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 the mainpage?
1858          * @note Title::newFromText seams to be sufficiently optimized by the title
1859          * cache that we don't need to over-optimize by doing direct comparisons and
1860          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1861          * ends up reporting something differently than $title->isMainPage();
1862          *
1863          * @return Bool
1864          */
1865         public function isMainPage() {
1866                 return $this->equals( Title::newMainPage() );
1867         }
1868
1869         /**
1870          * Is this a talk page of some sort?
1871          *
1872          * @return Bool
1873          */
1874         public function isTalkPage() {
1875                 return MWNamespace::isTalk( $this->getNamespace() );
1876         }
1877
1878         /**
1879          * Is this a subpage?
1880          *
1881          * @return Bool
1882          */
1883         public function isSubpage() {
1884                 return MWNamespace::hasSubpages( $this->mNamespace )
1885                         ? strpos( $this->getText(), '/' ) !== false
1886                         : false;
1887         }
1888
1889         /**
1890          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1891          *
1892          * @return Bool
1893          */
1894         public function hasSubpages() {
1895                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1896                         # Duh
1897                         return false;
1898                 }
1899
1900                 # We dynamically add a member variable for the purpose of this method
1901                 # alone to cache the result.  There's no point in having it hanging
1902                 # around uninitialized in every Title object; therefore we only add it
1903                 # if needed and don't declare it statically.
1904                 if ( isset( $this->mHasSubpages ) ) {
1905                         return $this->mHasSubpages;
1906                 }
1907
1908                 $subpages = $this->getSubpages( 1 );
1909                 if ( $subpages instanceof TitleArray ) {
1910                         return $this->mHasSubpages = (bool)$subpages->count();
1911                 }
1912                 return $this->mHasSubpages = false;
1913         }
1914
1915         /**
1916          * Get all subpages of this page.
1917          *
1918          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1919          * @return mixed TitleArray, or empty array if this page's namespace
1920          *  doesn't allow subpages
1921          */
1922         public function getSubpages( $limit = -1 ) {
1923                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1924                         return array();
1925                 }
1926
1927                 $dbr = wfGetDB( DB_SLAVE );
1928                 $conds['page_namespace'] = $this->getNamespace();
1929                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1930                 $options = array();
1931                 if ( $limit > -1 ) {
1932                         $options['LIMIT'] = $limit;
1933                 }
1934                 return $this->mSubpages = TitleArray::newFromResult(
1935                         $dbr->select( 'page',
1936                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1937                                 $conds,
1938                                 __METHOD__,
1939                                 $options
1940                         )
1941                 );
1942         }
1943
1944         /**
1945          * Could this page contain custom CSS or JavaScript, based
1946          * on the title?
1947          *
1948          * @return Bool
1949          */
1950         public function isCssOrJsPage() {
1951                 return $this->mNamespace == NS_MEDIAWIKI
1952                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1953         }
1954
1955         /**
1956          * Is this a .css or .js subpage of a user page?
1957          * @return Bool
1958          */
1959         public function isCssJsSubpage() {
1960                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1961         }
1962
1963         /**
1964          * Is this a *valid* .css or .js subpage of a user page?
1965          *
1966          * @return Bool
1967          * @deprecated
1968          */
1969         public function isValidCssJsSubpage() {
1970                 return $this->isCssJsSubpage();
1971         }
1972
1973         /**
1974          * Trim down a .css or .js subpage title to get the corresponding skin name
1975          *
1976          * @return string containing skin name from .css or .js subpage title
1977          */
1978         public function getSkinFromCssJsSubpage() {
1979                 $subpage = explode( '/', $this->mTextform );
1980                 $subpage = $subpage[ count( $subpage ) - 1 ];
1981                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1982         }
1983
1984         /**
1985          * Is this a .css subpage of a user page?
1986          *
1987          * @return Bool
1988          */
1989         public function isCssSubpage() {
1990                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1991         }
1992
1993         /**
1994          * Is this a .js subpage of a user page?
1995          *
1996          * @return Bool
1997          */
1998         public function isJsSubpage() {
1999                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2000         }
2001
2002         /**
2003          * Protect css 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 userCanEditCssSubpage() {
2010                 global $wgUser;
2011                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
2012                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2013         }
2014
2015         /**
2016          * Protect js subpages of user pages: can $wgUser edit
2017          * this page?
2018          *
2019          * @return Bool
2020          * @todo XXX: this might be better using restrictions
2021          */
2022         public function userCanEditJsSubpage() {
2023                 global $wgUser;
2024                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
2025                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2026         }
2027
2028         /**
2029          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2030          *
2031          * @return Bool If the page is subject to cascading restrictions.
2032          */
2033         public function isCascadeProtected() {
2034                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2035                 return ( $sources > 0 );
2036         }
2037
2038         /**
2039          * Cascading protection: Get the source of any cascading restrictions on this page.
2040          *
2041          * @param $getPages Bool Whether or not to retrieve the actual pages
2042          *        that the restrictions have come from.
2043          * @return Mixed Array of the Title
2044          *         objects of the pages from which cascading restrictions have come,
2045          *         false for none, or true if such restrictions exist, but $getPages was not set.
2046          *         The restriction array is an array of each type, each of which contains a
2047          *         array of unique groups.
2048          */
2049         public function getCascadeProtectionSources( $getPages = true ) {
2050                 $pagerestrictions = array();
2051
2052                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2053                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2054                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2055                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2056                 }
2057
2058                 wfProfileIn( __METHOD__ );
2059
2060                 $dbr = wfGetDB( DB_SLAVE );
2061
2062                 if ( $this->getNamespace() == NS_FILE ) {
2063                         $tables = array( 'imagelinks', 'page_restrictions' );
2064                         $where_clauses = array(
2065                                 'il_to' => $this->getDBkey(),
2066                                 'il_from=pr_page',
2067                                 'pr_cascade' => 1
2068                         );
2069                 } else {
2070                         $tables = array( 'templatelinks', 'page_restrictions' );
2071                         $where_clauses = array(
2072                                 'tl_namespace' => $this->getNamespace(),
2073                                 'tl_title' => $this->getDBkey(),
2074                                 'tl_from=pr_page',
2075                                 'pr_cascade' => 1
2076                         );
2077                 }
2078
2079                 if ( $getPages ) {
2080                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2081                                                    'pr_expiry', 'pr_type', 'pr_level' );
2082                         $where_clauses[] = 'page_id=pr_page';
2083                         $tables[] = 'page';
2084                 } else {
2085                         $cols = array( 'pr_expiry' );
2086                 }
2087
2088                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2089
2090                 $sources = $getPages ? array() : false;
2091                 $now = wfTimestampNow();
2092                 $purgeExpired = false;
2093
2094                 foreach ( $res as $row ) {
2095                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2096                         if ( $expiry > $now ) {
2097                                 if ( $getPages ) {
2098                                         $page_id = $row->pr_page;
2099                                         $page_ns = $row->page_namespace;
2100                                         $page_title = $row->page_title;
2101                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2102                                         # Add groups needed for each restriction type if its not already there
2103                                         # Make sure this restriction type still exists
2104
2105                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2106                                                 $pagerestrictions[$row->pr_type] = array();
2107                                         }
2108
2109                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2110                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2111                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2112                                         }
2113                                 } else {
2114                                         $sources = true;
2115                                 }
2116                         } else {
2117                                 // Trigger lazy purge of expired restrictions from the db
2118                                 $purgeExpired = true;
2119                         }
2120                 }
2121                 if ( $purgeExpired ) {
2122                         Title::purgeExpiredRestrictions();
2123                 }
2124
2125                 wfProfileOut( __METHOD__ );
2126
2127                 if ( $getPages ) {
2128                         $this->mCascadeSources = $sources;
2129                         $this->mCascadingRestrictions = $pagerestrictions;
2130                 } else {
2131                         $this->mHasCascadingRestrictions = $sources;
2132                 }
2133
2134                 return array( $sources, $pagerestrictions );
2135         }
2136
2137         /**
2138          * Returns cascading restrictions for the current article
2139          *
2140          * @return Boolean
2141          */
2142         function areRestrictionsCascading() {
2143                 if ( !$this->mRestrictionsLoaded ) {
2144                         $this->loadRestrictions();
2145                 }
2146
2147                 return $this->mCascadeRestriction;
2148         }
2149
2150         /**
2151          * Loads a string into mRestrictions array
2152          *
2153          * @param $res Resource restrictions as an SQL result.
2154          * @param $oldFashionedRestrictions string comma-separated list of page
2155          *        restrictions from page table (pre 1.10)
2156          */
2157         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2158                 $rows = array();
2159
2160                 foreach ( $res as $row ) {
2161                         $rows[] = $row;
2162                 }
2163
2164                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2165         }
2166
2167         /**
2168          * Compiles list of active page restrictions from both page table (pre 1.10)
2169          * and page_restrictions table for this existing page.
2170          * Public for usage by LiquidThreads.
2171          *
2172          * @param $rows array of db result objects
2173          * @param $oldFashionedRestrictions string comma-separated list of page
2174          *        restrictions from page table (pre 1.10)
2175          */
2176         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2177                 $dbr = wfGetDB( DB_SLAVE );
2178
2179                 $restrictionTypes = $this->getRestrictionTypes();
2180
2181                 foreach ( $restrictionTypes as $type ) {
2182                         $this->mRestrictions[$type] = array();
2183                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2184                 }
2185
2186                 $this->mCascadeRestriction = false;
2187
2188                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2189
2190                 if ( $oldFashionedRestrictions === null ) {
2191                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2192                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2193                 }
2194
2195                 if ( $oldFashionedRestrictions != '' ) {
2196
2197                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2198                                 $temp = explode( '=', trim( $restrict ) );
2199                                 if ( count( $temp ) == 1 ) {
2200                                         // old old format should be treated as edit/move restriction
2201                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2202                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2203                                 } else {
2204                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2205                                 }
2206                         }
2207
2208                         $this->mOldRestrictions = true;
2209
2210                 }
2211
2212                 if ( count( $rows ) ) {
2213                         # Current system - load second to make them override.
2214                         $now = wfTimestampNow();
2215                         $purgeExpired = false;
2216
2217                         foreach ( $rows as $row ) {
2218                                 # Cycle through all the restrictions.
2219
2220                                 // Don't take care of restrictions types that aren't allowed
2221
2222                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2223                                         continue;
2224
2225                                 // This code should be refactored, now that it's being used more generally,
2226                                 // But I don't really see any harm in leaving it in Block for now -werdna
2227                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2228
2229                                 // Only apply the restrictions if they haven't expired!
2230                                 if ( !$expiry || $expiry > $now ) {
2231                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2232                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2233
2234                                         $this->mCascadeRestriction |= $row->pr_cascade;
2235                                 } else {
2236                                         // Trigger a lazy purge of expired restrictions
2237                                         $purgeExpired = true;
2238                                 }
2239                         }
2240
2241                         if ( $purgeExpired ) {
2242                                 Title::purgeExpiredRestrictions();
2243                         }
2244                 }
2245
2246                 $this->mRestrictionsLoaded = true;
2247         }
2248
2249         /**
2250          * Load restrictions from the page_restrictions table
2251          *
2252          * @param $oldFashionedRestrictions string comma-separated list of page
2253          *        restrictions from page table (pre 1.10)
2254          */
2255         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2256                 if ( !$this->mRestrictionsLoaded ) {
2257                         if ( $this->exists() ) {
2258                                 $dbr = wfGetDB( DB_SLAVE );
2259
2260                                 $res = $dbr->select( 'page_restrictions', '*',
2261                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2262
2263                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2264                         } else {
2265                                 $title_protection = $this->getTitleProtection();
2266
2267                                 if ( $title_protection ) {
2268                                         $now = wfTimestampNow();
2269                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2270
2271                                         if ( !$expiry || $expiry > $now ) {
2272                                                 // Apply the restrictions
2273                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2274                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2275                                         } else { // Get rid of the old restrictions
2276                                                 Title::purgeExpiredRestrictions();
2277                                                 $this->mTitleProtection = false;
2278                                         }
2279                                 } else {
2280                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2281                                 }
2282                                 $this->mRestrictionsLoaded = true;
2283                         }
2284                 }
2285         }
2286
2287         /**
2288          * Purge expired restrictions from the page_restrictions table
2289          */
2290         static function purgeExpiredRestrictions() {
2291                 $dbw = wfGetDB( DB_MASTER );
2292                 $dbw->delete(
2293                         'page_restrictions',
2294                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2295                         __METHOD__
2296                 );
2297
2298                 $dbw->delete(
2299                         'protected_titles',
2300                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2301                         __METHOD__
2302                 );
2303         }
2304
2305         /**
2306          * Accessor/initialisation for mRestrictions
2307          *
2308          * @param $action String action that permission needs to be checked for
2309          * @return Array of Strings the array of groups allowed to edit this article
2310          */
2311         public function getRestrictions( $action ) {
2312                 if ( !$this->mRestrictionsLoaded ) {
2313                         $this->loadRestrictions();
2314                 }
2315                 return isset( $this->mRestrictions[$action] )
2316                                 ? $this->mRestrictions[$action]
2317                                 : array();
2318         }
2319
2320         /**
2321          * Get the expiry time for the restriction against a given action
2322          *
2323          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2324          *      or not protected at all, or false if the action is not recognised.
2325          */
2326         public function getRestrictionExpiry( $action ) {
2327                 if ( !$this->mRestrictionsLoaded ) {
2328                         $this->loadRestrictions();
2329                 }
2330                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2331         }
2332
2333         /**
2334          * Is there a version of this page in the deletion archive?
2335          *
2336          * @return Int the number of archived revisions
2337          */
2338         public function isDeleted() {
2339                 if ( $this->getNamespace() < 0 ) {
2340                         $n = 0;
2341                 } else {
2342                         $dbr = wfGetDB( DB_SLAVE );
2343                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2344                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2345                                 __METHOD__
2346                         );
2347                         if ( $this->getNamespace() == NS_FILE ) {
2348                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2349                                         array( 'fa_name' => $this->getDBkey() ),
2350                                         __METHOD__
2351                                 );
2352                         }
2353                 }
2354                 return (int)$n;
2355         }
2356
2357         /**
2358          * Is there a version of this page in the deletion archive?
2359          *
2360          * @return Boolean
2361          */
2362         public function isDeletedQuick() {
2363                 if ( $this->getNamespace() < 0 ) {
2364                         return false;
2365                 }
2366                 $dbr = wfGetDB( DB_SLAVE );
2367                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2368                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2369                         __METHOD__
2370                 );
2371                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2372                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2373                                 array( 'fa_name' => $this->getDBkey() ),
2374                                 __METHOD__
2375                         );
2376                 }
2377                 return $deleted;
2378         }
2379
2380         /**
2381          * Get the article ID for this Title from the link cache,
2382          * adding it if necessary
2383          *
2384          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2385          *  for update
2386          * @return Int the ID
2387          */
2388         public function getArticleID( $flags = 0 ) {
2389                 if ( $this->getNamespace() < 0 ) {
2390                         return $this->mArticleID = 0;
2391                 }
2392                 $linkCache = LinkCache::singleton();
2393                 if ( $flags & self::GAID_FOR_UPDATE ) {
2394                         $oldUpdate = $linkCache->forUpdate( true );
2395                         $linkCache->clearLink( $this );
2396                         $this->mArticleID = $linkCache->addLinkObj( $this );
2397                         $linkCache->forUpdate( $oldUpdate );
2398                 } else {
2399                         if ( -1 == $this->mArticleID ) {
2400                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2401                         }
2402                 }
2403                 return $this->mArticleID;
2404         }
2405
2406         /**
2407          * Is this an article that is a redirect page?
2408          * Uses link cache, adding it if necessary
2409          *
2410          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2411          * @return Bool
2412          */
2413         public function isRedirect( $flags = 0 ) {
2414                 if ( !is_null( $this->mRedirect ) ) {
2415                         return $this->mRedirect;
2416                 }
2417                 # Calling getArticleID() loads the field from cache as needed
2418                 if ( !$this->getArticleID( $flags ) ) {
2419                         return $this->mRedirect = false;
2420                 }
2421                 $linkCache = LinkCache::singleton();
2422                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2423
2424                 return $this->mRedirect;
2425         }
2426
2427         /**
2428          * What is the length of this page?
2429          * Uses link cache, adding it if necessary
2430          *
2431          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2432          * @return Int
2433          */
2434         public function getLength( $flags = 0 ) {
2435                 if ( $this->mLength != -1 ) {
2436                         return $this->mLength;
2437                 }
2438                 # Calling getArticleID() loads the field from cache as needed
2439                 if ( !$this->getArticleID( $flags ) ) {
2440                         return $this->mLength = 0;
2441                 }
2442                 $linkCache = LinkCache::singleton();
2443                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2444
2445                 return $this->mLength;
2446         }
2447
2448         /**
2449          * What is the page_latest field for this page?
2450          *
2451          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2452          * @return Int or 0 if the page doesn't exist
2453          */
2454         public function getLatestRevID( $flags = 0 ) {
2455                 if ( $this->mLatestID !== false ) {
2456                         return intval( $this->mLatestID );
2457                 }
2458                 # Calling getArticleID() loads the field from cache as needed
2459                 if ( !$this->getArticleID( $flags ) ) {
2460                         return $this->mLatestID = 0;
2461                 }
2462                 $linkCache = LinkCache::singleton();
2463                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2464
2465                 return $this->mLatestID;
2466         }
2467
2468         /**
2469          * This clears some fields in this object, and clears any associated
2470          * keys in the "bad links" section of the link cache.
2471          *
2472          * - This is called from Article::doEdit() and Article::insertOn() to allow
2473          * loading of the new page_id. It's also called from
2474          * Article::doDeleteArticle()
2475          *
2476          * @param $newid Int the new Article ID
2477          */
2478         public function resetArticleID( $newid ) {
2479                 $linkCache = LinkCache::singleton();
2480                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2481
2482                 if ( $newid === false ) {
2483                         $this->mArticleID = -1;
2484                 } else {
2485                         $this->mArticleID = intval( $newid );
2486                 }
2487                 $this->mRestrictionsLoaded = false;
2488                 $this->mRestrictions = array();
2489                 $this->mRedirect = null;
2490                 $this->mLength = -1;
2491                 $this->mLatestID = false;
2492         }
2493
2494         /**
2495          * Updates page_touched for this page; called from LinksUpdate.php
2496          *
2497          * @return Bool true if the update succeded
2498          */
2499         public function invalidateCache() {
2500                 if ( wfReadOnly() ) {
2501                         return;
2502                 }
2503                 $dbw = wfGetDB( DB_MASTER );
2504                 $success = $dbw->update(
2505                         'page',
2506                         array( 'page_touched' => $dbw->timestamp() ),
2507                         $this->pageCond(),
2508                         __METHOD__
2509                 );
2510                 HTMLFileCache::clearFileCache( $this );
2511                 return $success;
2512         }
2513
2514         /**
2515          * Prefix some arbitrary text with the namespace or interwiki prefix
2516          * of this object
2517          *
2518          * @param $name String the text
2519          * @return String the prefixed text
2520          * @private
2521          */
2522         /* private */ function prefix( $name ) {
2523                 $p = '';
2524                 if ( $this->mInterwiki != '' ) {
2525                         $p = $this->mInterwiki . ':';
2526                 }
2527                 if ( 0 != $this->mNamespace ) {
2528                         $p .= $this->getNsText() . ':';
2529                 }
2530                 return $p . $name;
2531         }
2532
2533         /**
2534          * Returns a simple regex that will match on characters and sequences invalid in titles.
2535          * Note that this doesn't pick up many things that could be wrong with titles, but that
2536          * replacing this regex with something valid will make many titles valid.
2537          *
2538          * @return string regex string
2539          */
2540         static function getTitleInvalidRegex() {
2541                 static $rxTc = false;
2542                 if ( !$rxTc ) {
2543                         # Matching titles will be held as illegal.
2544                         $rxTc = '/' .
2545                                 # Any character not allowed is forbidden...
2546                                 '[^' . Title::legalChars() . ']' .
2547                                 # URL percent encoding sequences interfere with the ability
2548                                 # to round-trip titles -- you can't link to them consistently.
2549                                 '|%[0-9A-Fa-f]{2}' .
2550                                 # XML/HTML character references produce similar issues.
2551                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2552                                 '|&#[0-9]+;' .
2553                                 '|&#x[0-9A-Fa-f]+;' .
2554                                 '/S';
2555                 }
2556
2557                 return $rxTc;
2558         }
2559
2560         /**
2561          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2562          *
2563          * @param $text string containing title to capitalize
2564          * @param $ns int namespace index, defaults to NS_MAIN
2565          * @return String containing capitalized title
2566          */
2567         public static function capitalize( $text, $ns = NS_MAIN ) {
2568                 global $wgContLang;
2569
2570                 if ( MWNamespace::isCapitalized( $ns ) ) {
2571                         return $wgContLang->ucfirst( $text );
2572                 } else {
2573                         return $text;
2574                 }
2575         }
2576
2577         /**
2578          * Secure and split - main initialisation function for this object
2579          *
2580          * Assumes that mDbkeyform has been set, and is urldecoded
2581          * and uses underscores, but not otherwise munged.  This function
2582          * removes illegal characters, splits off the interwiki and
2583          * namespace prefixes, sets the other forms, and canonicalizes
2584          * everything.
2585          *
2586          * @return Bool true on success
2587          */
2588         private function secureAndSplit() {
2589                 global $wgContLang, $wgLocalInterwiki;
2590
2591                 # Initialisation
2592                 $rxTc = self::getTitleInvalidRegex();
2593
2594                 $this->mInterwiki = $this->mFragment = '';
2595                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2596
2597                 $dbkey = $this->mDbkeyform;
2598
2599                 # Strip Unicode bidi override characters.
2600                 # Sometimes they slip into cut-n-pasted page titles, where the
2601                 # override chars get included in list displays.
2602                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2603
2604                 # Clean up whitespace
2605                 # Note: use of the /u option on preg_replace here will cause
2606                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2607                 # conveniently disabling them.
2608                 #
2609                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2610                 $dbkey = trim( $dbkey, '_' );
2611
2612                 if ( $dbkey == '' ) {
2613                         return false;
2614                 }
2615
2616                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2617                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2618                         return false;
2619                 }
2620
2621                 $this->mDbkeyform = $dbkey;
2622
2623                 # Initial colon indicates main namespace rather than specified default
2624                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2625                 if ( ':' == $dbkey { 0 } ) {
2626                         $this->mNamespace = NS_MAIN;
2627                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2628                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2629                 }
2630
2631                 # Namespace or interwiki prefix
2632                 $firstPass = true;
2633                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2634                 do {
2635                         $m = array();
2636                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2637                                 $p = $m[1];
2638                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2639                                         # Ordinary namespace
2640                                         $dbkey = $m[2];
2641                                         $this->mNamespace = $ns;
2642                                         # For Talk:X pages, check if X has a "namespace" prefix
2643                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2644                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2645                                                         return false; # Disallow Talk:File:x type titles...
2646                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2647                                                         return false; # Disallow Talk:Interwiki:x type titles...
2648                                                 }
2649                                         }
2650                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2651                                         if ( !$firstPass ) {
2652                                                 # Can't make a local interwiki link to an interwiki link.
2653                                                 # That's just crazy!
2654                                                 return false;
2655                                         }
2656
2657                                         # Interwiki link
2658                                         $dbkey = $m[2];
2659                                         $this->mInterwiki = $wgContLang->lc( $p );
2660
2661                                         # Redundant interwiki prefix to the local wiki
2662                                         if ( $wgLocalInterwiki !== false
2663                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2664                                         {
2665                                                 if ( $dbkey == '' ) {
2666                                                         # Can't have an empty self-link
2667                                                         return false;
2668                                                 }
2669                                                 $this->mInterwiki = '';
2670                                                 $firstPass = false;
2671                                                 # Do another namespace split...
2672                                                 continue;
2673                                         }
2674
2675                                         # If there's an initial colon after the interwiki, that also
2676                                         # resets the default namespace
2677                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2678                                                 $this->mNamespace = NS_MAIN;
2679                                                 $dbkey = substr( $dbkey, 1 );
2680                                         }
2681                                 }
2682                                 # If there's no recognized interwiki or namespace,
2683                                 # then let the colon expression be part of the title.
2684                         }
2685                         break;
2686                 } while ( true );
2687
2688                 # We already know that some pages won't be in the database!
2689                 #
2690                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2691                         $this->mArticleID = 0;
2692                 }
2693                 $fragment = strstr( $dbkey, '#' );
2694                 if ( false !== $fragment ) {
2695                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2696                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2697                         # remove whitespace again: prevents "Foo_bar_#"
2698                         # becoming "Foo_bar_"
2699                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2700                 }
2701
2702                 # Reject illegal characters.
2703                 #
2704                 if ( preg_match( $rxTc, $dbkey ) ) {
2705                         return false;
2706                 }
2707
2708                 /**
2709                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2710                  * reachable due to the way web browsers deal with 'relative' URLs.
2711                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2712                  */
2713                 if ( strpos( $dbkey, '.' ) !== false &&
2714                      ( $dbkey === '.' || $dbkey === '..' ||
2715                        strpos( $dbkey, './' ) === 0  ||
2716                        strpos( $dbkey, '../' ) === 0 ||
2717                        strpos( $dbkey, '/./' ) !== false ||
2718                        strpos( $dbkey, '/../' ) !== false  ||
2719                        substr( $dbkey, -2 ) == '/.' ||
2720                        substr( $dbkey, -3 ) == '/..' ) )
2721                 {
2722                         return false;
2723                 }
2724
2725                 /**
2726                  * Magic tilde sequences? Nu-uh!
2727                  */
2728                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2729                         return false;
2730                 }
2731
2732                 /**
2733                  * Limit the size of titles to 255 bytes.
2734                  * This is typically the size of the underlying database field.
2735                  * We make an exception for special pages, which don't need to be stored
2736                  * in the database, and may edge over 255 bytes due to subpage syntax
2737                  * for long titles, e.g. [[Special:Block/Long name]]
2738                  */
2739                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2740                   strlen( $dbkey ) > 512 )
2741                 {
2742                         return false;
2743                 }
2744
2745                 /**
2746                  * Normally, all wiki links are forced to have
2747                  * an initial capital letter so [[foo]] and [[Foo]]
2748                  * point to the same place.
2749                  *
2750                  * Don't force it for interwikis, since the other
2751                  * site might be case-sensitive.
2752                  */
2753                 $this->mUserCaseDBKey = $dbkey;
2754                 if ( $this->mInterwiki == '' ) {
2755                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2756                 }
2757
2758                 /**
2759                  * Can't make a link to a namespace alone...
2760                  * "empty" local links can only be self-links
2761                  * with a fragment identifier.
2762                  */
2763                 if ( $dbkey == '' &&
2764                         $this->mInterwiki == '' &&
2765                         $this->mNamespace != NS_MAIN ) {
2766                         return false;
2767                 }
2768                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2769                 // IP names are not allowed for accounts, and can only be referring to
2770                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2771                 // there are numerous ways to present the same IP. Having sp:contribs scan
2772                 // them all is silly and having some show the edits and others not is
2773                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2774                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2775                         IP::sanitizeIP( $dbkey ) : $dbkey;
2776                 // Any remaining initial :s are illegal.
2777                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2778                         return false;
2779                 }
2780
2781                 # Fill fields
2782                 $this->mDbkeyform = $dbkey;
2783                 $this->mUrlform = wfUrlencode( $dbkey );
2784
2785                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2786
2787                 return true;
2788         }
2789
2790         /**
2791          * Set the fragment for this title. Removes the first character from the
2792          * specified fragment before setting, so it assumes you're passing it with
2793          * an initial "#".
2794          *
2795          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2796          * Still in active use privately.
2797          *
2798          * @param $fragment String text
2799          */
2800         public function setFragment( $fragment ) {
2801                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2802         }
2803
2804         /**
2805          * Get a Title object associated with the talk page of this article
2806          *
2807          * @return Title the object for the talk page
2808          */
2809         public function getTalkPage() {
2810                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2811         }
2812
2813         /**
2814          * Get a title object associated with the subject page of this
2815          * talk page
2816          *
2817          * @return Title the object for the subject page
2818          */
2819         public function getSubjectPage() {
2820                 // Is this the same title?
2821                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2822                 if ( $this->getNamespace() == $subjectNS ) {
2823                         return $this;
2824                 }
2825                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2826         }
2827
2828         /**
2829          * Get an array of Title objects linking to this Title
2830          * Also stores the IDs in the link cache.
2831          *
2832          * WARNING: do not use this function on arbitrary user-supplied titles!
2833          * On heavily-used templates it will max out the memory.
2834          *
2835          * @param $options Array: may be FOR UPDATE
2836          * @param $table String: table name
2837          * @param $prefix String: fields prefix
2838          * @return Array of Title objects linking here
2839          */
2840         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2841                 $linkCache = LinkCache::singleton();
2842
2843                 if ( count( $options ) > 0 ) {
2844                         $db = wfGetDB( DB_MASTER );
2845                 } else {
2846                         $db = wfGetDB( DB_SLAVE );
2847                 }
2848
2849                 $res = $db->select(
2850                         array( 'page', $table ),
2851                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2852                         array(
2853                                 "{$prefix}_from=page_id",
2854                                 "{$prefix}_namespace" => $this->getNamespace(),
2855                                 "{$prefix}_title"     => $this->getDBkey() ),
2856                         __METHOD__,
2857                         $options
2858                 );
2859
2860                 $retVal = array();
2861                 if ( $db->numRows( $res ) ) {
2862                         foreach ( $res as $row ) {
2863                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2864                                 if ( $titleObj ) {
2865                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2866                                         $retVal[] = $titleObj;
2867                                 }
2868                         }
2869                 }
2870                 return $retVal;
2871         }
2872
2873         /**
2874          * Get an array of Title objects using this Title as a template
2875          * Also stores the IDs in the link cache.
2876          *
2877          * WARNING: do not use this function on arbitrary user-supplied titles!
2878          * On heavily-used templates it will max out the memory.
2879          *
2880          * @param $options Array: may be FOR UPDATE
2881          * @return Array of Title the Title objects linking here
2882          */
2883         public function getTemplateLinksTo( $options = array() ) {
2884                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2885         }
2886
2887         /**
2888          * Get an array of Title objects referring to non-existent articles linked from this page
2889          *
2890          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2891          * @return Array of Title the Title objects
2892          */
2893         public function getBrokenLinksFrom() {
2894                 if ( $this->getArticleId() == 0 ) {
2895                         # All links from article ID 0 are false positives
2896                         return array();
2897                 }
2898
2899                 $dbr = wfGetDB( DB_SLAVE );
2900                 $res = $dbr->select(
2901                         array( 'page', 'pagelinks' ),
2902                         array( 'pl_namespace', 'pl_title' ),
2903                         array(
2904                                 'pl_from' => $this->getArticleId(),
2905                                 'page_namespace IS NULL'
2906                         ),
2907                         __METHOD__, array(),
2908                         array(
2909                                 'page' => array(
2910                                         'LEFT JOIN',
2911                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2912                                 )
2913                         )
2914                 );
2915
2916                 $retVal = array();
2917                 foreach ( $res as $row ) {
2918                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2919                 }
2920                 return $retVal;
2921         }
2922
2923
2924         /**
2925          * Get a list of URLs to purge from the Squid cache when this
2926          * page changes
2927          *
2928          * @return Array of String the URLs
2929          */
2930         public function getSquidURLs() {
2931                 global $wgContLang;
2932
2933                 $urls = array(
2934                         $this->getInternalURL(),
2935                         $this->getInternalURL( 'action=history' )
2936                 );
2937
2938                 // purge variant urls as well
2939                 if ( $wgContLang->hasVariants() ) {
2940                         $variants = $wgContLang->getVariants();
2941                         foreach ( $variants as $vCode ) {
2942                                 $urls[] = $this->getInternalURL( '', $vCode );
2943                         }
2944                 }
2945
2946                 return $urls;
2947         }
2948
2949         /**
2950          * Purge all applicable Squid URLs
2951          */
2952         public function purgeSquid() {
2953                 global $wgUseSquid;
2954                 if ( $wgUseSquid ) {
2955                         $urls = $this->getSquidURLs();
2956                         $u = new SquidUpdate( $urls );
2957                         $u->doUpdate();
2958                 }
2959         }
2960
2961         /**
2962          * Move this page without authentication
2963          *
2964          * @param $nt Title the new page Title
2965          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2966          */
2967         public function moveNoAuth( &$nt ) {
2968                 return $this->moveTo( $nt, false );
2969         }
2970
2971         /**
2972          * Check whether a given move operation would be valid.
2973          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2974          *
2975          * @param $nt Title the new title
2976          * @param $auth Bool indicates whether $wgUser's permissions
2977          *  should be checked
2978          * @param $reason String is the log summary of the move, used for spam checking
2979          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2980          */
2981         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2982                 global $wgUser;
2983
2984                 $errors = array();
2985                 if ( !$nt ) {
2986                         // Normally we'd add this to $errors, but we'll get
2987                         // lots of syntax errors if $nt is not an object
2988                         return array( array( 'badtitletext' ) );
2989                 }
2990                 if ( $this->equals( $nt ) ) {
2991                         $errors[] = array( 'selfmove' );
2992                 }
2993                 if ( !$this->isMovable() ) {
2994                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2995                 }
2996                 if ( $nt->getInterwiki() != '' ) {
2997                         $errors[] = array( 'immobile-target-namespace-iw' );
2998                 }
2999                 if ( !$nt->isMovable() ) {
3000                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3001                 }
3002
3003                 $oldid = $this->getArticleID();
3004                 $newid = $nt->getArticleID();
3005
3006                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3007                         $errors[] = array( 'articleexists' );
3008                 }
3009                 if ( ( $this->getDBkey() == '' ) ||
3010                          ( !$oldid ) ||
3011                      ( $nt->getDBkey() == '' ) ) {
3012                         $errors[] = array( 'badarticleerror' );
3013                 }
3014
3015                 // Image-specific checks
3016                 if ( $this->getNamespace() == NS_FILE ) {
3017                         if ( $nt->getNamespace() != NS_FILE ) {
3018                                 $errors[] = array( 'imagenocrossnamespace' );
3019                         }
3020                         $file = wfLocalFile( $this );
3021                         if ( $file->exists() ) {
3022                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3023                                         $errors[] = array( 'imageinvalidfilename' );
3024                                 }
3025                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3026                                         $errors[] = array( 'imagetypemismatch' );
3027                                 }
3028                         }
3029                         $destfile = wfLocalFile( $nt );
3030                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
3031                                 $errors[] = array( 'file-exists-sharedrepo' );
3032                         }
3033                 }
3034
3035                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3036                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3037                 }
3038
3039                 if ( $auth ) {
3040                         $errors = wfMergeErrorArrays( $errors,
3041                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3042                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3043                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3044                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3045                 }
3046
3047                 $match = EditPage::matchSummarySpamRegex( $reason );
3048                 if ( $match !== false ) {
3049                         // This is kind of lame, won't display nice
3050                         $errors[] = array( 'spamprotectiontext' );
3051                 }
3052
3053                 $err = null;
3054                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3055                         $errors[] = array( 'hookaborted', $err );
3056                 }
3057
3058                 # The move is allowed only if (1) the target doesn't exist, or
3059                 # (2) the target is a redirect to the source, and has no history
3060                 # (so we can undo bad moves right after they're done).
3061
3062                 if ( 0 != $newid ) { # Target exists; check for validity
3063                         if ( !$this->isValidMoveTarget( $nt ) ) {
3064                                 $errors[] = array( 'articleexists' );
3065                         }
3066                 } else {
3067                         $tp = $nt->getTitleProtection();
3068                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3069                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3070                                 $errors[] = array( 'cantmove-titleprotected' );
3071                         }
3072                 }
3073                 if ( empty( $errors ) ) {
3074                         return true;
3075                 }
3076                 return $errors;
3077         }
3078
3079         /**
3080          * Move a title to a new location
3081          *
3082          * @param $nt Title the new title
3083          * @param $auth Bool indicates whether $wgUser's permissions
3084          *  should be checked
3085          * @param $reason String The reason for the move
3086          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3087          *  Ignored if the user doesn't have the suppressredirect right.
3088          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3089          */
3090         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3091                 global $wgContLang;
3092
3093                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3094                 if ( is_array( $err ) ) {
3095                         return $err;
3096                 }
3097
3098                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3099                 $dbw = wfGetDB( DB_MASTER );
3100                 if ( $this->getNamespace() == NS_FILE ) {
3101                         $file = wfLocalFile( $this );
3102                         if ( $file->exists() ) {
3103                                 $status = $file->move( $nt );
3104                                 if ( !$status->isOk() ) {
3105                                         return $status->getErrorsArray();
3106                                 }
3107                         }
3108                 }
3109
3110                 $pageid = $this->getArticleID();
3111                 $protected = $this->isProtected();
3112                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3113
3114                 // Do the actual move
3115                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3116                 if ( is_array( $err ) ) {
3117                         return $err;
3118                 }
3119
3120                 $redirid = $this->getArticleID();
3121
3122                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3123                 // cl_timestamp, which may disturb time-based lists on some sites.
3124                 $prefix = $dbw->selectField(
3125                         'categorylinks',
3126                         'cl_sortkey_prefix',
3127                         array( 'cl_from' => $pageid ),
3128                         __METHOD__
3129                 );
3130                 $dbw->update( 'categorylinks',
3131                         array(
3132                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3133                                 'cl_timestamp=cl_timestamp' ),
3134                         array( 'cl_from' => $pageid ),
3135                         __METHOD__ );
3136
3137                 if ( $protected ) {
3138                         # Protect the redirect title as the title used to be...
3139                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3140                                 array(
3141                                         'pr_page'    => $redirid,
3142                                         'pr_type'    => 'pr_type',
3143                                         'pr_level'   => 'pr_level',
3144                                         'pr_cascade' => 'pr_cascade',
3145                                         'pr_user'    => 'pr_user',
3146                                         'pr_expiry'  => 'pr_expiry'
3147                                 ),
3148                                 array( 'pr_page' => $pageid ),
3149                                 __METHOD__,
3150                                 array( 'IGNORE' )
3151                         );
3152                         # Update the protection log
3153                         $log = new LogPage( 'protect' );
3154                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3155                         if ( $reason ) {
3156                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3157                         }
3158                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3159                 }
3160
3161                 # Update watchlists
3162                 $oldnamespace = $this->getNamespace() & ~1;
3163                 $newnamespace = $nt->getNamespace() & ~1;
3164                 $oldtitle = $this->getDBkey();
3165                 $newtitle = $nt->getDBkey();
3166
3167                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3168                         WatchedItem::duplicateEntries( $this, $nt );
3169                 }
3170
3171                 # Update search engine
3172                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3173                 $u->doUpdate();
3174                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3175                 $u->doUpdate();
3176
3177                 # Update site_stats
3178                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3179                         # No longer a content page
3180                         # Not viewed, edited, removing
3181                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3182                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3183                         # Now a content page
3184                         # Not viewed, edited, adding
3185                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3186                 } elseif ( $pageCountChange ) {
3187                         # Redirect added
3188                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3189                 } else {
3190                         # Nothing special
3191                         $u = false;
3192                 }
3193                 if ( $u ) {
3194                         $u->doUpdate();
3195                 }
3196                 # Update message cache for interface messages
3197                 global $wgMessageCache;
3198                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3199                         # @bug 17860: old article can be deleted, if this the case,
3200                         # delete it from message cache
3201                         if ( $this->getArticleID() === 0 ) {
3202                                 $wgMessageCache->replace( $this->getDBkey(), false );
3203                         } else {
3204                                 $oldarticle = new Article( $this );
3205                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3206                         }
3207                 }
3208                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3209                         $newarticle = new Article( $nt );
3210                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3211                 }
3212
3213                 global $wgUser;
3214                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3215                 return true;
3216         }
3217
3218         /**
3219          * Move page to a title which is either a redirect to the
3220          * source page or nonexistent
3221          *
3222          * @param $nt Title the page to move to, which should
3223          * be a redirect or nonexistent
3224          * @param $reason String The reason for the move
3225          * @param $createRedirect Bool Whether to leave a
3226          * redirect at the old title.  Ignored if the user doesn't
3227          * have the suppressredirect right
3228          */
3229         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3230                 global $wgUser, $wgContLang;
3231
3232                 $moveOverRedirect = $nt->exists();
3233
3234                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3235                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3236
3237                 if ( $reason ) {
3238                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3239                 }
3240                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3241                 $comment = $wgContLang->truncate( $comment, 250 );
3242
3243                 $oldid = $this->getArticleID();
3244                 $latest = $this->getLatestRevID();
3245
3246                 $dbw = wfGetDB( DB_MASTER );
3247
3248                 if ( $moveOverRedirect ) {
3249                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3250
3251                         $newid = $nt->getArticleID();
3252                         $newns = $nt->getNamespace();
3253                         $newdbk = $nt->getDBkey();
3254
3255                         # Delete the old redirect. We don't save it to history since
3256                         # by definition if we've got here it's rather uninteresting.
3257                         # We have to remove it so that the next step doesn't trigger
3258                         # a conflict on the unique namespace+title index...
3259                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3260                         if ( !$dbw->cascadingDeletes() ) {
3261                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3262                                 global $wgUseTrackbacks;
3263                                 if ( $wgUseTrackbacks ) {
3264                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3265                                 }
3266                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3267                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3268                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3269                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3270                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3271                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3272                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3273                         }
3274                         // If the target page was recently created, it may have an entry in recentchanges still
3275                         $dbw->delete( 'recentchanges',
3276                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3277                                 __METHOD__
3278                         );
3279                 }
3280
3281                 # Save a null revision in the page's history notifying of the move
3282                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3283                 if ( !is_object( $nullRevision ) ) {
3284                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3285                 }
3286                 $nullRevId = $nullRevision->insertOn( $dbw );
3287
3288                 $article = new Article( $this );
3289                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3290
3291                 # Change the name of the target page:
3292                 $dbw->update( 'page',
3293                         /* SET */ array(
3294                                 'page_touched'   => $dbw->timestamp(),
3295                                 'page_namespace' => $nt->getNamespace(),
3296                                 'page_title'     => $nt->getDBkey(),
3297                                 'page_latest'    => $nullRevId,
3298                         ),
3299                         /* WHERE */ array( 'page_id' => $oldid ),
3300                         __METHOD__
3301                 );
3302                 $nt->resetArticleID( $oldid );
3303
3304                 # Recreate the redirect, this time in the other direction.
3305                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3306                         $mwRedir = MagicWord::get( 'redirect' );
3307                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3308                         $redirectArticle = new Article( $this );
3309                         $newid = $redirectArticle->insertOn( $dbw );
3310                         $redirectRevision = new Revision( array(
3311                                 'page'    => $newid,
3312                                 'comment' => $comment,
3313                                 'text'    => $redirectText ) );
3314                         $redirectRevision->insertOn( $dbw );
3315                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3316
3317                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3318
3319                         # Now, we record the link from the redirect to the new title.
3320                         # It should have no other outgoing links...
3321                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3322                         $dbw->insert( 'pagelinks',
3323                                 array(
3324                                         'pl_from'      => $newid,
3325                                         'pl_namespace' => $nt->getNamespace(),
3326                                         'pl_title'     => $nt->getDBkey() ),
3327                                 __METHOD__ );
3328                         $redirectSuppressed = false;
3329                 } else {
3330                         $this->resetArticleID( 0 );
3331                         $redirectSuppressed = true;
3332                 }
3333
3334                 # Log the move
3335                 $log = new LogPage( 'move' );
3336                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3337                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3338
3339                 # Purge caches for old and new titles
3340                 if ( $moveOverRedirect ) {
3341                         # A simple purge is enough when moving over a redirect
3342                         $nt->purgeSquid();
3343                 } else {
3344                         # Purge caches as per article creation, including any pages that link to this title
3345                         Article::onArticleCreate( $nt );
3346                 }
3347                 $this->purgeSquid();
3348         }
3349
3350         /**
3351          * Move this page's subpages to be subpages of $nt
3352          *
3353          * @param $nt Title Move target
3354          * @param $auth bool Whether $wgUser's permissions should be checked
3355          * @param $reason string The reason for the move
3356          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3357          *  Ignored if the user doesn't have the 'suppressredirect' right
3358          * @return mixed array with old page titles as keys, and strings (new page titles) or
3359          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3360          */
3361         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3362                 global $wgMaximumMovedPages;
3363                 // Check permissions
3364                 if ( !$this->userCan( 'move-subpages' ) ) {
3365                         return array( 'cant-move-subpages' );
3366                 }
3367                 // Do the source and target namespaces support subpages?
3368                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3369                         return array( 'namespace-nosubpages',
3370                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3371                 }
3372                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3373                         return array( 'namespace-nosubpages',
3374                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3375                 }
3376
3377                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3378                 $retval = array();
3379                 $count = 0;
3380                 foreach ( $subpages as $oldSubpage ) {
3381                         $count++;
3382                         if ( $count > $wgMaximumMovedPages ) {
3383                                 $retval[$oldSubpage->getPrefixedTitle()] =
3384                                                 array( 'movepage-max-pages',
3385                                                         $wgMaximumMovedPages );
3386                                 break;
3387                         }
3388
3389                         // We don't know whether this function was called before
3390                         // or after moving the root page, so check both
3391                         // $this and $nt
3392                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3393                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3394                         {
3395                                 // When moving a page to a subpage of itself,
3396                                 // don't move it twice
3397                                 continue;
3398                         }
3399                         $newPageName = preg_replace(
3400                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3401                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3402                                         $oldSubpage->getDBkey() );
3403                         if ( $oldSubpage->isTalkPage() ) {
3404                                 $newNs = $nt->getTalkPage()->getNamespace();
3405                         } else {
3406                                 $newNs = $nt->getSubjectPage()->getNamespace();
3407                         }
3408                         # Bug 14385: we need makeTitleSafe because the new page names may
3409                         # be longer than 255 characters.
3410                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3411
3412                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3413                         if ( $success === true ) {
3414                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3415                         } else {
3416                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3417                         }
3418                 }
3419                 return $retval;
3420         }
3421
3422         /**
3423          * Checks if this page is just a one-rev redirect.
3424          * Adds lock, so don't use just for light purposes.
3425          *
3426          * @return Bool
3427          */
3428         public function isSingleRevRedirect() {
3429                 $dbw = wfGetDB( DB_MASTER );
3430                 # Is it a redirect?
3431                 $row = $dbw->selectRow( 'page',
3432                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3433                         $this->pageCond(),
3434                         __METHOD__,
3435                         array( 'FOR UPDATE' )
3436                 );
3437                 # Cache some fields we may want
3438                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3439                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3440                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3441                 if ( !$this->mRedirect ) {
3442                         return false;
3443                 }
3444                 # Does the article have a history?
3445                 $row = $dbw->selectField( array( 'page', 'revision' ),
3446                         'rev_id',
3447                         array( 'page_namespace' => $this->getNamespace(),
3448                                 'page_title' => $this->getDBkey(),
3449                                 'page_id=rev_page',
3450                                 'page_latest != rev_id'
3451                         ),
3452                         __METHOD__,
3453                         array( 'FOR UPDATE' )
3454                 );
3455                 # Return true if there was no history
3456                 return ( $row === false );
3457         }
3458
3459         /**
3460          * Checks if $this can be moved to a given Title
3461          * - Selects for update, so don't call it unless you mean business
3462          *
3463          * @param $nt Title the new title to check
3464          * @return Bool TRUE or FALSE
3465          */
3466         public function isValidMoveTarget( $nt ) {
3467                 # Is it an existing file?
3468                 if ( $nt->getNamespace() == NS_FILE ) {
3469                         $file = wfLocalFile( $nt );
3470                         if ( $file->exists() ) {
3471                                 wfDebug( __METHOD__ . ": file exists\n" );
3472                                 return false;
3473                         }
3474                 }
3475                 # Is it a redirect with no history?
3476                 if ( !$nt->isSingleRevRedirect() ) {
3477                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3478                         return false;
3479                 }
3480                 # Get the article text
3481                 $rev = Revision::newFromTitle( $nt );
3482                 $text = $rev->getText();
3483                 # Does the redirect point to the source?
3484                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3485                 $m = array();
3486                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3487                         $redirTitle = Title::newFromText( $m[1] );
3488                         if ( !is_object( $redirTitle ) ||
3489                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3490                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3491                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3492                                 return false;
3493                         }
3494                 } else {
3495                         # Fail safe
3496                         wfDebug( __METHOD__ . ": failsafe\n" );
3497                         return false;
3498                 }
3499                 return true;
3500         }
3501
3502         /**
3503          * Can this title be added to a user's watchlist?
3504          *
3505          * @return Bool TRUE or FALSE
3506          */
3507         public function isWatchable() {
3508                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3509         }
3510
3511         /**
3512          * Get categories to which this Title belongs and return an array of
3513          * categories' names.
3514          *
3515          * @return Array of parents in the form:
3516          *      $parent => $currentarticle
3517          */
3518         public function getParentCategories() {
3519                 global $wgContLang;
3520
3521                 $titlekey = $this->getArticleId();
3522                 $dbr = wfGetDB( DB_SLAVE );
3523                 $categorylinks = $dbr->tableName( 'categorylinks' );
3524
3525                 # NEW SQL
3526                 $sql = "SELECT * FROM $categorylinks"
3527                      . " WHERE cl_from='$titlekey'"
3528                          . " AND cl_from <> '0'"
3529                          . " ORDER BY cl_sortkey";
3530
3531                 $res = $dbr->query( $sql );
3532                 $data = array();
3533
3534                 if ( $dbr->numRows( $res ) > 0 ) {
3535                         foreach ( $res as $row ) {
3536                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3537                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3538                         }
3539                 }
3540                 return $data;
3541         }
3542
3543         /**
3544          * Get a tree of parent categories
3545          *
3546          * @param $children Array with the children in the keys, to check for circular refs
3547          * @return Array Tree of parent categories
3548          */
3549         public function getParentCategoryTree( $children = array() ) {
3550                 $stack = array();
3551                 $parents = $this->getParentCategories();
3552
3553                 if ( $parents ) {
3554                         foreach ( $parents as $parent => $current ) {
3555                                 if ( array_key_exists( $parent, $children ) ) {
3556                                         # Circular reference
3557                                         $stack[$parent] = array();
3558                                 } else {
3559                                         $nt = Title::newFromText( $parent );
3560                                         if ( $nt ) {
3561                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3562                                         }
3563                                 }
3564                         }
3565                 }
3566
3567                 return $stack;
3568         }
3569
3570
3571         /**
3572          * Get an associative array for selecting this title from
3573          * the "page" table
3574          *
3575          * @return Array Selection array
3576          */
3577         public function pageCond() {
3578                 if ( $this->mArticleID > 0 ) {
3579                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3580                         return array( 'page_id' => $this->mArticleID );
3581                 } else {
3582                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3583                 }
3584         }
3585
3586         /**
3587          * Get the revision ID of the previous revision
3588          *
3589          * @param $revId Int Revision ID. Get the revision that was before this one.
3590          * @param $flags Int Title::GAID_FOR_UPDATE
3591          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3592          */
3593         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3594                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3595                 return $db->selectField( 'revision', 'rev_id',
3596                         array(
3597                                 'rev_page' => $this->getArticleId( $flags ),
3598                                 'rev_id < ' . intval( $revId )
3599                         ),
3600                         __METHOD__,
3601                         array( 'ORDER BY' => 'rev_id DESC' )
3602                 );
3603         }
3604
3605         /**
3606          * Get the revision ID of the next revision
3607          *
3608          * @param $revId Int Revision ID. Get the revision that was after this one.
3609          * @param $flags Int Title::GAID_FOR_UPDATE
3610          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3611          */
3612         public function getNextRevisionID( $revId, $flags = 0 ) {
3613                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3614                 return $db->selectField( 'revision', 'rev_id',
3615                         array(
3616                                 'rev_page' => $this->getArticleId( $flags ),
3617                                 'rev_id > ' . intval( $revId )
3618                         ),
3619                         __METHOD__,
3620                         array( 'ORDER BY' => 'rev_id' )
3621                 );
3622         }
3623
3624         /**
3625          * Get the first revision of the page
3626          *
3627          * @param $flags Int Title::GAID_FOR_UPDATE
3628          * @return Revision (or NULL if page doesn't exist)
3629          */
3630         public function getFirstRevision( $flags = 0 ) {
3631                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3632                 $pageId = $this->getArticleId( $flags );
3633                 if ( !$pageId ) {
3634                         return null;
3635                 }
3636                 $row = $db->selectRow( 'revision', '*',
3637                         array( 'rev_page' => $pageId ),
3638                         __METHOD__,
3639                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3640                 );
3641                 if ( !$row ) {
3642                         return null;
3643                 } else {
3644                         return new Revision( $row );
3645                 }
3646         }
3647
3648         /**
3649          * Check if this is a new page
3650          *
3651          * @return bool
3652          */
3653         public function isNewPage() {
3654                 $dbr = wfGetDB( DB_SLAVE );
3655                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3656         }
3657
3658         /**
3659          * Get the oldest revision timestamp of this page
3660          *
3661          * @return String: MW timestamp
3662          */
3663         public function getEarliestRevTime() {
3664                 $dbr = wfGetDB( DB_SLAVE );
3665                 if ( $this->exists() ) {
3666                         $min = $dbr->selectField( 'revision',
3667                                 'MIN(rev_timestamp)',
3668                                 array( 'rev_page' => $this->getArticleId() ),
3669                                 __METHOD__ );
3670                         return wfTimestampOrNull( TS_MW, $min );
3671                 }
3672                 return null;
3673         }
3674
3675         /**
3676          * Get the number of revisions between the given revision IDs.
3677          * Used for diffs and other things that really need it.
3678          *
3679          * @param $old Int Revision ID.
3680          * @param $new Int Revision ID.
3681          * @return Int Number of revisions between these IDs.
3682          */
3683         public function countRevisionsBetween( $old, $new ) {
3684                 $dbr = wfGetDB( DB_SLAVE );
3685                 return (int)$dbr->selectField( 'revision', 'count(*)', array(
3686                                 'rev_page' => intval( $this->getArticleId() ),
3687                                 'rev_id > ' . intval( $old ),
3688                                 'rev_id < ' . intval( $new )
3689                         ), __METHOD__
3690                 );
3691         }
3692
3693         /**
3694          * Get the number of authors between the given revision IDs.
3695          * Used for diffs and other things that really need it.
3696          *
3697          * @param $fromRevId Int Revision ID (first before range)
3698          * @param $toRevId Int Revision ID (first after range)
3699          * @param $limit Int Maximum number of authors
3700          * @param $flags Int Title::GAID_FOR_UPDATE
3701          * @return Int
3702          */
3703         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3704                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3705                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3706                         array(
3707                                 'rev_page' => $this->getArticleID(),
3708                                 'rev_id > ' . (int)$fromRevId,
3709                                 'rev_id < ' . (int)$toRevId
3710                         ), __METHOD__,
3711                         array( 'LIMIT' => $limit )
3712                 );
3713                 return (int)$db->numRows( $res );
3714         }
3715
3716         /**
3717          * Compare with another title.
3718          *
3719          * @param $title Title
3720          * @return Bool TRUE or FALSE
3721          */
3722         public function equals( Title $title ) {
3723                 // Note: === is necessary for proper matching of number-like titles.
3724                 return $this->getInterwiki() === $title->getInterwiki()
3725                         && $this->getNamespace() == $title->getNamespace()
3726                         && $this->getDBkey() === $title->getDBkey();
3727         }
3728
3729         /**
3730          * Callback for usort() to do title sorts by (namespace, title)
3731          *
3732          * @return Integer: result of string comparison, or namespace comparison
3733          */
3734         public static function compare( $a, $b ) {
3735                 if ( $a->getNamespace() == $b->getNamespace() ) {
3736                         return strcmp( $a->getText(), $b->getText() );
3737                 } else {
3738                         return $a->getNamespace() - $b->getNamespace();
3739                 }
3740         }
3741
3742         /**
3743          * Return a string representation of this title
3744          *
3745          * @return String String representation of this title
3746          */
3747         public function __toString() {
3748                 return $this->getPrefixedText();
3749         }
3750
3751         /**
3752          * Check if page exists.  For historical reasons, this function simply
3753          * checks for the existence of the title in the page table, and will
3754          * thus return false for interwiki links, special pages and the like.
3755          * If you want to know if a title can be meaningfully viewed, you should
3756          * probably call the isKnown() method instead.
3757          *
3758          * @return Bool
3759          */
3760         public function exists() {
3761                 return $this->getArticleId() != 0;
3762         }
3763
3764         /**
3765          * Should links to this title be shown as potentially viewable (i.e. as
3766          * "bluelinks"), even if there's no record by this title in the page
3767          * table?
3768          *
3769          * This function is semi-deprecated for public use, as well as somewhat
3770          * misleadingly named.  You probably just want to call isKnown(), which
3771          * calls this function internally.
3772          *
3773          * (ISSUE: Most of these checks are cheap, but the file existence check
3774          * can potentially be quite expensive.  Including it here fixes a lot of
3775          * existing code, but we might want to add an optional parameter to skip
3776          * it and any other expensive checks.)
3777          *
3778          * @return Bool
3779          */
3780         public function isAlwaysKnown() {
3781                 if ( $this->mInterwiki != '' ) {
3782                         return true;  // any interwiki link might be viewable, for all we know
3783                 }
3784                 switch( $this->mNamespace ) {
3785                         case NS_MEDIA:
3786                         case NS_FILE:
3787                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3788                         case NS_SPECIAL:
3789                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3790                         case NS_MAIN:
3791                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3792                         case NS_MEDIAWIKI:
3793                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3794                                 // the full l10n of that language to be loaded. That takes much memory and
3795                                 // isn't needed. So we strip the language part away.
3796                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3797                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3798                         default:
3799                                 return false;
3800                 }
3801         }
3802
3803         /**
3804          * Does this title refer to a page that can (or might) be meaningfully
3805          * viewed?  In particular, this function may be used to determine if
3806          * links to the title should be rendered as "bluelinks" (as opposed to
3807          * "redlinks" to non-existent pages).
3808          *
3809          * @return Bool
3810          */
3811         public function isKnown() {
3812                 return $this->isAlwaysKnown() || $this->exists();
3813         }
3814
3815         /**
3816          * Does this page have source text?
3817          *
3818          * @return Boolean
3819          */
3820         public function hasSourceText() {
3821                 if ( $this->exists() ) {
3822                         return true;
3823                 }
3824
3825                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3826                         // If the page doesn't exist but is a known system message, default
3827                         // message content will be displayed, same for language subpages
3828                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3829                         // causes the full l10n of that language to be loaded. That takes much
3830                         // memory and isn't needed. So we strip the language part away.
3831                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3832                         return (bool)wfMsgWeirdKey( $basename );
3833                 }
3834
3835                 return false;
3836         }
3837
3838         /**
3839          * Is this in a namespace that allows actual pages?
3840          *
3841          * @return Bool
3842          * @internal note -- uses hardcoded namespace index instead of constants
3843          */
3844         public function canExist() {
3845                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3846         }
3847
3848         /**
3849          * Update page_touched timestamps and send squid purge messages for
3850          * pages linking to this title. May be sent to the job queue depending
3851          * on the number of links. Typically called on create and delete.
3852          */
3853         public function touchLinks() {
3854                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3855                 $u->doUpdate();
3856
3857                 if ( $this->getNamespace() == NS_CATEGORY ) {
3858                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3859                         $u->doUpdate();
3860                 }
3861         }
3862
3863         /**
3864          * Get the last touched timestamp
3865          *
3866          * @param $db DatabaseBase: optional db
3867          * @return String Last touched timestamp
3868          */
3869         public function getTouched( $db = null ) {
3870                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3871                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3872                 return $touched;
3873         }
3874
3875         /**
3876          * Get the timestamp when this page was updated since the user last saw it.
3877          *
3878          * @param $user User
3879          * @return Mixed: string/null
3880          */
3881         public function getNotificationTimestamp( $user = null ) {
3882                 global $wgUser, $wgShowUpdatedMarker;
3883                 // Assume current user if none given
3884                 if ( !$user ) {
3885                         $user = $wgUser;
3886                 }
3887                 // Check cache first
3888                 $uid = $user->getId();
3889                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3890                         return $this->mNotificationTimestamp[$uid];
3891                 }
3892                 if ( !$uid || !$wgShowUpdatedMarker ) {
3893                         return $this->mNotificationTimestamp[$uid] = false;
3894                 }
3895                 // Don't cache too much!
3896                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3897                         $this->mNotificationTimestamp = array();
3898                 }
3899                 $dbr = wfGetDB( DB_SLAVE );
3900                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3901                         'wl_notificationtimestamp',
3902                         array( 'wl_namespace' => $this->getNamespace(),
3903                                 'wl_title' => $this->getDBkey(),
3904                                 'wl_user' => $user->getId()
3905                         ),
3906                         __METHOD__
3907                 );
3908                 return $this->mNotificationTimestamp[$uid];
3909         }
3910
3911         /**
3912          * Get the trackback URL for this page
3913          *
3914          * @return String Trackback URL
3915          */
3916         public function trackbackURL() {
3917                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3918
3919                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3920                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3921         }
3922
3923         /**
3924          * Get the trackback RDF for this page
3925          *
3926          * @return String Trackback RDF
3927          */
3928         public function trackbackRDF() {
3929                 $url = htmlspecialchars( $this->getFullURL() );
3930                 $title = htmlspecialchars( $this->getText() );
3931                 $tburl = $this->trackbackURL();
3932
3933                 // Autodiscovery RDF is placed in comments so HTML validator
3934                 // won't barf. This is a rather icky workaround, but seems
3935                 // frequently used by this kind of RDF thingy.
3936                 //
3937                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3938                 return "<!--
3939 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3940          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3941          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3942 <rdf:Description
3943    rdf:about=\"$url\"
3944    dc:identifier=\"$url\"
3945    dc:title=\"$title\"
3946    trackback:ping=\"$tburl\" />
3947 </rdf:RDF>
3948 -->";
3949         }
3950
3951         /**
3952          * Generate strings used for xml 'id' names in monobook tabs
3953          *
3954          * @param $prepend string defaults to 'nstab-'
3955          * @return String XML 'id' name
3956          */
3957         public function getNamespaceKey( $prepend = 'nstab-' ) {
3958                 global $wgContLang;
3959                 // Gets the subject namespace if this title
3960                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3961                 // Checks if cononical namespace name exists for namespace
3962                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3963                         // Uses canonical namespace name
3964                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3965                 } else {
3966                         // Uses text of namespace
3967                         $namespaceKey = $this->getSubjectNsText();
3968                 }
3969                 // Makes namespace key lowercase
3970                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3971                 // Uses main
3972                 if ( $namespaceKey == '' ) {
3973                         $namespaceKey = 'main';
3974                 }
3975                 // Changes file to image for backwards compatibility
3976                 if ( $namespaceKey == 'file' ) {
3977                         $namespaceKey = 'image';
3978                 }
3979                 return $prepend . $namespaceKey;
3980         }
3981
3982         /**
3983          * Returns true if this is a special page.
3984          *
3985          * @return boolean
3986          */
3987         public function isSpecialPage() {
3988                 return $this->getNamespace() == NS_SPECIAL;
3989         }
3990
3991         /**
3992          * Returns true if this title resolves to the named special page
3993          *
3994          * @param $name String The special page name
3995          * @return boolean
3996          */
3997         public function isSpecial( $name ) {
3998                 if ( $this->getNamespace() == NS_SPECIAL ) {
3999                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
4000                         if ( $name == $thisName ) {
4001                                 return true;
4002                         }
4003                 }
4004                 return false;
4005         }
4006
4007         /**
4008          * If the Title refers to a special page alias which is not the local default,
4009          *
4010          * @return Title A new Title which points to the local default.
4011          *         Otherwise, returns $this.
4012          */
4013         public function fixSpecialName() {
4014                 if ( $this->getNamespace() == NS_SPECIAL ) {
4015                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4016                         if ( $canonicalName ) {
4017                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4018                                 if ( $localName != $this->mDbkeyform ) {
4019                                         return Title::makeTitle( NS_SPECIAL, $localName );
4020                                 }
4021                         }
4022                 }
4023                 return $this;
4024         }
4025
4026         /**
4027          * Is this Title in a namespace which contains content?
4028          * In other words, is this a content page, for the purposes of calculating
4029          * statistics, etc?
4030          *
4031          * @return Boolean
4032          */
4033         public function isContentPage() {
4034                 return MWNamespace::isContent( $this->getNamespace() );
4035         }
4036
4037         /**
4038          * Get all extant redirects to this Title
4039          *
4040          * @param $ns Int|Null Single namespace to consider;
4041          *            NULL to consider all namespaces
4042          * @return Array of Title redirects to this title
4043          */
4044         public function getRedirectsHere( $ns = null ) {
4045                 $redirs = array();
4046
4047                 $dbr = wfGetDB( DB_SLAVE );
4048                 $where = array(
4049                         'rd_namespace' => $this->getNamespace(),
4050                         'rd_title' => $this->getDBkey(),
4051                         'rd_from = page_id'
4052                 );
4053                 if ( !is_null( $ns ) ) {
4054                         $where['page_namespace'] = $ns;
4055                 }
4056
4057                 $res = $dbr->select(
4058                         array( 'redirect', 'page' ),
4059                         array( 'page_namespace', 'page_title' ),
4060                         $where,
4061                         __METHOD__
4062                 );
4063
4064                 foreach ( $res as $row ) {
4065                         $redirs[] = self::newFromRow( $row );
4066                 }
4067                 return $redirs;
4068         }
4069
4070         /**
4071          * Check if this Title is a valid redirect target
4072          *
4073          * @return Bool
4074          */
4075         public function isValidRedirectTarget() {
4076                 global $wgInvalidRedirectTargets;
4077
4078                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4079                 if ( $this->isSpecial( 'Userlogout' ) ) {
4080                         return false;
4081                 }
4082
4083                 foreach ( $wgInvalidRedirectTargets as $target ) {
4084                         if ( $this->isSpecial( $target ) ) {
4085                                 return false;
4086                         }
4087                 }
4088
4089                 return true;
4090         }
4091
4092         /**
4093          * Get a backlink cache object
4094          *
4095          * @return object BacklinkCache
4096          */
4097         function getBacklinkCache() {
4098                 if ( is_null( $this->mBacklinkCache ) ) {
4099                         $this->mBacklinkCache = new BacklinkCache( $this );
4100                 }
4101                 return $this->mBacklinkCache;
4102         }
4103
4104         /**
4105          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4106          * this page.
4107          *
4108          * @return Boolean
4109          */
4110         public function canUseNoindex() {
4111                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4112
4113                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4114                         ? $wgContentNamespaces
4115                         : $wgExemptFromUserRobotsControl;
4116
4117                 return !in_array( $this->mNamespace, $bannedNamespaces );
4118
4119         }
4120
4121         /**
4122          * Returns restriction types for the current Title
4123          *
4124          * @return array applicable restriction types
4125          */
4126         public function getRestrictionTypes() {
4127                 global $wgRestrictionTypes;
4128
4129                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4130
4131                 if ( $this->getNamespace() != NS_FILE ) {
4132                         $types = array_diff( $types, array( 'upload' ) );
4133                 }
4134
4135                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4136
4137                 return $types;
4138         }
4139
4140         /**
4141          * Returns the raw sort key to be used for categories, with the specified
4142          * prefix.  This will be fed to Language::convertToSortkey() to get a
4143          * binary sortkey that can be used for actual sorting.
4144          *
4145          * @param $prefix string The prefix to be used, specified using
4146          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4147          *   prefix.
4148          * @return string
4149          */
4150         public function getCategorySortkey( $prefix = '' ) {
4151                 $unprefixed = $this->getText();
4152                 if ( $prefix !== '' ) {
4153                         # Separate with a null byte, so the unprefixed part is only used as
4154                         # a tiebreaker when two pages have the exact same prefix -- null
4155                         # sorts before everything else (hopefully).
4156                         return "$prefix\0$unprefixed";
4157                 }
4158                 return $unprefixed;
4159         }
4160 }