * @return Bool
1148          */
1149         public function isNamespaceProtected( User $user = null ) {
1150                 global $wgNamespaceProtection;
1151
1152                 if ( $user === null ) {
1153                         global $wgUser;
1154                         $user = $wgUser;
1155                 }
1156
1157                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1158                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1159                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1160                                         return true;
1161                                 }
1162                         }
1163                 }
1164                 return false;
1165         }
1166
1167         /**
1168          * Can $wgUser perform $action on this page?
1169          *
1170          * @param $action String action that permission needs to be checked for
1171          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1172          * @return Bool
1173          */
1174         public function userCan( $action, $doExpensiveQueries = true ) {
1175                 global $wgUser;
1176                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1177         }
1178
1179         /**
1180          * Can $user perform $action on this page?
1181          *
1182          * FIXME: This *does not* check throttles (User::pingLimiter()).
1183          *
1184          * @param $action String action that permission needs to be checked for
1185          * @param $user User to check
1186          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1187          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1188          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1189          */
1190         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1191                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1192
1193                 // Remove the errors being ignored.
1194                 foreach ( $errors as $index => $error ) {
1195                         $error_key = is_array( $error ) ? $error[0] : $error;
1196
1197                         if ( in_array( $error_key, $ignoreErrors ) ) {
1198                                 unset( $errors[$index] );
1199                         }
1200                 }
1201
1202                 return $errors;
1203         }
1204
1205         /**
1206          * Permissions checks that fail most often, and which are easiest to test.
1207          *
1208          * @param $action String the action to check
1209          * @param $user User user to check
1210          * @param $errors Array list of current errors
1211          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1212          * @param $short Boolean short circuit on first error
1213          *
1214          * @return Array list of errors
1215          */
1216         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1217                 if ( $action == 'create' ) {
1218                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1219                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1220                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1221                         }
1222                 } elseif ( $action == 'move' ) {
1223                         if ( !$user->isAllowed( 'move-rootuserpages' )
1224                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1225                                 // Show user page-specific message only if the user can move other pages
1226                                 $errors[] = array( 'cant-move-user-page' );
1227                         }
1228
1229                         // Check if user is allowed to move files if it's a file
1230                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1231                                 $errors[] = array( 'movenotallowedfile' );
1232                         }
1233
1234                         if ( !$user->isAllowed( 'move' ) ) {
1235                                 // User can't move anything
1236                                 global $wgGroupPermissions;
1237                                 $userCanMove = false;
1238                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1239                                         $userCanMove = $wgGroupPermissions['user']['move'];
1240                                 }
1241                                 $autoconfirmedCanMove = false;
1242                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1243                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1244                                 }
1245                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1246                                         // custom message if logged-in users without any special rights can move
1247                                         $errors[] = array( 'movenologintext' );
1248                                 } else {
1249                                         $errors[] = array( 'movenotallowed' );
1250                                 }
1251                         }
1252                 } elseif ( $action == 'move-target' ) {
1253                         if ( !$user->isAllowed( 'move' ) ) {
1254                                 // User can't move anything
1255                                 $errors[] = array( 'movenotallowed' );
1256                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1257                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1258                                 // Show user page-specific message only if the user can move other pages
1259                                 $errors[] = array( 'cant-move-to-user-page' );
1260                         }
1261                 } elseif ( !$user->isAllowed( $action ) ) {
1262                         // We avoid expensive display logic for quickUserCan's and such
1263                         $groups = false;
1264                         if ( !$short ) {
1265                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1266                                         User::getGroupsWithPermission( $action ) );
1267                         }
1268
1269                         if ( $groups ) {
1270                                 global $wgLang;
1271                                 $return = array(
1272                                         'badaccess-groups',
1273                                         $wgLang->commaList( $groups ),
1274                                         count( $groups )
1275                                 );
1276                         } else {
1277                                 $return = array( 'badaccess-group0' );
1278                         }
1279                         $errors[] = $return;
1280                 }
1281
1282                 return $errors;
1283         }
1284
1285         /**
1286          * Add the resulting error code to the errors array
1287          *
1288          * @param $errors Array list of current errors
1289          * @param $result Mixed result of errors
1290          *
1291          * @return Array list of errors
1292          */
1293         private function resultToError( $errors, $result ) {
1294                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1295                         // A single array representing an error
1296                         $errors[] = $result;
1297                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1298                         // A nested array representing multiple errors
1299                         $errors = array_merge( $errors, $result );
1300                 } else if ( $result !== '' && is_string( $result ) ) {
1301                         // A string representing a message-id
1302                         $errors[] = array( $result );
1303                 } else if ( $result === false ) {
1304                         // a generic "We don't want them to do that"
1305                         $errors[] = array( 'badaccess-group0' );
1306                 }
1307                 return $errors;
1308         }
1309
1310         /**
1311          * Check various permission hooks
1312          *
1313          * @param $action String the action to check
1314          * @param $user User user to check
1315          * @param $errors Array list of current errors
1316          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1317          * @param $short Boolean short circuit on first error
1318          *
1319          * @return Array list of errors
1320          */
1321         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1322                 // Use getUserPermissionsErrors instead
1323                 $result = '';
1324                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1325                         return $result ? array() : array( array( 'badaccess-group0' ) );
1326                 }
1327                 // Check getUserPermissionsErrors hook
1328                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1329                         $errors = $this->resultToError( $errors, $result );
1330                 }
1331                 // Check getUserPermissionsErrorsExpensive hook
1332                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1333                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1334                         $errors = $this->resultToError( $errors, $result );
1335                 }
1336
1337                 return $errors;
1338         }
1339
1340         /**
1341          * Check permissions on special pages & namespaces
1342          *
1343          * @param $action String the action to check
1344          * @param $user User user to check
1345          * @param $errors Array list of current errors
1346          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1347          * @param $short Boolean short circuit on first error
1348          *
1349          * @return Array list of errors
1350          */
1351         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1352                 # Only 'createaccount' and 'execute' can be performed on
1353                 # special pages, which don't actually exist in the DB.
1354                 $specialOKActions = array( 'createaccount', 'execute' );
1355                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1356                         $errors[] = array( 'ns-specialprotected' );
1357                 }
1358
1359                 # Check $wgNamespaceProtection for restricted namespaces
1360                 if ( $this->isNamespaceProtected( $user ) ) {
1361                         $ns = $this->mNamespace == NS_MAIN ?
1362                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1363                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1364                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1365                 }
1366
1367                 return $errors;
1368         }
1369
1370         /**
1371          * Check CSS/JS sub-page permissions
1372          *
1373          * @param $action String the action to check
1374          * @param $user User user to check
1375          * @param $errors Array list of current errors
1376          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1377          * @param $short Boolean short circuit on first error
1378          *
1379          * @return Array list of errors
1380          */
1381         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1382                 # Protect css/js subpages of user pages
1383                 # XXX: this might be better using restrictions
1384                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1385                 #      and $this->userCanEditJsSubpage() from working
1386                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1387                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1388                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1389                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1390                                 $errors[] = array( 'customcssjsprotected' );
1391                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1392                                 $errors[] = array( 'customcssjsprotected' );
1393                         }
1394                 }
1395
1396                 return $errors;
1397         }
1398
1399         /**
1400          * Check against page_restrictions table requirements on this
1401          * page. The user must possess all required rights for this
1402          * action.
1403          *
1404          * @param $action String the action to check
1405          * @param $user User user to check
1406          * @param $errors Array list of current errors
1407          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1408          * @param $short Boolean short circuit on first error
1409          *
1410          * @return Array list of errors
1411          */
1412         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1413                 foreach ( $this->getRestrictions( $action ) as $right ) {
1414                         // Backwards compatibility, rewrite sysop -> protect
1415                         if ( $right == 'sysop' ) {
1416                                 $right = 'protect';
1417                         }
1418                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1419                                 // Users with 'editprotected' permission can edit protected pages
1420                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1421                                         // Users with 'editprotected' permission cannot edit protected pages
1422                                         // with cascading option turned on.
1423                                         if ( $this->mCascadeRestriction ) {
1424                                                 $errors[] = array( 'protectedpagetext', $right );
1425                                         }
1426                                 } else {
1427                                         $errors[] = array( 'protectedpagetext', $right );
1428                                 }
1429                         }
1430                 }
1431
1432                 return $errors;
1433         }
1434
1435         /**
1436          * Check restrictions on cascading pages.
1437          *
1438          * @param $action String the action to check
1439          * @param $user User user to check
1440          * @param $errors Array list of current errors
1441          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1442          * @param $short Boolean short circuit on first error
1443          *
1444          * @return Array list of errors
1445          */
1446         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1447                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1448                         # We /could/ use the protection level on the source page, but it's
1449                         # fairly ugly as we have to establish a precedence hierarchy for pages
1450                         # included by multiple cascade-protected pages. So just restrict
1451                         # it to people with 'protect' permission, as they could remove the
1452                         # protection anyway.
1453                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1454                         # Cascading protection depends on more than this page...
1455                         # Several cascading protected pages may include this page...
1456                         # Check each cascading level
1457                         # This is only for protection restrictions, not for all actions
1458                         if ( isset( $restrictions[$action] ) ) {
1459                                 foreach ( $restrictions[$action] as $right ) {
1460                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1461                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1462                                                 $pages = '';
1463                                                 foreach ( $cascadingSources as $page )
1464                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1465                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1466                                         }
1467                                 }
1468                         }
1469                 }
1470
1471                 return $errors;
1472         }
1473
1474         /**
1475          * Check action permissions not already checked in checkQuickPermissions
1476          *
1477          * @param $action String the action to check
1478          * @param $user User user to check
1479          * @param $errors Array list of current errors
1480          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1481          * @param $short Boolean short circuit on first error
1482          *
1483          * @return Array list of errors
1484          */
1485         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1486                 if ( $action == 'protect' ) {
1487                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1488                                 // If they can't edit, they shouldn't protect.
1489                                 $errors[] = array( 'protect-cantedit' );
1490                         }
1491                 } elseif ( $action == 'create' ) {
1492                         $title_protection = $this->getTitleProtection();
1493                         if( $title_protection ) {
1494                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1495                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1496                                 }
1497                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1498                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1499                                 }
1500                         }
1501                 } elseif ( $action == 'move' ) {
1502                         // Check for immobile pages
1503                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1504                                 // Specific message for this case
1505                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1506                         } elseif ( !$this->isMovable() ) {
1507                                 // Less specific message for rarer cases
1508                                 $errors[] = array( 'immobile-page' );
1509                         }
1510                 } elseif ( $action == 'move-target' ) {
1511                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1512                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1513                         } elseif ( !$this->isMovable() ) {
1514                                 $errors[] = array( 'immobile-target-page' );
1515                         }
1516                 }
1517                 return $errors;
1518         }
1519
1520         /**
1521          * Check that the user isn't blocked from editting.
1522          *
1523          * @param $action String the action to check
1524          * @param $user User user to check
1525          * @param $errors Array list of current errors
1526          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1527          * @param $short Boolean short circuit on first error
1528          *
1529          * @return Array list of errors
1530          */
1531         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1532                 if( $short && count( $errors ) > 0 ) {
1533                         return $errors;
1534                 }
1535
1536                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1537
1538                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1539                         $errors[] = array( 'confirmedittext' );
1540                 }
1541
1542                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1543                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1544                         $block = $user->mBlock;
1545
1546                         // This is from OutputPage::blockedPage
1547                         // Copied at r23888 by werdna
1548
1549                         $id = $user->blockedBy();
1550                         $reason = $user->blockedFor();
1551                         if ( $reason == '' ) {
1552                                 $reason = wfMsg( 'blockednoreason' );
1553                         }
1554                         $ip = wfGetIP();
1555
1556                         if ( is_numeric( $id ) ) {
1557                                 $name = User::whoIs( $id );
1558                         } else {
1559                                 $name = $id;
1560                         }
1561
1562                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1563                         $blockid = $block->mId;
1564                         $blockExpiry = $user->mBlock->mExpiry;
1565                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1566                         if ( $blockExpiry == 'infinity' ) {
1567                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1568                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1569
1570                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1571                                         if ( !strpos( $option, ':' ) )
1572                                                 continue;
1573
1574                                         list( $show, $value ) = explode( ':', $option );
1575
1576                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1577                                                 $blockExpiry = $show;
1578                                                 break;
1579                                         }
1580                                 }
1581                         } else {
1582                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1583                         }
1584
1585                         $intended = $user->mBlock->mAddress;
1586
1587                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1588                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1589                 }
1590
1591                 return $errors;
1592         }
1593
1594         /**
1595          * Can $user perform $action on this page? This is an internal function,
1596          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1597          * checks on wfReadOnly() and blocks)
1598          *
1599          * @param $action String action that permission needs to be checked for
1600          * @param $user User to check
1601          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1602          * @param $short Bool Set this to true to stop after the first permission error.
1603          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1604          */
1605         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1606                 wfProfileIn( __METHOD__ );
1607
1608                 $errors = array();
1609                 $checks = array(
1610                         'checkQuickPermissions',
1611                         'checkPermissionHooks',
1612                         'checkSpecialsAndNSPermissions',
1613                         'checkCSSandJSPermissions',
1614                         'checkPageRestrictions',
1615                         'checkCascadingSourcesRestrictions',
1616                         'checkActionPermissions',
1617                         'checkUserBlock'
1618                 );
1619
1620                 while( count( $checks ) > 0 &&
1621                            !( $short && count( $errors ) > 0 ) ) {
1622                         $method = array_shift( $checks );
1623                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1624                 }
1625
1626                 wfProfileOut( __METHOD__ );
1627                 return $errors;
1628         }
1629
1630         /**
1631          * Is this title subject to title protection?
1632          * Title protection is the one applied against creation of such title.
1633          *
1634          * @return Mixed An associative array representing any existent title
1635          *   protection, or false if there's none.
1636          */
1637         private function getTitleProtection() {
1638                 // Can't protect pages in special namespaces
1639                 if ( $this->getNamespace() < 0 ) {
1640                         return false;
1641                 }
1642
1643                 // Can't protect pages that exist.
1644                 if ( $this->exists() ) {
1645                         return false;
1646                 }
1647
1648                 if ( !isset( $this->mTitleProtection ) ) {
1649                         $dbr = wfGetDB( DB_SLAVE );
1650                         $res = $dbr->select( 'protected_titles', '*',
1651                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1652                                 __METHOD__ );
1653
1654                         // fetchRow returns false if there are no rows.
1655                         $this->mTitleProtection = $dbr->fetchRow( $res );
1656                 }
1657                 return $this->mTitleProtection;
1658         }
1659
1660         /**
1661          * Update the title protection status
1662          *
1663          * @param $create_perm String Permission required for creation
1664          * @param $reason String Reason for protection
1665          * @param $expiry String Expiry timestamp
1666          * @return boolean true
1667          */
1668         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1669                 global $wgUser, $wgContLang;
1670
1671                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1672                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1673                         // No change
1674                         return true;
1675                 }
1676
1677                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1678
1679                 $dbw = wfGetDB( DB_MASTER );
1680
1681                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1682
1683                 $expiry_description = '';
1684                 if ( $encodedExpiry != 'infinity' ) {
1685                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1686                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1687                 } else {
1688                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1689                 }
1690
1691                 # Update protection table
1692                 if ( $create_perm != '' ) {
1693                         $this->mTitleProtection = array(
1694                                         'pt_namespace' => $namespace,
1695                                         'pt_title' => $title,
1696                                         'pt_create_perm' => $create_perm,
1697                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1698                                         'pt_expiry' => $encodedExpiry,
1699                                         'pt_user' => $wgUser->getId(),
1700                                         'pt_reason' => $reason,
1701                                 );
1702                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1703                                 $this->mTitleProtection, __METHOD__     );
1704                 } else {
1705                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1706                                 'pt_title' => $title ), __METHOD__ );
1707                         $this->mTitleProtection = false;
1708                 }
1709
1710                 # Update the protection log
1711                 if ( $dbw->affectedRows() ) {
1712                         $log = new LogPage( 'protect' );
1713
1714                         if ( $create_perm ) {
1715                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1716                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1717                         } else {
1718                                 $log->addEntry( 'unprotect', $this, $reason );
1719                         }
1720                 }
1721
1722                 return true;
1723         }
1724
1725         /**
1726          * Remove any title protection due to page existing
1727          */
1728         public function deleteTitleProtection() {
1729                 $dbw = wfGetDB( DB_MASTER );
1730
1731                 $dbw->delete(
1732                         'protected_titles',
1733                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1734                         __METHOD__
1735                 );
1736                 $this->mTitleProtection = false;
1737         }
1738
1739         /**
1740          * Would anybody with sufficient privileges be able to move this page?
1741          * Some pages just aren't movable.
1742          *
1743          * @return Bool TRUE or FALSE
1744          */
1745         public function isMovable() {
1746                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1747         }
1748
1749         /**
1750          * Can $wgUser read this page?
1751          *
1752          * @return Bool
1753          * @todo fold these checks into userCan()
1754          */
1755         public function userCanRead() {
1756                 global $wgUser, $wgGroupPermissions;
1757
1758                 static $useShortcut = null;
1759
1760                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1761                 if ( is_null( $useShortcut ) ) {
1762                         global $wgRevokePermissions;
1763                         $useShortcut = true;
1764                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1765                                 # Not a public wiki, so no shortcut
1766                                 $useShortcut = false;
1767                         } elseif ( !empty( $wgRevokePermissions ) ) {
1768                                 /*
1769                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1770                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1771                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1772                                  * reading is allowed.
1773                                  */
1774                                 foreach ( $wgRevokePermissions as $perms ) {
1775                                         if ( !empty( $perms['read'] ) ) {
1776                                                 # We might be removing the read right from the user, so no shortcut
1777                                                 $useShortcut = false;
1778                                                 break;
1779                                         }
1780                                 }
1781                         }
1782                 }
1783
1784                 $result = null;
1785                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1786                 if ( $result !== null ) {
1787                         return $result;
1788                 }
1789
1790                 # Shortcut for public wikis, allows skipping quite a bit of code
1791                 if ( $useShortcut ) {
1792                         return true;
1793                 }
1794
1795                 if ( $wgUser->isAllowed( 'read' ) ) {
1796                         return true;
1797                 } else {
1798                         global $wgWhitelistRead;
1799
1800                         /**
1801                          * Always grant access to the login page.
1802                          * Even anons need to be able to log in.
1803                         */
1804                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1805                                 return true;
1806                         }
1807
1808                         /**
1809                          * Bail out if there isn't whitelist
1810                          */
1811                         if ( !is_array( $wgWhitelistRead ) ) {
1812                                 return false;
1813                         }
1814
1815                         /**
1816                          * Check for explicit whitelisting
1817                          */
1818                         $name = $this->getPrefixedText();
1819                         $dbName = $this->getPrefixedDBKey();
1820                         // Check with and without underscores
1821                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1822                                 return true;
1823
1824                         /**
1825                          * Old settings might have the title prefixed with
1826                          * a colon for main-namespace pages
1827                          */
1828                         if ( $this->getNamespace() == NS_MAIN ) {
1829                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1830                                         return true;
1831                                 }
1832                         }
1833
1834                         /**
1835                          * If it's a special page, ditch the subpage bit
1836                          * and check again
1837                          */
1838                         if ( $this->getNamespace() == NS_SPECIAL ) {
1839                                 $name = $this->getDBkey();
1840                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1841                                 if ( $name === false ) {
1842                                         # Invalid special page, but we show standard login required message
1843                                         return false;
1844                                 }
1845
1846                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1847                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1848                                         return true;
1849                                 }
1850                         }
1851
1852                 }
1853                 return false;
1854         }
1855
1856         /**
1857          * Is this a talk page of some sort?
1858          *
1859          * @return Bool
1860          */
1861         public function isTalkPage() {
1862                 return MWNamespace::isTalk( $this->getNamespace() );
1863         }
1864
1865         /**
1866          * Is this a subpage?
1867          *
1868          * @return Bool
1869          */
1870         public function isSubpage() {
1871                 return MWNamespace::hasSubpages( $this->mNamespace )
1872                         ? strpos( $this->getText(), '/' ) !== false
1873                         : false;
1874         }
1875
1876         /**
1877          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1878          *
1879          * @return Bool
1880          */
1881         public function hasSubpages() {
1882                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1883                         # Duh
1884                         return false;
1885                 }
1886
1887                 # We dynamically add a member variable for the purpose of this method
1888                 # alone to cache the result.  There's no point in having it hanging
1889                 # around uninitialized in every Title object; therefore we only add it
1890                 # if needed and don't declare it statically.
1891                 if ( isset( $this->mHasSubpages ) ) {
1892                         return $this->mHasSubpages;
1893                 }
1894
1895                 $subpages = $this->getSubpages( 1 );
1896                 if ( $subpages instanceof TitleArray ) {
1897                         return $this->mHasSubpages = (bool)$subpages->count();
1898                 }
1899                 return $this->mHasSubpages = false;
1900         }
1901
1902         /**
1903          * Get all subpages of this page.
1904          *
1905          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1906          * @return mixed TitleArray, or empty array if this page's namespace
1907          *  doesn't allow subpages
1908          */
1909         public function getSubpages( $limit = -1 ) {
1910                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1911                         return array();
1912                 }
1913
1914                 $dbr = wfGetDB( DB_SLAVE );
1915                 $conds['page_namespace'] = $this->getNamespace();
1916                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1917                 $options = array();
1918                 if ( $limit > -1 ) {
1919                         $options['LIMIT'] = $limit;
1920                 }
1921                 return $this->mSubpages = TitleArray::newFromResult(
1922                         $dbr->select( 'page',
1923                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1924                                 $conds,
1925                                 __METHOD__,
1926                                 $options
1927                         )
1928                 );
1929         }
1930
1931         /**
1932          * Could this page contain custom CSS or JavaScript, based
1933          * on the title?
1934          *
1935          * @return Bool
1936          */
1937         public function isCssOrJsPage() {
1938                 return $this->mNamespace == NS_MEDIAWIKI
1939                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1940         }
1941
1942         /**
1943          * Is this a .css or .js subpage of a user page?
1944          * @return Bool
1945          */
1946         public function isCssJsSubpage() {
1947                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1948         }
1949
1950         /**
1951          * Is this a *valid* .css or .js subpage of a user page?
1952          *
1953          * @return Bool
1954          * @deprecated
1955          */
1956         public function isValidCssJsSubpage() {
1957                 return $this->isCssJsSubpage();
1958         }
1959
1960         /**
1961          * Trim down a .css or .js subpage title to get the corresponding skin name
1962          *
1963          * @return string containing skin name from .css or .js subpage title
1964          */
1965         public function getSkinFromCssJsSubpage() {
1966                 $subpage = explode( '/', $this->mTextform );
1967                 $subpage = $subpage[ count( $subpage ) - 1 ];
1968                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1969         }
1970
1971         /**
1972          * Is this a .css subpage of a user page?
1973          *
1974          * @return Bool
1975          */
1976         public function isCssSubpage() {
1977                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1978         }
1979
1980         /**
1981          * Is this a .js subpage of a user page?
1982          *
1983          * @return Bool
1984          */
1985         public function isJsSubpage() {
1986                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1987         }
1988
1989         /**
1990          * Protect css subpages of user pages: can $wgUser edit
1991          * this page?
1992          *
1993          * @return Bool
1994          * @todo XXX: this might be better using restrictions
1995          */
1996         public function userCanEditCssSubpage() {
1997                 global $wgUser;
1998                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1999                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2000         }
2001
2002         /**
2003          * Protect js subpages of user pages: can $wgUser edit
2004          * this page?
2005          *
2006          * @return Bool
2007          * @todo XXX: this might be better using restrictions
2008          */
2009         public function userCanEditJsSubpage() {
2010                 global $wgUser;
2011                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
2012                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2013         }
2014
2015         /**
2016          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2017          *
2018          * @return Bool If the page is subject to cascading restrictions.
2019          */
2020         public function isCascadeProtected() {
2021                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2022                 return ( $sources > 0 );
2023         }
2024
2025         /**
2026          * Cascading protection: Get the source of any cascading restrictions on this page.
2027          *
2028          * @param $getPages Bool Whether or not to retrieve the actual pages
2029          *        that the restrictions have come from.
2030          * @return Mixed Array of the Title
2031          *         objects of the pages from which cascading restrictions have come,
2032          *         false for none, or true if such restrictions exist, but $getPages was not set.
2033          *         The restriction array is an array of each type, each of which contains a
2034          *         array of unique groups.
2035          */
2036         public function getCascadeProtectionSources( $getPages = true ) {
2037                 $pagerestrictions = array();
2038
2039                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2040                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2041                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2042                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2043                 }
2044
2045                 wfProfileIn( __METHOD__ );
2046
2047                 $dbr = wfGetDB( DB_SLAVE );
2048
2049                 if ( $this->getNamespace() == NS_FILE ) {
2050                         $tables = array( 'imagelinks', 'page_restrictions' );
2051                         $where_clauses = array(
2052                                 'il_to' => $this->getDBkey(),
2053                                 'il_from=pr_page',
2054                                 'pr_cascade' => 1
2055                         );
2056                 } else {
2057                         $tables = array( 'templatelinks', 'page_restrictions' );
2058                         $where_clauses = array(
2059                                 'tl_namespace' => $this->getNamespace(),
2060                                 'tl_title' => $this->getDBkey(),
2061                                 'tl_from=pr_page',
2062                                 'pr_cascade' => 1
2063                         );
2064                 }
2065
2066                 if ( $getPages ) {
2067                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2068                                                    'pr_expiry', 'pr_type', 'pr_level' );
2069                         $where_clauses[] = 'page_id=pr_page';
2070                         $tables[] = 'page';
2071                 } else {
2072                         $cols = array( 'pr_expiry' );
2073                 }
2074
2075                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2076
2077                 $sources = $getPages ? array() : false;
2078                 $now = wfTimestampNow();
2079                 $purgeExpired = false;
2080
2081                 foreach ( $res as $row ) {
2082                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2083                         if ( $expiry > $now ) {
2084                                 if ( $getPages ) {
2085                                         $page_id = $row->pr_page;
2086                                         $page_ns = $row->page_namespace;
2087                                         $page_title = $row->page_title;
2088                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2089                                         # Add groups needed for each restriction type if its not already there
2090                                         # Make sure this restriction type still exists
2091
2092                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2093                                                 $pagerestrictions[$row->pr_type] = array();
2094                                         }
2095
2096                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2097                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2098                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2099                                         }
2100                                 } else {
2101                                         $sources = true;
2102                                 }
2103                         } else {
2104                                 // Trigger lazy purge of expired restrictions from the db
2105                                 $purgeExpired = true;
2106                         }
2107                 }
2108                 if ( $purgeExpired ) {
2109                         Title::purgeExpiredRestrictions();
2110                 }
2111
2112                 wfProfileOut( __METHOD__ );
2113
2114                 if ( $getPages ) {
2115                         $this->mCascadeSources = $sources;
2116                         $this->mCascadingRestrictions = $pagerestrictions;
2117                 } else {
2118                         $this->mHasCascadingRestrictions = $sources;
2119                 }
2120
2121                 return array( $sources, $pagerestrictions );
2122         }
2123
2124         /**
2125          * Returns cascading restrictions for the current article
2126          *
2127          * @return Boolean
2128          */
2129         function areRestrictionsCascading() {
2130                 if ( !$this->mRestrictionsLoaded ) {
2131                         $this->loadRestrictions();
2132                 }
2133
2134                 return $this->mCascadeRestriction;
2135         }
2136
2137         /**
2138          * Loads a string into mRestrictions array
2139          *
2140          * @param $res Resource restrictions as an SQL result.
2141          * @param $oldFashionedRestrictions string comma-separated list of page
2142          *        restrictions from page table (pre 1.10)
2143          */
2144         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2145                 $rows = array();
2146
2147                 foreach ( $res as $row ) {
2148                         $rows[] = $row;
2149                 }
2150
2151                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2152         }
2153
2154         /**
2155          * Compiles list of active page restrictions from both page table (pre 1.10)
2156          * and page_restrictions table for this existing page.
2157          * Public for usage by LiquidThreads.
2158          *
2159          * @param $rows array of db result objects
2160          * @param $oldFashionedRestrictions string comma-separated list of page
2161          *        restrictions from page table (pre 1.10)
2162          */
2163         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2164                 $dbr = wfGetDB( DB_SLAVE );
2165
2166                 $restrictionTypes = $this->getRestrictionTypes();
2167
2168                 foreach ( $restrictionTypes as $type ) {
2169                         $this->mRestrictions[$type] = array();
2170                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2171                 }
2172
2173                 $this->mCascadeRestriction = false;
2174
2175                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2176
2177                 if ( $oldFashionedRestrictions === null ) {
2178                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2179                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2180                 }
2181
2182                 if ( $oldFashionedRestrictions != '' ) {
2183
2184                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2185                                 $temp = explode( '=', trim( $restrict ) );
2186                                 if ( count( $temp ) == 1 ) {
2187                                         // old old format should be treated as edit/move restriction
2188                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2189                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2190                                 } else {
2191                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2192                                 }
2193                         }
2194
2195                         $this->mOldRestrictions = true;
2196
2197                 }
2198
2199                 if ( count( $rows ) ) {
2200                         # Current system - load second to make them override.
2201                         $now = wfTimestampNow();
2202                         $purgeExpired = false;
2203
2204                         foreach ( $rows as $row ) {
2205                                 # Cycle through all the restrictions.
2206
2207                                 // Don't take care of restrictions types that aren't allowed
2208
2209                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2210                                         continue;
2211
2212                                 // This code should be refactored, now that it's being used more generally,
2213                                 // But I don't really see any harm in leaving it in Block for now -werdna
2214                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2215
2216                                 // Only apply the restrictions if they haven't expired!
2217                                 if ( !$expiry || $expiry > $now ) {
2218                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2219                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2220
2221                                         $this->mCascadeRestriction |= $row->pr_cascade;
2222                                 } else {
2223                                         // Trigger a lazy purge of expired restrictions
2224                                         $purgeExpired = true;
2225                                 }
2226                         }
2227
2228                         if ( $purgeExpired ) {
2229                                 Title::purgeExpiredRestrictions();
2230                         }
2231                 }
2232
2233                 $this->mRestrictionsLoaded = true;
2234         }
2235
2236         /**
2237          * Load restrictions from the page_restrictions table
2238          *
2239          * @param $oldFashionedRestrictions string comma-separated list of page
2240          *        restrictions from page table (pre 1.10)
2241          */
2242         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2243                 if ( !$this->mRestrictionsLoaded ) {
2244                         if ( $this->exists() ) {
2245                                 $dbr = wfGetDB( DB_SLAVE );
2246
2247                                 $res = $dbr->select( 'page_restrictions', '*',
2248                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2249
2250                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2251                         } else {
2252                                 $title_protection = $this->getTitleProtection();
2253
2254                                 if ( $title_protection ) {
2255                                         $now = wfTimestampNow();
2256                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2257
2258                                         if ( !$expiry || $expiry > $now ) {
2259                                                 // Apply the restrictions
2260                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2261                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2262                                         } else { // Get rid of the old restrictions
2263                                                 Title::purgeExpiredRestrictions();
2264                                                 $this->mTitleProtection = false;
2265                                         }
2266                                 } else {
2267                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2268                                 }
2269                                 $this->mRestrictionsLoaded = true;
2270                         }
2271                 }
2272         }
2273
2274         /**
2275          * Purge expired restrictions from the page_restrictions table
2276          */
2277         static function purgeExpiredRestrictions() {
2278                 $dbw = wfGetDB( DB_MASTER );
2279                 $dbw->delete(
2280                         'page_restrictions',
2281                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2282                         __METHOD__
2283                 );
2284
2285                 $dbw->delete(
2286                         'protected_titles',
2287                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2288                         __METHOD__
2289                 );
2290         }
2291
2292         /**
2293          * Accessor/initialisation for mRestrictions
2294          *
2295          * @param $action String action that permission needs to be checked for
2296          * @return Array of Strings the array of groups allowed to edit this article
2297          */
2298         public function getRestrictions( $action ) {
2299                 if ( !$this->mRestrictionsLoaded ) {
2300                         $this->loadRestrictions();
2301                 }
2302                 return isset( $this->mRestrictions[$action] )
2303                                 ? $this->mRestrictions[$action]
2304                                 : array();
2305         }
2306
2307         /**
2308          * Get the expiry time for the restriction against a given action
2309          *
2310          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2311          *      or not protected at all, or false if the action is not recognised.
2312          */
2313         public function getRestrictionExpiry( $action ) {
2314                 if ( !$this->mRestrictionsLoaded ) {
2315                         $this->loadRestrictions();
2316                 }
2317                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2318         }
2319
2320         /**
2321          * Is there a version of this page in the deletion archive?
2322          *
2323          * @return Int the number of archived revisions
2324          */
2325         public function isDeleted() {
2326                 if ( $this->getNamespace() < 0 ) {
2327                         $n = 0;
2328                 } else {
2329                         $dbr = wfGetDB( DB_SLAVE );
2330                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2331                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2332                                 __METHOD__
2333                         );
2334                         if ( $this->getNamespace() == NS_FILE ) {
2335                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2336                                         array( 'fa_name' => $this->getDBkey() ),
2337                                         __METHOD__
2338                                 );
2339                         }
2340                 }
2341                 return (int)$n;
2342         }
2343
2344         /**
2345          * Is there a version of this page in the deletion archive?
2346          *
2347          * @return Boolean
2348          */
2349         public function isDeletedQuick() {
2350                 if ( $this->getNamespace() < 0 ) {
2351                         return false;
2352                 }
2353                 $dbr = wfGetDB( DB_SLAVE );
2354                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2355                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2356                         __METHOD__
2357                 );
2358                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2359                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2360                                 array( 'fa_name' => $this->getDBkey() ),
2361                                 __METHOD__
2362                         );
2363                 }
2364                 return $deleted;
2365         }
2366
2367         /**
2368          * Get the article ID for this Title from the link cache,
2369          * adding it if necessary
2370          *
2371          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2372          *  for update
2373          * @return Int the ID
2374          */
2375         public function getArticleID( $flags = 0 ) {
2376                 if ( $this->getNamespace() < 0 ) {
2377                         return $this->mArticleID = 0;
2378                 }
2379                 $linkCache = LinkCache::singleton();
2380                 if ( $flags & self::GAID_FOR_UPDATE ) {
2381                         $oldUpdate = $linkCache->forUpdate( true );
2382                         $linkCache->clearLink( $this );
2383                         $this->mArticleID = $linkCache->addLinkObj( $this );
2384                         $linkCache->forUpdate( $oldUpdate );
2385                 } else {
2386                         if ( -1 == $this->mArticleID ) {
2387                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2388                         }
2389                 }
2390                 return $this->mArticleID;
2391         }
2392
2393         /**
2394          * Is this an article that is a redirect page?
2395          * Uses link cache, adding it if necessary
2396          *
2397          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2398          * @return Bool
2399          */
2400         public function isRedirect( $flags = 0 ) {
2401                 if ( !is_null( $this->mRedirect ) ) {
2402                         return $this->mRedirect;
2403                 }
2404                 # Calling getArticleID() loads the field from cache as needed
2405                 if ( !$this->getArticleID( $flags ) ) {
2406                         return $this->mRedirect = false;
2407                 }
2408                 $linkCache = LinkCache::singleton();
2409                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2410
2411                 return $this->mRedirect;
2412         }
2413
2414         /**
2415          * What is the length of this page?
2416          * Uses link cache, adding it if necessary
2417          *
2418          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2419          * @return Int
2420          */
2421         public function getLength( $flags = 0 ) {
2422                 if ( $this->mLength != -1 ) {
2423                         return $this->mLength;
2424                 }
2425                 # Calling getArticleID() loads the field from cache as needed
2426                 if ( !$this->getArticleID( $flags ) ) {
2427                         return $this->mLength = 0;
2428                 }
2429                 $linkCache = LinkCache::singleton();
2430                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2431
2432                 return $this->mLength;
2433         }
2434
2435         /**
2436          * What is the page_latest field for this page?
2437          *
2438          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2439          * @return Int or 0 if the page doesn't exist
2440          */
2441         public function getLatestRevID( $flags = 0 ) {
2442                 if ( $this->mLatestID !== false ) {
2443                         return intval( $this->mLatestID );
2444                 }
2445                 # Calling getArticleID() loads the field from cache as needed
2446                 if ( !$this->getArticleID( $flags ) ) {
2447                         return $this->mLatestID = 0;
2448                 }
2449                 $linkCache = LinkCache::singleton();
2450                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2451
2452                 return $this->mLatestID;
2453         }
2454
2455         /**
2456          * This clears some fields in this object, and clears any associated
2457          * keys in the "bad links" section of the link cache.
2458          *
2459          * - This is called from Article::doEdit() and Article::insertOn() to allow
2460          * loading of the new page_id. It's also called from
2461          * Article::doDeleteArticle()
2462          *
2463          * @param $newid Int the new Article ID
2464          */
2465         public function resetArticleID( $newid ) {
2466                 $linkCache = LinkCache::singleton();
2467                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2468
2469                 if ( $newid === false ) {
2470                         $this->mArticleID = -1;
2471                 } else {
2472                         $this->mArticleID = intval( $newid );
2473                 }
2474                 $this->mRestrictionsLoaded = false;
2475                 $this->mRestrictions = array();
2476                 $this->mRedirect = null;
2477                 $this->mLength = -1;
2478                 $this->mLatestID = false;
2479         }
2480
2481         /**
2482          * Updates page_touched for this page; called from LinksUpdate.php
2483          *
2484          * @return Bool true if the update succeded
2485          */
2486         public function invalidateCache() {
2487                 if ( wfReadOnly() ) {
2488                         return;
2489                 }
2490                 $dbw = wfGetDB( DB_MASTER );
2491                 $success = $dbw->update(
2492                         'page',
2493                         array( 'page_touched' => $dbw->timestamp() ),
2494                         $this->pageCond(),
2495                         __METHOD__
2496                 );
2497                 HTMLFileCache::clearFileCache( $this );
2498                 return $success;
2499         }
2500
2501         /**
2502          * Prefix some arbitrary text with the namespace or interwiki prefix
2503          * of this object
2504          *
2505          * @param $name String the text
2506          * @return String the prefixed text
2507          * @private
2508          */
2509         /* private */ function prefix( $name ) {
2510                 $p = '';
2511                 if ( $this->mInterwiki != '' ) {
2512                         $p = $this->mInterwiki . ':';
2513                 }
2514                 if ( 0 != $this->mNamespace ) {
2515                         $p .= $this->getNsText() . ':';
2516                 }
2517                 return $p . $name;
2518         }
2519
2520         /**
2521          * Returns a simple regex that will match on characters and sequences invalid in titles.
2522          * Note that this doesn't pick up many things that could be wrong with titles, but that
2523          * replacing this regex with something valid will make many titles valid.
2524          *
2525          * @return string regex string
2526          */
2527         static function getTitleInvalidRegex() {
2528                 static $rxTc = false;
2529                 if ( !$rxTc ) {
2530                         # Matching titles will be held as illegal.
2531                         $rxTc = '/' .
2532                                 # Any character not allowed is forbidden...
2533                                 '[^' . Title::legalChars() . ']' .
2534                                 # URL percent encoding sequences interfere with the ability
2535                                 # to round-trip titles -- you can't link to them consistently.
2536                                 '|%[0-9A-Fa-f]{2}' .
2537                                 # XML/HTML character references produce similar issues.
2538                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2539                                 '|&#[0-9]+;' .
2540                                 '|&#x[0-9A-Fa-f]+;' .
2541                                 '/S';
2542                 }
2543
2544                 return $rxTc;
2545         }
2546
2547         /**
2548          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2549          *
2550          * @param $text string containing title to capitalize
2551          * @param $ns int namespace index, defaults to NS_MAIN
2552          * @return String containing capitalized title
2553          */
2554         public static function capitalize( $text, $ns = NS_MAIN ) {
2555                 global $wgContLang;
2556
2557                 if ( MWNamespace::isCapitalized( $ns ) ) {
2558                         return $wgContLang->ucfirst( $text );
2559                 } else {
2560                         return $text;
2561                 }
2562         }
2563
2564         /**
2565          * Secure and split - main initialisation function for this object
2566          *
2567          * Assumes that mDbkeyform has been set, and is urldecoded
2568          * and uses underscores, but not otherwise munged.  This function
2569          * removes illegal characters, splits off the interwiki and
2570          * namespace prefixes, sets the other forms, and canonicalizes
2571          * everything.
2572          *
2573          * @return Bool true on success
2574          */
2575         private function secureAndSplit() {
2576                 global $wgContLang, $wgLocalInterwiki;
2577
2578                 # Initialisation
2579                 $rxTc = self::getTitleInvalidRegex();
2580
2581                 $this->mInterwiki = $this->mFragment = '';
2582                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2583
2584                 $dbkey = $this->mDbkeyform;
2585
2586                 # Strip Unicode bidi override characters.
2587                 # Sometimes they slip into cut-n-pasted page titles, where the
2588                 # override chars get included in list displays.
2589                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2590
2591                 # Clean up whitespace
2592                 # Note: use of the /u option on preg_replace here will cause
2593                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2594                 # conveniently disabling them.
2595                 #
2596                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2597                 $dbkey = trim( $dbkey, '_' );
2598
2599                 if ( $dbkey == '' ) {
2600                         return false;
2601                 }
2602
2603                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2604                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2605                         return false;
2606                 }
2607
2608                 $this->mDbkeyform = $dbkey;
2609
2610                 # Initial colon indicates main namespace rather than specified default
2611                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2612                 if ( ':' == $dbkey { 0 } ) {
2613                         $this->mNamespace = NS_MAIN;
2614                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2615                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2616                 }
2617
2618                 # Namespace or interwiki prefix
2619                 $firstPass = true;
2620                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2621                 do {
2622                         $m = array();
2623                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2624                                 $p = $m[1];
2625                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2626                                         # Ordinary namespace
2627                                         $dbkey = $m[2];
2628                                         $this->mNamespace = $ns;
2629                                         # For Talk:X pages, check if X has a "namespace" prefix
2630                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2631                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2632                                                         return false; # Disallow Talk:File:x type titles...
2633                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2634                                                         return false; # Disallow Talk:Interwiki:x type titles...
2635                                                 }
2636                                         }
2637                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2638                                         if ( !$firstPass ) {
2639                                                 # Can't make a local interwiki link to an interwiki link.
2640                                                 # That's just crazy!
2641                                                 return false;
2642                                         }
2643
2644                                         # Interwiki link
2645                                         $dbkey = $m[2];
2646                                         $this->mInterwiki = $wgContLang->lc( $p );
2647
2648                                         # Redundant interwiki prefix to the local wiki
2649                                         if ( $wgLocalInterwiki !== false
2650                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2651                                         {
2652                                                 if ( $dbkey == '' ) {
2653                                                         # Can't have an empty self-link
2654                                                         return false;
2655                                                 }
2656                                                 $this->mInterwiki = '';
2657                                                 $firstPass = false;
2658                                                 # Do another namespace split...
2659                                                 continue;
2660                                         }
2661
2662                                         # If there's an initial colon after the interwiki, that also
2663                                         # resets the default namespace
2664                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2665                                                 $this->mNamespace = NS_MAIN;
2666                                                 $dbkey = substr( $dbkey, 1 );
2667                                         }
2668                                 }
2669                                 # If there's no recognized interwiki or namespace,
2670                                 # then let the colon expression be part of the title.
2671                         }
2672                         break;
2673                 } while ( true );
2674
2675                 # We already know that some pages won't be in the database!
2676                 #
2677                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2678                         $this->mArticleID = 0;
2679                 }
2680                 $fragment = strstr( $dbkey, '#' );
2681                 if ( false !== $fragment ) {
2682                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2683                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2684                         # remove whitespace again: prevents "Foo_bar_#"
2685                         # becoming "Foo_bar_"
2686                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2687                 }
2688
2689                 # Reject illegal characters.
2690                 #
2691                 if ( preg_match( $rxTc, $dbkey ) ) {
2692                         return false;
2693                 }
2694
2695                 /**
2696                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2697                  * reachable due to the way web browsers deal with 'relative' URLs.
2698                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2699                  */
2700                 if ( strpos( $dbkey, '.' ) !== false &&
2701                      ( $dbkey === '.' || $dbkey === '..' ||
2702                        strpos( $dbkey, './' ) === 0  ||
2703                        strpos( $dbkey, '../' ) === 0 ||
2704                        strpos( $dbkey, '/./' ) !== false ||
2705                        strpos( $dbkey, '/../' ) !== false  ||
2706                        substr( $dbkey, -2 ) == '/.' ||
2707                        substr( $dbkey, -3 ) == '/..' ) )
2708                 {
2709                         return false;
2710                 }
2711
2712                 /**
2713                  * Magic tilde sequences? Nu-uh!
2714                  */
2715                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2716                         return false;
2717                 }
2718
2719                 /**
2720                  * Limit the size of titles to 255 bytes.
2721                  * This is typically the size of the underlying database field.
2722                  * We make an exception for special pages, which don't need to be stored
2723                  * in the database, and may edge over 255 bytes due to subpage syntax
2724                  * for long titles, e.g. [[Special:Block/Long name]]
2725                  */
2726                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2727                   strlen( $dbkey ) > 512 )
2728                 {
2729                         return false;
2730                 }
2731
2732                 /**
2733                  * Normally, all wiki links are forced to have
2734                  * an initial capital letter so [[foo]] and [[Foo]]
2735                  * point to the same place.
2736                  *
2737                  * Don't force it for interwikis, since the other
2738                  * site might be case-sensitive.
2739                  */
2740                 $this->mUserCaseDBKey = $dbkey;
2741                 if ( $this->mInterwiki == '' ) {
2742                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2743                 }
2744
2745                 /**
2746                  * Can't make a link to a namespace alone...
2747                  * "empty" local links can only be self-links
2748                  * with a fragment identifier.
2749                  */
2750                 if ( $dbkey == '' &&
2751                         $this->mInterwiki == '' &&
2752                         $this->mNamespace != NS_MAIN ) {
2753                         return false;
2754                 }
2755                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2756                 // IP names are not allowed for accounts, and can only be referring to
2757                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2758                 // there are numerous ways to present the same IP. Having sp:contribs scan
2759                 // them all is silly and having some show the edits and others not is
2760                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2761                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2762                         IP::sanitizeIP( $dbkey ) : $dbkey;
2763                 // Any remaining initial :s are illegal.
2764                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2765                         return false;
2766                 }
2767
2768                 # Fill fields
2769                 $this->mDbkeyform = $dbkey;
2770                 $this->mUrlform = wfUrlencode( $dbkey );
2771
2772                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2773
2774                 return true;
2775         }
2776
2777         /**
2778          * Set the fragment for this title. Removes the first character from the
2779          * specified fragment before setting, so it assumes you're passing it with
2780          * an initial "#".
2781          *
2782          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2783          * Still in active use privately.
2784          *
2785          * @param $fragment String text
2786          */
2787         public function setFragment( $fragment ) {
2788                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2789         }
2790
2791         /**
2792          * Get a Title object associated with the talk page of this article
2793          *
2794          * @return Title the object for the talk page
2795          */
2796         public function getTalkPage() {
2797                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2798         }
2799
2800         /**
2801          * Get a title object associated with the subject page of this
2802          * talk page
2803          *
2804          * @return Title the object for the subject page
2805          */
2806         public function getSubjectPage() {
2807                 // Is this the same title?
2808                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2809                 if ( $this->getNamespace() == $subjectNS ) {
2810                         return $this;
2811                 }
2812                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2813         }
2814
2815         /**
2816          * Get an array of Title objects linking to this Title
2817          * Also stores the IDs in the link cache.
2818          *
2819          * WARNING: do not use this function on arbitrary user-supplied titles!
2820          * On heavily-used templates it will max out the memory.
2821          *
2822          * @param $options Array: may be FOR UPDATE
2823          * @param $table String: table name
2824          * @param $prefix String: fields prefix
2825          * @return Array of Title objects linking here
2826          */
2827         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2828                 $linkCache = LinkCache::singleton();
2829
2830                 if ( count( $options ) > 0 ) {
2831                         $db = wfGetDB( DB_MASTER );
2832                 } else {
2833                         $db = wfGetDB( DB_SLAVE );
2834                 }
2835
2836                 $res = $db->select(
2837                         array( 'page', $table ),
2838                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2839                         array(
2840                                 "{$prefix}_from=page_id",
2841                                 "{$prefix}_namespace" => $this->getNamespace(),
2842                                 "{$prefix}_title"     => $this->getDBkey() ),
2843                         __METHOD__,
2844                         $options
2845                 );
2846
2847                 $retVal = array();
2848                 if ( $db->numRows( $res ) ) {
2849                         foreach ( $res as $row ) {
2850                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2851                                 if ( $titleObj ) {
2852                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2853                                         $retVal[] = $titleObj;
2854                                 }
2855                         }
2856                 }
2857                 return $retVal;
2858         }
2859
2860         /**
2861          * Get an array of Title objects using this Title as a template
2862          * Also stores the IDs in the link cache.
2863          *
2864          * WARNING: do not use this function on arbitrary user-supplied titles!
2865          * On heavily-used templates it will max out the memory.
2866          *
2867          * @param $options Array: may be FOR UPDATE
2868          * @return Array of Title the Title objects linking here
2869          */
2870         public function getTemplateLinksTo( $options = array() ) {
2871                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2872         }
2873
2874         /**
2875          * Get an array of Title objects referring to non-existent articles linked from this page
2876          *
2877          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2878          * @return Array of Title the Title objects
2879          */
2880         public function getBrokenLinksFrom() {
2881                 if ( $this->getArticleId() == 0 ) {
2882                         # All links from article ID 0 are false positives
2883                         return array();
2884                 }
2885
2886                 $dbr = wfGetDB( DB_SLAVE );
2887                 $res = $dbr->select(
2888                         array( 'page', 'pagelinks' ),
2889                         array( 'pl_namespace', 'pl_title' ),
2890                         array(
2891                                 'pl_from' => $this->getArticleId(),
2892                                 'page_namespace IS NULL'
2893                         ),
2894                         __METHOD__, array(),
2895                         array(
2896                                 'page' => array(
2897                                         'LEFT JOIN',
2898                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2899                                 )
2900                         )
2901                 );
2902
2903                 $retVal = array();
2904                 foreach ( $res as $row ) {
2905                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2906                 }
2907                 return $retVal;
2908         }
2909
2910
2911         /**
2912          * Get a list of URLs to purge from the Squid cache when this
2913          * page changes
2914          *
2915          * @return Array of String the URLs
2916          */
2917         public function getSquidURLs() {
2918                 global $wgContLang;
2919
2920                 $urls = array(
2921                         $this->getInternalURL(),
2922                         $this->getInternalURL( 'action=history' )
2923                 );
2924
2925                 // purge variant urls as well
2926                 if ( $wgContLang->hasVariants() ) {
2927                         $variants = $wgContLang->getVariants();
2928                         foreach ( $variants as $vCode ) {
2929                                 $urls[] = $this->getInternalURL( '', $vCode );
2930                         }
2931                 }
2932
2933                 return $urls;
2934         }
2935
2936         /**
2937          * Purge all applicable Squid URLs
2938          */
2939         public function purgeSquid() {
2940                 global $wgUseSquid;
2941                 if ( $wgUseSquid ) {
2942                         $urls = $this->getSquidURLs();
2943                         $u = new SquidUpdate( $urls );
2944                         $u->doUpdate();
2945                 }
2946         }
2947
2948         /**
2949          * Move this page without authentication
2950          *
2951          * @param $nt Title the new page Title
2952          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2953          */
2954         public function moveNoAuth( &$nt ) {
2955                 return $this->moveTo( $nt, false );
2956         }
2957
2958         /**
2959          * Check whether a given move operation would be valid.
2960          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2961          *
2962          * @param $nt Title the new title
2963          * @param $auth Bool indicates whether $wgUser's permissions
2964          *  should be checked
2965          * @param $reason String is the log summary of the move, used for spam checking
2966          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2967          */
2968         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2969                 global $wgUser;
2970
2971                 $errors = array();
2972                 if ( !$nt ) {
2973                         // Normally we'd add this to $errors, but we'll get
2974                         // lots of syntax errors if $nt is not an object
2975                         return array( array( 'badtitletext' ) );
2976                 }
2977                 if ( $this->equals( $nt ) ) {
2978                         $errors[] = array( 'selfmove' );
2979                 }
2980                 if ( !$this->isMovable() ) {
2981                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2982                 }
2983                 if ( $nt->getInterwiki() != '' ) {
2984                         $errors[] = array( 'immobile-target-namespace-iw' );
2985                 }
2986                 if ( !$nt->isMovable() ) {
2987                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2988                 }
2989
2990                 $oldid = $this->getArticleID();
2991                 $newid = $nt->getArticleID();
2992
2993                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2994                         $errors[] = array( 'articleexists' );
2995                 }
2996                 if ( ( $this->getDBkey() == '' ) ||
2997                          ( !$oldid ) ||
2998                      ( $nt->getDBkey() == '' ) ) {
2999                         $errors[] = array( 'badarticleerror' );
3000                 }
3001
3002                 // Image-specific checks
3003                 if ( $this->getNamespace() == NS_FILE ) {
3004                         if ( $nt->getNamespace() != NS_FILE ) {
3005                                 $errors[] = array( 'imagenocrossnamespace' );
3006                         }
3007                         $file = wfLocalFile( $this );
3008                         if ( $file->exists() ) {
3009                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3010                                         $errors[] = array( 'imageinvalidfilename' );
3011                                 }
3012                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3013                                         $errors[] = array( 'imagetypemismatch' );
3014                                 }
3015                         }
3016                         $destfile = wfLocalFile( $nt );
3017                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
3018                                 $errors[] = array( 'file-exists-sharedrepo' );
3019                         }
3020                 }
3021
3022                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3023                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3024                 }
3025
3026                 if ( $auth ) {
3027                         $errors = wfMergeErrorArrays( $errors,
3028                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3029                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3030                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3031                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3032                 }
3033
3034                 $match = EditPage::matchSummarySpamRegex( $reason );
3035                 if ( $match !== false ) {
3036                         // This is kind of lame, won't display nice
3037                         $errors[] = array( 'spamprotectiontext' );
3038                 }
3039
3040                 $err = null;
3041                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3042                         $errors[] = array( 'hookaborted', $err );
3043                 }
3044
3045                 # The move is allowed only if (1) the target doesn't exist, or
3046                 # (2) the target is a redirect to the source, and has no history
3047                 # (so we can undo bad moves right after they're done).
3048
3049                 if ( 0 != $newid ) { # Target exists; check for validity
3050                         if ( !$this->isValidMoveTarget( $nt ) ) {
3051                                 $errors[] = array( 'articleexists' );
3052                         }
3053                 } else {
3054                         $tp = $nt->getTitleProtection();
3055                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3056                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3057                                 $errors[] = array( 'cantmove-titleprotected' );
3058                         }
3059                 }
3060                 if ( empty( $errors ) ) {
3061                         return true;
3062                 }
3063                 return $errors;
3064         }
3065
3066         /**
3067          * Move a title to a new location
3068          *
3069          * @param $nt Title the new title
3070          * @param $auth Bool indicates whether $wgUser's permissions
3071          *  should be checked
3072          * @param $reason String The reason for the move
3073          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3074          *  Ignored if the user doesn't have the suppressredirect right.
3075          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3076          */
3077         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3078                 global $wgContLang;
3079
3080                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3081                 if ( is_array( $err ) ) {
3082                         return $err;
3083                 }
3084
3085                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3086                 $dbw = wfGetDB( DB_MASTER );
3087                 if ( $this->getNamespace() == NS_FILE ) {
3088                         $file = wfLocalFile( $this );
3089                         if ( $file->exists() ) {
3090                                 $status = $file->move( $nt );
3091                                 if ( !$status->isOk() ) {
3092                                         return $status->getErrorsArray();
3093                                 }
3094                         }
3095                 }
3096
3097                 $pageid = $this->getArticleID();
3098                 $protected = $this->isProtected();
3099                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3100
3101                 // Do the actual move
3102                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3103                 if ( is_array( $err ) ) {
3104                         return $err;
3105                 }
3106
3107                 $redirid = $this->getArticleID();
3108
3109                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3110                 // cl_timestamp, which may disturb time-based lists on some sites.
3111                 $prefix = $dbw->selectField(
3112                         'categorylinks',
3113                         'cl_sortkey_prefix',
3114                         array( 'cl_from' => $pageid ),
3115                         __METHOD__
3116                 );
3117                 $dbw->update( 'categorylinks',
3118                         array(
3119                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3120                                 'cl_timestamp=cl_timestamp' ),
3121                         array( 'cl_from' => $pageid ),
3122                         __METHOD__ );
3123
3124                 if ( $protected ) {
3125                         # Protect the redirect title as the title used to be...
3126                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3127                                 array(
3128                                         'pr_page'    => $redirid,
3129                                         'pr_type'    => 'pr_type',
3130                                         'pr_level'   => 'pr_level',
3131                                         'pr_cascade' => 'pr_cascade',
3132                                         'pr_user'    => 'pr_user',
3133                                         'pr_expiry'  => 'pr_expiry'
3134                                 ),
3135                                 array( 'pr_page' => $pageid ),
3136                                 __METHOD__,
3137                                 array( 'IGNORE' )
3138                         );
3139                         # Update the protection log
3140                         $log = new LogPage( 'protect' );
3141                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3142                         if ( $reason ) {
3143                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3144                         }
3145                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3146                 }
3147
3148                 # Update watchlists
3149                 $oldnamespace = $this->getNamespace() & ~1;
3150                 $newnamespace = $nt->getNamespace() & ~1;
3151                 $oldtitle = $this->getDBkey();
3152                 $newtitle = $nt->getDBkey();
3153
3154                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3155                         WatchedItem::duplicateEntries( $this, $nt );
3156                 }
3157
3158                 # Update search engine
3159                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3160                 $u->doUpdate();
3161                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3162                 $u->doUpdate();
3163
3164                 # Update site_stats
3165                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3166                         # No longer a content page
3167                         # Not viewed, edited, removing
3168                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3169                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3170                         # Now a content page
3171                         # Not viewed, edited, adding
3172                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3173                 } elseif ( $pageCountChange ) {
3174                         # Redirect added
3175                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3176                 } else {
3177                         # Nothing special
3178                         $u = false;
3179                 }
3180                 if ( $u ) {
3181                         $u->doUpdate();
3182                 }
3183                 # Update message cache for interface messages
3184                 global $wgMessageCache;
3185                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3186                         # @bug 17860: old article can be deleted, if this the case,
3187                         # delete it from message cache
3188                         if ( $this->getArticleID() === 0 ) {
3189                                 $wgMessageCache->replace( $this->getDBkey(), false );
3190                         } else {
3191                                 $oldarticle = new Article( $this );
3192                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3193                         }
3194                 }
3195                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3196                         $newarticle = new Article( $nt );
3197                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3198                 }
3199
3200                 global $wgUser;
3201                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3202                 return true;
3203         }
3204
3205         /**
3206          * Move page to a title which is either a redirect to the
3207          * source page or nonexistent
3208          *
3209          * @param $nt Title the page to move to, which should
3210          * be a redirect or nonexistent
3211          * @param $reason String The reason for the move
3212          * @param $createRedirect Bool Whether to leave a
3213          * redirect at the old title.  Ignored if the user doesn't
3214          * have the suppressredirect right
3215          */
3216         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3217                 global $wgUser, $wgContLang;
3218
3219                 $moveOverRedirect = $nt->exists();
3220
3221                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3222                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3223
3224                 if ( $reason ) {
3225                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3226                 }
3227                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3228                 $comment = $wgContLang->truncate( $comment, 250 );
3229
3230                 $oldid = $this->getArticleID();
3231                 $latest = $this->getLatestRevID();
3232
3233                 $dbw = wfGetDB( DB_MASTER );
3234
3235                 if ( $moveOverRedirect ) {
3236                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3237
3238                         $newid = $nt->getArticleID();
3239                         $newns = $nt->getNamespace();
3240                         $newdbk = $nt->getDBkey();
3241
3242                         # Delete the old redirect. We don't save it to history since
3243                         # by definition if we've got here it's rather uninteresting.
3244                         # We have to remove it so that the next step doesn't trigger
3245                         # a conflict on the unique namespace+title index...
3246                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3247                         if ( !$dbw->cascadingDeletes() ) {
3248                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3249                                 global $wgUseTrackbacks;
3250                                 if ( $wgUseTrackbacks ) {
3251                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3252                                 }
3253                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3254                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3255                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3256                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3257                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3258                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3259                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3260                         }
3261                         // If the target page was recently created, it may have an entry in recentchanges still
3262                         $dbw->delete( 'recentchanges',
3263                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3264                                 __METHOD__
3265                         );
3266                 }
3267
3268                 # Save a null revision in the page's history notifying of the move
3269                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3270                 if ( !is_object( $nullRevision ) ) {
3271                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3272                 }
3273                 $nullRevId = $nullRevision->insertOn( $dbw );
3274
3275                 $article = new Article( $this );
3276                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3277
3278                 # Change the name of the target page:
3279                 $dbw->update( 'page',
3280                         /* SET */ array(
3281                                 'page_touched'   => $dbw->timestamp(),
3282                                 'page_namespace' => $nt->getNamespace(),
3283                                 'page_title'     => $nt->getDBkey(),
3284                                 'page_latest'    => $nullRevId,
3285                         ),
3286                         /* WHERE */ array( 'page_id' => $oldid ),
3287                         __METHOD__
3288                 );
3289                 $nt->resetArticleID( $oldid );
3290
3291                 # Recreate the redirect, this time in the other direction.
3292                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3293                         $mwRedir = MagicWord::get( 'redirect' );
3294                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3295                         $redirectArticle = new Article( $this );
3296                         $newid = $redirectArticle->insertOn( $dbw );
3297                         $redirectRevision = new Revision( array(
3298                                 'page'    => $newid,
3299                                 'comment' => $comment,
3300                                 'text'    => $redirectText ) );
3301                         $redirectRevision->insertOn( $dbw );
3302                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3303
3304                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3305
3306                         # Now, we record the link from the redirect to the new title.
3307                         # It should have no other outgoing links...
3308                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3309                         $dbw->insert( 'pagelinks',
3310                                 array(
3311                                         'pl_from'      => $newid,
3312                                         'pl_namespace' => $nt->getNamespace(),
3313                                         'pl_title'     => $nt->getDBkey() ),
3314                                 __METHOD__ );
3315                         $redirectSuppressed = false;
3316                 } else {
3317                         $this->resetArticleID( 0 );
3318                         $redirectSuppressed = true;
3319                 }
3320
3321                 # Log the move
3322                 $log = new LogPage( 'move' );
3323                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3324                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3325
3326                 # Purge caches for old and new titles
3327                 if ( $moveOverRedirect ) {
3328                         # A simple purge is enough when moving over a redirect
3329                         $nt->purgeSquid();
3330                 } else {
3331                         # Purge caches as per article creation, including any pages that link to this title
3332                         Article::onArticleCreate( $nt );
3333                 }
3334                 $this->purgeSquid();
3335         }
3336
3337         /**
3338          * Move this page's subpages to be subpages of $nt
3339          *
3340          * @param $nt Title Move target
3341          * @param $auth bool Whether $wgUser's permissions should be checked
3342          * @param $reason string The reason for the move
3343          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3344          *  Ignored if the user doesn't have the 'suppressredirect' right
3345          * @return mixed array with old page titles as keys, and strings (new page titles) or
3346          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3347          */
3348         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3349                 global $wgMaximumMovedPages;
3350                 // Check permissions
3351                 if ( !$this->userCan( 'move-subpages' ) ) {
3352                         return array( 'cant-move-subpages' );
3353                 }
3354                 // Do the source and target namespaces support subpages?
3355                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3356                         return array( 'namespace-nosubpages',
3357                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3358                 }
3359                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3360                         return array( 'namespace-nosubpages',
3361                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3362                 }
3363
3364                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3365                 $retval = array();
3366                 $count = 0;
3367                 foreach ( $subpages as $oldSubpage ) {
3368                         $count++;
3369                         if ( $count > $wgMaximumMovedPages ) {
3370                                 $retval[$oldSubpage->getPrefixedTitle()] =
3371                                                 array( 'movepage-max-pages',
3372                                                         $wgMaximumMovedPages );
3373                                 break;
3374                         }
3375
3376                         // We don't know whether this function was called before
3377                         // or after moving the root page, so check both
3378                         // $this and $nt
3379                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3380                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3381                         {
3382                                 // When moving a page to a subpage of itself,
3383                                 // don't move it twice
3384                                 continue;
3385                         }
3386                         $newPageName = preg_replace(
3387                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3388                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3389                                         $oldSubpage->getDBkey() );
3390                         if ( $oldSubpage->isTalkPage() ) {
3391                                 $newNs = $nt->getTalkPage()->getNamespace();
3392                         } else {
3393                                 $newNs = $nt->getSubjectPage()->getNamespace();
3394                         }
3395                         # Bug 14385: we need makeTitleSafe because the new page names may
3396                         # be longer than 255 characters.
3397                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3398
3399                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3400                         if ( $success === true ) {
3401                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3402                         } else {
3403                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3404                         }
3405                 }
3406                 return $retval;
3407         }
3408
3409         /**
3410          * Checks if this page is just a one-rev redirect.
3411          * Adds lock, so don't use just for light purposes.
3412          *
3413          * @return Bool
3414          */
3415         public function isSingleRevRedirect() {
3416                 $dbw = wfGetDB( DB_MASTER );
3417                 # Is it a redirect?
3418                 $row = $dbw->selectRow( 'page',
3419                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3420                         $this->pageCond(),
3421                         __METHOD__,
3422                         array( 'FOR UPDATE' )
3423                 );
3424                 # Cache some fields we may want
3425                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3426                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3427                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3428                 if ( !$this->mRedirect ) {
3429                         return false;
3430                 }
3431                 # Does the article have a history?
3432                 $row = $dbw->selectField( array( 'page', 'revision' ),
3433                         'rev_id',
3434                         array( 'page_namespace' => $this->getNamespace(),
3435                                 'page_title' => $this->getDBkey(),
3436                                 'page_id=rev_page',
3437                                 'page_latest != rev_id'
3438                         ),
3439                         __METHOD__,
3440                         array( 'FOR UPDATE' )
3441                 );
3442                 # Return true if there was no history
3443                 return ( $row === false );
3444         }
3445
3446         /**
3447          * Checks if $this can be moved to a given Title
3448          * - Selects for update, so don't call it unless you mean business
3449          *
3450          * @param $nt Title the new title to check
3451          * @return Bool TRUE or FALSE
3452          */
3453         public function isValidMoveTarget( $nt ) {
3454                 # Is it an existing file?
3455                 if ( $nt->getNamespace() == NS_FILE ) {
3456                         $file = wfLocalFile( $nt );
3457                         if ( $file->exists() ) {
3458                                 wfDebug( __METHOD__ . ": file exists\n" );
3459                                 return false;
3460                         }
3461                 }
3462                 # Is it a redirect with no history?
3463                 if ( !$nt->isSingleRevRedirect() ) {
3464                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3465                         return false;
3466                 }
3467                 # Get the article text
3468                 $rev = Revision::newFromTitle( $nt );
3469                 $text = $rev->getText();
3470                 # Does the redirect point to the source?
3471                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3472                 $m = array();
3473                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3474                         $redirTitle = Title::newFromText( $m[1] );
3475                         if ( !is_object( $redirTitle ) ||
3476                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3477                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3478                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3479                                 return false;
3480                         }
3481                 } else {
3482                         # Fail safe
3483                         wfDebug( __METHOD__ . ": failsafe\n" );
3484                         return false;
3485                 }
3486                 return true;
3487         }
3488
3489         /**
3490          * Can this title be added to a user's watchlist?
3491          *
3492          * @return Bool TRUE or FALSE
3493          */
3494         public function isWatchable() {
3495                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3496         }
3497
3498         /**
3499          * Get categories to which this Title belongs and return an array of
3500          * categories' names.
3501          *
3502          * @return Array of parents in the form:
3503          *      $parent => $currentarticle
3504          */
3505         public function getParentCategories() {
3506                 global $wgContLang;
3507
3508                 $titlekey = $this->getArticleId();
3509                 $dbr = wfGetDB( DB_SLAVE );
3510                 $categorylinks = $dbr->tableName( 'categorylinks' );
3511
3512                 # NEW SQL
3513                 $sql = "SELECT * FROM $categorylinks"
3514                      . " WHERE cl_from='$titlekey'"
3515                          . " AND cl_from <> '0'"
3516                          . " ORDER BY cl_sortkey";
3517
3518                 $res = $dbr->query( $sql );
3519                 $data = array();
3520
3521                 if ( $dbr->numRows( $res ) > 0 ) {
3522                         foreach ( $res as $row ) {
3523                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3524                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3525                         }
3526                 }
3527                 return $data;
3528         }
3529
3530         /**
3531          * Get a tree of parent categories
3532          *
3533          * @param $children Array with the children in the keys, to check for circular refs
3534          * @return Array Tree of parent categories
3535          */
3536         public function getParentCategoryTree( $children = array() ) {
3537                 $stack = array();
3538                 $parents = $this->getParentCategories();
3539
3540                 if ( $parents ) {
3541                         foreach ( $parents as $parent => $current ) {
3542                                 if ( array_key_exists( $parent, $children ) ) {
3543                                         # Circular reference
3544                                         $stack[$parent] = array();
3545                                 } else {
3546                                         $nt = Title::newFromText( $parent );
3547                                         if ( $nt ) {
3548                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3549                                         }
3550                                 }
3551                         }
3552                 }
3553
3554                 return $stack;
3555         }
3556
3557
3558         /**
3559          * Get an associative array for selecting this title from
3560          * the "page" table
3561          *
3562          * @return Array Selection array
3563          */
3564         public function pageCond() {
3565                 if ( $this->mArticleID > 0 ) {
3566                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3567                         return array( 'page_id' => $this->mArticleID );
3568                 } else {
3569                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3570                 }
3571         }
3572
3573         /**
3574          * Get the revision ID of the previous revision
3575          *
3576          * @param $revId Int Revision ID. Get the revision that was before this one.
3577          * @param $flags Int Title::GAID_FOR_UPDATE
3578          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3579          */
3580         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3581                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3582                 return $db->selectField( 'revision', 'rev_id',
3583                         array(
3584                                 'rev_page' => $this->getArticleId( $flags ),
3585                                 'rev_id < ' . intval( $revId )
3586                         ),
3587                         __METHOD__,
3588                         array( 'ORDER BY' => 'rev_id DESC' )
3589                 );
3590         }
3591
3592         /**
3593          * Get the revision ID of the next revision
3594          *
3595          * @param $revId Int Revision ID. Get the revision that was after this one.
3596          * @param $flags Int Title::GAID_FOR_UPDATE
3597          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3598          */
3599         public function getNextRevisionID( $revId, $flags = 0 ) {
3600                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3601                 return $db->selectField( 'revision', 'rev_id',
3602                         array(
3603                                 'rev_page' => $this->getArticleId( $flags ),
3604                                 'rev_id > ' . intval( $revId )
3605                         ),
3606                         __METHOD__,
3607                         array( 'ORDER BY' => 'rev_id' )
3608                 );
3609         }
3610
3611         /**
3612          * Get the first revision of the page
3613          *
3614          * @param $flags Int Title::GAID_FOR_UPDATE
3615          * @return Revision (or NULL if page doesn't exist)
3616          */
3617         public function getFirstRevision( $flags = 0 ) {
3618                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3619                 $pageId = $this->getArticleId( $flags );
3620                 if ( !$pageId ) {
3621                         return null;
3622                 }
3623                 $row = $db->selectRow( 'revision', '*',
3624                         array( 'rev_page' => $pageId ),
3625                         __METHOD__,
3626                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3627                 );
3628                 if ( !$row ) {
3629                         return null;
3630                 } else {
3631                         return new Revision( $row );
3632                 }
3633         }
3634
3635         /**
3636          * Check if this is a new page
3637          *
3638          * @return bool
3639          */
3640         public function isNewPage() {
3641                 $dbr = wfGetDB( DB_SLAVE );
3642                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3643         }
3644
3645         /**
3646          * Get the oldest revision timestamp of this page
3647          *
3648          * @return String: MW timestamp
3649          */
3650         public function getEarliestRevTime() {
3651                 $dbr = wfGetDB( DB_SLAVE );
3652                 if ( $this->exists() ) {
3653                         $min = $dbr->selectField( 'revision',
3654                                 'MIN(rev_timestamp)',
3655                                 array( 'rev_page' => $this->getArticleId() ),
3656                                 __METHOD__ );
3657                         return wfTimestampOrNull( TS_MW, $min );
3658                 }
3659                 return null;
3660         }
3661
3662         /**
3663          * Get the number of revisions between the given revision IDs.
3664          * Used for diffs and other things that really need it.
3665          *
3666          * @param $old Int Revision ID.
3667          * @param $new Int Revision ID.
3668          * @return Int Number of revisions between these IDs.
3669          */
3670         public function countRevisionsBetween( $old, $new ) {
3671                 $dbr = wfGetDB( DB_SLAVE );
3672                 return (int)$dbr->selectField( 'revision', 'count(*)', array(
3673                                 'rev_page' => intval( $this->getArticleId() ),
3674                                 'rev_id > ' . intval( $old ),
3675                                 'rev_id < ' . intval( $new )
3676                         ), __METHOD__
3677                 );
3678         }
3679
3680         /**
3681          * Get the number of authors between the given revision IDs.
3682          * Used for diffs and other things that really need it.
3683          *
3684          * @param $fromRevId Int Revision ID (first before range)
3685          * @param $toRevId Int Revision ID (first after range)
3686          * @param $limit Int Maximum number of authors
3687          * @param $flags Int Title::GAID_FOR_UPDATE
3688          * @return Int
3689          */
3690         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3691                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3692                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3693                         array(
3694                                 'rev_page' => $this->getArticleID(),
3695                                 'rev_id > ' . (int)$fromRevId,
3696                                 'rev_id < ' . (int)$toRevId
3697                         ), __METHOD__,
3698                         array( 'LIMIT' => $limit )
3699                 );
3700                 return (int)$db->numRows( $res );
3701         }
3702
3703         /**
3704          * Compare with another title.
3705          *
3706          * @param $title Title
3707          * @return Bool TRUE or FALSE
3708          */
3709         public function equals( Title $title ) {
3710                 // Note: === is necessary for proper matching of number-like titles.
3711                 return $this->getInterwiki() === $title->getInterwiki()
3712                         && $this->getNamespace() == $title->getNamespace()
3713                         && $this->getDBkey() === $title->getDBkey();
3714         }
3715
3716         /**
3717          * Callback for usort() to do title sorts by (namespace, title)
3718          *
3719          * @return Integer: result of string comparison, or namespace comparison
3720          */
3721         public static function compare( $a, $b ) {
3722                 if ( $a->getNamespace() == $b->getNamespace() ) {
3723                         return strcmp( $a->getText(), $b->getText() );
3724                 } else {
3725                         return $a->getNamespace() - $b->getNamespace();
3726                 }
3727         }
3728
3729         /**
3730          * Return a string representation of this title
3731          *
3732          * @return String String representation of this title
3733          */
3734         public function __toString() {
3735                 return $this->getPrefixedText();
3736         }
3737
3738         /**
3739          * Check if page exists.  For historical reasons, this function simply
3740          * checks for the existence of the title in the page table, and will
3741          * thus return false for interwiki links, special pages and the like.
3742          * If you want to know if a title can be meaningfully viewed, you should
3743          * probably call the isKnown() method instead.
3744          *
3745          * @return Bool
3746          */
3747         public function exists() {
3748                 return $this->getArticleId() != 0;
3749         }
3750
3751         /**
3752          * Should links to this title be shown as potentially viewable (i.e. as
3753          * "bluelinks"), even if there's no record by this title in the page
3754          * table?
3755          *
3756          * This function is semi-deprecated for public use, as well as somewhat
3757          * misleadingly named.  You probably just want to call isKnown(), which
3758          * calls this function internally.
3759          *
3760          * (ISSUE: Most of these checks are cheap, but the file existence check
3761          * can potentially be quite expensive.  Including it here fixes a lot of
3762          * existing code, but we might want to add an optional parameter to skip
3763          * it and any other expensive checks.)
3764          *
3765          * @return Bool
3766          */
3767         public function isAlwaysKnown() {
3768                 if ( $this->mInterwiki != '' ) {
3769                         return true;  // any interwiki link might be viewable, for all we know
3770                 }
3771                 switch( $this->mNamespace ) {
3772                         case NS_MEDIA:
3773                         case NS_FILE:
3774                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3775                         case NS_SPECIAL:
3776                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3777                         case NS_MAIN:
3778                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3779                         case NS_MEDIAWIKI:
3780                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3781                                 // the full l10n of that language to be loaded. That takes much memory and
3782                                 // isn't needed. So we strip the language part away.
3783                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3784                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3785                         default:
3786                                 return false;
3787                 }
3788         }
3789
3790         /**
3791          * Does this title refer to a page that can (or might) be meaningfully
3792          * viewed?  In particular, this function may be used to determine if
3793          * links to the title should be rendered as "bluelinks" (as opposed to
3794          * "redlinks" to non-existent pages).
3795          *
3796          * @return Bool
3797          */
3798         public function isKnown() {
3799                 return $this->isAlwaysKnown() || $this->exists();
3800         }
3801
3802         /**
3803          * Does this page have source text?
3804          *
3805          * @return Boolean
3806          */
3807         public function hasSourceText() {
3808                 if ( $this->exists() ) {
3809                         return true;
3810                 }
3811
3812                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3813                         // If the page doesn't exist but is a known system message, default
3814                         // message content will be displayed, same for language subpages
3815                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3816                         // causes the full l10n of that language to be loaded. That takes much
3817                         // memory and isn't needed. So we strip the language part away.
3818                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3819                         return (bool)wfMsgWeirdKey( $basename );
3820                 }
3821
3822                 return false;
3823         }
3824
3825         /**
3826          * Is this in a namespace that allows actual pages?
3827          *
3828          * @return Bool
3829          * @internal note -- uses hardcoded namespace index instead of constants
3830          */
3831         public function canExist() {
3832                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3833         }
3834
3835         /**
3836          * Update page_touched timestamps and send squid purge messages for
3837          * pages linking to this title. May be sent to the job queue depending
3838          * on the number of links. Typically called on create and delete.
3839          */
3840         public function touchLinks() {
3841                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3842                 $u->doUpdate();
3843
3844                 if ( $this->getNamespace() == NS_CATEGORY ) {
3845                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3846                         $u->doUpdate();
3847                 }
3848         }
3849
3850         /**
3851          * Get the last touched timestamp
3852          *
3853          * @param $db DatabaseBase: optional db
3854          * @return String Last touched timestamp
3855          */
3856         public function getTouched( $db = null ) {
3857                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3858                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3859                 return $touched;
3860         }
3861
3862         /**
3863          * Get the timestamp when this page was updated since the user last saw it.
3864          *
3865          * @param $user User
3866          * @return Mixed: string/null
3867          */
3868         public function getNotificationTimestamp( $user = null ) {
3869                 global $wgUser, $wgShowUpdatedMarker;
3870                 // Assume current user if none given
3871                 if ( !$user ) {
3872                         $user = $wgUser;
3873                 }
3874                 // Check cache first
3875                 $uid = $user->getId();
3876                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3877                         return $this->mNotificationTimestamp[$uid];
3878                 }
3879                 if ( !$uid || !$wgShowUpdatedMarker ) {
3880                         return $this->mNotificationTimestamp[$uid] = false;
3881                 }
3882                 // Don't cache too much!
3883                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3884                         $this->mNotificationTimestamp = array();
3885                 }
3886                 $dbr = wfGetDB( DB_SLAVE );
3887                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3888                         'wl_notificationtimestamp',
3889                         array( 'wl_namespace' => $this->getNamespace(),
3890                                 'wl_title' => $this->getDBkey(),
3891                                 'wl_user' => $user->getId()
3892                         ),
3893                         __METHOD__
3894                 );
3895                 return $this->mNotificationTimestamp[$uid];
3896         }
3897
3898         /**
3899          * Get the trackback URL for this page
3900          *
3901          * @return String Trackback URL
3902          */
3903         public function trackbackURL() {
3904                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3905
3906                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3907                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3908         }
3909
3910         /**
3911          * Get the trackback RDF for this page
3912          *
3913          * @return String Trackback RDF
3914          */
3915         public function trackbackRDF() {
3916                 $url = htmlspecialchars( $this->getFullURL() );
3917                 $title = htmlspecialchars( $this->getText() );
3918                 $tburl = $this->trackbackURL();
3919
3920                 // Autodiscovery RDF is placed in comments so HTML validator
3921                 // won't barf. This is a rather icky workaround, but seems
3922                 // frequently used by this kind of RDF thingy.
3923                 //
3924                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3925                 return "<!--
3926 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3927          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3928          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3929 <rdf:Description
3930    rdf:about=\"$url\"
3931    dc:identifier=\"$url\"
3932    dc:title=\"$title\"
3933    trackback:ping=\"$tburl\" />
3934 </rdf:RDF>
3935 -->";
3936         }
3937
3938         /**
3939          * Generate strings used for xml 'id' names in monobook tabs
3940          *
3941          * @param $prepend string defaults to 'nstab-'
3942          * @return String XML 'id' name
3943          */
3944         public function getNamespaceKey( $prepend = 'nstab-' ) {
3945                 global $wgContLang;
3946                 // Gets the subject namespace if this title
3947                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3948                 // Checks if cononical namespace name exists for namespace
3949                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3950                         // Uses canonical namespace name
3951                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3952                 } else {
3953                         // Uses text of namespace
3954                         $namespaceKey = $this->getSubjectNsText();
3955                 }
3956                 // Makes namespace key lowercase
3957                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3958                 // Uses main
3959                 if ( $namespaceKey == '' ) {
3960                         $namespaceKey = 'main';
3961                 }
3962                 // Changes file to image for backwards compatibility
3963                 if ( $namespaceKey == 'file' ) {
3964                         $namespaceKey = 'image';
3965                 }
3966                 return $prepend . $namespaceKey;
3967         }
3968
3969         /**
3970          * Returns true if this is a special page.
3971          *
3972          * @return boolean
3973          */
3974         public function isSpecialPage() {
3975                 return $this->getNamespace() == NS_SPECIAL;
3976         }
3977
3978         /**
3979          * Returns true if this title resolves to the named special page
3980          *
3981          * @param $name String The special page name
3982          * @return boolean
3983          */
3984         public function isSpecial( $name ) {
3985                 if ( $this->getNamespace() == NS_SPECIAL ) {
3986                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3987                         if ( $name == $thisName ) {
3988                                 return true;
3989                         }
3990                 }
3991                 return false;
3992         }
3993
3994         /**
3995          * If the Title refers to a special page alias which is not the local default,
3996          *
3997          * @return Title A new Title which points to the local default.
3998          *         Otherwise, returns $this.
3999          */
4000         public function fixSpecialName() {
4001                 if ( $this->getNamespace() == NS_SPECIAL ) {
4002                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4003                         if ( $canonicalName ) {
4004                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4005                                 if ( $localName != $this->mDbkeyform ) {
4006                                         return Title::makeTitle( NS_SPECIAL, $localName );
4007                                 }
4008                         }
4009                 }
4010                 return $this;
4011         }
4012
4013         /**
4014          * Is this Title in a namespace which contains content?
4015          * In other words, is this a content page, for the purposes of calculating
4016          * statistics, etc?
4017          *
4018          * @return Boolean
4019          */
4020         public function isContentPage() {
4021                 return MWNamespace::isContent( $this->getNamespace() );
4022         }
4023
4024         /**
4025          * Get all extant redirects to this Title
4026          *
4027          * @param $ns Int|Null Single namespace to consider;
4028          *            NULL to consider all namespaces
4029          * @return Array of Title redirects to this title
4030          */
4031         public function getRedirectsHere( $ns = null ) {
4032                 $redirs = array();
4033
4034                 $dbr = wfGetDB( DB_SLAVE );
4035                 $where = array(
4036                         'rd_namespace' => $this->getNamespace(),
4037                         'rd_title' => $this->getDBkey(),
4038                         'rd_from = page_id'
4039                 );
4040                 if ( !is_null( $ns ) ) {
4041                         $where['page_namespace'] = $ns;
4042                 }
4043
4044                 $res = $dbr->select(
4045                         array( 'redirect', 'page' ),
4046                         array( 'page_namespace', 'page_title' ),
4047                         $where,
4048                         __METHOD__
4049                 );
4050
4051                 foreach ( $res as $row ) {
4052                         $redirs[] = self::newFromRow( $row );
4053                 }
4054                 return $redirs;
4055         }
4056
4057         /**
4058          * Check if this Title is a valid redirect target
4059          *
4060          * @return Bool
4061          */
4062         public function isValidRedirectTarget() {
4063                 global $wgInvalidRedirectTargets;
4064
4065                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4066                 if ( $this->isSpecial( 'Userlogout' ) ) {
4067                         return false;
4068                 }
4069
4070                 foreach ( $wgInvalidRedirectTargets as $target ) {
4071                         if ( $this->isSpecial( $target ) ) {
4072                                 return false;
4073                         }
4074                 }
4075
4076                 return true;
4077         }
4078
4079         /**
4080          * Get a backlink cache object
4081          *
4082          * @return object BacklinkCache
4083          */
4084         function getBacklinkCache() {
4085                 if ( is_null( $this->mBacklinkCache ) ) {
4086                         $this->mBacklinkCache = new BacklinkCache( $this );
4087                 }
4088                 return $this->mBacklinkCache;
4089         }
4090
4091         /**
4092          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4093          * this page.
4094          *
4095          * @return Boolean
4096          */
4097         public function canUseNoindex() {
4098                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4099
4100                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4101                         ? $wgContentNamespaces
4102                         : $wgExemptFromUserRobotsControl;
4103
4104                 return !in_array( $this->mNamespace, $bannedNamespaces );
4105
4106         }
4107
4108         /**
4109          * Returns restriction types for the current Title
4110          *
4111          * @return array applicable restriction types
4112          */
4113         public function getRestrictionTypes() {
4114                 global $wgRestrictionTypes;
4115
4116                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4117
4118                 if ( $this->getNamespace() != NS_FILE ) {
4119                         $types = array_diff( $types, array( 'upload' ) );
4120                 }
4121
4122                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4123
4124                 return $types;
4125         }
4126
4127         /**
4128          * Returns the raw sort key to be used for categories, with the specified
4129          * prefix.  This will be fed to Language::convertToSortkey() to get a
4130          * binary sortkey that can be used for actual sorting.
4131          *
4132          * @param $prefix string The prefix to be used, specified using
4133          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4134          *   prefix.
4135          * @return string
4136          */
4137         public function getCategorySortkey( $prefix = '' ) {
4138                 $unprefixed = $this->getText();
4139                 if ( $prefix !== '' ) {
4140                         # Separate with a null byte, so the unprefixed part is only used as
4141                         # a tiebreaker when two pages have the exact same prefix -- null
4142                         # sorts before everything else (hopefully).
4143                         return "$prefix\0$unprefixed";
4144                 }
4145                 return $unprefixed;
4146         }
4147 }